Commit Graph

1024 Commits

Author SHA1 Message Date
Lei Jin
fb84c49a36 convert Tickers back to array with padding and alignment
Summary:
Pad each Ticker structure to be 64 bytes and make them align on 64 bytes
boundary to avoid cache line false sharing issue.
Please refer to task 3615553 for more details

Test Plan:
db_bench

LevelDB:    version 2.0s
Date:       Wed Jan 29 12:23:17 2014
CPU:        32 * Intel(R) Xeon(R) CPU E5-2660 0 @ 2.20GHz
CPUCache:   20480 KB
rocksdb.build.overwrite.qps 49638
rocksdb.build.overwrite.p50_micros 58.73
rocksdb.build.overwrite.p75_micros 210.56
rocksdb.build.overwrite.p99_micros 733.28
rocksdb.build.fillseq.qps 366729
rocksdb.build.fillseq.p50_micros 1.00
rocksdb.build.fillseq.p75_micros 1.00
rocksdb.build.fillseq.p99_micros 2.65
rocksdb.build.readrandom.qps 1152995
rocksdb.build.readrandom.p50_micros 11.27
rocksdb.build.readrandom.p75_micros 15.69
rocksdb.build.readrandom.p99_micros 33.59
rocksdb.build.readrandom_smallblockcache.qps 956047
rocksdb.build.readrandom_smallblockcache.p50_micros 15.23
rocksdb.build.readrandom_smallblockcache.p75_micros 17.31
rocksdb.build.readrandom_smallblockcache.p99_micros 31.49
rocksdb.build.readrandom_memtable_sst.qps 1105183
rocksdb.build.readrandom_memtable_sst.p50_micros 12.04
rocksdb.build.readrandom_memtable_sst.p75_micros 15.78
rocksdb.build.readrandom_memtable_sst.p99_micros 32.49
rocksdb.build.readrandom_fillunique_random.qps 487856
rocksdb.build.readrandom_fillunique_random.p50_micros 29.65
rocksdb.build.readrandom_fillunique_random.p75_micros 40.93
rocksdb.build.readrandom_fillunique_random.p99_micros 78.68
rocksdb.build.memtablefillrandom.qps 91304
rocksdb.build.memtablefillrandom.p50_micros 171.05
rocksdb.build.memtablefillrandom.p75_micros 196.12
rocksdb.build.memtablefillrandom.p99_micros 291.73
rocksdb.build.memtablereadrandom.qps 1340411
rocksdb.build.memtablereadrandom.p50_micros 9.48
rocksdb.build.memtablereadrandom.p75_micros 13.95
rocksdb.build.memtablereadrandom.p99_micros 30.36
rocksdb.build.readwhilewriting.qps 491004
rocksdb.build.readwhilewriting.p50_micros 29.58
rocksdb.build.readwhilewriting.p75_micros 40.34
rocksdb.build.readwhilewriting.p99_micros 76.78

Reviewers: igor, haobo

Reviewed By: igor

CC: leveldb

Differential Revision: https://reviews.facebook.net/D15573
2014-01-29 15:08:41 -08:00
Kai Liu
b7db241118 LIBNAME in Makefile is not really configurable
Summary:
In new third-party release tool, `LIBNAME=<customized_library> make`
will not really change the LIBNAME.

However it's very odd that the same approach works with old third-party
release tools. I checked previous rocksdb version and both librocksdb.a
and librocksdb_debug.a were correctly generated and copied to the
right place.

Test Plan:
`LIBNAME=hello make -j32` generates hello.a
`make -j32` generates librocksdb.a

Reviewers: igor, sdong, haobo, dhruba

Reviewed By: igor

CC: leveldb

Differential Revision: https://reviews.facebook.net/D15555
2014-01-29 11:35:05 -08:00
kailiu
b1874af8bc Canonicalize "RocksDB" in make_new_version.sh
Summary: Change all occurrences of "rocksdb" to its canonical form "RocksDB".

Test Plan: N/A

Reviewers: igor

Reviewed By: igor

CC: leveldb

Differential Revision: https://reviews.facebook.net/D15549
2014-01-29 10:19:34 -08:00
kailiu
c9eef784b7 Improve make_new_version.sh 2014-01-29 10:04:53 -08:00
Igor Canadi
9a597dc696 Installation instructions for CentOS 2014-01-29 08:43:11 -08:00
Igor Canadi
e57f0cc1a1 add include <atomic> to version_set.h 2014-01-29 08:17:43 -08:00
kailiu
9fe60d50ff Add history log and revise script
Summary:
* Add a change log for rocksdb releases.
* Remove the hacky parts of make_new_version.sh, which are either
  no longer useful or will be done in our dedicated 3rd-party release
  tool.

Test Plan: N/A

Reviewers: igor, haobo, sdong, dhruba

CC: leveldb

Differential Revision: https://reviews.facebook.net/D15543
2014-01-28 20:24:41 -08:00
Lei Jin
9a126ba3b3 only corrupt private file checksum in backupable_db_test
Summary:
if it happens (randomly) to corrupt shared file in the test, then the
    checksum will be inconsistent between meta files from different backup.
    BackupEngine will then detect this issue and fail. But in reality, this
    does not happen since the checksum is checked on every backup. So here,
    only corrupt checksum of private file to let BackupEngine to construct
    properly (but fail during restore).

Test Plan: run test with valgrind

Reviewers: igor

Reviewed By: igor

CC: leveldb

Differential Revision: https://reviews.facebook.net/D15531
2014-01-28 16:03:55 -08:00
Igor Canadi
5d2c62822e Only get the manifest file size if there is no error
Summary:
I came across this while working on column families. CorruptionTest::RecoverWriteError threw a SIGSEG because the descriptor_log_->file() was nullptr. I'm not sure why it doesn't happen in master, but better safe than sorry.

@kailiu, can we get this in release, too?

Test Plan: make check

Reviewers: kailiu, dhruba, haobo

Reviewed By: haobo

CC: leveldb, kailiu

Differential Revision: https://reviews.facebook.net/D15513
2014-01-28 16:02:51 -08:00
Igor Canadi
e5ec7384a0 Better interface to create BackupEngine
Summary: I think it looks nicer. In RocksDB we have both styles, but I think that static method is the more common version.

Test Plan: backupable_db_test

Reviewers: ljin, benj, swk

Reviewed By: ljin

CC: leveldb

Differential Revision: https://reviews.facebook.net/D15519
2014-01-28 16:01:53 -08:00
Igor Canadi
ec2fa4a690 Export BackupEngine
Summary:
Lots of clients have problems with using StackableDB interface. It's nice to have BackupableDB as a layer on top of DB, but not necessary.

This diff exports BackupEngine, which can be used to create backups without forcing clients to use StackableDB interface.

Test Plan: backupable_db_test

Reviewers: dhruba, ljin, swk

Reviewed By: ljin

CC: leveldb, benj

Differential Revision: https://reviews.facebook.net/D15477
2014-01-28 11:26:07 -08:00
Lei Jin
9dc29414e3 add checksum for backup files
Summary: Keep checksum of each backuped file in meta file. When it restores these files, compute their checksum on the fly and compare against what is in the meta file. Fail the restore process if checksum mismatch.

Test Plan: unit test

Reviewers: haobo, igor, sdong, kailiu

Reviewed By: igor

CC: leveldb, dhruba

Differential Revision: https://reviews.facebook.net/D15381
2014-01-28 09:43:36 -08:00
Mark Callaghan
90f29ccbef Update monitoring to include average time per compaction and stall
Summary:
The new columns are msComp and msStall that provide average time per compaction and stall for that level in milliseconds.
Level  Files Size(MB) Score Time(sec)  Read(MB) Write(MB)    Rn(MB)  Rnp1(MB)  Wnew(MB) RW-Amplify Read(MB/s) Write(MB/s)      Rn     Rnp1     Wnp1     NewW    Count   msComp   msStall  Ln-stall Stall-cnt
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
  0        8       15   1.5         2         0        30         0         0        30        0.0       0.0        15.5        0        0        0        0       16      112       0.2       1.3      7568
  1        8       16   1.6         1        26        26        15        11        16        3.5      17.6        18.1        8        6       13        7        3      362       0.0       0.0         0
  2        1        2   0.0         0         0         2         0         0         2        0.0       0.0        18.4        0        0        0        0        1       50       0.0       0.0         0

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: haobo

Reviewed By: haobo

CC: leveldb

Differential Revision: https://reviews.facebook.net/D15345
2014-01-27 15:06:04 -08:00
Schalk-Willem Kruger
3d33da75ef Fix UnmarkEOF for partial blocks
Summary:
Blocks in the transaction log are a fixed size, but the last block in the transaction log file is usually a partial block. When a new record is added after the reader hit the end of the file, a new physical record will be appended to the last block. ReadPhysicalRecord can only read full blocks and assumes that the file position indicator is aligned to the start of a block. If the reader is forced to read further by simply clearing the EOF flag, ReadPhysicalRecord will read a full block starting from somewhere in the middle of a real block, causing it to lose alignment and to have a partial physical record at the end of the read buffer. This will result in length mismatches and checksum failures. When the log file is tailed for replication this will cause the log iterator to become invalid, necessitating the creation of a new iterator which will have to read the log file from scratch.

This diff fixes this issue by reading the remaining portion of the last block we read from. This is done when the reader is forced to read further (UnmarkEOF is called).

Test Plan:
- Added unit tests
- Stress test (with replication). Check dbdir/LOG file for corruptions.
- Test on test tier

Reviewers: emayanke, haobo, dhruba

Reviewed By: haobo

CC: vamsi, sheki, dhruba, kailiu, igor

Differential Revision: https://reviews.facebook.net/D15249
2014-01-27 14:49:10 -08:00
Igor Canadi
832158e7f7 Fsync directory after we create a new file
Summary:
@dhruba, I'm not sure where we need to sync the directory. I implemented the function in Env() and added the dir sync just after we close the newly created file in the builder.

Should I also add FsyncDir() to new files that get created by a compaction?

Test Plan: Confirmed that FsyncDir is returning Status::OK()

Reviewers: dhruba, haobo

Reviewed By: dhruba

CC: leveldb, dhruba

Differential Revision: https://reviews.facebook.net/D14751
2014-01-27 11:02:21 -08:00
Igor Canadi
6c2ca1d3e6 Move NeedsCompaction() from VersionSet to Version
Summary: There is no reason to have functions NeedCompaction(), MaxCompactionScore() and MaxCompactionScoreLevel() in VersionSet, since they don't access any data in VersionSet.

Test Plan: make check

Reviewers: kailiu, haobo, sdong

Reviewed By: kailiu

CC: leveldb

Differential Revision: https://reviews.facebook.net/D15333
2014-01-27 09:59:00 -08:00
Igor Canadi
e55b3c040c Fixing ref-counting memtables 2014-01-26 18:03:38 -08:00
Igor Canadi
983fafa56c Fix memory leak 2014-01-25 13:57:11 -08:00
Igor Canadi
04afa32134 Fix reduce levels
ReduceNumberOfLevels had segmentation fault in WriteSnapshot() since we
didn't change the number of levels in VersionSet (we consider them
immutable from now on). This fixes the problem.
2014-01-24 18:32:38 -08:00
Siying Dong
8477255da3 Moving Some includes from options.h to forward declaration
Summary: By removing some includes form options.h and reply on forward declaration, we can more easily reason the dependencies.

Test Plan: make all check

Reviewers: kailiu, haobo, igor, dhruba

Reviewed By: kailiu

CC: leveldb

Differential Revision: https://reviews.facebook.net/D15411
2014-01-24 17:16:22 -08:00
Igor Canadi
f653fdcf5a Fixing iterator cleanup for Tailing iterator
Immutable tailing iterator doesn't set CleanupState::mem, so we don't
have to unref it.
2014-01-24 15:51:06 -08:00
Igor Canadi
b13bdfa500 Add a call DisownData() to Cache, which should speed up shutdown
Summary: On a shutdown, freeing memory takes a long time. If we're shutting down, we don't really care about memory leaks. I added a call to Cache that will avoid freeing all objects in cache.

Test Plan:
I created a script to test the speedup and demonstrate how to use the call: https://phabricator.fb.com/P3864368

Clean shutdown took 7.2 seconds, while fast and dirty one took 6.3 seconds. Unfortunately, the speedup is not that big, but should be bigger with bigger block_cache. I have set up the capacity to 80GB, but the script filled up only ~7GB.

Reviewers: dhruba, haobo, MarkCallaghan, xjin

Reviewed By: dhruba

CC: leveldb

Differential Revision: https://reviews.facebook.net/D15069
2014-01-24 14:57:52 -08:00
Igor Canadi
677fee27c6 Make VersionSet::ReduceNumberOfLevels() static
Summary:
A lot of our code implicitly assumes number_levels to be static. ReduceNumberOfLevels() breaks that assumption. For example, after calling ReduceNumberOfLevels(), DBImpl::NumberLevels() will be different from VersionSet::NumberLevels(). This is dangerous. Thankfully, it's not in public headers and is only used from LDB cmd tool. LDB tool is only using it statically, i.e. it never calls it with running DB instance. With this diff, we make it explicitly static. This way, we can assume number_levels to be immutable and not break assumption that lot of our code is relying upon. LDB tool can still use the method.

Also, I removed the method from a separate file since it breaks filename completition. version_se<TAB> now completes to "version_set." instead of "version_set" (without the dot). I don't see a big reason that the function should be in a different file.

Test Plan: reduce_levels_test

Reviewers: dhruba, haobo, kailiu, sdong

Reviewed By: kailiu

CC: leveldb

Differential Revision: https://reviews.facebook.net/D15303
2014-01-24 14:57:04 -08:00
Igor Canadi
c583157d49 MemTableListVersion
Summary:
MemTableListVersion is to MemTableList what Version is to VersionSet. I took almost the same ideas to develop MemTableListVersion. The reason is to have copying std::list done in background, while flushing, rather than in foreground (MultiGet() and NewIterator()) under a mutex! Also, whenever we copied MemTableList, we copied also some MemTableList metadata (flush_requested_, commit_in_progress_, etc.), which was wasteful.

This diff avoids std::list copy under a mutex in both MultiGet() and NewIterator(). I created a small database with some number of immutable memtables, and creating 100.000 iterators in a single-thread (!) decreased from {188739, 215703, 198028} to {154352, 164035, 159817}. A lot of the savings come from code under a mutex, so we should see much higher savings with multiple threads. Creating new iterator is very important to LogDevice team.

I also think this diff will make SuperVersion obsolete for performance reasons. I will try it in the next diff. SuperVersion gave us huge savings on Get() code path, but I think that most of the savings came from copying MemTableList under a mutex. If we had MemTableListVersion, we would never need to copy the entire object (like we still do in NewIterator() and MultiGet())

Test Plan: `make check` works. I will also do `make valgrind_check` before commit

Reviewers: dhruba, haobo, kailiu, sdong, emayanke, tnovak

Reviewed By: kailiu

CC: leveldb

Differential Revision: https://reviews.facebook.net/D15255
2014-01-24 14:52:08 -08:00
kailiu
f131d4c280 Add a make target for shared library
Summary:
Previous we made `make release` also compile shared library. However it takes a long time to complete.

To make our development process more efficient. I added a new make target shared_lib.

User can of course run `make <library_name>` for direct compilation. However the <library_name> changed under certain condition. Thus we need `make shared_lib` to get rid of the memorization from users' side.

Test Plan: make shared_lib

Reviewers: igor, sdong, haobo, dhruba

Reviewed By: igor

CC: leveldb

Differential Revision: https://reviews.facebook.net/D15309
2014-01-24 11:56:01 -08:00
Igor Canadi
e832e72b31 Revert "Moving to glibc-fb"
This reverts commit d24961b65e.

For some reason, glibc2.17-fb breaks gflags. Reverting for now
2014-01-24 11:50:38 -08:00
kailiu
66dc033af3 Temporarily disable caching index/filter blocks
Summary:
Mixing index/filter blocks with data blocks resulted in some known
issues.  To make sure in next release our users won't be affected,
we added a new option in BlockBasedTableFactory::TableOption to
conceal this functionality for now.

This patch also introduced a BlockBasedTableReader::OpenOptions,
which avoids the "infinite" growth of parameters in
BlockBasedTableReader::Open().

Test Plan: make check

Reviewers: haobo, sdong, igor, dhruba

Reviewed By: igor

CC: leveldb, tnovak

Differential Revision: https://reviews.facebook.net/D15327
2014-01-24 10:57:15 -08:00
Igor Canadi
d24961b65e Moving to glibc-fb
Summary:
It looks like we might have some trouble when building the new release with 4.8, since fbcode is using glibc2.17-fb by default and we are using glibc2.17. It was reported by Benjamin Renard in our internal group.

This diff moves our fbcode build to use glibc2.17-fb by default. I got some linker errors when compiling, complaining that `google::SetUsageMessage()` was undefined. After deleting all offending lines, the compile was successful and everything works.

Test Plan:
Compiled
Ran ./db_bench ./db_stress ./db_repl_stress

Reviewers: kailiu

Reviewed By: kailiu

CC: leveldb

Differential Revision: https://reviews.facebook.net/D15405
2014-01-24 10:24:08 -08:00
Siying Dong
4605e20c58 If User setting of compaction multipliers overflow, use default value 1 instead
Summary: Currently, compaction multipliers can overflow and cause unexpected behaviors. In this patch, we detect those overflows and use multiplier 1 for them.

Test Plan: make all check

Reviewers: dhruba, haobo, igor, kailiu

Reviewed By: kailiu

CC: leveldb

Differential Revision: https://reviews.facebook.net/D15321
2014-01-24 10:14:23 -08:00
Lei Jin
aba2acb5ec CompactRange() to return status
Summary: as title

Test Plan:
make all check
What else tests shall I cover?

Reviewers: igor, haobo

CC:

Differential Revision: https://reviews.facebook.net/D15339
2014-01-23 16:41:46 -08:00
Tomislav Novak
81c9cc9b3b Tailing iterator
Summary:
This diff implements a special type of iterator that doesn't create a snapshot
(can be used to read newly inserted data) and is optimized for doing sequential
reads.

TailingIterator uses current superversion number to determine whether to
invalidate its internal iterators. If the version hasn't changed, it can often
avoid doing expensive seeks over immutable structures (sst files and immutable
memtables).

Test Plan:
* new unit tests
* running LD with this patch

Reviewers: igor, dhruba, haobo, sdong, kailiu

Reviewed By: sdong

CC: leveldb, lovro, march

Differential Revision: https://reviews.facebook.net/D15285
2014-01-23 16:26:08 -08:00
Igor Canadi
4e91f27c3a Fix performance regression in statistics
Summary:
For some reason, D15099 caused a big performance regression: https://fburl.com/16059000

After digging a bit, I figured out that the reason was that std::atomic_uint_fast64_t was allocated in an array. When I switched from an array to vector, the QPS returned to the previous level. I'm not sure why this is happening, but this diff seems to fix the performance regression.

Test Plan: I ran the regression script, observed the performance going back to normal

Reviewers: tnovak, kailiu, haobo

Reviewed By: kailiu

CC: leveldb

Differential Revision: https://reviews.facebook.net/D15375
2014-01-23 16:11:55 -08:00
kailiu
d0458469c8 Add google-style checker to "arc lint"
Summary:
After we reached a consensus on code format, which follows exactly
Google's coding style, a natural follow-up is to have a style checker
that can handle stuffs beyond format.

Google already has a powerful style checker "cpplint.py" and,
luckily, phabricator already provides the built-in linter for it!
Next time with "arc lint" most style inconsistency will be detected
(but will not be fixed).

Also I copied cpplint.py to linters directory, which is mostly
because we may need the flexibility to make some modifications on
it for our own need.

Test Plan:
ran arc lint table/block_based_table_builder.cc to see the amazing
results.

Reviewers: haobo, sdong, igor, dhruba

Reviewed By: haobo

CC: leveldb

Differential Revision: https://reviews.facebook.net/D15369
2014-01-23 15:04:12 -08:00
Igor Canadi
fb01755aa4 Unfriending classes
Summary:
In this diff I made some effort to reduce usage of friending. To do that, I had to expose Compaction::inputs_ through a method inputs(). Not sure if this is a good idea, there is a trade-off. I think it's less confusing than having lots of friends.

I also thought about other friendship relationships, but they are too much tangled at this point. Once you friend two classes, it's very hard to unfriend them :)

Test Plan: make check

Reviewers: haobo, kailiu, sdong, dhruba

Reviewed By: kailiu

CC: leveldb

Differential Revision: https://reviews.facebook.net/D15267
2014-01-22 10:55:16 -08:00
Igor Canadi
6fe9b57748 Refactor Recover() code
Summary:
This diff does two things:
* Rethinks how we call Recover() with read_only option. Before, we call it with pointer to memtable where we'd like to apply those changes to. This memtable is set in db_impl_readonly.cc and it's actually DBImpl::mem_. Why don't we just apply updates to mem_ right away? It seems more intuitive.
* Changes when we apply updates to manifest. Before, the process is to recover all the logs, flush it to sst files and then do one giant commit that atomically adds all recovered sst files and sets the next log number. This works good enough, but causes some small troubles for my column family approach, since I can't have one VersionEdit apply to more than single column family[1]. The change here is to commit the files recovered from logs right away. Here is the state of the world before the change:
1. Recover log 5, add new sst files to edit
2. Recover log 7, add new sst files to edit
3. Recover log 8, add new sst files to edit
4. Commit all added sst files to manifest and mark log files 5, 7 and 8 as recoverd (via SetLogNumber(9) function)
After the change, we'll do:
1. Recover log 5, commit the new sst files and set log 5 as recovered
2. Recover log 7, commit the new sst files and set log 7 as recovered
3. Recover log 8, commit the new sst files and set log 8 as recovered

The added (small) benefit is that if we fail after (2), the new recovery will only have to recover log 8. In previous case, we'll have to restart the recovery from the beginning. The bigger benefit will be to enable easier integration of multiple column families in Recovery code path.

[1] I'm happy to dicuss this decison, but I believe this is the cleanest way to go. It also makes backward compatibility much easier. We don't have a requirement of adding multiple column families atomically.

Test Plan: make check

Reviewers: dhruba, haobo, kailiu, sdong

Reviewed By: kailiu

CC: leveldb

Differential Revision: https://reviews.facebook.net/D15237
2014-01-22 10:45:26 -08:00
kailiu
4036d58dc9 Fix a Statistics-related unit test faulure
Summary:
In my MacOS, the member variables are populated with random numbers after initialization.
This diff fixes it by fill these arrays with 0.

Test Plan: make && ./table_test

Reviewers: igor

CC: leveldb

Differential Revision: https://reviews.facebook.net/D15315
2014-01-21 18:02:55 -08:00
Mark Callaghan
4e8321bfea Boost access before mutex is unlocked
Summary:
This moves the use of versions_ to before the mutex is unlocked
to avoid a possible race.

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: haobo, dhruba

Reviewed By: dhruba

CC: leveldb

Differential Revision: https://reviews.facebook.net/D15279
2014-01-17 21:32:23 -08:00
Igor Canadi
83681bf9ef Statistics code cleanup
Summary: I'm separating code-cleanup part of https://reviews.facebook.net/D14517. This will make D14517 easier to understand and this diff easier to review.

Test Plan: make check

Reviewers: haobo, kailiu, sdong, dhruba, tnovak

Reviewed By: tnovak

CC: leveldb

Differential Revision: https://reviews.facebook.net/D15099
2014-01-17 12:46:06 -08:00
Igor Canadi
0f4a75b710 Fix SIGSEGV in compaction picker
Summary:
The SIGSEGV was introduced by https://reviews.facebook.net/D15171

I also fixed ExpandWhileOverlapping() which returned the failure by setting it's own stack variable to nullptr (!). This bug is present in 2.6 release, so I guess ExpandWhileOverlapping never fails :)

Test Plan: `make check`. Also MarkCallaghan confirmed it fixed the SIGSEGV he reported.

Reviewers: MarkCallaghan, kailiu, sdong, dhruba, haobo

Reviewed By: kailiu

CC: leveldb

Differential Revision: https://reviews.facebook.net/D15261
2014-01-17 12:02:03 -08:00
Mark Callaghan
439e36db21 Fix SlowdownAmount
Summary:
This had a few bugs.
1) bottom and top were reversed. top is for the max value but the callers were passing the max
value to bottom. The result is that the max sleep is used when n >= bottom.
2) one of the callers passed values with type double and these values are frequently between
1.0 and 2.0 so rounding will do some bad things
3) sometimes the function returned 0 when there should be a stall

With this change and one other diff (out for review soon) there are slightly fewer stalls on one workload.

With the fix.
Stalls(secs): 160.166 level0_slowdown, 0.000 level0_numfiles, 0.000 memtable_compaction, 58.495 leveln_slowdown
Stalls(count): 910261 level0_slowdown, 0 level0_numfiles, 0 memtable_compaction, 54526 leveln_slowdown

Without the fix.
Stalls(secs): 172.227 level0_slowdown, 0.000 level0_numfiles, 0.000 memtable_compaction, 56.538 leveln_slowdown
Stalls(count): 160831 level0_slowdown, 0 level0_numfiles, 0 memtable_compaction, 52845 leveln_slowdown

Task ID: #

Blame Rev:

Test Plan:
run db_bench for --benchmarks=overwrite with IO-bound database

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/D15243
2014-01-17 10:15:30 -08:00
Kai Liu
e19bad9bbd Fix some "make format" issue
Summary:
* make sure when some pre-check fails, the script won't halt immediately.
* change fburl to google's short url.
* Fix a bug in this script: now it checks the uncommitted code only.

Test Plan: Ran the script under differnet environments.

Reviewers: igor

Reviewed By: igor

CC: leveldb

Differential Revision: https://reviews.facebook.net/D15231
2014-01-16 14:26:51 -08:00
Igor Canadi
6d6fb70960 Remove compaction pointers
Summary: The only thing we do with compaction pointers is set them to some values, we never actually read them. I don't know what we used them for, but it doesn't look like we use them anymore.

Test Plan: make check

Reviewers: dhruba, haobo, kailiu, sdong

Reviewed By: kailiu

CC: leveldb

Differential Revision: https://reviews.facebook.net/D15225
2014-01-16 14:06:53 -08:00
Igor Canadi
c699c84af4 CompactionPicker
Summary:
This is a big one. This diff moves all the code related to picking compactions from VersionSet to new class CompactionPicker. Column families' compactions will be completely separate processes, so we need to have multiple CompactionPickers.

To make this easier to review, most of the code change is just copy/paste. There is also a small change not to use VersionSet::current_, but rather to take `Version* version` as a parameter. Most of the other code is exactly the same.

In future diffs, I will also make some improvements to CompactionPickers. I think the most important part will be encapsulating it better. Currently Version, VersionSet, Compaction and CompactionPicker are all friend classes, which makes it harder to change the implementation.

This diff depends on D15171, D15183, D15189 and D15201

Test Plan: `make check`

Reviewers: kailiu, sdong, dhruba, haobo

Reviewed By: kailiu

CC: leveldb

Differential Revision: https://reviews.facebook.net/D15207
2014-01-16 13:03:52 -08:00
kailiu
eae1804f29 Remove the unnecessary use of shared_ptr
Summary:
shared_ptr is slower than unique_ptr (which literally comes with no performance cost compare with raw pointers).
In memtable and memtable rep, we use shared_ptr when we'd actually should use unique_ptr.

According to igor's previous work, we are likely to make quite some performance gain from this diff.

Test Plan: make check

Reviewers: dhruba, igor, sdong, haobo

CC: leveldb

Differential Revision: https://reviews.facebook.net/D15213
2014-01-15 18:22:01 -08:00
Igor Canadi
787f11bb3b Move more functions from VersionSet to Version
Summary:
This moves functions:
* VersionSet::Finalize() -> Version::UpdateCompactionStats()
* VersionSet::UpdateFilesBySize() -> Version::UpdateFilesBySize()

The diff depends on D15189, D15183 and D15171

Test Plan: make check

Reviewers: kailiu, sdong, haobo, dhruba

Reviewed By: sdong

CC: leveldb

Differential Revision: https://reviews.facebook.net/D15201
2014-01-15 16:23:36 -08:00
Igor Canadi
615d1ea2f4 Moving Compaction class to separate header file
Summary:
I'm sure we'll all agree that version_set.cc needs simplifying. This diff moves Compaction class to a separate file.

The diff depends on D15171 and D15183

Test Plan: make check

Reviewers: dhruba, haobo, kailiu, sdong

Reviewed By: kailiu

CC: leveldb

Differential Revision: https://reviews.facebook.net/D15189
2014-01-15 16:22:34 -08:00
Igor Canadi
2f4eda7890 Move functions from VersionSet to Version
Summary:
There were some functions in VersionSet that had no reason to be there instead of Version. Moving them to Version will make column families implementation easier.

The functions moved are:
* NumLevelBytes
* LevelSummary
* LevelFileSummary
* MaxNextLevelOverlappingBytes
* AddLiveFiles (previously AddLiveFilesCurrentVersion())
* NeedSlowdownForNumLevel0Files

The diff continues on (and depends on) D15171

Test Plan: make check

Reviewers: dhruba, haobo, kailiu, sdong, emayanke

Reviewed By: sdong

CC: leveldb

Differential Revision: https://reviews.facebook.net/D15183
2014-01-15 16:18:04 -08:00
Igor Canadi
65a8a52b54 Decrease reliance on VersionSet::NumberLevels()
Summary:
With column families VersionSet will not have a constant number of levels (each CF can have different options), so we'll need to eliminate call to VersionSet::NumberLevels()

This diff decreases number of callsites, but we're not there yet. It associates number of levels with Version (each version is associated with single CF) instead of VersionSet.

I have also slightly changed how VersionSet keeps track of manifest size.

This diff also modifies constructor of Compaction such that it takes input_version and automatically Ref()s it. Before this was done outside of constructor.

In next diffs I will continue to decrease number of callsites of VersionSet::NumberLevels() and also references to current_

Test Plan: make check

Reviewers: haobo, dhruba, kailiu, sdong

Reviewed By: sdong

Differential Revision: https://reviews.facebook.net/D15171
2014-01-15 16:15:43 -08:00
kailiu
c8f16221ed Fix the return type of WriteBatch::Data().
Summary: Quick fix for https://reviews.facebook.net/D15123

Test Plan: Make check

Reviewers: sdong, vkrest

CC: leveldb

Differential Revision: https://reviews.facebook.net/D15165
2014-01-14 20:24:48 -08:00
Siying Dong
9b51af5a17 [RocksDB Performance Branch] DBImpl.NewInternalIterator() to reduce works inside mutex
Summary: To reduce mutex contention caused by DBImpl.NewInternalIterator(), in this function, move all the iteration creation works out of mutex, only leaving object ref and get.

Test Plan:
make all check
will run db_stress for a while too to make sure no problem.

Reviewers: haobo, dhruba, kailiu

Reviewed By: haobo

CC: igor, leveldb

Differential Revision: https://reviews.facebook.net/D14589

Conflicts:
	db/db_impl.cc
2014-01-14 17:41:44 -08:00