Commit Graph

480 Commits

Author SHA1 Message Date
Dhruba Borthakur
c5de1b9391 Print name of user comparator in LOG.
Summary:
The current code prints the name of the InternalKeyComparator
in the log file. We would also like to print the name of the
user-specified comparator for easier debugging.

Test Plan: make check

Reviewers: sheki

Reviewed By: sheki

CC: leveldb

Differential Revision: https://reviews.facebook.net/D11181
2013-06-10 12:11:55 -07:00
Mayank Agarwal
184343a061 Max_mem_compaction_level can have maximum value of num_levels-1
Summary:
Without this files could be written out to a level greater than the maximum level possible and is the source of the segfaults that wormhole awas getting. The sequence of steps that was followed:
1. WriteLevel0Table was called when memtable was to be flushed for a file.
2. PickLevelForMemTableOutput was called to determine the level to which this file should be pushed.
3. PickLevelForMemTableOutput returned a wrong result because max_mem_compaction_level was equal to 2 even when num_levels was equal to 0.
The fix to re-initialize max_mem_compaction_level based on num_levels passed seems correct.

Test Plan: make all check; Also made a dummy file to mimic the wormhole-file behaviour which was causing the segfaults and found that the same segfault occurs without this change and not with this.

Reviewers: dhruba, haobo

Reviewed By: dhruba

CC: leveldb

Differential Revision: https://reviews.facebook.net/D11157
2013-06-09 10:38:55 -07:00
Abhishek Kona
e982b5a489 [Rocksdb] measure table open io in a histogram
Summary: as title

Test Plan: db_bench --statistics=1 check for statistic.

Reviewers: dhruba, haobo

Reviewed By: dhruba

CC: leveldb

Differential Revision: https://reviews.facebook.net/D11109
2013-06-07 10:02:28 -07:00
Deon Nicholas
db1f0cddf3 Fixed valgrind errors 2013-06-05 17:25:16 -07:00
Deon Nicholas
d8c7c45ea0 Very basic Multiget and simple test cases.
Summary:
Implemented the MultiGet operator which takes in a list of keys
and returns their associated values. Currently uses std::vector as its
container data structure. Otherwise, it works identically to "Get".

Test Plan:
 1. make db_test      ; compile it
 2. ./db_test         ; test it
 3. make all check    ; regress / run all tests
 4. make release      ; (optional) compile with release settings

Reviewers: haobo, MarkCallaghan, dhruba

Reviewed By: dhruba

CC: leveldb

Differential Revision: https://reviews.facebook.net/D10875
2013-06-05 11:22:38 -07:00
Abhishek Kona
d91b42ee27 [Rocksdb] Measure all FSYNC/SYNC times
Summary: Add stop watches around all sync calls.

Test Plan: db_bench check if respective histograms are printed

Reviewers: haobo, dhruba

Reviewed By: haobo

CC: leveldb

Differential Revision: https://reviews.facebook.net/D11073
2013-06-05 11:06:21 -07:00
Abhishek Kona
ee522d0032 [Rocksdb] Log on disable/enable file deletions
Summary: as title

Test Plan: compile

Reviewers: dhruba, haobo

Reviewed By: dhruba

CC: leveldb

Differential Revision: https://reviews.facebook.net/D11085
2013-06-05 10:48:24 -07:00
Mark Callaghan
d9f538e1a9 Improve output for GetProperty('leveldb.stats')
Summary:
Display separate values for read, write & total compaction IO.
Display compaction amplification and write amplification.
Add similar values for the period since the last call to GetProperty. Results since the server started
are reported as "cumulative" stats. Results since the last call to GetProperty are reported as
"interval" stats.

Level  Files Size(MB) Time(sec)  Read(MB) Write(MB)    Rn(MB)  Rnp1(MB)  Wnew(MB) Amplify Read(MB/s) Write(MB/s)      Rn     Rnp1     Wnp1     NewW    Count  Ln-stall
----------------------------------------------------------------------------------------------------------------------------------------------------------------------
  0        7       13        21         0       211         0         0       211     0.0       0.0        10.1        0        0        0        0      113       0.0
  1       79      157        88       993       989       198       795       194     9.0      11.3        11.2      106      405      502       97       14       0.0
  2       19       36         5        63        63        37        27        36     2.4      12.3        12.2       19       14       32       18       12       0.0
>>>>>>>>>>>>>>>>>>>>>>>>> text below has been is new and/or reformatted
Uptime(secs): 122.2 total, 0.9 interval
Compaction IO cumulative (GB): 0.21 new, 1.03 read, 1.23 write, 2.26 read+write
Compaction IO cumulative (MB/sec): 1.7 new, 8.6 read, 10.3 write, 19.0 read+write
Amplification cumulative: 6.0 write, 11.0 compaction
Compaction IO interval (MB): 5.59 new, 0.00 read, 5.59 write, 5.59 read+write
Compaction IO interval (MB/sec): 6.5 new, 0.0 read, 6.5 write, 6.5 read+write
Amplification interval: 1.0 write, 1.0 compaction
>>>>>>>>>>>>>>>>>>>>>>>> text above is new and/or reformatted
Stalls(secs): 90.574 level0_slowdown, 0.000 level0_numfiles, 10.165 memtable_compaction, 0.000 leveln_slowdown

Task ID: #

Blame Rev:

Test Plan:
make check, run db_bench

Revert Plan:

Database Impact:

Memcache Impact:

Other Notes:

EImportant:

- begin *PUBLIC* platform impact section -
Bugzilla: #
- end platform impact -

Reviewers: haobo

Reviewed By: haobo

CC: leveldb

Differential Revision: https://reviews.facebook.net/D11049
2013-06-03 20:24:49 -07:00
Haobo Xu
2b1fb5b01d [RocksDB] Add score column to leveldb.stats
Summary: Added the 'score' column to the compaction stats output, which shows the level total size devided by level target size. Could be useful when monitoring compaction decisions...

Test Plan: make check; db_bench

Reviewers: dhruba

CC: leveldb, MarkCallaghan

Differential Revision: https://reviews.facebook.net/D11025
2013-06-03 17:38:27 -07:00
Haobo Xu
d897d33bf1 [RocksDB] Introduce Fast Mutex option
Summary:
This diff adds an option to specify whether PTHREAD_MUTEX_ADAPTIVE_NP will be enabled for the rocksdb single big kernel lock. db_bench also have this option now.
Quickly tested 8 thread cpu bound 100 byte random read.
No fast mutex: ~750k/s ops
With fast mutex: ~880k/s ops

Test Plan: make check; db_bench; db_stress

Reviewers: dhruba

CC: MarkCallaghan, leveldb

Differential Revision: https://reviews.facebook.net/D11031
2013-06-01 23:11:34 -07:00
Haobo Xu
ab8d2f6ab2 [RocksDB] [Performance] Allow different posix advice to be applied to the same table file
Summary:
Current posix advice implementation ties up the access pattern hint with the creation of a file.
It is not possible to apply different advice for different access (random get vs compaction read),
without keeping two open files for the same table. This patch extended the RandomeAccessFile interface
to accept new access hint at anytime. Particularly, we are able to set different access hint on the same
table file based on when/how the file is used.
Two options are added to set the access hint, after the file is first opened and after the file is being
compacted.

Test Plan: make check; db_stress; db_bench

Reviewers: dhruba

Reviewed By: dhruba

CC: MarkCallaghan, leveldb

Differential Revision: https://reviews.facebook.net/D10905
2013-05-30 19:08:44 -07:00
Haobo Xu
2df65c118c [RocksDB] Dump counters and histogram data periodically with compaction stats
Summary: As title

Test Plan: make check

Reviewers: dhruba

Reviewed By: dhruba

CC: leveldb

Differential Revision: https://reviews.facebook.net/D10995
2013-05-29 12:00:18 -07:00
Dhruba Borthakur
a8d807ee91 Record the number of open db iterators.
Summary: Enhance the statitics to report the number of open db iterators.

Test Plan: make check

Reviewers: haobo, emayanke

Reviewed By: emayanke

CC: leveldb

Differential Revision: https://reviews.facebook.net/D10983
2013-05-29 08:47:08 -07:00
Haobo Xu
fb684da082 [RocksDB] Fix CorruptionTest
Summary: Overriding block_size_deviation to zero, so that CorruptionTest can pass.

Test Plan: make check

Reviewers: dhruba

Reviewed By: dhruba

Differential Revision: https://reviews.facebook.net/D10977
2013-05-28 12:36:42 -07:00
heyongqiang
4b29651206 add block deviation option to terminate a block before it exceeds block_size
Summary: a new option block_size_deviation is added.

Test Plan: run db_test and db_bench

Reviewers: dhruba, haobo

Reviewed By: haobo

Differential Revision: https://reviews.facebook.net/D10821
2013-05-24 15:52:49 -07:00
Haobo Xu
ef15b9d178 [RocksDB] Fix MaybeDumpStats
Summary: MaybeDumpStats was causing lock problem

Test Plan: make check; db_stress

Reviewers: dhruba

Reviewed By: dhruba

Differential Revision: https://reviews.facebook.net/D10935
2013-05-24 15:43:16 -07:00
Haobo Xu
0e879c93de [RocksDB] dump leveldb.stats periodically in LOG file.
Summary:
Added an option stats_dump_period_sec to dump leveldb.stats to LOG periodically for diagnosis.
By defauly, it's set to a very big number 3600 (1 hour).

Test Plan: make check;

Reviewers: dhruba

Reviewed By: dhruba

CC: leveldb, zshao

Differential Revision: https://reviews.facebook.net/D10761
2013-05-23 16:56:59 -07:00
Dhruba Borthakur
26541860d3 The max size of the write buffer size can be 64 GB.
Summary: There was an artifical limit on the size of the write buffer size.

Test Plan: make check

Reviewers: haobo

Reviewed By: haobo

CC: leveldb

Differential Revision: https://reviews.facebook.net/D10911
2013-05-23 15:00:27 -07:00
Dhruba Borthakur
898f79372f Fix valgrind errors introduced by https://reviews.facebook.net/D10863
Summary:
The valgrind errors were in the unit tests where we change the
number of levels of a database using internal methods.

Test Plan:
valgrind ./reduce_levels_test
valgrind ./db_test

Reviewers: emayanke

Reviewed By: emayanke

CC: leveldb

Differential Revision: https://reviews.facebook.net/D10893
2013-05-23 12:14:41 -07:00
Haobo Xu
c2e2460f8a [RocksDB] Expose DBStatistics
Summary: Make Statistics usable by client

Test Plan: make check; db_bench

Reviewers: dhruba

Reviewed By: dhruba

Differential Revision: https://reviews.facebook.net/D10899
2013-05-23 11:49:38 -07:00
Haobo Xu
87d0af15d8 [RocksDB] Introduce an option to skip log error on recovery
Summary:
Currently, with paranoid_check on, DB::Open will fail on any log read error on recovery.
If client is ok with losing most recent updates, we could simply skip those errors.
However, it's important to introduce an additional flag, so that paranoid_check can
still guard against more serious problems.

Test Plan: make check; db_stress

Reviewers: dhruba, emayanke

Reviewed By: emayanke

CC: leveldb, emayanke

Differential Revision: https://reviews.facebook.net/D10869
2013-05-21 14:30:36 -07:00
Dhruba Borthakur
d1aaaf718c Ability to set different size fanout multipliers for every level.
Summary:
There is an existing field Options.max_bytes_for_level_multiplier that
sets the multiplier for the size of each level in the database.

This patch introduces the ability to set different multipliers
for every level in the database. The size of a level is determined
by using both max_bytes_for_level_multiplier as well as the
per-level fanout.

size of level[i] = size of level[i-1] * max_bytes_for_level_multiplier
                   * fanout[i-1]

The default value of fanout is 1, so that it is backward compatible.

Test Plan: make check

Reviewers: haobo, emayanke

Reviewed By: emayanke

CC: leveldb

Differential Revision: https://reviews.facebook.net/D10863
2013-05-21 13:50:20 -07:00
Haobo Xu
c3c13db346 [RocksDB] [Performance Bug] MemTable::Get Slow
Summary:
The merge operator diff introduced a performance problem in MemTable::Get.
An exit condition is missed when the current key does not match the user key.
This could lead to full memtable scan if the user key is not found.

Test Plan: make check; db_bench

Reviewers: dhruba

Reviewed By: dhruba

CC: leveldb

Differential Revision: https://reviews.facebook.net/D10851
2013-05-21 13:40:38 -07:00
Abhishek Kona
e1174306c5 [RocksDB] Simplify StopWatch implementation
Summary:
Make stop watch a simple implementation, instead of subclass of a virtual class
Allocate stop watches off the stack instead of heap.
Code is more terse now.

Test Plan: make all check, db_bench with --statistics=1

Reviewers: haobo, dhruba

Reviewed By: haobo

CC: leveldb

Differential Revision: https://reviews.facebook.net/D10809
2013-05-17 10:55:34 -07:00
Abhishek Kona
446151cd20 [Rocksdb] Remove unused double apis to record into histograms
Summary: Statistics.h and histogram.h had double based api's to record values. Remove them as they are not used anywhere

Test Plan: make all check

Reviewers: haobo, dhruba

Reviewed By: haobo

CC: leveldb

Differential Revision: https://reviews.facebook.net/D10815
2013-05-16 10:40:30 -07:00
Haobo Xu
4ca3c67bd3 [RocksDB] Cleanup compaction filter to use a class interface, instead of function pointer and additional context pointer.
Summary:
This diff replaces compaction_filter_args and CompactionFilter with a single compaction_filter parameter. It gives CompactionFilter better encapsulation and a similar look to Comparator and MergeOpertor, which improves consistency of the overall interface.
The change is not backward compatible. Nevertheless, the two references in fbcode are not in production yet.

Test Plan: make check

Reviewers: dhruba

Reviewed By: dhruba

CC: leveldb, zshao

Differential Revision: https://reviews.facebook.net/D10773
2013-05-13 14:06:10 -07:00
Haobo Xu
73c0a33346 [RocksDB] fix compaction filter trigger condition
Summary:
Currently, compaction filter is run on internal key older than the oldest snapshot, which is incorrect.
Compaction filter should really be run on the most recent internal key when there is no external snapshot.

Test Plan: make check; db_stress

Reviewers: dhruba

Reviewed By: dhruba

Differential Revision: https://reviews.facebook.net/D10641
2013-05-13 12:33:02 -07:00
Abhishek Kona
8d58ecdc29 [RocksDB] Expose compaction stalls via db_statistics
Test Plan: make check

Reviewers: dhruba, haobo

Reviewed By: dhruba

CC: leveldb

Differential Revision: https://reviews.facebook.net/D10575
2013-05-10 14:41:45 -07:00
Dhruba Borthakur
a8d3aa2c26 Assertion failure for L0-L1 compactions.
Summary:
For level-0 compactions, we try to find if can include more L0 files
in the same compaction run. This causes the 'smallest' and 'largest'
key to get extended to a larger range. But the suceeding call to
ParentRangeInCompaction() was still using the earlier
values of 'smallest' and 'largest',

Because of this bug, a file in L1 can be part of two concurrent
compactions: one L0-L1 compaction and the other L1-L2 compaction.

This should not cause any data loss, but will cause an assertion
failure with debug builds.

Test Plan: make check

Differential Revision: https://reviews.facebook.net/D10677
2013-05-08 17:10:11 -07:00
Abhishek Kona
988c20b9f7 [RocksDB] Clear Archive WAL files
Summary:
WAL files are moved to archive directory and clear only at DB::Open.
Can lead to a lot of space consumption in a Database. Added logic to periodically clear Archive Directory too.

Test Plan: make all check + add unit test

Reviewers: dhruba, heyongqiang

Reviewed By: heyongqiang

CC: leveldb

Differential Revision: https://reviews.facebook.net/D10617
2013-05-06 11:41:01 -07:00
Haobo Xu
05e8854085 [Rocksdb] Support Merge operation in rocksdb
Summary:
This diff introduces a new Merge operation into rocksdb.
The purpose of this review is mostly getting feedback from the team (everyone please) on the design.

Please focus on the four files under include/leveldb/, as they spell the client visible interface change.
include/leveldb/db.h
include/leveldb/merge_operator.h
include/leveldb/options.h
include/leveldb/write_batch.h

Please go over local/my_test.cc carefully, as it is a concerete use case.

Please also review the impelmentation files to see if the straw man implementation makes sense.

Note that, the diff does pass all make check and truly supports forward iterator over db and a version
of Get that's based on iterator.

Future work:
- Integration with compaction
- A raw Get implementation

I am working on a wiki that explains the design and implementation choices, but coding comes
just naturally and I think it might be a good idea to share the code earlier. The code is
heavily commented.

Test Plan: run all local tests

Reviewers: dhruba, heyongqiang

Reviewed By: dhruba

CC: leveldb, zshao, sheki, emayanke, MarkCallaghan

Differential Revision: https://reviews.facebook.net/D9651
2013-05-03 16:59:02 -07:00
Abhishek Kona
41cb922b34 Allocate the LogReporter from heap. Summary:
Summary:
The current code has a bug that take address of stack allocated LogReporter.
It is causing SIGSEGV because the stack address is no longer valid when referenced.

Test Plan: Tested on prod.

Reviewers: haobo, dhruba, heyongqiang

Reviewed By: heyongqiang

Differential Revision: https://reviews.facebook.net/D10557
2013-04-29 13:19:24 -07:00
Abhishek Kona
fb96ec1686 [RocksDB] Print all internally collected histograms in db_bench. Also print p95
Summary: $title

Test Plan: make db_bench . run db_bench and check for expected output

Reviewers: haobo, dhruba

Reviewed By: haobo

CC: leveldb

Differential Revision: https://reviews.facebook.net/D10521
2013-04-25 13:36:47 -07:00
Haobo Xu
eb6d139666 [RocksDB] Move table.h to table/
Summary:
- don't see a point exposing table.h to the public.
- fixed make clean to remove also *.d files.

Test Plan: make check; db_stress

Reviewers: dhruba, heyongqiang

Reviewed By: dhruba

CC: leveldb

Differential Revision: https://reviews.facebook.net/D10479
2013-04-22 16:07:56 -07:00
Abhishek Kona
344e832f55 [RocksDB] Fix ReadMissing in db_bench
Summary: D8943 Broke read_missing. Fix it by adding a "." at the end of the generated key

Test Plan: generate, print and check the key has a "."

Reviewers: dhruba, haobo

Reviewed By: dhruba

CC: leveldb

Differential Revision: https://reviews.facebook.net/D10455
2013-04-22 15:44:19 -07:00
Haobo Xu
b4243e5a3d [RocksDB] CompactionFilter cleanup
Summary:
- removed the compaction_filter_value from the callback interface. Restrict compaction filter to purging values.
- modify some comments to reflect curent status.

Test Plan: make check

Reviewers: dhruba

Reviewed By: dhruba

CC: leveldb

Differential Revision: https://reviews.facebook.net/D10335
2013-04-20 10:26:51 -07:00
Mark Callaghan
b1ff9ac9c5 Add --writes_per_second rate limit, print p99.99 in histogram
Summary:
Adds the --writes_per_second rate limit for the readwhilewriting test.
The purpose is to optionally avoid saturating storage with writes & compaction
and test read response time when some writes are being done.

Changes the histogram code to also print the p99.99 value

Task ID: #

Blame Rev:

Test Plan:
make check, ran db_bench with it

Revert Plan:

Database Impact:

Memcache Impact:

Other Notes:

EImportant:

- begin *PUBLIC* platform impact section -
Bugzilla: #
- end platform impact -

Reviewers: haobo

Reviewed By: haobo

CC: leveldb

Differential Revision: https://reviews.facebook.net/D10305
2013-04-20 10:26:51 -07:00
Haobo Xu
1255dcd446 [RocksDB] Add stacktrace signal handler
Summary:
This diff provides the ability to print out a stacktrace when the process receives certain signals.
Currently, we enable this for the following signals (program error related):
SIGILL SIGSEGV SIGBUS SIGABRT
Application simply #include "util/stack_trace.h" and call leveldb::InstallStackTraceHandler() during initialization, if signal handler is needed. It's not done automatically when openning db, because it's the application(process)'s responsibility to install signal handler and some applications might already have their own (like fbcode).

Sample output:
Received signal 11 (Segmentation fault)
#0  0x408ff0 ./signal_test() [0x408ff0] /home/haobo/rocksdb/util/signal_test.cc:4
#1  0x40827d ./signal_test() [0x40827d] /home/haobo/rocksdb/util/signal_test.cc:24
#2  0x7f8bb183172e /usr/local/fbcode/gcc-4.7.1-glibc-2.14.1/lib/libc.so.6(__libc_start_main+0x10e) [0x7f8bb183172e] ??:0
#3  0x408ebc ./signal_test() [0x408ebc] /home/engshare/third-party/src/glibc/glibc-2.14.1/glibc-2.14.1/csu/../sysdeps/x86_64/elf/start.S:113
Segmentation fault (core dumped)

For each frame, we print the raw pointer, the symbol provided by backtrace_symbols (still not good enough), and the source file/line. Note that address translation is done by directly shell out to addr2line. ??:0 means addr2line fails to do the translation. Hacky, but I think it's good for now.

Test Plan: signal_test.cc

Reviewers: dhruba, MarkCallaghan

Reviewed By: dhruba

CC: leveldb

Differential Revision: https://reviews.facebook.net/D10173
2013-04-20 10:26:50 -07:00
Abhishek Kona
7c6c3c0ff4 [Rockdsdb] Better Error messages. Closing db instead of deleting db
Summary: A better error message. A local change. Did not look at other places where this could be done.

Test Plan: compile

Reviewers: dhruba, MarkCallaghan

Reviewed By: dhruba

CC: leveldb

Differential Revision: https://reviews.facebook.net/D10251
2013-04-15 15:27:15 -07:00
Dhruba Borthakur
9b81d3c406 Simplified level_ptrs by using a std:vector
Summary: Simplified level_ptrs by using a std:vector

Test Plan: make check

Reviewers: sheki, emayanke

Reviewed By: emayanke

CC: leveldb

Differential Revision: https://reviews.facebook.net/D10245
2013-04-15 13:52:51 -07:00
Haobo Xu
013e9ebbf1 [RocksDB] [Performance] Speed up FindObsoleteFiles
Summary:
FindObsoleteFiles was slow, holding the single big lock, resulted in bad p99 behavior.
Didn't profile anything, but several things could be improved:
1. VersionSet::AddLiveFiles works with std::set, which is by itself slow (a tree).
   You also don't know how many dynamic allocations occur just for building up this tree.
   switched to std::vector, also added logic to pre-calculate total size and do just one allocation
2. Don't see why env_->GetChildren() needs to be mutex proteced, moved to PurgeObsoleteFiles where
   mutex could be unlocked.
3. switched std::set to std:unordered_set, the conversion from vector is also inside PurgeObsoleteFiles
I have a feeling this should pretty much fix it.

Test Plan: make check;  db_stress

Reviewers: dhruba, heyongqiang, MarkCallaghan

Reviewed By: dhruba

CC: leveldb, zshao

Differential Revision: https://reviews.facebook.net/D10197
2013-04-12 11:29:27 -07:00
Mayank Agarwal
94d86b25a9 Fix memory leak for probableWALfiles in db_impl.cc
Summary: using unique_ptr to have automatic delete for probableWALfiles in db_impl.cc

Test Plan: make

Reviewers: sheki, dhruba

Reviewed By: sheki

CC: leveldb

Differential Revision: https://reviews.facebook.net/D10083
2013-04-11 16:57:15 -07:00
Dhruba Borthakur
7730587120 Prevent segfault in OpenCompactionOutputFile
Summary:
The segfault was happening because the program was unable to open a new
sst file (as part of the compaction) because the process ran out of
file descriptors.

The fix is to check the return status of the file creation before taking
any other action.

Program received signal SIGSEGV, Segmentation fault.
[Switching to Thread 0x7fabf03f9700 (LWP 29904)]
leveldb::DBImpl::OpenCompactionOutputFile (this=this@entry=0x7fabf9011400, compact=compact@entry=0x7fabf741a2b0) at db/db_impl.cc:1399
1399    db/db_impl.cc: No such file or directory.
(gdb) where

Test Plan: make check

Reviewers: MarkCallaghan, sheki

Reviewed By: MarkCallaghan

CC: leveldb

Differential Revision: https://reviews.facebook.net/D10101
2013-04-10 09:59:48 -07:00
Abhishek Kona
574b76f710 [RocksDB][Bug] Look at all the files, not just the first file in TransactionLogIter as BatchWrites can leave it in Limbo
Summary:
Transaction Log Iterator did not move to the next file in the series if there was a write batch at the end of the currentFile.
The solution is if the last seq no. of the current file is < RequestedSeqNo. Assume the first seqNo. of the next file has to satisfy the request.

Also major refactoring around the code. Moved opening the logreader to a seperate function, got rid of goto.

Test Plan: added a unit test for it.

Reviewers: dhruba, heyongqiang

Reviewed By: heyongqiang

CC: leveldb, emayanke

Differential Revision: https://reviews.facebook.net/D10029
2013-04-08 16:28:09 -07:00
Abhishek Kona
0e40185a7d [Rocksdb] Remove useless struct TableAndFile
Summary:
TableAndFile was a struct used earlier to delete the file as we did not have std::unique_ptr in the codebase.
With Chip introducing C++11 hotness like std::unique_ptr we can do away with the struct.

Test Plan: make all check

Reviewers: haobo, heyongqiang

Reviewed By: heyongqiang

CC: dhruba, leveldb

Differential Revision: https://reviews.facebook.net/D9975
2013-04-05 11:26:46 -07:00
Abhishek Kona
ca789a10cc [Rocksdb] Recover last updated sequence number from manifest also.
Summary:
During recovery, last_updated_manifest number was not set if there were no records in the Write-ahead log.
Now check for the recovered manifest also and set last_updated_manifest file to the max value.

Test Plan: unit test

Reviewers: heyongqiang

Reviewed By: heyongqiang

CC: leveldb

Differential Revision: https://reviews.facebook.net/D9891
2013-04-02 17:18:27 -07:00
Haobo Xu
6763110867 [RocksDB] Replace iterator based loop with range based loop for stl containers
Summary:
As title.
Code is shorter and cleaner
See https://our.dev.facebook.com/intern/tasks/?t=2233981

Test Plan: make check

Reviewers: dhruba, heyongqiang

Reviewed By: dhruba

CC: leveldb, zshao

Differential Revision: https://reviews.facebook.net/D9789
2013-04-02 11:46:45 -07:00
Haobo Xu
645ff8f231 Let's get rid of delete as much as possible, here are some examples.
Summary:
If a class owns an object:
 - If the object can be null => use a unique_ptr. no delete
 - If the object can not be null => don't even need new, let alone delete
 - for runtime sized array => use vector, no delete.

Test Plan: make check

Reviewers: dhruba, heyongqiang

Reviewed By: heyongqiang

CC: leveldb, zshao, sheki, emayanke, MarkCallaghan

Differential Revision: https://reviews.facebook.net/D9783
2013-03-28 17:31:44 -07:00
Abhishek Kona
3b51605b8d [RocksDB] Fix binary search while finding probable wal files
Summary:
RocksDB does a binary search to look at the files which might contain the requested sequence number at the call GetUpdatesSince.
There was a bug in the binary search => when the file pointed by the middle index of bsearch was empty/corrupt it needst to resize the vector and update indexes.
This now fixes that.

Test Plan: existing unit tests pass.

Reviewers: heyongqiang, dhruba

Reviewed By: heyongqiang

CC: leveldb

Differential Revision: https://reviews.facebook.net/D9777
2013-03-28 13:37:15 -07:00
Abhishek Kona
8e9c781ae5 [Rocksdb] Fix Crash on finding a db with no log files. Error out instead
Summary:
If the vector returned by GetUpdatesSince is empty, it is still returned to the
user. This causes it throw an std::range error.
The probable file list is checked and it returns an IOError status instead of OK now.

Test Plan: added a unit test.

Reviewers: dhruba, heyongqiang

Reviewed By: heyongqiang

CC: leveldb

Differential Revision: https://reviews.facebook.net/D9771
2013-03-28 13:19:07 -07:00
Abhishek Kona
7fdd5f5b33 Use non-mmapd files for Write-Ahead Files
Summary:
Use non mmapd files for Write-Ahead log.
Earlier use of MMaped files. made the log iterator read ahead and miss records.
Now the reader and writer will point to the same physical location.

There is no perf regression :
./db_bench --benchmarks=fillseq --db=/dev/shm/mmap_test --num=$(million 20) --use_existing_db=0 --threads=2
with This diff :
fillseq      :      10.756 micros/op 185281 ops/sec;   20.5 MB/s
without this dif :
fillseq      :      11.085 micros/op 179676 ops/sec;   19.9 MB/s

Test Plan: unit test included

Reviewers: dhruba, heyongqiang

Reviewed By: heyongqiang

CC: leveldb

Differential Revision: https://reviews.facebook.net/D9741
2013-03-28 13:13:35 -07:00
Abhishek Kona
63f216ee0a memory manage statistics
Summary:
Earlier Statistics object was a raw pointer. This meant the user had to clear up
the Statistics object after creating the database. In most use cases the database is created in a function and the statistics pointer is out of scope. Hence the statistics object would never be deleted.
Now Using a shared_ptr to manage this.

Want this in before the next release.

Test Plan: make all check.

Reviewers: dhruba, emayanke

Reviewed By: emayanke

CC: leveldb

Differential Revision: https://reviews.facebook.net/D9735
2013-03-27 11:27:39 -07:00
Haobo Xu
ecd8db0200 [RocksDB] Minimize Mutex protected code section in the critical path
Summary: rocksdb uses a single global lock to protect in memory metadata. We should minimize the mutex protected code section to increase the effective parallelism of the program. See https://our.intern.facebook.com/intern/tasks/?t=2218928

Test Plan:
make check
db_bench

Reviewers: dhruba, heyongqiang

CC: zshao, leveldb

Differential Revision: https://reviews.facebook.net/D9705
2013-03-26 22:42:26 -07:00
Abhishek Kona
9b70529c86 Disable Unit Test for TransactionLogIteratorStall
Summary:
The unit test fails as our solution does not work with MMap'd files.
Disable the failing unit test. Put it back with the next diff which should fix the problem.

Test Plan: db_test

Reviewers: heyongqiang

CC: dhruba

Differential Revision: https://reviews.facebook.net/D9645
2013-03-21 15:51:18 -07:00
Abhishek Kona
27c15fb67e TransactionLogIter should stall at the last record. Currently it errors out
Summary:
* Add a method to check if the log reader is at EOF.
* If we know a record has been flushed force the log_reader to believe it is not at EOF, using a new method UnMarkEof().

This does not work with MMpaed files.

Test Plan: added a unit test.

Reviewers: dhruba, heyongqiang

Reviewed By: heyongqiang

CC: leveldb

Differential Revision: https://reviews.facebook.net/D9567
2013-03-21 15:12:35 -07:00
Dhruba Borthakur
d0798f67f4 Run compactions even if workload is readonly or read-mostly.
Summary:
The events that trigger compaction:
* opening the database
* Get -> only if seek compaction is not disabled and other checks are true
* MakeRoomForWrite -> when memtable is full
* BackgroundCall ->
  If the background thread is about to do a compaction run, it schedules
  a new background task to trigger a possible compaction. This will cause
  additional background threads to find and process other compactions that
  can run concurrently.

Test Plan: ran db_bench with overwrite and readonly alternatively.

Reviewers: sheki, MarkCallaghan

Reviewed By: sheki

CC: leveldb

Differential Revision: https://reviews.facebook.net/D9579
2013-03-20 23:43:29 -07:00
Dhruba Borthakur
ad96563b79 Ability to configure bufferedio-reads, filesystem-readaheads and mmap-read-write per database.
Summary:
This patch allows an application to specify whether to use bufferedio,
reads-via-mmaps and writes-via-mmaps per database. Earlier, there
was a global static variable that was used to configure this functionality.

The default setting remains the same (and is backward compatible):
 1. use bufferedio
 2. do not use mmaps for reads
 3. use mmap for writes
 4. use readaheads for reads needed for compaction

I also added a parameter to db_bench to be able to explicitly specify
whether to do readaheads for compactions or not.

Test Plan: make check

Reviewers: sheki, heyongqiang, MarkCallaghan

Reviewed By: sheki

CC: leveldb

Differential Revision: https://reviews.facebook.net/D9429
2013-03-20 23:14:03 -07:00
Mayank Agarwal
b1bea58457 Fix more signed-unsigned comparisons
Summary: Some comparisons left in log_test.cc and db_test.cc complained by make

Test Plan: make

Reviewers: dhruba, sheki

Reviewed By: dhruba

Differential Revision: https://reviews.facebook.net/D9537
2013-03-19 17:21:36 -07:00
Mayank Agarwal
487168cdcf Fixed sign-comparison in rocksdb code-base and fixed Makefile
Summary: Makefile had options to ignore sign-comparisons and unused-parameters, which should be there. Also fixed the specific errors in the code-base

Test Plan: make

Reviewers: chip, dhruba

Reviewed By: dhruba

CC: leveldb

Differential Revision: https://reviews.facebook.net/D9531
2013-03-19 14:35:23 -07:00
Mark Callaghan
72d14eafd3 add --benchmarks=levelstats option to db_bench, prevent "nan" in stats output
Summary:
Add --benchmarks=levelstats option to report per-level stats (#files, #bytes)
Change readwhilewriting test to report response time for writes but exclude
them from the stats merged by all threads.
Prevent "NaN" in stats output by preventing division by 0.
Remove "o" file I committed by mistake.

Task ID: #

Blame Rev:

Test Plan:
make check

Revert Plan:

Database Impact:

Memcache Impact:

Other Notes:

EImportant:

- begin *PUBLIC* platform impact section -
Bugzilla: #
- end platform impact -

Reviewers: dhruba

Reviewed By: dhruba

Differential Revision: https://reviews.facebook.net/D9513
2013-03-19 13:14:44 -07:00
Abhishek Kona
02c459805b Ignore a zero-sized file while looking for a seq-no in GetUpdatesSince
Summary:
Rocksdb can create 0 sized log files when it is opened and closed without any operations.
The GetUpdatesSince fails currently if there is a log file of size zero.

This diff fixes this. If there is a log file is 0, it is removed form the probable_file_list

Test Plan: unit test

Reviewers: dhruba, heyongqiang

Reviewed By: heyongqiang

CC: leveldb

Differential Revision: https://reviews.facebook.net/D9507
2013-03-19 11:00:09 -07:00
Abhishek Kona
7b9db9c98e DO not report level size as zero when there are no files in L0
Summary:
Instead of checking for number of files in L0. Check for number of files in the requested level.

Bug introduced in D4929 (diff trying to do too many things).

Test Plan: db_test.

Reviewers: dhruba, MarkCallaghan

Reviewed By: dhruba

Differential Revision: https://reviews.facebook.net/D9483
2013-03-18 12:04:38 -07:00
Mark Callaghan
5a8c8845a9 Enhance db_bench
Summary:
Add --benchmarks=updaterandom for read-modify-write workloads. This is different
from --benchmarks=readrandomwriterandom in a few ways. First, an "operation" is the
combined time to do the read & write rather than treating them as two ops. Second,
the same key is used for the read & write.

Change RandomGenerator to support rows larger than 1M. That was using "assert"
to fail and assert is compiled-away when -DNDEBUG is used.

Add more options to db_bench
--duration - sets the number of seconds for tests to run. When not set the
operation count continues to be the limit. This is used by random operation
tests.

--use_snapshot - when set GetSnapshot() is called prior to each random read.
This is to measure the overhead from using snapshots.

--get_approx - when set GetApproximateSizes() is called prior to each random
read. This is to measure the overhead for a query optimizer.

Task ID: #

Blame Rev:

Test Plan:
run db_bench

Revert Plan:

Database Impact:

Memcache Impact:

Other Notes:

EImportant:

- begin *PUBLIC* platform impact section -
Bugzilla: #
- end platform impact -

Reviewers: dhruba

Reviewed By: dhruba

Differential Revision: https://reviews.facebook.net/D9267
2013-03-14 16:00:23 -07:00
Mayank Agarwal
5b278b53ae Fix valgrind errors in rocksdb tests: auto_roll_logger_test, reduce_levels_test
Summary: Fix for memory leaks in rocksdb tests. Also modified the variable NUM_FAILED_TESTS to print the actual number of failed tests.

Test Plan: make <test>; valgrind --leak-check=full ./<test>

Reviewers: sheki, dhruba

Reviewed By: sheki

CC: leveldb

Differential Revision: https://reviews.facebook.net/D9333
2013-03-12 16:03:16 -07:00
Dhruba Borthakur
ebf16f57c9 Prevent segfault because SizeUnderCompaction was called without any locks.
Summary:
SizeBeingCompacted was called without any lock protection. This causes
crashes, especially when running db_bench with value_size=128K.
The fix is to compute SizeUnderCompaction while holding the mutex and
passing in these values into the call to Finalize.

(gdb) where
#4  leveldb::VersionSet::SizeBeingCompacted (this=this@entry=0x7f0b490931c0, level=level@entry=4) at db/version_set.cc:1827
#5  0x000000000043a3c8 in leveldb::VersionSet::Finalize (this=this@entry=0x7f0b490931c0, v=v@entry=0x7f0b3b86b480) at db/version_set.cc:1420
#6  0x00000000004418d1 in leveldb::VersionSet::LogAndApply (this=0x7f0b490931c0, edit=0x7f0b3dc8c200, mu=0x7f0b490835b0, new_descriptor_log=<optimized out>) at db/version_set.cc:1016
#7  0x00000000004222b2 in leveldb::DBImpl::InstallCompactionResults (this=this@entry=0x7f0b49083400, compact=compact@entry=0x7f0b2b8330f0) at db/db_impl.cc:1473
#8  0x0000000000426027 in leveldb::DBImpl::DoCompactionWork (this=this@entry=0x7f0b49083400, compact=compact@entry=0x7f0b2b8330f0) at db/db_impl.cc:1757
#9  0x0000000000426690 in leveldb::DBImpl::BackgroundCompaction (this=this@entry=0x7f0b49083400, madeProgress=madeProgress@entry=0x7f0b41bf2d1e, deletion_state=...) at db/db_impl.cc:1268
#10 0x0000000000428f42 in leveldb::DBImpl::BackgroundCall (this=0x7f0b49083400) at db/db_impl.cc:1170
#11 0x000000000045348e in BGThread (this=0x7f0b49023100) at util/env_posix.cc:941
#12 leveldb::(anonymous namespace)::PosixEnv::BGThreadWrapper (arg=0x7f0b49023100) at util/env_posix.cc:874
#13 0x00007f0b4a7cf10d in start_thread (arg=0x7f0b41bf3700) at pthread_create.c:301
#14 0x00007f0b49b4b11d in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:115

Test Plan:
make check

I am running db_bench with a value size of 128K to see if the segfault is fixed.

Reviewers: MarkCallaghan, sheki, emayanke

Reviewed By: sheki

CC: leveldb

Differential Revision: https://reviews.facebook.net/D9279
2013-03-11 14:09:01 -07:00
Dhruba Borthakur
6d812b6afb A mechanism to detect manifest file write errors and put db in readonly mode.
Summary:
If there is an error while writing an edit to the manifest file, the manifest
file is closed and reopened to check if the edit made it in. However, if the
re-opening of the manifest is unsuccessful and options.paranoid_checks is set
t true, then the db refuses to accept new puts, effectively putting the db
in readonly mode.

In a future diff, I would like to make the default value of paranoid_check
to true.

Test Plan: make check

Reviewers: sheki

Reviewed By: sheki

CC: leveldb

Differential Revision: https://reviews.facebook.net/D9201
2013-03-07 09:45:49 -08:00
Abhishek Kona
d68880a1b9 Do not allow Transaction Log Iterator to fall ahead when writer is writing the same file
Summary:
Store the last flushed, seq no. in db_impl. Check against it in
transaction Log iterator. Do not attempt to read ahead if we do not know
if the data is flushed completely.
Does not work if flush is disabled. Any ideas on fixing that?
* Minor change, iter->Next is called the first time automatically for
* the first time.

Test Plan:
existing test pass.
More ideas on testing this?
Planning to run some stress test.

Reviewers: dhruba, heyongqiang

CC: leveldb

Differential Revision: https://reviews.facebook.net/D9087
2013-03-06 14:05:53 -08:00
Dhruba Borthakur
afed60938f Fox db_stress crash by copying keys before changing sequencenum to zero.
Summary:
The compaction process zeros out sequence numbers if the output is
part of the bottommost level.
The Slice is supposed to refer to an immutable data buffer. The
merger that implements the priority queue while reading kvs as
the input of a compaction run reies on this fact. The bug was that
were updating the sequence number of a record in-place and that was
causing suceeding invocations of the merger to return kvs in
arbitrary order of sequence numbers.
The fix is to copy the key to a local memory buffer before setting
its seqno to 0.

Test Plan:
Set Options.purge_redundant_kvs_while_flush = false and then run
db_stress --ops_per_thread=1000 --max_key=320

Reviewers: emayanke, sheki

Reviewed By: emayanke

CC: leveldb

Differential Revision: https://reviews.facebook.net/D9147
2013-03-06 10:52:08 -08:00
Dhruba Borthakur
f5896681b4 Removed unnecesary file object in table_cache.
Summary:
TableCache->file is not used. remove it.
I kept the TableAndFile structure and will clean it up in a future patch.

Test Plan: make clean check

Reviewers: sheki, chip

Reviewed By: chip

CC: leveldb

Differential Revision: https://reviews.facebook.net/D9075
2013-03-04 13:56:23 -08:00
Mark Callaghan
993543d1be Add rate_delay_limit_milliseconds
Summary:
This adds the rate_delay_limit_milliseconds option to make the delay
configurable in MakeRoomForWrite when the max compaction score is too high.
This delay is called the Ln slowdown. This change also counts the Ln slowdown
per level to make it possible to see where the stalls occur.

From IO-bound performance testing, the Level N stalls occur:
* with compression -> at the largest uncompressed level. This makes sense
                      because compaction for compressed levels is much
                      slower. When Lx is uncompressed and Lx+1 is compressed
                      then files pile up at Lx because the (Lx,Lx+1)->Lx+1
                      compaction process is the first to be slowed by
                      compression.
* without compression -> at level 1

Task ID: #1832108

Blame Rev:

Test Plan:
run with real data, added test

Revert Plan:

Database Impact:

Memcache Impact:

Other Notes:

EImportant:

- begin *PUBLIC* platform impact section -
Bugzilla: #
- end platform impact -

Reviewers: dhruba

Reviewed By: dhruba

Differential Revision: https://reviews.facebook.net/D9045
2013-03-04 07:41:15 -08:00
Dhruba Borthakur
806e264350 Ability for rocksdb to compact when flushing the in-memory memtable to a file in L0.
Summary:
Rocks accumulates recent writes and deletes in the in-memory memtable.
When the memtable is full, it writes the contents on the memtable to
a file in L0.

This patch removes redundant records at the time of the flush. If there
are multiple versions of the same key in the memtable, then only the
most recent one is dumped into the output file. The purging of
redundant records occur only if the most recent snapshot is earlier
than the earliest record in the memtable.

Should we switch on this feature by default or should we keep this feature
turned off in the default settings?

Test Plan: Added test case to db_test.cc

Reviewers: sheki, vamsi, emayanke, heyongqiang

Reviewed By: sheki

CC: leveldb

Differential Revision: https://reviews.facebook.net/D8991
2013-03-04 00:01:47 -08:00
bil
4992633751 enable the ability to set key size in db_bench in rocksdb
Summary:
1. the default value for key size is still 16
2. enable the ability to set the key size via command line --key_size=

Test Plan:
build & run db_banch and pass some value via command line.
verify it works correctly.

Reviewers: sheki

Reviewed By: sheki

CC: leveldb

Differential Revision: https://reviews.facebook.net/D8943
2013-03-01 14:10:09 -08:00
Abhishek Kona
c41f1e995c Codemod NULL to nullptr
Summary:
scripted NULL to nullptr in
* include/leveldb/
* db/
* table/
* util/

Test Plan: make all check

Reviewers: dhruba, emayanke

Reviewed By: emayanke

CC: leveldb

Differential Revision: https://reviews.facebook.net/D9003
2013-02-28 18:04:58 -08:00
Dhruba Borthakur
e45c7a8444 Abilty to support upto a million .sst files in the database
Summary:
There was an artifical limit of 50K files per database. This is
insifficient if the database is 1 TB in size and each file is 2 MB.

Test Plan: make check

Reviewers: sheki, emayanke

Reviewed By: emayanke

CC: leveldb

Differential Revision: https://reviews.facebook.net/D8919
2013-02-26 16:27:51 -08:00
Abhishek Kona
a9866b721b Refactor statistics. Remove individual functions like incNumFileOpens
Summary:
Use only the counter mechanism. Do away with
incNumFileOpens, incNumFileClose, incNumFileErrors
s/NULL/nullptr/g in db/table_cache.cc

Test Plan: make clean check

Reviewers: dhruba, heyongqiang, emayanke

Reviewed By: dhruba

CC: leveldb

Differential Revision: https://reviews.facebook.net/D8841
2013-02-25 13:58:34 -08:00
Abhishek Kona
959337ed5b Measure compaction time.
Summary: just record time consumed in compaction

Test Plan: compile

Reviewers: dhruba

Reviewed By: dhruba

CC: leveldb

Differential Revision: https://reviews.facebook.net/D8781
2013-02-22 11:38:40 -08:00
Abhishek Kona
ec77366e14 Counters for bytes written and read.
Summary:
* Counters for bytes read and write.
as a part of this diff, I want to=>
* Measure compaction times. @dhruba can you point which function, should
* I time to get Compaction-times. Was looking at CompactRange.

Test Plan: db_test

Reviewers: dhruba, emayanke

CC: leveldb

Differential Revision: https://reviews.facebook.net/D8763
2013-02-21 16:06:32 -08:00
Vamsi Ponnekanti
6abb30d4d0 [Missed adding cmdline parsing for new flags added in D8685]
Summary:
I had added FLAGS_numdistinct and FLAGS_deletepercent for randomwithverify
but forgot to add cmdline parsing for those flags.

Test Plan:
[nponnekanti@dev902 /data/users/nponnekanti/rocksdb] ./db_bench --benchmarks=randomwithverify --numdistinct=500
LevelDB:    version 1.5
Date:       Thu Feb 21 10:34:40 2013
CPU:        24 * Intel(R) Xeon(R) CPU           X5650  @ 2.67GHz
CPUCache:   12288 KB
Keys:       16 bytes each
Values:     100 bytes each (50 bytes after compression)
Entries:    1000000
RawSize:    110.6 MB (estimated)
FileSize:   62.9 MB (estimated)
Compression: snappy
WARNING: Assertions are enabled; benchmarks unnecessarily slow
------------------------------------------------
Created bg thread 0x7fbf90bff700
randomwithverify :       4.693 micros/op 213098 ops/sec; ( get:900000 put:80000 del:20000 total:1000000 found:714556)

[nponnekanti@dev902 /data/users/nponnekanti/rocksdb] ./db_bench --benchmarks=randomwithverify --deletepercent=5
LevelDB:    version 1.5
Date:       Thu Feb 21 10:35:03 2013
CPU:        24 * Intel(R) Xeon(R) CPU           X5650  @ 2.67GHz
CPUCache:   12288 KB
Keys:       16 bytes each
Values:     100 bytes each (50 bytes after compression)
Entries:    1000000
RawSize:    110.6 MB (estimated)
FileSize:   62.9 MB (estimated)
Compression: snappy
WARNING: Assertions are enabled; benchmarks unnecessarily slow
------------------------------------------------
Created bg thread 0x7fe14dfff700
randomwithverify :       4.883 micros/op 204798 ops/sec; ( get:900000 put:50000 del:50000 total:1000000 found:443847)
[nponnekanti@dev902 /data/users/nponnekanti/rocksdb]
[nponnekanti@dev902 /data/users/nponnekanti/rocksdb] ./db_bench --benchmarks=randomwithverify --deletepercent=5 --numdistinct=500
LevelDB:    version 1.5
Date:       Thu Feb 21 10:36:18 2013
CPU:        24 * Intel(R) Xeon(R) CPU           X5650  @ 2.67GHz
CPUCache:   12288 KB
Keys:       16 bytes each
Values:     100 bytes each (50 bytes after compression)
Entries:    1000000
RawSize:    110.6 MB (estimated)
FileSize:   62.9 MB (estimated)
Compression: snappy
WARNING: Assertions are enabled; benchmarks unnecessarily slow
------------------------------------------------
Created bg thread 0x7fc31c7ff700
randomwithverify :       4.920 micros/op 203233 ops/sec; ( get:900000 put:50000 del:50000 total:1000000 found:445522)

Revert Plan: OK

Task ID: #

Reviewers: dhruba, emayanke

Reviewed By: dhruba

CC: leveldb

Differential Revision: https://reviews.facebook.net/D8769
2013-02-21 12:26:32 -08:00
Vamsi Ponnekanti
945d2b59b9 [Add randomwithverify benchmark option]
Summary: Added RandomWithVerify benchmark option.

Test Plan:
This whole diff is to test.
[nponnekanti@dev902 /data/users/nponnekanti/rocksdb] ./db_bench --benchmarks=randomwithverify
LevelDB:    version 1.5
Date:       Tue Feb 19 17:50:28 2013
CPU:        24 * Intel(R) Xeon(R) CPU           X5650  @ 2.67GHz
CPUCache:   12288 KB
Keys:       16 bytes each
Values:     100 bytes each (50 bytes after compression)
Entries:    1000000
RawSize:    110.6 MB (estimated)
FileSize:   62.9 MB (estimated)
Compression: snappy
WARNING: Assertions are enabled; benchmarks unnecessarily slow
------------------------------------------------
Created bg thread 0x7fa9c3fff700
randomwithverify :       5.004 micros/op 199836 ops/sec; ( get:900000 put:80000 del:20000 total:1000000 found:711992)

Revert Plan: OK

Task ID: #

Reviewers: dhruba, emayanke

Reviewed By: dhruba

CC: leveldb

Differential Revision: https://reviews.facebook.net/D8685
2013-02-21 10:27:02 -08:00
amayank
b2c50f1c3f Fix for the weird behaviour encountered by ldb Get where it could read only the second-latest value
Summary:
Changed the Get and Scan options with openForReadOnly mode to have access to the memtable.
Changed the visibility of NewInternalIterator in db_impl from private to protected so that
the derived class db_impl_read_only can call that in its NewIterator function for the
scan case. The previous approach which changed the default for flush_on_destroy_ from false to true
caused many problems in the unit tests due to empty sst files that it created. All
unit tests pass now.

Test Plan: make clean; make all check; ldb put and get and scans

Reviewers: dhruba, heyongqiang, sheki

Reviewed By: dhruba

CC: kosievdmerwe, zshao, dilipj, kailiu

Differential Revision: https://reviews.facebook.net/D8697
2013-02-20 10:45:52 -08:00
Abhishek Kona
fe10200ddc Introduce histogram in statistics.h
Summary:
* Introduce is histogram in statistics.h
* stop watch to measure time.
* introduce two timers as a poc.
Replaced NULL with nullptr to fight some lint errors
Should be useful for google.

Test Plan:
ran db_bench and check stats.
make all check

Reviewers: dhruba, heyongqiang

Reviewed By: dhruba

CC: leveldb

Differential Revision: https://reviews.facebook.net/D8637
2013-02-20 10:43:32 -08:00
amayank
f3901e0647 Revert "Fix for the weird behaviour encountered by ldb Get where it could read only the second-latest value"
This reverts commit 4c696ed001.
2013-02-18 22:32:27 -08:00
Dhruba Borthakur
fd367e677e Fix unit test failure in db_filename.cc
Summary:
    c_test: db/filename.cc:74: std::string leveldb::DescriptorFileName(const string&,....

Test Plan:
  this is a failure in a unit test

Differential Revision: https://reviews.facebook.net/D8667
2013-02-18 21:53:56 -08:00
Dhruba Borthakur
4564915446 Zero out redundant sequence numbers for kvs to increase compression efficiency
Summary:
The sequence numbers in each record eat up plenty of space on storage.
The optimization zeroes out sequence numbers on kvs in the Lmax
layer that are earlier than the earliest snapshot.

Test Plan: Unit test attached.

Differential Revision: https://reviews.facebook.net/D8619
2013-02-18 21:51:15 -08:00
amayank
4c696ed001 Fix for the weird behaviour encountered by ldb Get where it could read only the second-latest value
Summary:
flush_on_destroy has a default value of false and the memtable is flushed
in the dbimpl-destructor only when that is set to true. Because we want the memtable to be flushed everytime that
the destructor is called(db is closed) and the cases where we work with the memtable only are very less
it is a good idea to give this a default value of true. Thus the put from ldb
wil have its data flushed to disk in the destructor and the next Get will be able to
read it when opened with OpenForReadOnly. The reason that ldb could read the latest value when
the db was opened in the normal Open mode is that the Get from normal Open first reads
the memtable and directly finds the latest value written there and the Get from OpenForReadOnly
doesn't have access to the memtable (which is correct because all its Put/Modify) are disabled

Test Plan: make all; ldb put and get and scans

Reviewers: dhruba, heyongqiang, sheki

Reviewed By: heyongqiang

CC: kosievdmerwe, zshao, dilipj, kailiu

Differential Revision: https://reviews.facebook.net/D8631
2013-02-15 16:56:06 -08:00
Kai Liu
b63aafce42 Allow the logs to be purged by TTL.
Summary:
* Add a SplitByTTLLogger to enable this feature. In this diff I implemented generalized AutoSplitLoggerBase class to simplify the
development of such classes.
* Refactor the existing AutoSplitLogger and fix several bugs.

Test Plan:
* Added a unit tests for different types of "auto splitable" loggers individually.
* Tested the composited logger which allows the log files to be splitted by both TTL and log size.

Reviewers: heyongqiang, dhruba

Reviewed By: heyongqiang

CC: zshao, leveldb

Differential Revision: https://reviews.facebook.net/D8037
2013-02-04 19:42:40 -08:00
Chip Turner
0b83a83191 Fix poor error on num_levels mismatch and few other minor improvements
Summary:
Previously, if you opened a db with num_levels set lower than
the database, you received the unhelpful message "Corruption:
VersionEdit: new-file entry."  Now you get a more verbose message
describing the issue.

Also, fix handling of compression_levels (both the run-over-the-end
issue and the memory management of it).

Lastly, unique_ptr'ify a couple of minor calls.

Test Plan: make check

Reviewers: dhruba

Reviewed By: dhruba

CC: leveldb

Differential Revision: https://reviews.facebook.net/D8151
2013-01-25 15:37:26 -08:00
Chip Turner
772f75b3fb Stop continually re-creating build_version.c
Summary:
We continually rebuilt build_version.c because we put the
current date into it, but that's what __DATE__ already is.  This makes
builds faster.

This also fixes an issue with 'make clean FOO' not working properly.

Also tweak the build rules to be more consistent, always have warnings,
and add a 'make release' rule to handle flags for release builds.

Test Plan: make, make clean

Reviewers: dhruba

Reviewed By: dhruba

Differential Revision: https://reviews.facebook.net/D8139
2013-01-24 17:51:39 -08:00
Chip Turner
3dafdfb2c4 Use fallocate to prevent excessive allocation of sst files and logs
Summary:
On some filesystems, pre-allocation can be a considerable
amount of space.  xfs in our production environment pre-allocates by
1GB, for instance.  By using fallocate to inform the kernel of our
expected file sizes, we eliminate this wasteage (that isn't recovered
until the file is closed which, in the case of LOG files, can be a
considerable amount of time).

Test Plan:
created an xfs loopback filesystem, mounted with
allocsize=4M, and ran db_stress.  LOG file without this change was 4M,
and with it it was 128k then grew to normal size.

Reviewers: dhruba

Reviewed By: dhruba

CC: adsharma, leveldb

Differential Revision: https://reviews.facebook.net/D7953
2013-01-24 12:25:13 -08:00
Chip Turner
2fdf91a4f8 Fix a number of object lifetime/ownership issues
Summary:
Replace manual memory management with std::unique_ptr in a
number of places; not exhaustive, but this fixes a few leaks with file
handles as well as clarifies semantics of the ownership of file handles
with log classes.

Test Plan: db_stress, make check

Reviewers: dhruba

Reviewed By: dhruba

CC: zshao, leveldb, heyongqiang

Differential Revision: https://reviews.facebook.net/D8043
2013-01-23 16:54:11 -08:00
Abhishek Kona
16903c35b0 Add counters to count gets and writes
Summary: Add Tickers to count Write's and Get's

Test Plan: make check

Reviewers: dhruba, chip

Reviewed By: dhruba

CC: leveldb

Differential Revision: https://reviews.facebook.net/D7977
2013-01-17 12:27:56 -08:00
Kosie van der Merwe
3c3df7402f Fixed issues Valgrind found.
Summary:
Found issues with `db_test` and `db_stress` when running valgrind.

`DBImpl` had an issue where if an compaction failed then it will use the uninitialised file size of an output file is used. This manifested as the final call to output to the log in `DoCompactionWork()` branching on uninitialized memory (all the way down in printf's innards).

Test Plan:
Ran `valgrind --track_origins=yes ./db_test` and `valgrind ./db_stress` to see if issues disappeared.

Ran `make check` to see if there were no regressions.

Reviewers: vamsi, dhruba

Reviewed By: dhruba

CC: leveldb

Differential Revision: https://reviews.facebook.net/D8001
2013-01-17 10:04:45 -08:00
Abhishek Kona
7d5a4383bb rollover manifest file.
Summary:
Check in LogAndApply if the file size is more than the limit set in
Options.
Things to consider : will this be expensive?

Test Plan: make all check. Inputs on a new unit test?

Reviewers: dhruba

Reviewed By: dhruba

CC: leveldb

Differential Revision: https://reviews.facebook.net/D7701
2013-01-16 12:09:44 -08:00
Chip Turner
a2dcd79c1e Add optional clang compile mode
Summary:
clang is an alternate compiler based on llvm.  It produces
nicer error messages and finds some bugs that gcc doesn't, such as the
size_t change in this file (which caused some write return values to be
misinterpreted!)

Clang isn't the default; to try it, do "USE_CLANG=1 make" or "export
USE_CLANG=1" then make as normal

Test Plan: "make check" and "USE_CLANG=1 make check"

Reviewers: dhruba

Reviewed By: dhruba

Differential Revision: https://reviews.facebook.net/D7899
2013-01-15 18:48:37 -08:00
Chip Turner
9bbcab57a9 Fix broken build
Summary: Mis-merged from HEAD, had a duplicate declaration.

Test Plan: make -j32 OPT=-g

Reviewers: dhruba

Reviewed By: dhruba

Differential Revision: https://reviews.facebook.net/D7911
2013-01-15 14:05:49 -08:00
Kosie van der Merwe
28fe86c48a Fixed bug with seek compactions on Level 0
Summary: Due to how the code handled compactions in Level 0 in `PickCompaction()` it could be the case that two compactions on level 0 ran that produced tables in level 1 that overlap. However, this case seems like it would only occur on a seek compaction which is unlikely on level 0. Furthermore, level 0 and level 1 had to have a certain arrangement of files.

Test Plan:
make check

Reviewers: dhruba, vamsi

Reviewed By: dhruba

CC: leveldb, sheki

Differential Revision: https://reviews.facebook.net/D7923
2013-01-15 12:43:09 -08:00
Chip Turner
c0cb289d57 Various build cleanups/improvements
Summary:
Specific changes:

1) Turn on -Werror so all warnings are errors
2) Fix some warnings the above now complains about
3) Add proper dependency support so changing a .h file forces a .c file
to rebuild
4) Automatically use fbcode gcc on any internal machine rather than
whatever system compiler is laying around
5) Fix jemalloc to once again be used in the builds (seemed like it
wasn't being?)
6) Fix issue where 'git' would fail in build_detect_version because of
LD_LIBRARY_PATH being set in the third-party build system

Test Plan:
make, make check, make clean, touch a header file, make sure
rebuild is expected

Reviewers: dhruba

Reviewed By: dhruba

Differential Revision: https://reviews.facebook.net/D7887
2013-01-14 18:40:22 -08:00
Mark Callaghan
2ba125faf6 fix warning for unused variable
Test Plan: compile

Reviewers: dhruba

Reviewed By: dhruba

CC: leveldb

Differential Revision: https://reviews.facebook.net/D7857
2013-01-11 15:00:47 -08:00
Abhishek Kona
85ad13be1a Port fix for Leveldb manifest writing bug from Open-Source
Summary:
Pretty much a blind copy of the patch in open source.
Hope to get this in before we make a release

Test Plan: make clean check

Reviewers: dhruba, heyongqiang

Reviewed By: dhruba

CC: leveldb

Differential Revision: https://reviews.facebook.net/D7809
2013-01-10 12:06:03 -08:00
Kosie van der Merwe
d8371ef1f6 Fixing some issues Valgrind found
Summary: Found some issues running Valgrind on `db_test` (there are still some outstanding ones) and fixed them.

Test Plan:
make check

ran `valgrind ./db_test` and saw that errors no longer occur

Reviewers: dhruba, vamsi, emayanke, sheki

Reviewed By: dhruba

CC: leveldb

Differential Revision: https://reviews.facebook.net/D7803
2013-01-08 12:16:40 -08:00
Dhruba Borthakur
628dc2aad9 db_bench should use the default value for max_grandparent_overlap_factor.
Summary:
This was a peformance regression caused by https://reviews.facebook.net/D6729.
The default value of max_grandparent_overlap_factor was erroneously
set to 0 in db_bench.

This was causing compactions to create really really small files because the max_grandparent_overlap_factor was erroneously set to zero in the benchmark.

Test Plan: Run --benchmarks=overwrite

Reviewers: heyongqiang, emayanke, sheki, MarkCallaghan

Reviewed By: sheki

CC: leveldb

Differential Revision: https://reviews.facebook.net/D7797
2013-01-08 11:21:11 -08:00
Kosie van der Merwe
d6e873f22f Added clearer error message for failure to create db directory in DBImpl::Recover()
Summary:
Changed CreateDir() to CreateDirIfMissing() so a directory that already exists now causes and error.

Fixed CreateDirIfMissing() and added Env.DirExists()

Test Plan:
make check to test for regessions

Ran the following to test if the error message is not about lock files not existing
./db_bench --db=dir/testdb

After creating a file "testdb", ran the following to see if it failed with sane error message:
./db_bench --db=testdb

Reviewers: dhruba, emayanke, vamsi, sheki

Reviewed By: emayanke

CC: leveldb

Differential Revision: https://reviews.facebook.net/D7707
2013-01-07 10:11:18 -08:00
Mark Callaghan
4069f66cc7 Add --seed, --read_range to db_bench
Summary:
Adds the option --seed to db_bench to specify the base for the per-thread RNG.
When not set each thread uses the same value across runs of db_bench which defeats
IO stress testing.

Adds the option --read_range. When set to a value > 1 an iterator is created and
each query done for the randomread benchmark will do a range scan for that many
rows. When not set or set to 1 the existing behavior (a point lookup) is done.

Fixes a bug where a printf format string was missing.

Test Plan: run db_bench

Reviewers: dhruba

Reviewed By: dhruba

CC: leveldb

Differential Revision: https://reviews.facebook.net/D7749
2013-01-07 09:56:10 -08:00
Kosie van der Merwe
8cd86a7be5 Fixing and adding some comments
Summary:
`MemTableList::Add()` neglected to mention that it took ownership of the reference held by its caller.

The comment in `MemTable::Get()` was wrong in describing the format of the key.

Test Plan: None

Reviewers: dhruba, sheki, emayanke, vamsi

Reviewed By: dhruba

CC: leveldb

Differential Revision: https://reviews.facebook.net/D7755
2013-01-03 17:13:56 -08:00
Dhruba Borthakur
d7d43ae21a ExtendOverlappingInputs too slow for large databases.
Summary:
There was a bug in the ExtendOverlappingInputs method so that
the terminating condition for the backward search was incorrect.

Test Plan: make clean check

Reviewers: sheki, emayanke, MarkCallaghan

Reviewed By: MarkCallaghan

CC: leveldb

Differential Revision: https://reviews.facebook.net/D7725
2013-01-02 13:19:06 -08:00
Dhruba Borthakur
f4c2b7cf97 Enhance ReadOnly mode to process the all committed transactions.
Summary:
Leveldb has an api OpenForReadOnly() that opens the database
in readonly mode. This call had an option to not process the
transaction log.  This patch removes this option and always
processes all transactions that had been committed. It has
been done in such a way that it does not create/write to
any new files in the process. The invariant of "no-writes"
to the leveldb data directory is still true.

This enhancement allows multiple threads to open the same database
in readonly mode and access all trancations that were committed right
upto the OpenForReadOnly call.

I changed the public API to match the new semantics because
there are no users who are currently using this api.

Test Plan: make clean check

Reviewers: sheki

Reviewed By: sheki

CC: leveldb

Differential Revision: https://reviews.facebook.net/D7479
2012-12-19 16:30:46 -08:00
Dhruba Borthakur
3d1e92b05a Enhancements to rocksdb for better support for replication.
Summary:
1. The OpenForReadOnly() call should not lock the db. This is useful
so that multiple processes can open the same database concurrently
for reading.
2. GetUpdatesSince should not error out if the archive directory
does not exist.
3. A new constructor for WriteBatch that can takes a serialized
string as a parameter of the constructor.

Test Plan: make clean check

Reviewers: sheki

Reviewed By: sheki

CC: leveldb

Differential Revision: https://reviews.facebook.net/D7449
2012-12-17 11:40:19 -08:00
Kosie van der Merwe
62d48571de Added meta-database support.
Summary:
Added kMetaDatabase for meta-databases in db/filename.h along with supporting
fuctions.
Fixed switch in DBImpl so that it also handles kMetaDatabase.
Fixed DestroyDB() that it can handle destroying meta-databases.

Test Plan: make check

Reviewers: sheki, emayanke, vamsi, dhruba

Reviewed By: dhruba

Differential Revision: https://reviews.facebook.net/D7245
2012-12-17 11:26:59 -08:00
Abhishek Kona
2f0585fb97 Fix a bug. Where DestroyDB deletes a non-existant archive directory.
Summary:
C tests would fail sometimes as DestroyDB would return a Failure Status
message when deleting an archival directory which was not created
(WAL_ttl_seconds = 0).

Fix: Ignore the Status returned on Deleting Archival Directory.

Test Plan: * make check

Reviewers: dhruba, emayanke

Reviewed By: dhruba

CC: leveldb

Differential Revision: https://reviews.facebook.net/D7395
2012-12-17 10:25:26 -08:00
Zheng Shao
c28097538a manifest_dump: Add --hex=1 option
Summary: Without this option, manifest_dump does not print binary keys for files in a human-readable way.

Test Plan:
./manifest_dump --hex=1 --verbose=0 --file=/data/users/zshao/fdb_comparison/leveldb/fbobj.apprequest-0_0_original/MANIFEST-000002
manifest_file_number 589 next_file_number 590 last_sequence 2311567 log_number 543  prev_log_number 0
--- level 0 --- version# 0 ---
 532:1300357['0000455BABE20000' @ 2183973 : 1 .. 'FFFCA5D7ADE20000' @ 2184254 : 1]
 536:1308170['000198C75CE30000' @ 2203313 : 1 .. 'FFFCF94A79E30000' @ 2206463 : 1]
 542:1321644['0002931AA5E50000' @ 2267055 : 1 .. 'FFF77B31C5E50000' @ 2270754 : 1]
 544:1286390['000410A309E60000' @ 2278592 : 1 .. 'FFFE470A73E60000' @ 2289221 : 1]
 538:1298778['0006BCF4D8E30000' @ 2217050 : 1 .. 'FFFD77DAF7E30000' @ 2220489 : 1]
 540:1282353['00090D5356E40000' @ 2231156 : 1 .. 'FFFFF4625CE40000' @ 2231969 : 1]
--- level 1 --- version# 0 ---
 510:2112325['000007F9C2D40000' @ 1782099 : 1 .. '146F5B67B8D80000' @ 1905458 : 1]
 511:2121742['146F8A3023D60000' @ 1824388 : 1 .. '28BC8FBB9CD40000' @ 1777993 : 1]
 512:801631['28BCD396F1DE0000' @ 2080191 : 1 .. '3082DBE9ADDB0000' @ 1989927 : 1]

Reviewers: dhruba, sheki, emayanke

Reviewed By: dhruba

CC: leveldb

Differential Revision: https://reviews.facebook.net/D7425
2012-12-16 08:58:28 -08:00
Abhishek Kona
2ba866e0c5 GetSequence API in write batch.
Summary:
WriteBatch is now used by the GetUpdatesSinceAPI. This API is external
and will be used by the rocks server. Rocks Server and others will need
to know about the Sequence Number in the WriteBatch. This public method
will allow for that.

Test Plan: make all check.

Reviewers: dhruba

Reviewed By: dhruba

CC: leveldb

Differential Revision: https://reviews.facebook.net/D7293
2012-12-12 22:21:10 -08:00
Abhishek Kona
22c283625b Fix Bug in Binary Search for files containing a seq no. and delete Archived Log Files during Destroy DB.
Summary:
* Fixed implementation bug in Binary_Searvch introduced in https://reviews.facebook.net/D7119
* Binary search is also overflow safe.
* Delete archive log files and archive dir during DestroyDB

Test Plan: make check

Reviewers: dhruba

CC: kosievdmerwe, emayanke

Differential Revision: https://reviews.facebook.net/D7263
2012-12-11 16:15:02 -08:00
Dhruba Borthakur
24fc379273 An public api to fetch the latest transaction id.
Summary:
Implement a interface to retrieve the most current transaction
id from the database.

Test Plan: Added unit test.

Reviewers: sheki

Reviewed By: sheki

CC: leveldb

Differential Revision: https://reviews.facebook.net/D7269
2012-12-10 16:04:19 -08:00
Abhishek Kona
1c6742e32f Refactor GetArchivalDirectoryName to filename.h
Summary:
filename.h has functions to do similar things.
Moving code away from db_impl.cc

Test Plan: make check

Reviewers: dhruba

Reviewed By: dhruba

Differential Revision: https://reviews.facebook.net/D7251
2012-12-10 10:51:07 -08:00
Abhishek Kona
8055008909 GetUpdatesSince API to enable replication.
Summary:
How it works:
* GetUpdatesSince takes a SequenceNumber.
* A LogFile with the first SequenceNumber nearest and lesser than the requested Sequence Number is found.
* Seek in the logFile till the requested SeqNumber is found.
* Return an iterator which contains logic to return record's one by one.

Test Plan:
* Test case included to check the good code path.
* Will update with more test-cases.
* Feedback required on test-cases.

Reviewers: dhruba, emayanke

Reviewed By: dhruba

CC: leveldb

Differential Revision: https://reviews.facebook.net/D7119
2012-12-07 11:42:13 -08:00
Dhruba Borthakur
c847a31727 Print compaction score for every compaction run.
Summary:
A compaction is picked based on its score. It is useful to
print the compaction score in the LOG because it aids in
debugging. If one looks at the logs, one can find out why
a compaction was preferred over another.

Test Plan: make clean check

Differential Revision: https://reviews.facebook.net/D7137
2012-12-04 10:03:47 -08:00
sheki
d4627e6de4 Move WAL files to archive directory, instead of deleting.
Summary:
Create a directory "archive" in the DB directory.
During DeleteObsolteFiles move the WAL files (*.log) to the Archive directory,
instead of deleting.

Test Plan: Created a DB using DB_Bench. Reopened it. Checked if files move.

Reviewers: dhruba

Reviewed By: dhruba

Differential Revision: https://reviews.facebook.net/D6975
2012-11-28 17:28:08 -08:00
Abhishek Kona
d29f181923 Fix all the lint errors.
Summary:
Scripted and removed all trailing spaces and converted all tabs to
spaces.

Also fixed other lint errors.
All lint errors from this point of time should be taken seriously.

Test Plan: make all check

Reviewers: dhruba

Reviewed By: dhruba

CC: leveldb

Differential Revision: https://reviews.facebook.net/D7059
2012-11-28 17:18:41 -08:00
Dhruba Borthakur
9a357847eb Delete non-visible keys during a compaction even in the presense of snapshots.
Summary:
 LevelDB should delete almost-new keys when a long-open snapshot exists.
The previous behavior is to keep all versions that were created after the
oldest open snapshot. This can lead to database size bloat for
high-update workloads when there are long-open snapshots and long-open
snapshot will be used for logical backup. By "almost new" I mean that the
key was updated more than once after the oldest snapshot.

If there were two snapshots with seq numbers s1 and s2 (s1 < s2), and if
we find two instances of the same key k1 that lie entirely within s1 and
s2 (i.e. s1 < k1 < s2), then the earlier version
of k1 can be safely deleted because that version is not visible in any snapshot.

Test Plan:
unit test attached
make clean check

Differential Revision: https://reviews.facebook.net/D6999
2012-11-28 15:47:40 -08:00
Dhruba Borthakur
3366eda839 Print out status at the end of a compaction run.
Summary:
Print out status at the end of a compaction run. This helps in
debugging.

Test Plan: make clean check

Reviewers: sheki

Reviewed By: sheki

Differential Revision: https://reviews.facebook.net/D7035
2012-11-27 22:17:38 -08:00
sheki
43f5a07989 Remove unused varibles. Cause compiler warnings.
Test Plan: make check

Reviewers: dhruba

Reviewed By: dhruba

CC: emayanke

Differential Revision: https://reviews.facebook.net/D6993
2012-11-26 20:55:24 -08:00
Dhruba Borthakur
2a39699900 Assertion failure while running with unit tests with OPT=-g
Summary:
When we expand the range of keys for a level 0 compaction, we
need to invoke ParentFilesInCompaction() only once for the
entire range of keys that is being compacted. We were invoking
it for each file that was being compacted, but this triggers
an assertion because each file's range were contiguous but
non-overlapping.

I renamed ParentFilesInCompaction to ParentRangeInCompaction
to adequately represent that it is the range-of-keys and
not individual files that we compact in a single compaction run.

Here is the assertion that is fixed by this patch.
db_test: db/version_set.cc:585: void leveldb::Version::ExtendOverlappingInputs(int, const leveldb::Slice&, const leveldb::Slice&, std::vector<leveldb::FileMetaData*, std::allocator<leveldb::FileMetaData*> >*, int): Assertion `user_cmp->Compare(flimit, user_begin) >= 0' failed.

Test Plan: make clean check OPT=-g

Reviewers: sheki

Reviewed By: sheki

CC: MarkCallaghan, emayanke, leveldb

Differential Revision: https://reviews.facebook.net/D6963
2012-11-26 14:00:39 -08:00
Dhruba Borthakur
e0cd6bf0e9 The c_test was sometimes failing with an assertion.
Summary:
On fast filesystems (e.g. /dev/shm and ext4), the flushing
of memstore to disk was fast and quick, and the background compaction
thread was not getting scheduled fast enough to delete obsolete
files before the db was closed. This caused the repair method
to pick up those files that were not part of the db and the unit
test was failing.

The fix is to enhance the unti test to run a compaction before
closing the database so that all files that are not part of the
database are truly deleted from the filesystem.

Test Plan: make c_test; ./c_test

Reviewers: chip, emayanke, sheki

Reviewed By: chip

CC: leveldb

Differential Revision: https://reviews.facebook.net/D6915
2012-11-26 11:59:51 -08:00
Dhruba Borthakur
7632fdb5cb Support taking a configurable number of files from the same level to compact in a single compaction run.
Summary:
The compaction process takes some files from LevelK and
merges it into LevelK+1. The number of files it picks from
LevelK was capped such a way that the total amount of
data picked does not exceed the maxfilesize of that level.
This essentially meant that only one file from LevelK
is picked for a single compaction.

For bulkloads, we would like to take many many file from
LevelK and compact them using a single compaction run.

This patch introduces a option called the 'source_compaction_factor'
(similar to expanded_compaction_factor). It is a multiplier
that is multiplied by the maxfilesize of that level to arrive
at the limit that is used to throttle the number of source
files from LevelK.  For bulk loads, set source_compaction_factor
to a very high number so that multiple files from the same
level are picked for compaction in a single compaction.

The default value of source_compaction_factor is 1, so that
we can keep backward compatibilty with existing compaction semantics.

Test Plan: make clean check

Reviewers: emayanke, sheki

Reviewed By: emayanke

CC: leveldb

Differential Revision: https://reviews.facebook.net/D6867
2012-11-21 08:37:03 -08:00
Dhruba Borthakur
fbb73a4ac3 Support to disable background compactions on a database.
Summary:
This option is needed for fast bulk uploads. The goal is to load
all the data into files in L0 without any interference from
background compactions.

Test Plan: make clean check

Reviewers: sheki

Reviewed By: sheki

CC: leveldb

Differential Revision: https://reviews.facebook.net/D6849
2012-11-20 21:12:06 -08:00
Dhruba Borthakur
3754f2f4ff A major bug that was not considering the compaction score of the n-1 level.
Summary:
The method Finalize() recomputes the compaction score of each
level and then sorts these score from largest to smallest. The
idea is that the level with the largest compaction score will
be a better candidate for compaction.  There are usually very
few levels, and a bubble sort code was used to sort these
compaction scores. There existed a bug in the sorting code that
skipped looking at the score for the n-1 level. This meant that
even if the compaction score of the n-1 level is large, it will
not be picked for compaction.

This patch fixes the bug and also introduces "asserts" in the
code to detect any possible inconsistencies caused by future bugs.

This bug existed in the very first code change that introduced
multi-threaded compaction to the leveldb code. That version of
code was committed on Oct 19th via
1ca0584345

Test Plan: make clean check OPT=-g

Reviewers: emayanke, sheki, MarkCallaghan

Reviewed By: sheki

CC: leveldb

Differential Revision: https://reviews.facebook.net/D6837
2012-11-20 15:44:21 -08:00
Dhruba Borthakur
dde70898a1 Fix asserts
Summary:
make check OPT=-g fails with the following assert.
==== Test DBTest.ApproximateSizes
db_test: db/version_set.cc:765: void leveldb::VersionSet::Builder::CheckConsistencyForDeletes(leveldb::VersionEdit*, int, int): Assertion `found' failed.

The assertion was that file #7 that was being deleted did not
preexists, but actualy it did pre-exist as shown in the manifest
dump shows below. The bug was that we did not check for file
existance at the same level.

*************************Edit[0] = VersionEdit {
  Comparator: leveldb.BytewiseComparator
}

*************************Edit[1] = VersionEdit {
  LogNumber: 8
  PrevLogNumber: 0
  NextFile: 9
  LastSeq: 80
  AddFile: 0 7 8005319 'key000000' @ 1 : 1 .. 'key000079' @ 80 : 1
}

*************************Edit[2] = VersionEdit {
  LogNumber: 8
  PrevLogNumber: 0
  NextFile: 13
  LastSeq: 80
  CompactPointer: 0 'key000079' @ 80 : 1
  DeleteFile: 0 7
  AddFile: 1 9 2101425 'key000000' @ 1 : 1 .. 'key000020' @ 21 : 1
  AddFile: 1 10 2101425 'key000021' @ 22 : 1 .. 'key000041' @ 42 : 1
  AddFile: 1 11 2101425 'key000042' @ 43 : 1 .. 'key000062' @ 63 : 1
  AddFile: 1 12 1701165 'key000063' @ 64 : 1 .. 'key000079' @ 80 : 1
}

Test Plan:

Reviewers:

CC:

Task ID: #

Blame Rev:
2012-11-19 14:51:22 -08:00
Dhruba Borthakur
a4b79b6e28 Merge branch 'master' into performance 2012-11-19 13:20:25 -08:00
Dhruba Borthakur
74054fa993 Fix compilation error while compiling unit tests with OPT=-g
Summary:
Fix compilation error while compiling with OPT=-g

Test Plan:
make clean check OPT=-g

Reviewers:

CC:

Task ID: #

Blame Rev:
2012-11-19 13:16:46 -08:00
Dhruba Borthakur
48dafb2c59 Fix compilation error introduced by previous commit
7889e09455

Summary:
Fix compilation error introduced by previous commit
7889e09455

Test Plan:
make clean check
2012-11-19 12:16:45 -08:00
Dhruba Borthakur
7889e09455 Enhance manifest_dump to print each individual edit.
Summary:
The manifest file contains a series of edits. If the verbose
option is switched on, then print each individual edit in the
manifest file. This helps in debugging.

Test Plan: make clean manifest_dump

Reviewers: emayanke, sheki

Reviewed By: sheki

CC: leveldb

Differential Revision: https://reviews.facebook.net/D6807
2012-11-19 12:04:35 -08:00
amayank
65b035a47f Fix a coding error in db_test.cc
Summary: The new function MinLevelToCompress in db_test.cc was incomplete. It needs to tell the calling function-TEST whether the test has to be skipped or not

Test Plan: make all;./db_test

Reviewers: dhruba, heyongqiang

Reviewed By: dhruba

CC: sheki

Differential Revision: https://reviews.facebook.net/D6771
2012-11-19 12:04:35 -08:00
Dhruba Borthakur
4b622ab0f2 Enhance manifest_dump to print each individual edit.
Summary:
The manifest file contains a series of edits. If the verbose
option is switched on, then print each individual edit in the
manifest file. This helps in debugging.

Test Plan: make clean manifest_dump

Reviewers: emayanke, sheki

Reviewed By: sheki

CC: leveldb

Differential Revision: https://reviews.facebook.net/D6807
2012-11-19 12:02:27 -08:00
Dhruba Borthakur
62e7583f94 enhance dbstress to simulate hard crash
Summary:
dbstress has an option to reopen the database. Make it such that the
previous handle is not closed before we reopen, this simulates a
situation similar to a process crash.

Added new api to DMImpl to remove the lock file.

Test Plan: run db_stress

Reviewers: emayanke

Reviewed By: emayanke

CC: leveldb

Differential Revision: https://reviews.facebook.net/D6777
2012-11-18 23:16:17 -08:00
amayank
de278a6de9 Fix a coding error in db_test.cc
Summary: The new function MinLevelToCompress in db_test.cc was incomplete. It needs to tell the calling function-TEST whether the test has to be skipped or not

Test Plan: make all;./db_test

Reviewers: dhruba, heyongqiang

Reviewed By: dhruba

CC: sheki

Differential Revision: https://reviews.facebook.net/D6771
2012-11-16 14:56:50 -08:00
Dhruba Borthakur
6c5a4d646a Merge branch 'master' into performance
Conflicts:
	db/db_impl.h
2012-11-14 21:39:52 -08:00
Dhruba Borthakur
e988c11f58 Enhance db_bench to be able to specify a grandparent_overlap_factor.
Summary:
The value specified in max_grandparent_overlap_factor is used to
limit the file size in a compaction run. This patch makes it
configurable when using db_bench.

Test Plan: make clean db_bench

Reviewers: MarkCallaghan, heyongqiang

Reviewed By: heyongqiang

CC: leveldb

Differential Revision: https://reviews.facebook.net/D6729
2012-11-14 16:20:13 -08:00
Dhruba Borthakur
5d16e503a6 Improved CompactionFilter api: pass in a opaque argument to CompactionFilter invocation.
Summary:
There are applications that operate on multiple leveldb instances.
These applications will like to pass in an opaque type for each
leveldb instance and this type should be passed back to the application
with every invocation of the CompactionFilter api.

Test Plan: Enehanced unit test for opaque parameter to CompactionFilter.

Reviewers: heyongqiang

Reviewed By: heyongqiang

CC: MarkCallaghan, sheki, emayanke

Differential Revision: https://reviews.facebook.net/D6711
2012-11-13 16:22:26 -08:00
Dhruba Borthakur
43d9a8225a Fix asserts so that "make check OPT=-g" works on performance branch
Summary:
Compilation used to fail with the error:
db/version_set.cc:1773: error: ‘number_of_files_to_sort_’ is not a member of ‘leveldb::VersionSet’

I created a new method called CheckConsistencyForDeletes() so that
all the high cost checking is done only when OPT=-g is specified.

I also fixed a bug in PickCompactionBySize that was triggered when
OPT=-g was switched on. The base_index in the compaction record
was not set correctly.

Test Plan: make check OPT=-g

Differential Revision: https://reviews.facebook.net/D6687
2012-11-13 10:40:52 -08:00
Dhruba Borthakur
a785e029f7 The db_bench utility was broken in 1.5.4.fb because of a signed-unsigned comparision.
Summary:
The db_bench utility was broken in 1.5.4.fb because of a
signed-unsigned comparision.

The static variable FLAGS_min_level_to_compress was recently
changed from int to 'unsigned in' but it is initilized to a
nagative value -1.

The segfault is of this type:
Program received signal SIGSEGV, Segmentation fault.
Open (this=0x7fffffffdee0) at db/db_bench.cc:939
939	db/db_bench.cc: No such file or directory.
(gdb) where

Test Plan: run db_bench with no options.

Reviewers: heyongqiang

Reviewed By: heyongqiang

CC: MarkCallaghan, emayanke, sheki

Differential Revision: https://reviews.facebook.net/D6663
2012-11-12 13:59:35 -08:00
Dhruba Borthakur
9c6c232e47 Compilation error while compiling with OPT=-g
Summary:
make clean check OPT=-g fails
leveldb::DBStatistics::getTickerCount(leveldb::Tickers)’:
./db/db_statistics.h:34: error: ‘MAX_NO_TICKERS’ was not declared in this scope
util/ldb_cmd.cc:255: warning: left shift count >= width of type

Test Plan:
make clean check OPT=-g

Reviewers:

CC:

Task ID: #

Blame Rev:
2012-11-11 00:20:40 -08:00
Abhishek Kona
0f8e4721a5 Metrics: record compaction drop's and bloom filter effectiveness
Summary: Record BloomFliter hits and drop off reasons during compaction.

Test Plan: Unit tests work.

Reviewers: dhruba, heyongqiang

Reviewed By: dhruba

Differential Revision: https://reviews.facebook.net/D6591
2012-11-09 11:38:45 -08:00
heyongqiang
20d18a89a3 disable size compaction in ldb reduce_levels and added compression and file size parameter to it
Summary:
disable size compaction in ldb reduce_levels, this will avoid compactions rather than the manual comapction,

added --compression=none|snappy|zlib|bzip2 and --file_size= per-file size to ldb reduce_levels command

Test Plan: run ldb

Reviewers: dhruba, MarkCallaghan

Reviewed By: dhruba

CC: sheki, emayanke

Differential Revision: https://reviews.facebook.net/D6597
2012-11-09 10:14:47 -08:00
Abhishek Kona
391885c4e4 stat's collection in leveldb
Summary:
Prototype stat's collection. Diff is a good estimate of what
the final code will look like.
A few assumptions :
  * Used a global static instance of the statistics object. Plan to pass
  it to each internal function. Static allows metrics only at app
  level.
  * In the Ticker's do not do any locking. Depend on the mutex at each
   function of LevelDB. If we ever remove the mutex, we should change
   here too. The other option is use atomic objects anyways as there
   won't be any contention as they will be always acquired only by one
   thread.
  * The counters are dumb, increment through lifecycle. Plan to use ods
    etc to get last5min stat etc.

Test Plan:
made changes in db_bench
Ran ./db_bench --statistics=1 --num=10000 --cache_size=5000
This will print the cache hit/miss stats.

Reviewers: dhruba, heyongqiang

Differential Revision: https://reviews.facebook.net/D6441
2012-11-08 13:55:49 -08:00
Dhruba Borthakur
95dda37858 Move filesize-based-sorting to outside the Mutex
Summary:
When a new version is created, we sort all the files at every
level based on their size. This is necessary because we want
to compact the largest file first. The sorting takes quite a
bit of CPU.

Moved the sorting code to be outside the mutex. Also, the
earlier code was sorting files at all levels but we do not
need to sort the highest-number level because those files
are never the cause of any compaction. To reduce sorting
costs, we sort only the first few files in each level
because it is likely that those are the only files in that
level that will be picked for compaction.

At steady state, I have seen that this patch increase
throughout from 1500 writes/sec to 1700 writes/sec at the
end of a 72 hour run. The cpu saving by not sorting the
last level was not distinctive in this test run because
there were only 100K files in the highest numbered level.
I expect the cpu saving to be significant when the number of
files is much higher.

This is mostly an early preview and not ready for rigorous review.

With this patch, the writs/sec is now bottlenecked not by the sorting code but by GetOverlappingInputs. I am working on a patch to optimize GetOverlappingInputs.

Test Plan: make check

Reviewers: MarkCallaghan, heyongqiang

Reviewed By: heyongqiang

Differential Revision: https://reviews.facebook.net/D6411
2012-11-07 15:39:44 -08:00
Dhruba Borthakur
18cb6004d2 Fixed compilation error in previous merge.
Summary:
Fixed compilation error in previous merge.

Test Plan:

Reviewers:

CC:

Task ID: #

Blame Rev:
2012-11-07 15:24:47 -08:00
Dhruba Borthakur
8143062edd Merge branch 'master' into performance
Conflicts:
	db/db_impl.cc
	db/version_set.cc
	util/options.cc
2012-11-07 15:11:37 -08:00
heyongqiang
3fcf533ed0 Add a readonly db
Summary: as subject

Test Plan: run db_bench readrandom

Reviewers: dhruba

Reviewed By: dhruba

CC: MarkCallaghan, emayanke, sheki

Differential Revision: https://reviews.facebook.net/D6495
2012-11-07 14:19:48 -08:00
Dhruba Borthakur
9b87a2bae8 Avoid doing a exhaustive search when looking for overlapping files.
Summary:
The Version::GetOverlappingInputs() is called multiple times in
the compaction code path. Eack invocation does a binary search
for overlapping files in the specified key range.
This patch remembers the offset of an overlapped file when
GetOverlappingInputs() is called the first time within
a compaction run. Suceeding calls to GetOverlappingInputs()
uses the remembered index to avoid the binary search.

I measured that 1000 iterations of GetOverlappingInputs
takes around 4500 microseconds without this patch. If I use
this patch with the hint on every invocation, then 1000
iterations take about 3900 microsecond.

Test Plan: make check OPT=-g

Reviewers: heyongqiang

Reviewed By: heyongqiang

CC: MarkCallaghan, emayanke, sheki

Differential Revision: https://reviews.facebook.net/D6513
2012-11-07 11:47:17 -08:00
Abhishek Kona
4e413df3d0 Flush Data at object destruction if disableWal is used.
Summary:
Added a conditional flush in ~DBImpl to flush.
There is still a chance of writes not being persisted if there is a
crash (not a clean shutdown) before the DBImpl instance is destroyed.

Test Plan: modified db_test to meet the new expectations.

Reviewers: dhruba, heyongqiang

Differential Revision: https://reviews.facebook.net/D6519
2012-11-06 15:04:42 -08:00
Dhruba Borthakur
aa42c66814 Fix all warnings generated by -Wall option to the compiler.
Summary:
The default compilation process now uses "-Wall" to compile.
Fix all compilation error generated by gcc.

Test Plan: make all check

Reviewers: heyongqiang, emayanke, sheki

Reviewed By: heyongqiang

CC: MarkCallaghan

Differential Revision: https://reviews.facebook.net/D6525
2012-11-06 14:07:31 -08:00
Dhruba Borthakur
5f91868cee Merge branch 'master' into performance
Conflicts:
	db/version_set.cc
	util/options.cc
2012-11-05 16:51:55 -08:00
Dhruba Borthakur
cb7a00227f The method GetOverlappingInputs should use binary search.
Summary:
The method Version::GetOverlappingInputs used a sequential search
to map a kay-range to a set of files. But the files are arranged
in ascending order of key, so a biary search is more effective.

This patch implements Version::GetOverlappingInputsBinarySearch
that finds one file that corresponds to the specified key range
and then iterates backwards and forwards to find all overlapping
files.

This patch is critical for making compactions efficient, especially
when there are thousands of files in a single level.

I measured that 1000 iterations of TEST_MaxNextLevelOverlappingBytes
takes 16000 microseconds without this patch. With this patch, the
same method takes about 4600 microseconds.

Test Plan: Almost all unit tests in db_test uses this method to lookup keys.

Reviewers: heyongqiang

Reviewed By: heyongqiang

CC: MarkCallaghan, emayanke, sheki

Differential Revision: https://reviews.facebook.net/D6465
2012-11-05 16:08:01 -08:00
Dhruba Borthakur
5273c81483 Ability to invoke application hook for every key during compaction.
Summary:
There are certain use-cases where the application intends to
delete older keys aftre they have expired a certian time period.
One option for those applications is to periodically scan the
entire database and delete appropriate keys.

A better way is to allow the application to hook into the
compaction process. This patch allows the application to set
a method callback for every key that is being compacted. If
this method returns true, then the key is not preserved in
the output of the compaction.

Test Plan:
This is mostly to preview the proposed new public api.
Since it is a public api, please do due diligence on reviewing it.

I will be writing test cases for this api in mynext version of
this patch.

Reviewers: MarkCallaghan, heyongqiang

Reviewed By: heyongqiang

CC: sheki, adsharma

Differential Revision: https://reviews.facebook.net/D6285
2012-11-05 16:02:13 -08:00
heyongqiang
f1a7c735b5 fix complie error
Summary:

as subject

Test Plan:n/a
2012-11-05 10:30:19 -08:00
heyongqiang
d55c2ba305 Add a tool to change number of levels
Summary: as subject.

Test Plan: manually test it, will add a testcase

Reviewers: dhruba, MarkCallaghan

Differential Revision: https://reviews.facebook.net/D6345
2012-11-05 10:17:39 -08:00
Dhruba Borthakur
81f735d97c Merge branch 'master' into performance
Conflicts:
	db/db_impl.cc
	util/options.cc
2012-11-05 09:41:38 -08:00
Dhruba Borthakur
a1bd5b7752 Compilation problem introduced by previous
commit 854c66b089.

Summary:
Compilation problem introduced by previous
commit 854c66b089.

Test Plan:  make check
2012-11-04 22:04:14 -08:00
amayank
854c66b089 Make compression options configurable. These include window-bits, level and strategy for ZlibCompression
Summary: Leveldb currently uses windowBits=-14 while using zlib compression.(It was earlier 15). This makes the setting configurable. Related changes here: https://reviews.facebook.net/D6105

Test Plan: make all check

Reviewers: dhruba, MarkCallaghan, sheki, heyongqiang

Differential Revision: https://reviews.facebook.net/D6393
2012-11-02 11:26:39 -07:00
heyongqiang
3096fa7534 Add two more options: disable block cache and make table cache shard number configuable
Summary:

as subject

Test Plan:

run db_bench and db_test

Reviewers: dhruba

Reviewed By: dhruba

Differential Revision: https://reviews.facebook.net/D6111
2012-11-01 13:23:21 -07:00
Mark Callaghan
3e7e269292 Use timer to measure sleep rather than assume it is 1000 usecs
Summary:
This makes the stall timers in MakeRoomForWrite more accurate by timing
the sleeps. From looking at the logs the real sleep times are usually
about 2000 usecs each when SleepForMicros(1000) is called. The modified LOG messages are:
2012/10/29-12:06:33.271984 2b3cc872f700 delaying write 13 usecs for level0_slowdown_writes_trigger
2012/10/29-12:06:34.688939 2b3cc872f700 delaying write 1728 usecs for rate limits with max score 3.83

Task ID: #

Blame Rev:

Test Plan:
run db_bench, look at DB/LOG

Revert Plan:

Database Impact:

Memcache Impact:

Other Notes:

EImportant:

- begin *PUBLIC* platform impact section -
Bugzilla: #
- end platform impact -

Reviewers: dhruba

Reviewed By: dhruba

Differential Revision: https://reviews.facebook.net/D6297
2012-10-30 07:21:37 -07:00
heyongqiang
fb8d437325 fix test failure
Summary: as subject

Test Plan: db_test

Reviewers: dhruba, MarkCallaghan

Reviewed By: MarkCallaghan

Differential Revision: https://reviews.facebook.net/D6309
2012-10-29 18:55:52 -07:00
heyongqiang
925f60d39d add a test case to make sure chaning num_levels will fail Summary:
Summary: as subject

Test Plan: db_test

Reviewers: dhruba, MarkCallaghan

Reviewed By: MarkCallaghan

Differential Revision: https://reviews.facebook.net/D6303
2012-10-29 15:27:07 -07:00
Dhruba Borthakur
53e04311b1 Merge branch 'master' into performance
Conflicts:
	db/db_bench.cc
	util/options.cc
2012-10-29 14:18:00 -07:00
Dhruba Borthakur
321dfdc3ae Allow having different compression algorithms on different levels.
Summary:
The leveldb API is enhanced to support different compression algorithms at
different levels.

This adds the option min_level_to_compress to db_bench that specifies
the minimum level for which compression should be done when
compression is enabled. This can be used to disable compression for levels
0 and 1 which are likely to suffer from stalls because of the CPU load
for memtable flushes and (L0,L1) compaction.  Level 0 is special as it
gets frequent memtable flushes. Level 1 is special as it frequently
gets all:all file compactions between it and level 0. But all other levels
could be the same. For any level N where N > 1, the rate of sequential
IO for that level should be the same. The last level is the
exception because it might not be full and because files from it are
not read to compact with the next larger level.

The same amount of time will be spent doing compaction at any
level N excluding N=0, 1 or the last level. By this standard all
of those levels should use the same compression. The difference is that
the loss (using more disk space) from a faster compression algorithm
is less significant for N=2 than for N=3. So we might be willing to
trade disk space for faster write rates with no compression
for L0 and L1, snappy for L2, zlib for L3. Using a faster compression
algorithm for the mid levels also allows us to reclaim some cpu
without trading off much loss in disk space overhead.

Also note that little is to be gained by compressing levels 0 and 1. For
a 4-level tree they account for 10% of the data. For a 5-level tree they
account for 1% of the data.

With compression enabled:
* memtable flush rate is ~18MB/second
* (L0,L1) compaction rate is ~30MB/second

With compression enabled but min_level_to_compress=2
* memtable flush rate is ~320MB/second
* (L0,L1) compaction rate is ~560MB/second

This practicaly takes the same code from https://reviews.facebook.net/D6225
but makes the leveldb api more general purpose with a few additional
lines of code.

Test Plan: make check

Differential Revision: https://reviews.facebook.net/D6261
2012-10-29 11:48:09 -07:00
Mark Callaghan
acc8567b24 Add more rates to db_bench output
Summary:
Adds the "MB/sec in" and "MB/sec out" to this line:
Amplification: 1.7 rate, 0.01 GB in, 0.02 GB out, 8.24 MB/sec in, 13.75 MB/sec out

Changes all values to be reported per interval and since test start for this line:
... thread 0: (10000,60000) ops and (19155.6,27307.5) ops/second in (0.522041,2.197198) seconds

Task ID: #

Blame Rev:

Test Plan:
run db_bench

Revert Plan:

Database Impact:

Memcache Impact:

Other Notes:

EImportant:

- begin *PUBLIC* platform impact section -
Bugzilla: #
- end platform impact -

Reviewers: dhruba

Reviewed By: dhruba

Differential Revision: https://reviews.facebook.net/D6291
2012-10-29 11:30:07 -07:00
Dhruba Borthakur
de7689b1d7 Fix unit test failure caused by delaying deleting obsolete files.
Summary:
A previous commit 4c107587ed introduced
the idea that some version updates might not delete obsolete files.
This means that if a unit test blindly counts the number of files
in the db directory it might not represent the true state of the database.

Use GetLiveFiles() insteads to count the number of live files in the database.

Test Plan:
make check
2012-10-29 11:12:24 -07:00
Mark Callaghan
70c42bf05f Adds DB::GetNextCompaction and then uses that for rate limiting db_bench
Summary:
Adds a method that returns the score for the next level that most
needs compaction. That method is then used by db_bench to rate limit threads.
Threads are put to sleep at the end of each stats interval until the score
is less than the limit. The limit is set via the --rate_limit=$double option.
The specified value must be > 1.0. Also adds the option --stats_per_interval
to enable additional metrics reported every stats interval.

Task ID: #

Blame Rev:

Test Plan:
run db_bench

Revert Plan:

Database Impact:

Memcache Impact:

Other Notes:

EImportant:

- begin *PUBLIC* platform impact section -
Bugzilla: #
- end platform impact -

Reviewers: dhruba

Reviewed By: dhruba

Differential Revision: https://reviews.facebook.net/D6243
2012-10-29 10:17:43 -07:00
Kai Liu
d50f8eb603 Enable LevelDb to create a new log file if current log file is too large.
Summary: Enable LevelDb to create a new log file if current log file is too large.

Test Plan:
Write a script and manually check the generated info LOG.

Task ID: 1803577

Blame Rev:

Reviewers: dhruba, heyongqiang

Reviewed By: heyongqiang

CC: zshao

Differential Revision: https://reviews.facebook.net/D6003
2012-10-26 14:55:02 -07:00
Mark Callaghan
65855dd8d4 Normalize compaction stats by time in compaction
Summary:
I used server uptime to compute per-level IO throughput rates. I
intended to use time spent doing compaction at that level. This fixes that.

Task ID: #

Blame Rev:

Test Plan:
run db_bench, look at results

Revert Plan:

Database Impact:

Memcache Impact:

Other Notes:

EImportant:

- begin *PUBLIC* platform impact section -
Bugzilla: #
- end platform impact -

Reviewers: dhruba

Reviewed By: dhruba

Differential Revision: https://reviews.facebook.net/D6237
2012-10-26 14:19:13 -07:00
Dhruba Borthakur
ea9e087851 Merge branch 'master' into performance
Conflicts:
	db/db_bench.cc
	db/db_impl.cc
	db/db_test.cc
2012-10-26 08:57:56 -07:00
Dhruba Borthakur
8eedf13a82 Fix unit test failure caused by delaying deleting obsolete files.
Summary:
A previous commit 4c107587ed introduced
the idea that some version updates might not delete obsolete files.
This means that if a unit test blindly counts the number of files
in the db directory it might not represent the true state of the database.

Use GetLiveFiles() insteads to count the number of live files in the database.

Test Plan: make check

Reviewers: heyongqiang, MarkCallaghan

Reviewed By: MarkCallaghan

Differential Revision: https://reviews.facebook.net/D6207
2012-10-26 08:42:05 -07:00
Dhruba Borthakur
5b0fe6c73b Greedy algorithm for picking files to compact.
Summary:
It is best if we pick the largest file to compact in a level.
This reduces the write amplification factor for compactions.
Each level has an auxiliary data structure called files_by_size_
that sorts all files by their size. This data structure is
updated when a new version is created.

Test Plan: make check

Differential Revision: https://reviews.facebook.net/D6195
2012-10-25 18:27:53 -07:00
Dhruba Borthakur
8fb5f40468 firstIndex fix for multi-threaded compaction code.
Summary:
Prior to multi-threaded compaction, wrap-around would be done by using
current_->files_[level[0]. With this change we should be
using the first file for which f->being_compacted is not true.

1ca0584345 (commitcomment-2041516)

Test Plan: make check

Differential Revision: https://reviews.facebook.net/D6165
2012-10-25 08:44:47 -07:00
Mark Callaghan
e7206f43ee Improve statistics
Summary:
This adds more statistics to be reported by GetProperty("leveldb.stats").
The new stats include time spent waiting on stalls in MakeRoomForWrite.
This also includes the total amplification rate where that is:
    (#bytes of sequential IO during compaction) / (#bytes from Put)
This also includes a lot more data for the per-level compaction report.
* Rn(MB) - MB read from level N during compaction between levels N and N+1
* Rnp1(MB) - MB read from level N+1 during compaction between levels N and N+1
* Wnew(MB) - new data written to the level during compaction
* Amplify - ( Write(MB) + Rnp1(MB) ) / Rn(MB)
* Rn - files read from level N during compaction between levels N and N+1
* Rnp1 - files read from level N+1 during compaction between levels N and N+1
* Wnp1 - files written to level N+1 during compaction between levels N and N+1
* NewW - new files written to level N+1 during compaction
* Count - number of compactions done for this level

This is the new output from DB::GetProperty("leveldb.stats"). The old output stopped at Write(MB)

                               Compactions
Level  Files Size(MB) Time(sec) Read(MB) Write(MB)  Rn(MB) Rnp1(MB) Wnew(MB) Amplify Read(MB/s) Write(MB/s)   Rn Rnp1 Wnp1 NewW Count
-------------------------------------------------------------------------------------------------------------------------------------
  0        3        6        33        0       576       0        0      576    -1.0       0.0         1.3     0    0    0    0   290
  1      127      242       351     5316      5314     570     4747      567    17.0      12.1        12.1   287 2399 2685  286    32
  2      161      328        54      822       824     326      496      328     4.0       1.9         1.9   160  251  411  160   161
Amplification: 22.3 rate, 0.56 GB in, 12.55 GB out
Uptime(secs): 439.8
Stalls(secs): 206.938 level0_slowdown, 0.000 level0_numfiles, 24.129 memtable_compaction

Task ID: #

Blame Rev:

Test Plan:
run db_bench

Revert Plan:

Database Impact:

Memcache Impact:

Other Notes:

EImportant:

- begin *PUBLIC* platform impact section -
Bugzilla: #
- end platform impact -
(cherry picked from commit ecdeead38f86cc02e754d0032600742c4f02fec8)

Reviewers: dhruba

Differential Revision: https://reviews.facebook.net/D6153
2012-10-24 14:21:38 -07:00
Dhruba Borthakur
3b06f94fa2 Merge branch 'master' into performance
Conflicts:
	db/db_impl.cc
	db/db_impl.h
	db/version_set.cc
2012-10-23 22:30:07 -07:00
Dhruba Borthakur
4c107587ed Delete files outside the mutex.
Summary:
The compaction process deletes a large number of files. This takes
quite a bit of time and is best done outside the mutex lock.

Test Plan: make check

Differential Revision: https://reviews.facebook.net/D6123
2012-10-22 11:53:23 -07:00
heyongqiang
5010daa7a8 add "seek_compaction" to log for better debug Summary:
Summary: as subject

Test Plan: compile

Reviewers: dhruba

Reviewed By: dhruba

CC: MarkCallaghan

Differential Revision: https://reviews.facebook.net/D6117
2012-10-22 10:00:25 -07:00
Dhruba Borthakur
3489cd615c Merge branch 'master' into performance
Conflicts:
	db/db_impl.cc
	db/db_impl.h
2012-10-21 02:15:19 -07:00
Dhruba Borthakur
f95219fb32 Delete files outside the mutex.
Summary:
The compaction process deletes a large number of files. This takes
quite a bit of time and is best done outside the mutex lock.

Test Plan: make check

Differential Revision: https://reviews.facebook.net/D6123
2012-10-21 02:03:00 -07:00
Dhruba Borthakur
98f23cf04a Merge branch 'master' into performance
Conflicts:
	db/db_impl.cc
	db/db_impl.h
2012-10-21 01:55:19 -07:00
Dhruba Borthakur
64c4b9f0e2 Delete files outside the mutex.
Summary:
The compaction process deletes a large number of files. This takes
quite a bit of time and is best done outside the mutex lock.

Test Plan:

Reviewers:

CC:

Task ID: #

Blame Rev:
2012-10-21 01:49:48 -07:00
Dhruba Borthakur
e982f5a1d2 Merge branch 'master' into performance
Conflicts:
	util/options.cc
2012-10-19 15:16:42 -07:00
Dhruba Borthakur
cf5adc8016 db_bench was not correctly initializing the value for delete_obsolete_files_period_micros option.
Summary:
The parameter delete_obsolete_files_period_micros controls the
periodicity of deleting obsolete files. db_bench was reading in
this parameter intoa local variable called 'l' but was incorrectly
using another local variable called 'n' while setting it in the
db.options data structure.
This patch also logs the value of delete_obsolete_files_period_micros
in the LOG file at db startup time.

I am hoping that this will improve the overall write throughput drastically.

Test Plan: run db_bench

Reviewers: MarkCallaghan, heyongqiang

Reviewed By: MarkCallaghan

Differential Revision: https://reviews.facebook.net/D6099
2012-10-19 15:10:12 -07:00
Dhruba Borthakur
1ca0584345 This is the mega-patch multi-threaded compaction
published in https://reviews.facebook.net/D5997.

Summary:
This patch allows compaction to occur in multiple background threads
concurrently.

If a manual compaction is issued, the system falls back to a
single-compaction-thread model. This is done to ensure correctess
and simplicity of code. When the manual compaction is finished,
the system resumes its concurrent-compaction mode automatically.

The updates to the manifest are done via group-commit approach.

Test Plan: run db_bench
2012-10-19 14:00:53 -07:00
Dhruba Borthakur
aa73538f2a The deletion of obsolete files should not occur very frequently.
Summary:
The method DeleteObsolete files is a very costly methind, especially
when the number of files in a system is large. It makes a list of
all live-files and then scans the directory to compute the diff.
By default, this method is executed after every compaction run.

This patch makes it such that DeleteObsolete files is never
invoked twice within a configured period.

Test Plan: run all unit tests

Reviewers: heyongqiang, MarkCallaghan

Reviewed By: MarkCallaghan

Differential Revision: https://reviews.facebook.net/D6045
2012-10-16 10:26:10 -07:00
Dhruba Borthakur
0230866791 Enhance db_bench to allow setting the number of levels in a database.
Summary: Enhance db_bench to allow setting the number of levels in a database.

Test Plan: run db_bench and look at LOG

Reviewers: heyongqiang, MarkCallaghan

Reviewed By: MarkCallaghan

CC: MarkCallaghan

Differential Revision: https://reviews.facebook.net/D6027
2012-10-15 10:18:49 -07:00
Dhruba Borthakur
c1006d4276 An configurable option to write data using write instead of mmap.
Summary:
We have seen that reading data via the pread call (instead of
mmap) is much faster on Linux 2.6.x kernels. This patch makes
an equivalent option to switch off mmaps for the write path
as well.

db_bench --mmap_write=0 will use write() instead of mmap() to
write data to a file.

This change is backward compatible, the default
option is to continue using mmap for writing to a file.

Test Plan: "make check all"

Differential Revision: https://reviews.facebook.net/D5781
2012-10-03 17:08:13 -07:00
Mark Callaghan
e678a5947a Add --stats_interval option to db_bench
Summary:
The option is zero by default and in that case reporting is unchanged.
By unchanged, the interval at which stats are reported is scaled after each
report and newline is not issued after each report so one line is rewritten.
When non-zero it specifies the constant interval (in operations) at which
statistics are reported and the stats include the rate per interval. This
makes it easier to determine whether QPS changes over the duration of the test.

Task ID: #

Blame Rev:

Test Plan:
run db_bench

Revert Plan:

Database Impact:

Memcache Impact:

Other Notes:

EImportant:

- begin *PUBLIC* platform impact section -
Bugzilla: #
- end platform impact -

Reviewers: dhruba

Reviewed By: dhruba

CC: heyongqiang

Differential Revision: https://reviews.facebook.net/D5817
2012-10-03 09:54:33 -07:00
Mark Callaghan
d8763abecd Fix the bounds check for the --readwritepercent option
Summary:
see above

Task ID: #

Blame Rev:

Test Plan:
run db_bench with invalid value for option

Revert Plan:

Database Impact:

Memcache Impact:

Other Notes:

EImportant:

- begin *PUBLIC* platform impact section -
Bugzilla: #
- end platform impact -

Reviewers: dhruba

Reviewed By: dhruba

CC: heyongqiang

Differential Revision: https://reviews.facebook.net/D5823
2012-10-03 09:52:26 -07:00
Mark Callaghan
98804f914f Fix compiler warnings and errors in ldb.c
Summary:
stdlib.h is needed for exit()
--readhead --> --readahead

Task ID: #

Blame Rev:

Test Plan:
compile

Revert Plan:

Database Impact:

Memcache Impact:

Other Notes:

EImportant:

- begin *PUBLIC* platform impact section -
Bugzilla: #
- end platform impact -
fix compiler warnings & errors

Reviewers: dhruba

Reviewed By: dhruba

CC: heyongqiang

Differential Revision: https://reviews.facebook.net/D5805
2012-10-03 06:46:59 -07:00
Abhishek Kona
fec81318b0 Commandline tool to compace LevelDB databases.
Summary:
A simple CLI which calles DB->CompactRange()
Can take String key's as range.

Test Plan:
Inserted data into a table.
Waited for a minute, used compact tool on it. File modification time's
changed so Compact did something on the files.

Existing unit tests work.

Reviewers: heyongqiang, dhruba

Reviewed By: dhruba

Differential Revision: https://reviews.facebook.net/D5697
2012-10-01 10:49:19 -07:00
Dhruba Borthakur
c1bb32e1ba Trigger read compaction only if seeks to storage are incurred.
Summary:
In the current code, a Get() call can trigger compaction if it has to look at more than one file. This causes unnecessary compaction because looking at more than one file is a penalty only if the file is not yet in the cache. Also, th current code counts these files before the bloom filter check is applied.

This patch counts a 'seek' only if the file fails the bloom filter
check and has to read in data block(s) from the storage.

This patch also counts a 'seek' if a file is not present in the file-cache, because opening a file means that its index blocks need to be read into cache.

Test Plan: unit test attached. I will probably add one more unti tests.

Reviewers: heyongqiang

Reviewed By: heyongqiang

CC: MarkCallaghan

Differential Revision: https://reviews.facebook.net/D5709
2012-09-28 11:10:52 -07:00
Dhruba Borthakur
24eea931ef If ReadCompaction is switched off, then it is better to not even submit background compaction jobs.
Summary:
If ReadCompaction is switched off, then it is better to not even
submit background compaction jobs. I see about 3% increase in
read-throughput on a pure memory database.

Test Plan: run db_bench

Reviewers: heyongqiang

Reviewed By: heyongqiang

Differential Revision: https://reviews.facebook.net/D5673
2012-09-25 11:07:01 -07:00
Dhruba Borthakur
ae36e509f8 The BackupAPI should also list the length of the manifest file.
Summary:
The GetLiveFiles() api lists the set of sst files and the current
MANIFEST file. But the database continues to append new data to the
MANIFEST file even when the application is backing it up to the
backup location. This means that the database-version that is
stored in the MANIFEST FILE in the backup location
does not correspond to the sst files returned by GetLiveFiles.

This API adds a new parameter to GetLiveFiles. This new parmeter
returns the current size of the MANIFEST file.

Test Plan: Unit test attached.

Reviewers: heyongqiang

Reviewed By: heyongqiang

Differential Revision: https://reviews.facebook.net/D5631
2012-09-25 03:13:25 -07:00
Dhruba Borthakur
bb2dcd2457 Segfault in DoCompactionWork caused by buffer overflow
Summary:
The code was allocating 200 bytes on the stack but it
writes 256 bytes into the array.

x8a8ea5 std::_Rb_tree<>::erase()
    @     0x7f134bee7eb0 (unknown)
    @           0x8a8ea5 std::_Rb_tree<>::erase()
    @           0x8a35d6 leveldb::DBImpl::CleanupCompaction()
    @           0x8a7810 leveldb::DBImpl::BackgroundCompaction()
    @           0x8a804d leveldb::DBImpl::BackgroundCall()
    @           0x8c4eff leveldb::(anonymous namespace)::PosixEnv::BGThreadWrapper()
    @     0x7f134b3c010d start_thread
    @     0x7f134bf9f10d clone

Test Plan: run db_bench with overwrite option

Reviewers: heyongqiang

Reviewed By: heyongqiang

Differential Revision: https://reviews.facebook.net/D5595
2012-09-21 10:55:38 -07:00
Dhruba Borthakur
fb4b381a0c Print out the compile version in the LOG.
Summary: Print out the compile version in the LOG.

Test Plan: run dbbench and verify LOG

Reviewers: heyongqiang

Reviewed By: heyongqiang

Differential Revision: https://reviews.facebook.net/D5529
2012-09-18 13:24:32 -07:00
heyongqiang
a8464ed820 add an option to disable seek compaction
Summary:
as subject. This diff should be good for benchmarking.

will send another diff to make it better in the case the seek compaction is enable.
In that coming diff, will not count a seek if the bloomfilter filters.

Test Plan: build

Reviewers: dhruba, MarkCallaghan

Reviewed By: MarkCallaghan

Differential Revision: https://reviews.facebook.net/D5481
2012-09-17 13:59:57 -07:00
Dhruba Borthakur
ba55d77b5d Ability to take a file-lvel snapshot from leveldb.
Summary:
A set of apis that allows an application to backup data from the
leveldb database based on a set of files.

Test Plan: unint test attached. more coming soon.

Reviewers: heyongqiang

Reviewed By: heyongqiang

Differential Revision: https://reviews.facebook.net/D5439
2012-09-17 09:14:50 -07:00
heyongqiang
b85cdca690 add a global var leveldb::useMmapRead to enable mmap Summary:
Summary:
as subject. this can be used for benchmarking.
If we want it for some cases, we can do more changes to make this part of the option.

Test Plan: db_test

Reviewers: dhruba

CC: MarkCallaghan

Differential Revision: https://reviews.facebook.net/D5451
2012-09-16 22:07:35 -07:00
heyongqiang
dcbd6be340 remove boost
Summary: as subject

Test Plan: build

Reviewers: dhruba

Differential Revision: https://reviews.facebook.net/D5469
2012-09-16 19:33:43 -07:00
Mark Callaghan
fa29f82548 scan a long for FLAGS_cache_size to fix a compiler warning
Summary:
FLAGS_cache_size is a long, no need to scan %lld into a size_t
for it (which generates a compiler warning)

Test Plan: run db_bench

Reviewers: dhruba, heyongqiang

Reviewed By: heyongqiang

CC: heyongqiang

Differential Revision: https://reviews.facebook.net/D5427
2012-09-14 12:45:42 -07:00
Mark Callaghan
837113908c Add --compression_type=X option with valid values: snappy (default) none bzip2 zlib
Summary:
This adds an option to db_bench to specify the compression algorithm to
use for LevelDB

Test Plan: ran db_bench

Reviewers: dhruba

Reviewed By: dhruba

Differential Revision: https://reviews.facebook.net/D5421
2012-09-14 12:28:21 -07:00
Dhruba Borthakur
93f4952089 Ability to switch off filesystem read-aheads
Summary:
Ability to switch off filesystem read-aheads. This change is
backward-compatible: the default setting is to allow file
system read-aheads.

Test Plan: run benchmarks

Reviewers: heyongqiang, adsharma

Reviewed By: heyongqiang

Differential Revision: https://reviews.facebook.net/D5391
2012-09-13 12:09:56 -07:00
Dhruba Borthakur
7ecc5d4ad5 Enable db_bench to specify block size.
Summary: Enable db_bench to specify block size.

Test Plan: compile and run

Reviewers: heyongqiang

Reviewed By: heyongqiang

Differential Revision: https://reviews.facebook.net/D5373
2012-09-13 10:22:43 -07:00
Dhruba Borthakur
407727b75f Fix compiler warnings. Use uint64_t instead of uint.
Summary: Fix compiler warnings. Use uint64_t instead of uint.

Test Plan: build using -Wall

Reviewers: heyongqiang

Reviewed By: heyongqiang

Differential Revision: https://reviews.facebook.net/D5355
2012-09-12 14:42:36 -07:00
heyongqiang
0f43aa474e put log in a seperate dir
Summary: added a new option db_log_dir, which points the log dir. Inside that dir, in order to make log names unique, the log file name is prefixed with the leveldb data dir absolute path.

Test Plan: db_test

Reviewers: dhruba

Reviewed By: dhruba

Differential Revision: https://reviews.facebook.net/D5205
2012-09-06 17:52:08 -07:00
Dhruba Borthakur
536ca698ba The ReadnRandomWriteRandom was always looping FLAGS_num of times.
Summary: If none of reads or writes are specified by user, then pick the FLAGS_NUM as the number of iterations in the ReadRandomWriteRandom test. If either reads or writes are defined, then use their maximum.

Test Plan: run benchmark

Reviewers: heyongqiang

Reviewed By: heyongqiang

Differential Revision: https://reviews.facebook.net/D5217
2012-09-06 09:13:24 -07:00
Dhruba Borthakur
94208a7881 Benchmark with both reads and writes at the same time.
Summary:
This patch enables the db_bench benchmark to issue both random reads and random writes at the same time. This options can be trigged via
./db_bench --benchmarks=readrandomwriterandom

The default percetage of reads is 90.

One can change the percentage of reads by specifying the --readwritepercent.
./db_bench --benchmarks=readrandomwriterandom=50

This is a feature request from Jeffro asking for leveldb performance with a 90:10 read:write ratio.

Test Plan: run on test machine.

Reviewers: heyongqiang

Reviewed By: heyongqiang

Differential Revision: https://reviews.facebook.net/D5067
2012-09-04 12:06:26 -07:00
Dhruba Borthakur
fe93631678 Clean up compiler warnings generated by -Wall option.
Summary:
Clean up compiler warnings generated by -Wall option.
make clean all OPT=-Wall

This is a pre-requisite before making a new release.

Test Plan: compile and run unit tests

Reviewers: heyongqiang

Reviewed By: heyongqiang

Differential Revision: https://reviews.facebook.net/D5019
2012-08-29 14:24:51 -07:00
Dhruba Borthakur
e5fe80e4e3 The sharding of the block cache is limited to 2*20 pieces.
Summary:
The numbers of shards that the block cache is divided into is
configurable. However, if the user specifies that he/she wants
the block cache to be divided into more than 2**20 pieces, then
the system will rey to allocate a huge array of that size) that
could fail.

It is better to limit the sharding of the block cache to an
upper bound. The default sharding is 16 shards (i.e. 2**4)
and the maximum is now 2 million shards (i.e. 2**20).

Also, fixed a bug with the LRUCache where the numShardBits
should be a private member of the LRUCache object rather than
a static variable.

Test Plan:
run db_bench with --cache_numshardbits=64.

Task ID: #

Blame Rev:

Reviewers: heyongqiang

Reviewed By: heyongqiang

Differential Revision: https://reviews.facebook.net/D5013
2012-08-29 12:17:59 -07:00
heyongqiang
a4f9b8b49e merge 1.5
Summary:

as subject

Test Plan:

db_test table_test

Reviewers: dhruba
2012-08-28 11:43:33 -07:00
heyongqiang
6fee5a74f5 Do not spin in a tight loop attempting compactions if there is a compaction error
Summary: as subject. ported the change from google code leveldb 1.5

Test Plan: run db_test

Reviewers: dhruba

Differential Revision: https://reviews.facebook.net/D4839
2012-08-28 11:43:33 -07:00
heyongqiang
935fdd030b fix filename_test
Summary: as subject

Test Plan: run filename_test

Reviewers: dhruba

Differential Revision: https://reviews.facebook.net/D4965
2012-08-28 11:42:42 -07:00
heyongqiang
690bf88682 in db_stats_logger.cc, hold mutex_ while accessing versions_
Summary:

as subject

Test Plan:db_test

Reviewers: dhruba
2012-08-28 11:29:30 -07:00
heyongqiang
d3759ca121 fix db_test error with scribe logger turned on
Summary: as subject

Test Plan: db_test

Reviewers: dhruba

Reviewed By: dhruba

Differential Revision: https://reviews.facebook.net/D4929
2012-08-28 11:22:58 -07:00
Dhruba Borthakur
fc20273e73 Introduce a new method Env->Fsync() that issues fsync (instead of fdatasync).
Summary:
Introduce a new method Env->Fsync() that issues fsync (instead of fdatasync).
This is needed for data durability when running on ext3 filesystems.
Added options to the benchmark db_bench to generate performance numbers
with either fsync or fdatasync enabled.

Cleaned up Makefile to build leveldb_shell only when building the thrift
leveldb server.

Test Plan: build and run benchmark

Reviewers: heyongqiang

Reviewed By: heyongqiang

Differential Revision: https://reviews.facebook.net/D4911
2012-08-27 21:24:17 -07:00
heyongqiang
1de83cc2ac add more logs
Summary:
as subject

add a tool to read sst file

as subject.

./sst_reader --command=check --file=
./sst_reader --command=scan --file=

Test Plan:
db_test

run this command

Reviewers: dhruba

Reviewed By: dhruba

Differential Revision: https://reviews.facebook.net/D4881
2012-08-24 15:20:49 -07:00
heyongqiang
1c99b0a6b3 add more logs
Summary:

as subject

Test Plan:db_test

Reviewers: dhruba
2012-08-24 15:18:43 -07:00
Dhruba Borthakur
f3ee54526f Utility to dump manifest contents.
Summary:
./manifest_dump --file=/tmp/dbbench/MANIFEST-000002

Output looks like

manifest_file_number 30 next_file_number 31 last_sequence 388082 log_number 28  prev_log_number 0
--- level 0 ---
--- level 1 ---
--- level 2 ---
 5:3244155['0000000000000000' @ 1 : 1 .. '0000000000028220' @ 28221 : 1]
 7:3244177['0000000000028221' @ 28222 : 1 .. '0000000000056441' @ 56442 : 1]
 9:3244156['0000000000056442' @ 56443 : 1 .. '0000000000084662' @ 84663 : 1]
 11:3244178['0000000000084663' @ 84664 : 1 .. '0000000000112883' @ 112884 : 1]
 13:3244158['0000000000112884' @ 112885 : 1 .. '0000000000141104' @ 141105 : 1]
 15:3244176['0000000000141105' @ 141106 : 1 .. '0000000000169325' @ 169326 : 1]
 17:3244156['0000000000169326' @ 169327 : 1 .. '0000000000197546' @ 197547 : 1]
 19:3244178['0000000000197547' @ 197548 : 1 .. '0000000000225767' @ 225768 : 1]
 21:3244155['0000000000225768' @ 225769 : 1 .. '0000000000253988' @ 253989 : 1]
 23:3244179['0000000000253989' @ 253990 : 1 .. '0000000000282209' @ 282210 : 1]
 25:3244157['0000000000282210' @ 282211 : 1 .. '0000000000310430' @ 310431 : 1]
 27:3244176['0000000000310431' @ 310432 : 1 .. '0000000000338651' @ 338652 : 1]
 29:3244156['0000000000338652' @ 338653 : 1 .. '0000000000366872' @ 366873 : 1]
--- level 3 ---
--- level 4 ---
--- level 5 ---
--- level 6 ---

Test Plan: run on test directory created by dbbench

Reviewers: heyongqiang

Reviewed By: heyongqiang

CC: hustliubo

Differential Revision: https://reviews.facebook.net/D4743
2012-08-24 15:17:09 -07:00
Dhruba Borthakur
e5a7c8e580 Log the open-options to the LOG.
Summary: Log the open-options to the LOG. Use options_ instead of options because SanitizeOptions could modify the max_file_open limit.

Test Plan: num db_bench

Reviewers: heyongqiang

Reviewed By: heyongqiang

Differential Revision: https://reviews.facebook.net/D4833
2012-08-22 12:22:12 -07:00
heyongqiang
21082fa13c regression for trigger compaction logic
Summary: as subject

Test Plan: manually run db_bench confirmed

Reviewers: dhruba

Differential Revision: https://reviews.facebook.net/D4809
2012-08-21 18:11:21 -07:00
Dhruba Borthakur
a098207c95 Fixed unit test c_test by initializing logger=NULL.
Summary:
Fixed unit test c_test by initializing logger=NULL.

Removed "atomic" from last_log_ts so that unit tests do not require C11 compiler.
Anyway, last_log_ts is mostly used for logging, so it is ok if it is loosely
accurate.

Test Plan: run c_test

Reviewers: heyongqiang

Reviewed By: heyongqiang

Differential Revision: https://reviews.facebook.net/D4803
2012-08-21 17:10:29 -07:00
Dhruba Borthakur
f4e7febf22 Record the version of the source repository that was used to build the leveldb library.
Summary: Record the version of the source that we are compiling. We keep a record of the git revision in util/version.cc. This source file is then built as a regular source file as part of the compilation process. One can run "strings executable_filename | grep _build_" to find the version of the source that we used to build the executable file.

Test Plan: none

Differential Revision: https://reviews.facebook.net/D4785
2012-08-21 14:47:15 -07:00
heyongqiang
6ba1f17789 adding a scribe logger in leveldb to log leveldb deploy stats
Summary:
as subject.

A new log is written to scribe via thrift client when a new db is opened and when there is
a compaction.

a new option var scribe_log_db_stats is added.

Test Plan: manually checked using command "ptail -time 0 leveldb_deploy_stats"

Reviewers: dhruba

Differential Revision: https://reviews.facebook.net/D4659
2012-08-21 11:43:22 -07:00
Dhruba Borthakur
e56b2c5a31 Prevent concurrent multiple opens of leveldb database.
Summary:
The fcntl call cannot detect lock conflicts when invoked multiple times
from the same thread.
Use a static lockedFile Set to record the paths that are locked.
A lockfile request checks to see if htis filename already exists in
lockedFiles, if so, then it triggers an error. Otherwise, it inserts
the filename in the lockedFiles Set.
A unlock file request verifies that the filename is in the lockedFiles
set and removes it from lockedFiles set.

Test Plan: unit test attached

Reviewers: heyongqiang

Reviewed By: heyongqiang

Differential Revision: https://reviews.facebook.net/D4755
2012-08-20 23:55:04 -07:00
heyongqiang
deb1a1fa9b add disable wal to db_bench
Summary:
as subject.

./db_bench --benchmarks=fillrandom --num=1000000 --disable_data_sync=1 --write_buffer_size=50000000 --target_file_size_base=100000000 --disable_wal=1

LevelDB:    version 1.4
Date:       Sun Aug 19 16:01:59 2012
CPU:        8 * Intel(R) Xeon(R) CPU           L5630  @ 2.13GHz
CPUCache:   12288 KB
Keys:       16 bytes each
Values:     100 bytes each (50 bytes after compression)
Entries:    1000000
RawSize:    110.6 MB (estimated)
FileSize:   62.9 MB (estimated)
------------------------------------------------
fillrandom   :       4.591 micros/op 217797 ops/sec;   24.1 MB/s

./db_bench --benchmarks=fillrandom --num=1000000 --disable_data_sync=1 --write_buffer_size=50000000 --target_file_size_base=100000000

LevelDB:    version 1.4
Date:       Sun Aug 19 16:02:54 2012
CPU:        8 * Intel(R) Xeon(R) CPU           L5630  @ 2.13GHz
CPUCache:   12288 KB
Keys:       16 bytes each
Values:     100 bytes each (50 bytes after compression)
Entries:    1000000
RawSize:    110.6 MB (estimated)
FileSize:   62.9 MB (estimated)
------------------------------------------------
fillrandom   :       3.696 micros/op 270530 ops/sec;   29.9 MB/s

Test Plan: db_bench

Reviewers: dhruba

Differential Revision: https://reviews.facebook.net/D4767
2012-08-19 22:37:51 -07:00
Dhruba Borthakur
2aa514ec8c Utility to dump manifest contents.
Summary:
./manifest_dump --file=/tmp/dbbench/MANIFEST-000002

Output looks like

manifest_file_number 30 next_file_number 31 last_sequence 388082 log_number 28  prev_log_number 0
--- level 0 ---
--- level 1 ---
--- level 2 ---
 5:3244155['0000000000000000' @ 1 : 1 .. '0000000000028220' @ 28221 : 1]
 7:3244177['0000000000028221' @ 28222 : 1 .. '0000000000056441' @ 56442 : 1]
 9:3244156['0000000000056442' @ 56443 : 1 .. '0000000000084662' @ 84663 : 1]
 11:3244178['0000000000084663' @ 84664 : 1 .. '0000000000112883' @ 112884 : 1]
 13:3244158['0000000000112884' @ 112885 : 1 .. '0000000000141104' @ 141105 : 1]
 15:3244176['0000000000141105' @ 141106 : 1 .. '0000000000169325' @ 169326 : 1]
 17:3244156['0000000000169326' @ 169327 : 1 .. '0000000000197546' @ 197547 : 1]
 19:3244178['0000000000197547' @ 197548 : 1 .. '0000000000225767' @ 225768 : 1]
 21:3244155['0000000000225768' @ 225769 : 1 .. '0000000000253988' @ 253989 : 1]
 23:3244179['0000000000253989' @ 253990 : 1 .. '0000000000282209' @ 282210 : 1]
 25:3244157['0000000000282210' @ 282211 : 1 .. '0000000000310430' @ 310431 : 1]
 27:3244176['0000000000310431' @ 310432 : 1 .. '0000000000338651' @ 338652 : 1]
 29:3244156['0000000000338652' @ 338653 : 1 .. '0000000000366872' @ 366873 : 1]
--- level 3 ---
--- level 4 ---
--- level 5 ---
--- level 6 ---

Test Plan: run on test directory created by dbbench

Reviewers: heyongqiang

Reviewed By: heyongqiang

CC: hustliubo

Differential Revision: https://reviews.facebook.net/D4743
2012-08-17 22:36:59 -07:00
heyongqiang
680e571c4c add compaction log Summary:
Summary:
add compaction summary to log

log looks like:

2012/08/17-18:18:32.557334 7fdcaa2bb700 Compaction summary: Base level 0, input file:[11 9 7 ],[]

Test Plan: tested via db_test

Reviewers: dhruba

Differential Revision: https://reviews.facebook.net/D4749
2012-08-17 19:29:39 -07:00
heyongqiang
20ee76bd34 use ts as suffix for LOG.old files
Summary: as subject and only maintain 10 log files.

Test Plan: new test in db_test

Reviewers: dhruba

Differential Revision: https://reviews.facebook.net/D4731
2012-08-17 16:22:04 -07:00
heyongqiang
f16e393658 add more options to db_ben
Summary: as subject

Test Plan: run db_bench with new options

Reviewers: dhruba

Differential Revision: https://reviews.facebook.net/D4677
2012-08-15 17:42:33 -07:00
heyongqiang
fcb2ea4715 disable data sync options needs to be checked when doing level-0 dump Summary:
Summary: as subject

Test Plan: use db_bench

Reviewers: dhruba

Differential Revision: https://reviews.facebook.net/D4671
2012-08-15 16:39:02 -07:00
Dhruba Borthakur
c3096afd61 Introduce a new option disableDataSync for opening the database. If this is set to true, then the data written to newly created data files are not sycned to disk, instead depend on the OS to flush dirty data to stable storage. This option is good for bulk
Test Plan:
manual tests

Task ID: #

Blame Rev:

Differential Revision: https://reviews.facebook.net/D4515
2012-08-03 15:23:53 -07:00
heyongqiang
22ee777f68 add flush interface to DB
Summary: as subject. The flush will flush everything in the db.

Test Plan: new test in db_test.cc

Reviewers: dhruba

Reviewed By: dhruba

Differential Revision: https://reviews.facebook.net/D4029
2012-07-06 12:11:19 -07:00
heyongqiang
a347d4ac0d add disable WAL option
Summary: add disable WAL option

Test Plan: new testcase in db_test.cc

Reviewers: dhruba

Reviewed By: dhruba

Differential Revision: https://reviews.facebook.net/D4011
2012-07-05 15:06:56 -07:00
heyongqiang
4e4b6812ff Make some variables configurable for each db instance
Summary:
Make configurable 'targetFileSize', 'targetFileSizeMultiplier',
'maxBytesForLevelBase', 'maxBytesForLevelMultiplier',
'expandedCompactionFactor', 'maxGrandParentOverlapFactor'

Test Plan: N/A

Reviewers: dhruba

Reviewed By: dhruba

Differential Revision: https://reviews.facebook.net/D3801
2012-06-27 14:36:31 -07:00
Dhruba Borthakur
a35e574344 Make Leveldb save data into HDFS files. You have to set USE_HDFS in your environment variable to compile leveldb with HDFS support.
Test Plan: Run benchmark.

Differential Revision: https://reviews.facebook.net/D3549
2012-06-14 00:29:01 -07:00
Dhruba Borthakur
338939e5c1 Print log message when we are throttling writes.
Summary:
Added option --writes=xxx to specify the number of keys that we want to overwrite in the benchmark.

Task ID: #

Blame Rev:

Test Plan: Revert Plan:

Reviewers: adsharma

CC: sc

Differential Revision: https://reviews.facebook.net/D3465
2012-06-01 14:03:37 -07:00
Dhruba Borthakur
f50ece60c7 Fix table-cache size bug, gather table-cache statistics and prevent readahead done by fs. Summary:
Summary:
The db_bench test was not using the specified value for the max-file-open. Fixed.

The fs readhead is switched off.

Gather statistics about the table cache and print it out at the end of the tets run.

Test Plan: Revert Plan:

Reviewers: adsharma, sc

Reviewed By: adsharma

Differential Revision: https://reviews.facebook.net/D3441
2012-05-30 16:42:45 -07:00
Dhruba Borthakur
8f293b68a9 Support --bufferedio=[0,1] from db_bench. If bufferedio = 0, then the read code path clears the OS page cache after the IO is completed. The default remains as bufferedio=1
Summary:
Task ID: #

Blame Rev:

Test Plan: Revert Plan:

Differential Revision: https://reviews.facebook.net/D3429
2012-05-29 13:29:44 -07:00
Dhruba Borthakur
33a3c6ff6c Ability to make the benchmark issue a large number of IOs. This is helpful to populate many gigabytes of data for benchmarking at scale.
Summary:
Task ID: #

Blame Rev:

Test Plan: Revert Plan:

Differential Revision: https://reviews.facebook.net/D3333
2012-05-22 12:20:09 -07:00
Dhruba Borthakur
3b86a51cb1 Ability to switch on checksum verification from benchmark.
Summary:
Task ID: #

Blame Rev:

Test Plan: Revert Plan:

Differential Revision: https://reviews.facebook.net/D3309
2012-05-19 00:13:50 -07:00
Dhruba Borthakur
a2a0e358cb Add support to specify the number of shards for the Block cache. By default, the block cache is sharded into 16 parts.
Summary:
Task ID: #

Blame Rev:

Test Plan: Revert Plan:

Differential Revision: https://reviews.facebook.net/D3273
2012-05-16 17:23:49 -07:00
Dhruba Borthakur
37d0dcb9b1 Use the elapsed time (instead of the per-thread time) to compute ops/sec.
Summary:
Task ID: #

Blame Rev:

Test Plan: Revert Plan:

Differential Revision: https://reviews.facebook.net/D3147
2012-05-11 12:43:31 -07:00
Arun Sharma
90b2924fb2 skiplist: optimize for sequential insert pattern
Summary:
skiplist doesn't cache the location of the last insert and becomes
CPU bound when the input data has sequential keys.

Notes on thread safety: ::Insert() already requires external
synchronization. So this change is not making it any worse.

Test Plan: skiplist_test

Reviewers: dhruba

Reviewed By: dhruba

Differential Revision: https://reviews.facebook.net/D3129
2012-05-11 09:57:40 -07:00
Dhruba Borthakur
cc6c32535a Support arcdiff.
Summary:
Task ID: #

Blame Rev:

Test Plan: Revert Plan:

Differential Revision: https://reviews.facebook.net/D3105
2012-05-09 23:35:05 -07:00
Sanjay Ghemawat
85584d497e Added bloom filter support.
In particular, we add a new FilterPolicy class.  An instance
of this class can be supplied in Options when opening a
database.  If supplied, the instance is used to generate
summaries of keys (e.g., a bloom filter) which are placed in
sstables.  These summaries are consulted by DB::Get() so we
can avoid reading sstable blocks that are guaranteed to not
contain the key we are looking for.

This change provides one implementation of FilterPolicy
based on bloom filters.

Other changes:
- Updated version number to 1.4.
- Some build tweaks.
- C binding for CompactRange.
- A few more benchmarks: deleteseq, deleterandom, readmissing, seekrandom.
- Minor .gitignore update.
2012-04-17 08:36:46 -07:00
Sanjay Ghemawat
bc1ee4d25e build shared libraries; updated version to 1.3; add Status accessors 2012-03-30 13:15:49 -07:00
Sanjay Ghemawat
583f1499c0 fix LOCK file deletion to prevent crash on windows 2012-03-09 07:51:04 -08:00
Sanjay Ghemawat
d79762e273 added group commit; drastically speeds up mult-threaded synchronous write workloads 2012-03-08 16:23:21 -08:00