Commit Graph

1827 Commits

Author SHA1 Message Date
Haobo Xu
48e5ea0c34 [RocksDB] Fix TransformRepFactory related valgrind problem
Summary: Let TransformRepFactory own the passed in transform. Also make it better encapsulated.

Test Plan: make valgrind_check;

Reviewers: dhruba, emayanke

Reviewed By: emayanke

CC: leveldb

Differential Revision: https://reviews.facebook.net/D12591
2013-08-28 19:27:54 -07:00
Dhruba Borthakur
fc0c399d2e Introduced a new flag non_blocking_io in ReadOptions.
Summary:
If ReadOptions.non_blocking_io is set to true, then KeyMayExists
and Iterators will return data that is cached in RAM.
If the Iterator needs to do IO from storage to serve the data,
then the Iterator.status() will return Status::IsRetry().

Test Plan:
Enhanced unit test DBTest.KeyMayExist to detect if there were are IOs
issues from storage. Added DBTest.NonBlockingIteration to verify
nonblocking Iterations.

Reviewers: emayanke, haobo

Reviewed By: haobo

CC: leveldb

Maniphest Tasks: T63

Differential Revision: https://reviews.facebook.net/D12531
2013-08-28 10:49:14 -07:00
Jim Paton
5c3b254ef2 Fix memory leak
Summary: There is a memory leak because TransformRepFactory does not delete its SliceTransform pointer. This patch adds a delete to the destructor.

Test Plan:
make check
make valgrind_check

Reviewers: dhruba, emayanke, haobo

Reviewed By: dhruba

CC: leveldb

Differential Revision: https://reviews.facebook.net/D12513
2013-08-23 15:39:49 -07:00
Tyler Harter
4504c99030 Internal/user key bug fix.
Summary: Fix code so that the filter_block layer only assumes keys are internal when prefix_extractor is set.

Test Plan: ./filter_block_test

Reviewers: dhruba, haobo

Reviewed By: dhruba

CC: leveldb

Differential Revision: https://reviews.facebook.net/D12501
2013-08-23 14:49:57 -07:00
Dhruba Borthakur
1186192ed1 Replace include/leveldb with include/rocksdb.
Summary: Replace include/leveldb with include/rocksdb.

Test Plan:
make clean; make check
make clean; make release

Differential Revision: https://reviews.facebook.net/D12489
2013-08-23 10:51:00 -07:00
Jim Paton
74781a0c49 Add three new MemTableRep's
Summary:
This patch adds three new MemTableRep's: UnsortedRep, PrefixHashRep, and VectorRep.

UnsortedRep stores keys in an std::unordered_map of std::sets. When an iterator is requested, it dumps the keys into an std::set and iterates over that.

VectorRep stores keys in an std::vector. When an iterator is requested, it creates a copy of the vector and sorts it using std::sort. The iterator accesses that new vector.

PrefixHashRep stores keys in an unordered_map mapping prefixes to ordered sets.

I also added one API change. I added a function MemTableRep::MarkImmutable. This function is called when the rep is added to the immutable list. It doesn't do anything yet, but it seems like that could be useful. In particular, for the vectorrep, it means we could elide the extra copy and just sort in place. The only reason I haven't done that yet is because the use of the ArenaAllocator complicates things (I can elaborate on this if needed).

Test Plan:
make -j32 check
./db_stress --memtablerep=vector
./db_stress --memtablerep=unsorted
./db_stress --memtablerep=prefixhash --prefix_size=10

Reviewers: dhruba, haobo, emayanke

Reviewed By: dhruba

CC: leveldb

Differential Revision: https://reviews.facebook.net/D12117
2013-08-22 23:10:02 -07:00
Tyler Harter
94cf218720 Revert "Prefix scan: db_bench and bug fixes"
This reverts commit c2bd8f4824.
2013-08-22 18:01:11 -07:00
Tyler Harter
c2bd8f4824 Prefix scan: db_bench and bug fixes
Summary: If use_prefix_filters is set and read_range>1, then the random seeks will set a the prefix filter to be the prefix of the key which was randomly selected as the target.  Still need to add statistics (perhaps in a separate diff).

Test Plan: ./db_bench --benchmarks=fillseq,prefixscanrandom --num=10000000 --statistics=1 --use_prefix_blooms=1 --use_prefix_api=1 --bloom_bits=10

Reviewers: dhruba

Reviewed By: dhruba

CC: leveldb, haobo

Differential Revision: https://reviews.facebook.net/D12273
2013-08-22 16:06:50 -07:00
Simha Venkataramaiah
60bf2b7d4a Add APIs to query SST file metadata and to delete specific SST files
Summary: An api to query the level, key ranges, size etc for each SST file and an api to delete a specific file from the db and all associated state in the bookkeeping datastructures.

Notes: Editing the manifest version does not release the obsolete files right away. However deleting the file directly will mess up the iterator. We may need a more aggressive/timely file deletion api.

I have used std::unique_ptr - will switch to boost:: since this is external. thoughts?

Unit test is fragile right now as it expects the compaction at certain levels.

Test Plan: unittest

Reviewers: dhruba, vamsi, emayanke

CC: zshao, leveldb, haobo

Task ID: #

Blame Rev:
2013-08-22 15:27:19 -07:00
Jim Paton
cb703c9d03 Allow WriteBatch::Handler to abort iteration
Summary:
Sometimes you don't need to iterate through the whole WriteBatch. This diff makes the Handler member functions return a bool that indicates whether to abort or not. If they return true, the iteration stops.

One thing I just thought of is that this will break backwards-compability. Maybe it would be better to add a virtual member function WriteBatch::Handler::ShouldAbort() that returns false by default. Comments requested.

I still have to add a new unit test for the abort code, but let's finalize the API first.

Test Plan: make -j32 check

Reviewers: dhruba, haobo, vamsi, emayanke

Reviewed By: dhruba

CC: leveldb

Differential Revision: https://reviews.facebook.net/D12339
2013-08-21 18:27:48 -07:00
Mayank Agarwal
404d63ac3e Add TODO for DBToStackableDB function which doesn't work yet
Summary:

Test Plan:

Reviewers:

CC:

Task ID: #

Blame Rev:
2013-08-20 21:33:53 -07:00
Deon Nicholas
b87dcae1a3 Made merge_oprator a shared_ptr; and added TTL unit tests
Test Plan:
- make all check;
- make release;
- make stringappend_test; ./stringappend_test

Reviewers: haobo, emayanke

Reviewed By: haobo

CC: leveldb, kailiu

Differential Revision: https://reviews.facebook.net/D12381
2013-08-20 13:35:28 -07:00
Mayank Agarwal
3ab2792f93 Add default info to comment in leveldb/options.h for no_block_cache
Summary: to ley clients know

Test Plan: visual
2013-08-19 14:29:40 -07:00
Mayank Agarwal
28e6fe5e9f Correct documentation for no_block_cache in leveldb/options.h
Summary: false shoudl have been true in comment

Test Plan: visual
2013-08-19 14:27:19 -07:00
Mayank Agarwal
8a3547d38e API for getting archived log files
Summary: Also expanded class LogFile to have startSequene and FileSize and exposed it publicly

Test Plan: make all check

Reviewers: dhruba, haobo

Reviewed By: dhruba

CC: leveldb

Differential Revision: https://reviews.facebook.net/D12087
2013-08-19 13:37:04 -07:00
Deon Nicholas
e1346968d8 Merge operator fixes part 1.
Summary:
-Added null checks and revisions to DBIter::MergeValuesNewToOld()
-Added DBIter test to stringappend_test
-Major fix with Merge and TTL
More plans for fixes later.

Test Plan:
-make clean; make stringappend_test -j 32; ./stringappend_test
-make all check;

Reviewers: haobo, emayanke, vamsi, dhruba

Reviewed By: haobo

CC: leveldb

Differential Revision: https://reviews.facebook.net/D12315
2013-08-19 11:42:47 -07:00
Mayank Agarwal
387ac0f1e1 Expose statistic for sequence number and implement setTickerCount
Summary: statistic for sequence number is needed by wormhole. setTickerCount is demanded for this statistic. I can't simply recordTick(max_sequence) when db recovers because the statistic iobject is owned by client and may/may not be reset during reopen. Eg. statistic is reset in mcrocksdb whereas it is not in db_stress. Therefore it is best to go with setTickerCount

Test Plan: ./db_stress ... --statistics=1 and observed expected sequence number

Reviewers: dhruba

CC: leveldb

Differential Revision: https://reviews.facebook.net/D12327
2013-08-15 23:00:20 -07:00
Jim Paton
0307c5fe3a Implement log blobs
Summary:
This patch adds the ability for the user to add sequences of arbitrary data (blobs) to write batches. These blobs are saved to the log along with everything else in the write batch. You can add multiple blobs per WriteBatch and the ordering of blobs, puts, merges, and deletes are preserved.

Blobs are not saves to SST files. RocksDB ignores blobs in every way except for writing them to the log.

Before committing this patch, I need to add some test code. But I'm submitting it now so people can comment on the API.

Test Plan: make -j32 check

Reviewers: dhruba, haobo, vamsi

Reviewed By: dhruba

CC: leveldb

Differential Revision: https://reviews.facebook.net/D12195
2013-08-14 16:32:46 -07:00
Haobo Xu
d9dd2a1926 [RocksDB] Expose thread local perf counter for low overhead, per call level performance statistics.
Summary:
As title. No locking/atomic is needed due to thread local. There is also no need to modify the existing client interface, in order to expose related counters.

perf_context_test shows a simple example of retrieving the number of user key comparison done for each put and get call. More counters could be added later.

Sample output
./perf_context_test 1000000
==== Test PerfContextTest.KeyComparisonCount
Inserting 1000000 key/value pairs
...
total user key comparison get: 43446523
total user key comparison put: 8017877
max user key comparison get: 88939
avg user key comparison get:43

Basically, the current skiplist does well on average, but could perform poorly in extreme cases.

Test Plan: run perf_context_test <total number of entries to put/get>

Reviewers: dhruba

Differential Revision: https://reviews.facebook.net/D12225
2013-08-14 15:24:06 -07:00
Mayank Agarwal
f1bf169484 Counter for merge failure
Summary:
With Merge returning bool, it can keep failing silently(eg. While faling to fetch timestamp in TTL). We need to detect this through a rocksdb counter which can get bumped whenever Merge returns false. This will also be super-useful for the mcrocksdb-counter service where Merge may fail.
Added a counter NUMBER_MERGE_FAILURES and appropriately updated db/merge_helper.cc

I felt that it would be better to directly add counter-bumping in Merge as a default function of MergeOperator class but user should not be aware of this, so this approach seems better to me.

Test Plan: make all check

Reviewers: dnicholas, haobo, dhruba, vamsi

CC: leveldb

Differential Revision: https://reviews.facebook.net/D12129
2013-08-13 14:25:42 -07:00
Tyler Harter
f5f1842282 Prefix filters for scans (v4)
Summary: Similar to v2 (db and table code understands prefixes), but use ReadOptions as in v3.  Also, make the CreateFilter code faster and cleaner.

Test Plan: make db_test; export LEVELDB_TESTS=PrefixScan; ./db_test

Reviewers: dhruba

Reviewed By: dhruba

CC: haobo, emayanke

Differential Revision: https://reviews.facebook.net/D12027
2013-08-13 14:04:56 -07:00
sumeet
3b81df34bd Separate compaction filter for each compaction
Summary:
If we have same compaction filter for each compaction,
application cannot know about the different compaction processes.
Later on, we can put in more details in compaction filter for the
application to consume and use it according to its needs. For e.g. In
the universal compaction, we have a compaction process involving all the
files while others don't involve all the files. Applications may want to
collect some stats only when during full compaction.

Test Plan: run existing unit tests

Reviewers: haobo, dhruba

Reviewed By: dhruba

CC: xinyaohu, leveldb

Differential Revision: https://reviews.facebook.net/D12057
2013-08-13 10:56:20 -07:00
Dhruba Borthakur
f5fa26b6a9 Merge branch 'performance' of github.com:facebook/rocksdb into performance
Conflicts:
	db/builder.cc
	db/db_impl.cc
	db/version_set.cc
	include/leveldb/statistics.h
2013-08-07 11:58:06 -07:00
Deon Nicholas
c2d7826ced [RocksDB] [MergeOperator] The new Merge Interface! Uses merge sequences.
Summary:
Here are the major changes to the Merge Interface. It has been expanded
to handle cases where the MergeOperator is not associative. It does so by stacking
up merge operations while scanning through the key history (i.e.: during Get() or
Compaction), until a valid Put/Delete/end-of-history is encountered; it then
applies all of the merge operations in the correct sequence starting with the
base/sentinel value.

I have also introduced an "AssociativeMerge" function which allows the user to
take advantage of associative merge operations (such as in the case of counters).
The implementation will always attempt to merge the operations/operands themselves
together when they are encountered, and will resort to the "stacking" method if
and only if the "associative-merge" fails.

This implementation is conjectured to allow MergeOperator to handle the general
case, while still providing the user with the ability to take advantage of certain
efficiencies in their own merge-operator / data-structure.

NOTE: This is a preliminary diff. This must still go through a lot of review,
revision, and testing. Feedback welcome!

Test Plan:
  -This is a preliminary diff. I have only just begun testing/debugging it.
  -I will be testing this with the existing MergeOperator use-cases and unit-tests
(counters, string-append, and redis-lists)
  -I will be "desk-checking" and walking through the code with the help gdb.
  -I will find a way of stress-testing the new interface / implementation using
db_bench, db_test, merge_test, and/or db_stress.
  -I will ensure that my tests cover all cases: Get-Memtable,
Get-Immutable-Memtable, Get-from-Disk, Iterator-Range-Scan, Flush-Memtable-to-L0,
Compaction-L0-L1, Compaction-Ln-L(n+1), Put/Delete found, Put/Delete not-found,
end-of-history, end-of-file, etc.
  -A lot of feedback from the reviewers.

Reviewers: haobo, dhruba, zshao, emayanke

Reviewed By: haobo

CC: leveldb

Differential Revision: https://reviews.facebook.net/D11499
2013-08-05 20:14:32 -07:00
Jim Paton
8e792e5896 Add soft_rate_limit stats
Summary: This diff adds histogram stats for soft_rate_limit stalls. It also renames the old rate_limit stats to hard_rate_limit.

Test Plan: make -j32 check

Reviewers: dhruba, haobo, MarkCallaghan

Reviewed By: dhruba

CC: leveldb

Differential Revision: https://reviews.facebook.net/D12021
2013-08-05 18:45:23 -07:00
Mayank Agarwal
1d7b4765c3 Expose base db object from ttl wrapper
Summary: rocksdb replicaiton will need this when writing value+TS from master to slave 'as is'

Test Plan: make

Reviewers: dhruba, vamsi, haobo

Reviewed By: dhruba

CC: leveldb

Differential Revision: https://reviews.facebook.net/D11919
2013-08-05 18:44:14 -07:00
Jim Paton
1036537c94 Add soft and hard rate limit support
Summary:
This diff adds support for both soft and hard rate limiting. The following changes are included:

1) Options.rate_limit is renamed to Options.hard_rate_limit.
2) Options.rate_limit_delay_milliseconds is renamed to Options.rate_limit_delay_max_milliseconds.
3) Options.soft_rate_limit is added.
4) If the maximum compaction score is > hard_rate_limit and rate_limit_delay_max_milliseconds == 0, then writes are delayed by 1 ms at a time until the max compaction score falls below hard_rate_limit.
5) If the max compaction score is > soft_rate_limit but <= hard_rate_limit, then writes are delayed by 0-1 ms depending on how close we are to hard_rate_limit.
6) Users can disable 4 by setting hard_rate_limit = 0. They can add a limit to the maximum amount of time waited by setting rate_limit_delay_max_milliseconds > 0. Thus, the old behavior can be preserved by setting soft_rate_limit = 0, which is the default.

Test Plan:
make -j32 check
./db_stress

Reviewers: dhruba, haobo, MarkCallaghan

Reviewed By: dhruba

CC: leveldb

Differential Revision: https://reviews.facebook.net/D12003
2013-08-05 15:43:49 -07:00
Mayank Agarwal
cacd812fb2 Support user's compaction filter in TTL logic
Summary: TTL uses compaction filter to purge key-values and required the user to not pass one. This diff makes it accommodating of user's compaciton filter. Added test to ttl_test

Test Plan: make; ./ttl_test

Reviewers: dhruba, haobo, vamsi

Reviewed By: dhruba

CC: leveldb

Differential Revision: https://reviews.facebook.net/D11973
2013-08-05 11:28:01 -07:00
Dhruba Borthakur
711a30cb30 Merge branch 'master' into performance
Conflicts:
	include/leveldb/options.h
	include/leveldb/statistics.h
	util/options.cc
2013-08-02 10:22:08 -07:00
Mayank Agarwal
59d0b02f8b Expand KeyMayExist to return the proper value if it can be found in memory and also check block_cache
Summary: Removed KeyMayExistImpl because KeyMayExist demanded Get like semantics now. Removed no_io from memtable and imm because we need the proper value now and shouldn't just stop when we see Merge in memtable. Added checks to block_cache. Updated documentation and unit-test

Test Plan: make all check;db_stress for 1 hour

Reviewers: dhruba, haobo

Reviewed By: dhruba

CC: leveldb

Differential Revision: https://reviews.facebook.net/D11853
2013-08-01 09:07:46 -07:00
Jim Paton
9700677a2b Slow down writes gradually rather than suddenly
Summary:
Currently, when a certain number of level0 files (level0_slowdown_writes_trigger) are present, RocksDB will slow down each write by 1ms. There is a second limit of level0 files at which RocksDB will stop writes altogether (level0_stop_writes_trigger).

This patch enables the user to supply a third parameter specifying the number of files at which Rocks will start slowing down writes (level0_start_slowdown_writes). When this number is reached, Rocks will slow down writes as a quadratic function of level0_slowdown_writes_trigger - num_level0_files.

For some workloads, this improves latency and throughput. I will post some stats momentarily in https://our.intern.facebook.com/intern/tasks/?t=2613384.

Test Plan:
make -j32 check
./db_stress
./db_bench

Reviewers: dhruba, haobo, MarkCallaghan, xjin

Reviewed By: xjin

CC: leveldb, xjin, zshao

Differential Revision: https://reviews.facebook.net/D11859
2013-07-31 16:20:48 -07:00
Xing Jin
0f0a24e298 Make arena block size configurable
Summary:
Add an option for arena block size, default value 4096 bytes. Arena will allocate blocks with such size.

I am not sure about passing parameter to skiplist in the new virtualized framework, though I talked to Jim a bit. So add Jim as reviewer.

Test Plan:
new unit test, I am running db_test.

For passing paramter from configured option to Arena, I tried tests like:

  TEST(DBTest, Arena_Option) {
  std::string dbname = test::TmpDir() + "/db_arena_option_test";
  DestroyDB(dbname, Options());

  DB* db = nullptr;
  Options opts;
  opts.create_if_missing = true;
  opts.arena_block_size = 1000000; // tested 99, 999999
  Status s = DB::Open(opts, dbname, &db);
  db->Put(WriteOptions(), "a", "123");
  }

and printed some debug info. The results look good. Any suggestion for such a unit-test?

Reviewers: haobo, dhruba, emayanke, jpaton

Reviewed By: dhruba

CC: leveldb, zshao

Differential Revision: https://reviews.facebook.net/D11799
2013-07-31 12:42:23 -07:00
Jim Paton
18afff2e63 Add stall counts to statistics
Summary: Previously, statistics are kept on how much time is spent on stalls of different types. This patch adds support for keeping number of stalls of each type. For example, instead of just reporting how many microseconds are spent waiting for memtables to be compacted, it will also report how many times a write stalled for that to occur.

Test Plan:
make -j32 check
./db_stress

# Not really sure what else should be done...

Reviewers: dhruba, MarkCallaghan, haobo

Reviewed By: dhruba

CC: leveldb

Differential Revision: https://reviews.facebook.net/D11841
2013-07-29 10:34:23 -07:00
Jim Paton
52d7ecfc78 Virtualize SkipList Interface
Summary: This diff virtualizes the skiplist interface so that users can provide their own implementation of a backing store for MemTables. Eventually, the backing store will be responsible for its own synchronization, allowing users (and us) to experiment with different lockless implementations.

Test Plan:
make clean
make -j32 check
./db_stress

Reviewers: dhruba, emayanke, haobo

Reviewed By: dhruba

CC: leveldb

Differential Revision: https://reviews.facebook.net/D11739
2013-07-23 14:42:27 -07:00
Mayank Agarwal
bf66c10b13 Use KeyMayExist for WriteBatch-Deletes
Summary:
Introduced KeyMayExist checking during writebatch-delete and removed from Outer Delete API because it uses writebatch-delete.
Added code to skip getting Table from disk if not already present in table_cache.
Some renaming of variables.
Introduced KeyMayExistImpl which allows checking since specified sequence number in GetImpl useful to check partially written writebatch.
Changed KeyMayExist to not be pure virtual and provided a default implementation.
Expanded unit-tests in db_test to check appropriately.
Ran db_stress for 1 hour with ./db_stress --max_key=100000 --ops_per_thread=10000000 --delpercent=50 --filter_deletes=1 --statistics=1.

Test Plan: db_stress;make check

Reviewers: dhruba, haobo

Reviewed By: dhruba

CC: leveldb, xjin

Differential Revision: https://reviews.facebook.net/D11745
2013-07-23 13:36:50 -07:00
Haobo Xu
9ee68871dc [RocksDB] Enable manual compaction to move files back to an appropriate level.
Summary: As title. This diff added an option reduce_level to CompactRange. When set to true, it will try to move the files back to the minimum level sufficient to hold the data set. Note that the default is set to true now, just to excerise it in all existing tests. Will set the default to false before check-in, for backward compatibility.

Test Plan: make check;

Reviewers: dhruba, emayanke

CC: leveldb

Differential Revision: https://reviews.facebook.net/D11553
2013-07-19 16:20:36 -07:00
Dhruba Borthakur
4a745a5666 Merge branch 'master' into performance
Conflicts:
	db/version_set.cc
	include/leveldb/options.h
	util/options.cc
2013-07-17 15:05:57 -07:00
Mayank Agarwal
2a986919d6 Make rocksdb-deletes faster using bloom filter
Summary:
Wrote a new function in db_impl.c-CheckKeyMayExist that calls Get but with a new parameter turned on which makes Get return false only if bloom filters can guarantee that key is not in database. Delete calls this function and if the option- deletes_use_filter is turned on and CheckKeyMayExist returns false, the delete will be dropped saving:
1. Put of delete type
2. Space in the db,and
3. Compaction time

Test Plan:
make all check;
will run db_stress and db_bench and enhance unit-test once the basic design gets approved

Reviewers: dhruba, haobo, vamsi

Reviewed By: haobo

CC: leveldb

Differential Revision: https://reviews.facebook.net/D11607
2013-07-11 12:11:11 -07:00
Dhruba Borthakur
7cb8d462d5 Rename PickCompactionHybrid to PickCompactionUniversal.
Summary:
Rename PickCompactionHybrid to PickCompactionUniversal.
Changed a few LOG message from "Hybrid:" to "Universal:".

Test Plan:

Reviewers:

CC:

Task ID: #

Blame Rev:
2013-07-09 16:08:54 -07:00
Haobo Xu
a8d5f8dde2 [RocksDB] Remove old readahead options
Summary: As title.

Test Plan: make check; db_bench

Reviewers: dhruba, MarkCallaghan

CC: leveldb

Differential Revision: https://reviews.facebook.net/D11643
2013-07-09 11:22:33 -07:00
Dhruba Borthakur
116ec527f2 Renamed 'hybrid_compaction' tp be "Universal Compaction'.
Summary:
All the universal compaction parameters are encapsulated in
a new file universal_compaction.h

Test Plan:
make check
2013-07-03 15:47:53 -07:00
Mayank Agarwal
d56523c49c Update rocksdb version
Summary: rocksdb-2.0 released to third party

Test Plan: visual inspection

Reviewers: dhruba, haobo, sheki

Reviewed By: dhruba

CC: leveldb

Differential Revision: https://reviews.facebook.net/D11559
2013-07-01 14:30:04 -07:00
Dhruba Borthakur
47c4191fe8 Reduce write amplification by merging files in L0 back into L0
Summary:
There is a new option called hybrid_mode which, when switched on,
causes HBase style compactions.  Files from L0 are
compacted back into L0. This meat of this compaction algorithm
is in PickCompactionHybrid().

All files reside in L0. That means all files have overlapping
keys. Each file has a time-bound, i.e. each file contains a
range of keys that were inserted around the same time. The
start-seqno and the end-seqno refers to the timeframe when
these keys were inserted.  Files that have contiguous seqno
are compacted together into a larger file. All files are
ordered from most recent to the oldest.

The current compaction algorithm starts to look for
candidate files starting from the most recent file. It continues to
add more files to the same compaction run as long as the
sum of the files chosen till now is smaller than the next
candidate file size. This logic needs to be debated
and validated.

The above logic should reduce write amplification to a
large extent... will publish numbers shortly.

Test Plan: dbstress runs for 6 hours with no data corruption (tested so far).

Differential Revision: https://reviews.facebook.net/D11289
2013-06-30 20:07:04 -07:00
Haobo Xu
71e0f695c1 [RocksDB] Expose count for WriteBatch
Summary: As title. Exposed a Count function that returns the number of updates in a batch. Could be handy for replication sequence number check.

Test Plan: make check;

Reviewers: emayanke, sheki, dhruba

CC: leveldb

Differential Revision: https://reviews.facebook.net/D11523
2013-06-26 15:13:21 -07:00
Haobo Xu
4deaa0d48b [RocksDB] Minor change to statistics.h
Summary: as title, use initialize list so that lines fit in 80 chars.

Test Plan: make check;

Reviewers: sheki, dhruba

Differential Revision: https://reviews.facebook.net/D11385
2013-06-19 12:44:42 -07:00
Haobo Xu
96be2c4ee0 [RocksDB] Add mmap_read option for db_stress
Summary: as title, also removed an incorrect assertion

Test Plan: make check; db_stress --mmap_read=1; db_stress --mmap_read=0

Reviewers: dhruba, emayanke

CC: leveldb

Differential Revision: https://reviews.facebook.net/D11367
2013-06-19 10:28:32 -07:00
Abhishek Kona
5ef6bb8c37 [rocksdb][refactor] statistic printing code to one place
Summary: $title

Test Plan: db_bench --statistics=1

Reviewers: haobo

Reviewed By: haobo

CC: leveldb

Differential Revision: https://reviews.facebook.net/D11373
2013-06-18 20:28:41 -07:00
Haobo Xu
3cc1af2062 [RocksDB] Option for incremental sync
Summary: This diff added an option to control the incremenal sync frequency. db_bench has a new flag bytes_per_sync for easy tuning exercise.

Test Plan: make check; db_bench

Reviewers: dhruba

CC: leveldb

Differential Revision: https://reviews.facebook.net/D11295
2013-06-18 15:00:32 -07:00
Dhruba Borthakur
6acbe0fc45 Compact multiple memtables before flushing to storage.
Summary:
Merge multiple multiple memtables in memory before writing it
out to a file in L0.

There is a new config parameter min_write_buffer_number_to_merge
that specifies the number of write buffers that should be merged
together to a single file in storage. The system will not flush
wrte buffers to storage unless at least these many buffers have
accumulated in memory.
The default value of this new parameter is 1, which means that
a write buffer will be immediately flushed to disk as soon it is
ready.

Test Plan: make check

Differential Revision: https://reviews.facebook.net/D11241
2013-06-18 14:28:04 -07:00
Abhishek Kona
f561b3a324 [Rocksdb] Rename one stat key from leveldb to rocksdb 2013-06-17 14:33:05 -07:00
Abhishek Kona
39ee47fbf4 [Rocksdb] Record WriteBlock Times into a histogram
Summary: Add a histogram to track WriteBlock times

Test Plan: db_bench and print

Reviewers: haobo, dhruba

Reviewed By: haobo

CC: leveldb

Differential Revision: https://reviews.facebook.net/D11319
2013-06-17 10:11:10 -07:00
Abhishek Kona
7a5f71d19a [Rocksdb] measure table open io in a histogram
Summary: Table is setup for compaction using Table::SetupForCompaction. So read block calls can be differentiated b/w Gets/Compaction. Use this and measure times.

Test Plan: db_bench --statistics=1

Reviewers: dhruba, haobo

Reviewed By: haobo

CC: leveldb, MarkCallaghan

Differential Revision: https://reviews.facebook.net/D11217
2013-06-13 17:25:09 -07:00
Haobo Xu
778e179046 [RocksDB] Sync file to disk incrementally
Summary:
During compaction, we sync the output files after they are fully written out. This causes unnecessary blocking of the compaction thread and burstiness of the write traffic.
This diff simply asks the OS to sync data incrementally as they are written, on the background. The hope is that, at the final sync, most of the data are already on disk and we would block less on the sync call. Thus, each compaction runs faster and we could use fewer number of compaction threads to saturate IO.
In addition, the write traffic will be smoothed out, hopefully reducing the IO P99 latency too.

Some quick tests show 10~20% improvement in per thread compaction throughput. Combined with posix advice on compaction read, just 5 threads are enough to almost saturate the udb flash bandwidth for 800 bytes write only benchmark.
What's more promising is that, with saturated IO, iostat shows average wait time is actually smoother and much smaller.
For the write only test 800bytes test:
Before the change:  await  occillate between 10ms and 3ms
After the change: await ranges 1-3ms

Will test against read-modify-write workload too, see if high read latency P99 could be resolved.

Will introduce a parameter to control the sync interval in a follow up diff after cleaning up EnvOptions.

Test Plan: make check; db_bench; db_stress

Reviewers: dhruba

CC: leveldb

Differential Revision: https://reviews.facebook.net/D11115
2013-06-12 12:53:59 -07:00
Haobo Xu
bdf1085944 [RocksDB] cleanup EnvOptions
Summary:
This diff simplifies EnvOptions by treating it as POD, similar to Options.
- virtual functions are removed and member fields are accessed directly.
- StorageOptions is removed.
- Options.allow_readahead and Options.allow_readahead_compactions are deprecated.
- Unused global variables are removed: useOsBuffer, useFsReadAhead, useMmapRead, useMmapWrite

Test Plan: make check; db_stress

Reviewers: dhruba

CC: leveldb

Differential Revision: https://reviews.facebook.net/D11175
2013-06-12 11:17:19 -07:00
Abhishek Kona
4a8554d5bb [Rocksdb] fix wrong assert
Summary: the assert was wrong in D11145. Broke build

Test Plan: make db_bench run it

Reviewers: dhruba, haobo, emayanke

Reviewed By: dhruba

CC: leveldb

Differential Revision: https://reviews.facebook.net/D11187
2013-06-10 13:14:14 -07:00
Abhishek Kona
a4913c5170 [rocksdb] names for all metrics provided in statistics.h
Summary: Provide a  map of histograms and ticker vs strings. Fb303 libraries can use this to provide the mapping. We will not have to duplicate the code during release.

Test Plan: db_bench with statistics=1

Reviewers: dhruba, haobo

Reviewed By: dhruba

CC: leveldb

Differential Revision: https://reviews.facebook.net/D11145
2013-06-10 11:57:55 -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
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
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
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
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
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
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
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
Mayank Agarwal
3102628873 Bring read_only into ttl
Summary: added an argument to openttldb for read only and open the db in normal readonly mode if the arguments is set to true

Test Plan: make ttl_test; ./ttl_test

Reviewers: dhruba, haobo, vamsi, sheki

Reviewed By: dhruba

CC: leveldb

Differential Revision: https://reviews.facebook.net/D10749
2013-05-10 16:13:26 -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
Abhishek Kona
d98e56315d [RocksDB] Make Ticker Atomic
Summary:
Our ticker was not atomic. This was based on the assumption that we will increment counts at places only protected by Mutex. This is hard to program for and easy to make mistakes (mutex may be held a few layers above etc).
Also this increases the instructions executed when the mutex is held.

Test Plan: make check

Reviewers: haobo, dhruba

Reviewed By: dhruba

CC: leveldb

Differential Revision: https://reviews.facebook.net/D10569
2013-05-10 13:19:39 -07:00
Mayank Agarwal
ff1a0801fc Correct path of db.h in utility_db.h
Summary: Will not be caught properly from file in fbcode with old path. New path fixes it.

Test Plan: make

Reviewers: sheki, dhruba, haobo, vamsi

Reviewed By: sheki

Differential Revision: https://reviews.facebook.net/D10707
2013-05-09 17:32:39 -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
Mayank Agarwal
d786b25e2d Timestamp and TTL Wrapper for rocksdb
Summary:
When opened with DBTimestamp::Open call, timestamps are prepended to and stripped from the value during subsequent Put and Get calls respectively. The Timestamp is used to discard values in Get and custom compaction filter which have exceeded their TTL which is specified during Open.
Have made a temporary change to Makefile to let us test with the temporary file TestTime.cc. Have also changed the private members of db_impl.h to protected to let them be inherited by the new class DBTimestamp

Test Plan: make db_timestamp; TestTime.cc(will not check it in) shows how to use the apis currently, but I will write unit-tests shortly

Reviewers: dhruba, vamsi, haobo, sheki, heyongqiang, vkrest

Reviewed By: vamsi

CC: zshao, xjin, vkrest, MarkCallaghan

Differential Revision: https://reviews.facebook.net/D10311
2013-05-02 16:34:42 -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
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
Abhishek Kona
dae7379050 [RocksDB] Expose LDB functioanality as a library call - clients can build their own LDB binary with additional options
Summary: Primarily a refactor. Introduced LDBTool interface to which customers can plug in their options and this will create their own version of ldb tool.

Test Plan: made ldb tool and tried it.

Reviewers: dhruba, heyongqiang

Reviewed By: dhruba

CC: leveldb

Differential Revision: https://reviews.facebook.net/D10191
2013-04-11 20:21:49 -07:00
heyongqiang
e21ba94a69 Set FD_CLOEXEC after each file open
Summary: as subject. This is causing problem in adsconv. Ideally, this flags should be set in open. But that is only supported in Linux kernel ≥2.6.23 and glibc ≥2.7.

Test Plan:
db_test

run db_test

Reviewers: dhruba, MarkCallaghan, haobo

Reviewed By: dhruba

CC: leveldb, chip

Differential Revision: https://reviews.facebook.net/D10089
2013-04-10 14:44:06 -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
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
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
Dhruba Borthakur
469724be7f Add appropriate parameters to make bulk-load go faster.
Summary:
1. Create only 2 levels so that manual compactions are fast.
2. Set target file size to a large value

Test Plan: make clean check

Reviewers: kailiu, zshao

Reviewed By: zshao

CC: leveldb

Differential Revision: https://reviews.facebook.net/D9231
2013-03-08 10:52:16 -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
Zheng Shao
7b43500794 [RocksDB] Add bulk_load option to Options and ldb
Summary:
Add a shortcut function to make it easier for people
to efficiently bulk_load data into RocksDB.

Test Plan:
Tried ldb with "--bulk_load" and "--bulk_load --compact" and verified the outcome.
Needs to consult the team on how to test this automatically.

Reviewers: sheki, dhruba, emayanke, heyongqiang

Reviewed By: dhruba

CC: leveldb

Differential Revision: https://reviews.facebook.net/D8907
2013-03-05 00:34:53 -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
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
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
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
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
Kosie van der Merwe
4dcc0c89f4 Fixed cache key for block cache
Summary:
Added function to `RandomAccessFile` to generate an unique ID for that file. Currently only `PosixRandomAccessFile` has this behaviour implemented and only on Linux.

Changed how key is generated in `Table::BlockReader`.

Added tests to check whether the unique ID is stable, unique and not a prefix of another unique ID. Added tests to see that `Table` uses the cache more efficiently.

Test Plan: make check

Reviewers: chip, vamsi, dhruba

Reviewed By: chip

CC: leveldb

Differential Revision: https://reviews.facebook.net/D8145
2013-01-31 15:20:24 -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
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
amayank
4b1e9f0a35 Added an API in rocksdb for checking for "invalid argument" and "not supported" for leveldb::Status
Summary: a function added to status.h to check whether Status::code is InvalidArgument and similarly for NotSupported state

Test Plan: visual inspection

Reviewers: heyongqiang, dhruba

Reviewed By: dhruba

CC: leveldb

Differential Revision: https://reviews.facebook.net/D7989
2013-01-16 14:30:45 -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
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
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
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
Dhruba Borthakur
d0a30935c6 Expose the serialized string that represents a WriteBatch.
Summary:
Expose the serialized string that represents a WriteBatch. This
is helpful to replicate a writebatch operation from one machine
to another.

Test Plan: make clean check

Reviewers: sheki

Reviewed By: sheki

CC: leveldb

Differential Revision: https://reviews.facebook.net/D7317
2012-12-12 16:25:52 -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
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
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
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
6c5a4d646a Merge branch 'master' into performance
Conflicts:
	db/db_impl.h
2012-11-14 21:39:52 -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
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
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
5f91868cee Merge branch 'master' into performance
Conflicts:
	db/version_set.cc
	util/options.cc
2012-11-05 16:51:55 -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
Dhruba Borthakur
81f735d97c Merge branch 'master' into performance
Conflicts:
	db/db_impl.cc
	util/options.cc
2012-11-05 09:41:38 -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
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
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
Dhruba Borthakur
47bce26aca Merge branch 'master' into performance 2012-10-23 22:32:54 -07:00
Mark Callaghan
51d2adfbeb Fix broken build. Add stdint.h to get uint64_t
Summary:
I still get failures from this. Not sure whether there was a fix in progress.

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 -

Reviewers: dhruba

Reviewed By: dhruba

Differential Revision: https://reviews.facebook.net/D6147
2012-10-23 14:58:53 -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
72c45c66c6 Print the block cache size in the LOG.
Summary: Print the block cache size in the LOG.

Test Plan: run db_bench and look at LOG. This is helpful while I was debugging one use-case.

Reviewers: heyongqiang, MarkCallaghan

Reviewed By: heyongqiang

Differential Revision: https://reviews.facebook.net/D5739
2012-09-29 21:39:19 -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
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
9e84834eb4 Allow a configurable number of background threads.
Summary:
The background threads are necessary for compaction.
For slower storage, it might be necessary to have more than
one compaction thread per DB. This patch allows creating
a configurable number of worker threads.
The default reamins at 1 (to maintain backward compatibility).

Test Plan:
run all unit tests. changes to db-bench coming in
a separate patch.

Reviewers: heyongqiang

Reviewed By: heyongqiang

CC: MarkCallaghan

Differential Revision: https://reviews.facebook.net/D5559
2012-09-19 15:51:08 -07:00
heyongqiang
3662c2976a improve comments about target_file_size_base, target_file_size_multiplier, max_bytes_for_level_base, max_bytes_for_level_multiplier Summary:
Summary: as subject

Test Plan: compile

Reviewers: MarkCallaghan, dhruba

Differential Revision: https://reviews.facebook.net/D5499
2012-09-17 15:56:11 -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
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
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
heyongqiang
a4f9b8b49e merge 1.5
Summary:

as subject

Test Plan:

db_test table_test

Reviewers: dhruba
2012-08-28 11:43:33 -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
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
Dhruba Borthakur
407f020929 Unit test corruption_test do not compile.
Summary: Unit test corruption_test do not compile.

Test Plan: run unit tests

Reviewers: heyongqiang

Reviewed By: heyongqiang

Differential Revision: https://reviews.facebook.net/D4797
2012-08-21 15:46:16 -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
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
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
daa816c4a0 add bzip2 compression
Summary: add bzip2 compression

Test Plan: testcases in table_test

Reviewers: dhruba

Reviewed By: dhruba

Differential Revision: https://reviews.facebook.net/D3909
2012-06-29 10:27:28 -07:00
heyongqiang
054a5657f8 add zlib compression
Summary: add zlib compression

Test Plan: Will add more testcases

Reviewers: dhruba

Reviewed By: dhruba

Differential Revision: https://reviews.facebook.net/D3873
2012-06-28 16:28:57 -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
2067d22038 Support for java access to leveldb via leveldbjni.
Test Plan: unit tests.

Differential Revision: https://reviews.facebook.net/D3735
2012-06-20 15:17:03 -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
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
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
Hans Wennborg
36a5f8ed7f A number of fixes:
- Replace raw slice comparison with a call to user comparator.
  Added test for custom comparators.

- Fix end of namespace comments.

- Fixed bug in picking inputs for a level-0 compaction.

  When finding overlapping files, the covered range may expand
  as files are added to the input set.  We now correctly expand
  the range when this happens instead of continuing to use the
  old range.  For example, suppose L0 contains files with the
  following ranges:

      F1: a .. d
      F2:    c .. g
      F3:       f .. j

  and the initial compaction target is F3.  We used to search
  for range f..j which yielded {F2,F3}.  However we now expand
  the range as soon as another file is added.  In this case,
  when F2 is added, we expand the range to c..j and restart the
  search.  That picks up file F1 as well.

  This change fixes a bug related to deleted keys showing up
  incorrectly after a compaction as described in Issue 44.

(Sync with upstream @25072954)
2011-10-31 17:22:06 +00:00
Gabor Cselle
299ccedfec A number of bugfixes:
- Added DB::CompactRange() method.

  Changed manual compaction code so it breaks up compactions of
  big ranges into smaller compactions.

  Changed the code that pushes the output of memtable compactions
  to higher levels to obey the grandparent constraint: i.e., we
  must never have a single file in level L that overlaps too
  much data in level L+1 (to avoid very expensive L-1 compactions).

  Added code to pretty-print internal keys.

- Fixed bug where we would not detect overlap with files in
  level-0 because we were incorrectly using binary search
  on an array of files with overlapping ranges.

  Added "leveldb.sstables" property that can be used to dump
  all of the sstables and ranges that make up the db state.

- Removing post_write_snapshot support.  Email to leveldb mailing
  list brought up no users, just confusion from one person about
  what it meant.

- Fixing static_cast char to unsigned on BIG_ENDIAN platforms.

  Fixes	Issue 35 and Issue 36.

- Comment clarification to address leveldb Issue 37.

- Change license in posix_logger.h to match other files.

- A build problem where uint32 was used instead of uint32_t.

Sync with upstream @24408625
2011-10-05 16:30:28 -07:00
Hans Wennborg
213a68eb68 Sync with upstream @23860137.
Fix GCC -Wshadow warnings in LevelDB's public header files,
reported by Dustin.

Add in-memory Env implementation (helpers/memenv/*).
This enables users to create LevelDB databases in-memory.

Initialize ShardedLRUCache::last_id_ to zero.
This fixes a Valgrind warning.

(Also delete port/sha1_* which were removed upstream some time ago.)
2011-09-12 10:21:10 +01:00
gabor@google.com
021ee9c32b C binding for leveldb, better readseq benchmark for SQLite.
- Added a C binding for LevelDB.
  May be useful as a stable ABI that can be used by 
  programs that keep leveldb in a shared library, 
  or for JNI API.

- Replaced SQLite's readseq benchmark to a more efficient version. 
  SQLite readseq speeds increased by about a factor of 2x 
  from the previous version. Also updated benchmark page to
  reflect readseq speed up.



git-svn-id: https://leveldb.googlecode.com/svn/trunk@46 62dab493-f737-651d-591e-8d6aee1b9529
2011-08-05 20:40:49 +00:00
gabor@google.com
60bd8015f2 Speed up Snappy uncompression, new Logger interface.
- Removed one copy of an uncompressed block contents changing
  the signature of Snappy_Uncompress() so it uncompresses into a
  flat array instead of a std::string.
        
  Speeds up readrandom ~10%.

- Instead of a combination of Env/WritableFile, we now have a
  Logger interface that can be easily overridden applications
  that want to supply their own logging.

- Separated out the gcc and Sun Studio parts of atomic_pointer.h
  so we can use 'asm', 'volatile' keywords for Sun Studio.




git-svn-id: https://leveldb.googlecode.com/svn/trunk@39 62dab493-f737-651d-591e-8d6aee1b9529
2011-07-21 02:40:18 +00:00
gabor@google.com
6872ace901 Sun Studio support, and fix for test related memory fixes.
- LevelDB patch for Sun Studio
  Based on a patch submitted by Theo Schlossnagle - thanks!
  This fixes Issue 17.

- Fix a couple of test related memory leaks.



git-svn-id: https://leveldb.googlecode.com/svn/trunk@38 62dab493-f737-651d-591e-8d6aee1b9529
2011-07-19 23:36:47 +00:00
gabor@google.com
6699c7ebe6 Small tweaks and bugfixes for Issue 18 and 19.
Slight tweak to the no-overlap optimization: only push to
level 2 to reduce the amount of wasted space when the same
small key range is being repeatedly overwritten.

Fix for Issue 18: Avoid failure on Windows by avoiding
deletion of lock file until the end of DestroyDB().

Fix for Issue 19: Disregard sequence numbers when checking for 
overlap in sstable ranges. This fixes issue 19: when writing 
the same key over and over again, we would generate a sequence 
of sstables that were never merged together since their sequence
numbers were disjoint.

Don't ignore map/unmap error checks.

Miscellaneous fixes for small problems Sanjay found while diagnosing
issue/9 and issue/16 (corruption_testr failures).
- log::Reader reports the record type when it finds an unexpected type.
- log::Reader no longer reports an error when it encounters an expected
  zero record regardless of the setting of the "checksum" flag.
- Added a missing forward declaration.
- Documented a side-effects of larger write buffer sizes
  (longer recovery time).



git-svn-id: https://leveldb.googlecode.com/svn/trunk@37 62dab493-f737-651d-591e-8d6aee1b9529
2011-07-15 00:20:57 +00:00
dgrogan@chromium.org
da79909507 sync with upstream @ 21409451
Check the NEWS file for details of what changed.

git-svn-id: https://leveldb.googlecode.com/svn/trunk@28 62dab493-f737-651d-591e-8d6aee1b9529
2011-05-21 02:17:43 +00:00
dgrogan@chromium.org
ba6dac0e80 @20776309
* env_chromium.cc should not export symbols.
* Fix MSVC warnings.
* Removed large value support.
* Fix broken reference to documentation file

git-svn-id: https://leveldb.googlecode.com/svn/trunk@24 62dab493-f737-651d-591e-8d6aee1b9529
2011-04-20 22:48:11 +00:00
dgrogan@chromium.org
69c6d38342 reverting disastrous MOE commit, returning to r21
git-svn-id: https://leveldb.googlecode.com/svn/trunk@23 62dab493-f737-651d-591e-8d6aee1b9529
2011-04-19 23:11:15 +00:00
dgrogan@chromium.org
b743906eea Revision created by MOE tool push_codebase.
MOE_MIGRATION=


git-svn-id: https://leveldb.googlecode.com/svn/trunk@22 62dab493-f737-651d-591e-8d6aee1b9529
2011-04-19 23:01:25 +00:00
dgrogan@chromium.org
b409afe968 chmod a-x
git-svn-id: https://leveldb.googlecode.com/svn/trunk@21 62dab493-f737-651d-591e-8d6aee1b9529
2011-04-18 23:15:58 +00:00
dgrogan@chromium.org
f779e7a5d8 @20602303. Default file permission is now 755.
git-svn-id: https://leveldb.googlecode.com/svn/trunk@20 62dab493-f737-651d-591e-8d6aee1b9529
2011-04-12 19:38:58 +00:00
jorlow@chromium.org
9e33808a26 Fix last commit
git-svn-id: https://leveldb.googlecode.com/svn/trunk@19 62dab493-f737-651d-591e-8d6aee1b9529
2011-03-30 18:49:03 +00:00
jorlow@chromium.org
e2da744e12 Upstream changes.
git-svn-id: https://leveldb.googlecode.com/svn/trunk@16 62dab493-f737-651d-591e-8d6aee1b9529
2011-03-28 20:43:44 +00:00
jorlow@chromium.org
8303bb1b33 Pull from upstream.
git-svn-id: https://leveldb.googlecode.com/svn/trunk@14 62dab493-f737-651d-591e-8d6aee1b9529
2011-03-22 23:24:02 +00:00
jorlow@chromium.org
13b72af77b More changes from upstream.
git-svn-id: https://leveldb.googlecode.com/svn/trunk@12 62dab493-f737-651d-591e-8d6aee1b9529
2011-03-22 18:32:49 +00:00
jorlow@chromium.org
f67e15e50f Initial checkin.
git-svn-id: https://leveldb.googlecode.com/svn/trunk@2 62dab493-f737-651d-591e-8d6aee1b9529
2011-03-18 22:37:00 +00:00