Commit graph

397 commits

Author SHA1 Message Date
Siying Dong aa0ef6602d [Performance Branch] If options.max_open_files set to be -1, cache table readers in FileMetadata for Get() and NewIterator()
Summary:
In some use cases, table readers for all live files should always be cached. In that case, there will be an opportunity to avoid the table cache look-up while Get() and NewIterator().

We define options.max_open_files = -1 to be the mode that table readers for live files will always be kept. In that mode, table readers are cached in FileMetaData (with a reference count hold in table cache). So that when executing table_cache.Get() and table_cache.newInterator(), LRU cache checking can be by-passed, to reduce latency.

Test Plan: add a test case in db_test

Reviewers: haobo, kailiu

Reviewed By: haobo

CC: dhruba, igor, leveldb

Differential Revision: https://reviews.facebook.net/D15039
2014-01-10 15:57:49 -08:00
Siying Dong 237a3da677 StopWatch not to get time if it is created for statistics and it is disabled
Summary: Currently, even if statistics is not enabled, StopWatch only for the stats still gets the time of the day, which is wasteful. This patch adds a new option to StopWatch to disable this get in this case.

Test Plan: make all check

Reviewers: dhruba, haobo, igor

CC: leveldb

Differential Revision: https://reviews.facebook.net/D14703

Conflicts:
	db/db_impl.cc
2014-01-09 17:39:48 -08:00
Siying Dong 5575316350 StopWatch not to get time if it is created for statistics and it is disabled
Summary: Currently, even if statistics is not enabled, StopWatch only for the stats still gets the time of the day, which is wasteful. This patch adds a new option to StopWatch to disable this get in this case.

Test Plan: make all check

Reviewers: dhruba, haobo, igor

CC: leveldb

Differential Revision: https://reviews.facebook.net/D14703
2014-01-08 16:05:36 -08:00
Igor Canadi 19e3ee64ac Add column family information to WAL
Summary:
I have added three new value types:
* kTypeColumnFamilyDeletion
* kTypeColumnFamilyValue
* kTypeColumnFamilyMerge
which include column family Varint32 before the data (value, deletion and merge). These values are used only in WAL (not in memtables yet).

This endeavour required changing some WriteBatch internals.

Test Plan: Added a unittest

Reviewers: dhruba, haobo, sdong, kailiu

CC: leveldb

Differential Revision: https://reviews.facebook.net/D15045
2014-01-08 12:53:33 -08:00
Mark Callaghan 50994bf699 Don't always compress L0 files written by memtable flush
Summary:
Code was always compressing L0 files written by a memtable flush
when compression was enabled. Now this is done when
min_level_to_compress=0 for leveled compaction and when
universal_compaction_size_percent=-1 for universal compaction.

Task ID: #3416472

Blame Rev:

Test Plan:
ran db_bench with compression options

Revert Plan:

Database Impact:

Memcache Impact:

Other Notes:

EImportant:

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

Reviewers: dhruba, igor, sdong

Reviewed By: dhruba

CC: leveldb

Differential Revision: https://reviews.facebook.net/D14757
2014-01-07 21:50:26 -08:00
Igor Canadi 72918efffe [column families] Implement DB::OpenWithColumnFamilies()
Summary:
In addition to implementing OpenWithColumnFamilies, this diff also includes some minor changes:
* Changed all column family names from Slice() to std::string. The performance of column family name handling is not critical, and it's more convenient and cleaner to have names as std::strings
* Implemented ColumnFamilyOptions(const Options&) and DBOptions(const Options&)
* Added ColumnFamilyOptions to VersionSet::ColumnFamilyData. ColumnFamilyOptions are specified on OpenWithColumnFamilies() and CreateColumnFamily()

I will keep the diff in the Phabricator for a day or two and will push to the branch then. Feel free to comment even after the diff has been pushed.

Test Plan: Added a simple unit test

Reviewers: dhruba, haobo

CC: leveldb

Differential Revision: https://reviews.facebook.net/D15033
2014-01-07 11:05:50 -08:00
Igor Canadi d3a2ba9c64 Merge branch 'master' into columnfamilies 2014-01-07 11:05:03 -08:00
Igor Canadi 17a222670b Merge branch 'master' into performance 2014-01-07 11:04:21 -08:00
Tomislav Novak 9f690ec62c Fix a deadlock in CompactRange()
Summary:
The way DBImpl::TEST_CompactRange() throttles down the number of bg compactions
can cause it to deadlock when CompactRange() is called concurrently from
multiple threads. Imagine a following scenario with only two threads
(max_background_compactions is 10 and bg_compaction_scheduled_ is initially 0):

   1. Thread #1 increments bg_compaction_scheduled_ (to LargeNumber), sets
      bg_compaction_scheduled_ to 9 (newvalue), schedules the compaction
      (bg_compaction_scheduled_ is now 10) and waits for it to complete.
   2. Thread #2 calls TEST_CompactRange(), increments bg_compaction_scheduled_
      (now LargeNumber + 10) and waits on a cv for bg_compaction_scheduled_ to
      drop to LargeNumber.
   3. BG thread completes the first manual compaction, decrements
      bg_compaction_scheduled_ and wakes up all threads waiting on bg_cv_.
      Thread #1 runs, increments bg_compaction_scheduled_ by LargeNumber again
      (now 2*LargeNumber + 9). Since that's more than LargeNumber + newvalue,
      thread #2 also goes to sleep (waiting on bg_cv_), without resetting
      bg_compaction_scheduled_.

This diff attempts to address the problem by introducing a new counter
bg_manual_only_ (when positive, MaybeScheduleFlushOrCompaction() will only
schedule manual compactions).

Test Plan:
I could pretty much consistently reproduce the deadlock with a program that
calls CompactRange(nullptr, nullptr) immediately after Write() from multiple
threads. This no longer happens with this patch.

Tests (make check) pass.

Reviewers: dhruba, igor, sdong, haobo

Reviewed By: igor

CC: leveldb

Differential Revision: https://reviews.facebook.net/D14799
2014-01-07 10:37:34 -08:00
Igor Canadi ef6ad1708d [column families] Support to create and drop column families
Summary:
This diff provides basic implementations of CreateColumnFamily(), DropColumnFamily() and ListColumnFamilies(). It builds on top of https://reviews.facebook.net/D14733

It also includes a bug fix for DBImplReadOnly, where Get implementation would be redirected to DBImpl instead of DBImplReadOnly.

Test Plan: Added unit test

Reviewers: dhruba, haobo, kailiu

CC: leveldb

Differential Revision: https://reviews.facebook.net/D15021
2014-01-03 01:12:16 -08:00
Kai Liu 774ed89c24 Replace vector with autovector
Summary: this diff only replace the cases when we need to frequently create vector with small amount of entries. This diff doesn't aim to improve performance of a specific area, but more like a small scale test for the autovector and see how it works in real life.

Test Plan:
make check

I also ran the performance tests, however there is no performance gain/loss. All performance numbers are pretty much the same before/after the change.

Reviewers: dhruba, haobo, sdong, igor

CC: leveldb

Differential Revision: https://reviews.facebook.net/D14985
2014-01-02 16:43:35 -08:00
kailiu e72aa37cc5 Merge branch 'master' into performance
Conflicts:
	db/table_cache.cc
2014-01-02 16:34:59 -08:00
kailiu 476416c27c Some minor refactoring on the code
Summary: I made some cleanup while reading the source code in `db`. Most changes are about style, naming or C++ 11 new features.

Test Plan: ran `make check`

Reviewers: haobo, dhruba, sdong

CC: leveldb

Differential Revision: https://reviews.facebook.net/D15009
2014-01-02 16:32:31 -08:00
Igor Canadi 6de1b5b83e Merge branch 'master' into columnfamilies 2014-01-02 04:18:07 -08:00
Igor Canadi b60c14f6ee Support multi-threaded DisableFileDeletions() and EnableFileDeletions()
Summary:
We don't want two threads to clash if they concurrently call DisableFileDeletions() and EnableFileDeletions(). I'm adding a counter that will enable file deletions only after all DisableFileDeletions() calls have been negated with EnableFileDeletions().

However, we also don't want to break the old behavior, so I added a parameter force to EnableFileDeletions(). If force is true, we will still enable file deletions after every call to EnableFileDeletions(), which is what is happening now.

Test Plan: make check

Reviewers: dhruba, haobo, sanketh

Reviewed By: dhruba

CC: leveldb

Differential Revision: https://reviews.facebook.net/D14781
2014-01-02 03:33:42 -08:00
kailiu f1cec73a76 Merge branch 'master' into performance
Conflicts:
	db/db_impl.cc
	db/db_test.cc
	db/memtable.cc
	db/version_set.cc
	include/rocksdb/statistics.h
2013-12-27 12:23:17 -08:00
Igor Canadi 1fdb3f7dc6 [RocksDB] Optimize locking for Get
Summary:
Instead of locking and saving a DB state, we can cache a DB state and update it only when it changes. This change reduces lock contention and speeds up read operations on the DB.

Performance improvements are substantial, although there is some cost in no-read workloads. I ran the regression tests on my devserver and here are the numbers:

  overwrite                    56345  ->   63001
  fillseq                      193730 ->  185296
  readrandom                   771301 -> 1219803 (58% improvement!)
  readrandom_smallblockcache   677609 ->  862850
  readrandom_memtable_sst      710440 -> 1109223
  readrandom_fillunique_random 221589 ->  247869
  memtablefillrandom           105286 ->   92643
  memtablereadrandom           763033 -> 1288862

Test Plan:
make asan_check
I am also running db_stress

Reviewers: dhruba, haobo, sdong, kailiu

Reviewed By: haobo

CC: leveldb

Differential Revision: https://reviews.facebook.net/D14679
2013-12-20 09:57:58 -08:00
Igor Canadi 9385a5247e [RocksDB] [Column Family] Interface proposal
Summary:
<This diff is for Column Family branch>

Sharing some of the work I've done so far. This diff compiles and passes the tests.

The biggest change is in options.h - I broke down Options into two parts - DBOptions and ColumnFamilyOptions. DBOptions is DB-specific (env, create_if_missing, block_cache, etc.) and ColumnFamilyOptions is column family-specific (all compaction options, compresion options, etc.). Note that this does not break backwards compatibility at all.

Further, I created DBWithColumnFamily which inherits DB interface and adds new functions with column family support. Clients can transparently switch to DBWithColumnFamily and it will not break their backwards compatibility.
There are few methods worth checking out: ListColumnFamilies(), MultiNewIterator(), MultiGet() and GetSnapshot(). [GetSnapshot() returns the snapshot across all column families for now - I think that's what we agreed on]

Finally, I made small changes to WriteBatch so we are able to atomically insert data across column families.

Please provide feedback.

Test Plan: make check works, the code is backward compatible

Reviewers: dhruba, haobo, sdong, kailiu, emayanke

CC: leveldb

Differential Revision: https://reviews.facebook.net/D14445
2013-12-18 13:08:22 -08:00
Siying Dong a8b8b11dc4 Get() Does Not Reserve space for to_delete memtables
Summary: It seems to be a decision tradeoff in current codes: we make a malloc for every Get() to reduce one malloc for a flush inside mutex. It takes about 5% of CPU time in readrandom tests. We might consider the tradeoff to be the other way around.

Test Plan: make all check

Reviewers: dhruba, haobo, igor

Reviewed By: dhruba

CC: leveldb

Differential Revision: https://reviews.facebook.net/D14697
2013-12-17 17:16:16 -08:00
Mark Callaghan e9e6b00d29 Add monitoring for universal compaction and add counters for compaction IO
Summary:
Adds these counters
{ WAL_FILE_SYNCED, "rocksdb.wal.synced" }
  number of writes that request a WAL sync
{ WAL_FILE_BYTES, "rocksdb.wal.bytes" },
  number of bytes written to the WAL
{ WRITE_DONE_BY_SELF, "rocksdb.write.self" },
  number of writes processed by the calling thread
{ WRITE_DONE_BY_OTHER, "rocksdb.write.other" },
  number of writes not processed by the calling thread. Instead these were
  processed by the current holder of the write lock
{ WRITE_WITH_WAL, "rocksdb.write.wal" },
  number of writes that request WAL logging
{ COMPACT_READ_BYTES, "rocksdb.compact.read.bytes" },
  number of bytes read during compaction
{ COMPACT_WRITE_BYTES, "rocksdb.compact.write.bytes" },
  number of bytes written during compaction

Per-interval stats output was updated with WAL stats and correct stats for universal compaction
including a correct value for write-amplification. It now looks like:
                               Compactions
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  Ln-stall Stall-cnt
--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
  0        7      464  46.4       281      3411      3875      3411         0      3875        2.1      12.1        13.8      621        0      240      240      628       0.0         0
Uptime(secs): 310.8 total, 2.0 interval
Writes cumulative: 9999999 total, 9999999 batches, 1.0 per batch, 1.22 ingest GB
WAL cumulative: 9999999 WAL writes, 9999999 WAL syncs, 1.00 writes per sync, 1.22 GB written
Compaction IO cumulative (GB): 1.22 new, 3.33 read, 3.78 write, 7.12 read+write
Compaction IO cumulative (MB/sec): 4.0 new, 11.0 read, 12.5 write, 23.4 read+write
Amplification cumulative: 4.1 write, 6.8 compaction
Writes interval: 100000 total, 100000 batches, 1.0 per batch, 12.5 ingest MB
WAL interval: 100000 WAL writes, 100000 WAL syncs, 1.00 writes per sync, 0.01 MB written
Compaction IO interval (MB): 12.49 new, 14.98 read, 21.50 write, 36.48 read+write
Compaction IO interval (MB/sec): 6.4 new, 7.6 read, 11.0 write, 18.6 read+write
Amplification interval: 101.7 write, 102.9 compaction
Stalls(secs): 142.924 level0_slowdown, 0.000 level0_numfiles, 0.805 memtable_compaction, 0.000 leveln_slowdown
Stalls(count): 132461 level0_slowdown, 0 level0_numfiles, 3 memtable_compaction, 0 leveln_slowdown

Task ID: #3329644, #3301695

Blame Rev:

Test Plan:
Revert Plan:

Database Impact:

Memcache Impact:

Other Notes:

EImportant:

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

Reviewers: dhruba

CC: leveldb

Differential Revision: https://reviews.facebook.net/D14583
2013-12-12 13:27:43 -08:00
Siying Dong e8ab1934d9 [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
2013-12-12 11:30:00 -08:00
Siying Dong aaf9c6203c [RocksDB][Performance Branch]Iterator Cleanup method only tries to find obsolete files if it has the last reference to a version
Summary: When deconstructing an iterator, no need to check obsolete file if it doesn't hold last reference of any version.

Test Plan: make all check

Reviewers: haobo, igor, dhruba, kailiu

Reviewed By: haobo

CC: leveldb

Differential Revision: https://reviews.facebook.net/D14595
2013-12-11 13:59:43 -08:00
Siying Dong a8029fdc75 Introduce MergeContext to Lazily Initialize merge operand list
Summary: In get operations, merge_operands is only used in few cases. Lazily initialize it can reduce average latency in some cases

Test Plan: make all check

Reviewers: haobo, kailiu, dhruba

Reviewed By: haobo

CC: igor, nkg-, leveldb

Differential Revision: https://reviews.facebook.net/D14415

Conflicts:
	db/db_impl.cc
	db/memtable.cc
2013-12-11 11:37:28 -08:00
Siying Dong 0304e3d2ff When flushing mem tables, create iterators out of mutex
Summary:
creating new iterators of mem tables can be expensive. Move them out of mutex.
DBImpl::WriteLevel0Table()'s mems seems to be a local vector and is only used by flushing. memtables to flush are also immutable, so it should be safe to do so.

Test Plan: make all check

Reviewers: haobo, dhruba, kailiu

Reviewed By: dhruba

CC: igor, leveldb

Differential Revision: https://reviews.facebook.net/D14577

Conflicts:
	db/db_impl.cc
2013-12-11 10:02:17 -08:00
Siying Dong 95a411d853 When flushing mem tables, create iterators out of mutex
Summary:
creating new iterators of mem tables can be expensive. Move them out of mutex.
DBImpl::WriteLevel0Table()'s mems seems to be a local vector and is only used by flushing. memtables to flush are also immutable, so it should be safe to do so.

Test Plan: make all check

Reviewers: haobo, dhruba, kailiu

Reviewed By: dhruba

CC: igor, leveldb

Differential Revision: https://reviews.facebook.net/D14577
2013-12-11 09:57:19 -08:00
kailiu a82f42b765 rename db/memtablelist.{h,cc} 2013-12-10 19:03:13 -08:00
Igor Canadi 204bb9cffd Get rid of LogFlush() in InternalIterator 2013-12-10 10:59:00 -08:00
Igor Canadi 19f5463d3f Don't LogFlush() in foreground threads
Summary: So fflush() takes a lock which is heavyweight. I added flush_pending_, but more importantly, I removed LogFlush() from foreground threads.

Test Plan: ./db_test

Reviewers: dhruba, haobo

Reviewed By: dhruba

CC: leveldb

Differential Revision: https://reviews.facebook.net/D14535
2013-12-10 10:57:46 -08:00
Igor Canadi fb9fce4fc3 [RocksDB] BackupableDB
Summary:
In this diff I present you BackupableDB v1. You can easily use it to backup your DB and it will do incremental snapshots for you.
Let's first describe how you would use BackupableDB. It's inheriting StackableDB interface so you can easily construct it with your DB object -- it will add a method RollTheSnapshot() to the DB object. When you call RollTheSnapshot(), current snapshot of the DB will be stored in the backup dir. To restore, you can just call RestoreDBFromBackup() on a BackupableDB (which is a static method) and it will restore all files from the backup dir. In the next version, it will even support automatic backuping every X minutes.

There are multiple things you can configure:
1. backup_env and db_env can be different, which is awesome because then you can easily backup to HDFS or wherever you feel like.
2. sync - if true, it *guarantees* backup consistency on machine reboot
3. number of snapshots to keep - this will keep last N snapshots around if you want, for some reason, be able to restore from an earlier snapshot. All the backuping is done in incremental fashion - if we already have 00010.sst, we will not copy it again. *IMPORTANT* -- This is based on assumption that 00010.sst never changes - two files named 00010.sst from the same DB will always be exactly the same. Is this true? I always copy manifest, current and log files.
4. You can decide if you want to flush the memtables before you backup, or you're fine with backing up the log files -- either way, you get a complete and consistent view of the database at a time of backup.
5. More things you can find in BackupableDBOptions

Here is the directory structure I use:

   backup_dir/CURRENT_SNAPSHOT - just 4 bytes holding the latest snapshot
               0, 1, 2, ... - files containing serialized version of each snapshot - containing a list of files
               files/*.sst - sst files shared between snapshots - if one snapshot references 00010.sst and another one needs to backup it from the DB, it will just reference the same file
               files/ 0/, 1/, 2/, ... - snapshot directories containing private snapshot files - current, manifest and log files

All the files are ref counted and deleted immediatelly when they get out of scope.

Some other stuff in this diff:
1. Added GetEnv() method to the DB. Discussed with @haobo and we agreed that it seems right thing to do.
2. Fixed StackableDB interface. The way it was set up before, I was not able to implement BackupableDB.

Test Plan:
I have a unittest, but please don't look at this yet. I just hacked it up to help me with debugging. I will write a lot of good tests and update the diff.

Also, `make asan_check`

Reviewers: dhruba, haobo, emayanke

Reviewed By: dhruba

CC: leveldb, haobo

Differential Revision: https://reviews.facebook.net/D14295
2013-12-09 14:06:52 -08:00
kailiu 551e9428ce Merge branch 'master' into performance 2013-12-06 14:15:42 -08:00
Siying Dong ef2211a9ca [RocksDB Performance Branch] Introduce MergeContext to Lazily Initialize merge operand list
Summary: In get operations, merge_operands is only used in few cases. Lazily initialize it can reduce average latency in some cases

Test Plan: make all check

Reviewers: haobo, kailiu, dhruba

Reviewed By: haobo

CC: igor, nkg-, leveldb

Differential Revision: https://reviews.facebook.net/D14415
2013-12-06 10:28:59 -08:00
Mayank Agarwal 18802689b8 Make an API to get database identity from the IDENTITY file
Summary: This would enable rocksdb users to get the db identity without depending on implementation details(storing that in IDENTITY file)

Test Plan: db/db_test (has identity checks)

Reviewers: dhruba, haobo, igor, kailiu

Reviewed By: dhruba

CC: leveldb

Differential Revision: https://reviews.facebook.net/D14463
2013-12-04 22:39:17 -08:00
Sajal Jain 28a1b9b95f [rocksdb] statistics counters for memtable hits and misses
Summary:
added counters
rocksdb.memtable.hit - for memtable hit
rocksdb.memtable.miss - for memtable miss

Test Plan: db_bench tests

Reviewers: igor, dhruba, haobo

Reviewed By: dhruba

Differential Revision: https://reviews.facebook.net/D14433
2013-12-03 12:59:53 -08:00
Igor Canadi eb12e47e0e Killing Transform Rep
Summary:
Let's get rid of TransformRep and it's children. We have confirmed that HashSkipListRep works better with multifeed, so there is no benefit to keeping this around.

This diff is mostly just deleting references to obsoleted functions. I also have a diff for fbcode that we'll need to push when we switch to new release.

I had to expose HashSkipListRepFactory in the client header files because db_impl.cc needs access to GetTransform() function for SanitizeOptions.

Test Plan: make check

Reviewers: dhruba, haobo, kailiu, sdong

Reviewed By: dhruba

CC: leveldb

Differential Revision: https://reviews.facebook.net/D14397
2013-12-03 12:42:15 -08:00
Igor Canadi 043fc14c3e Get rid of some shared_ptrs
Summary:
I went through all remaining shared_ptrs and removed the ones that I found not-necessary. Only GenerateCachePrefix() is called fairly often, so don't expect much perf wins.

The ones that are left are accessed infrequently and I think we're fine with keeping them.

Test Plan: make asan_check

Reviewers: dhruba, haobo

Reviewed By: dhruba

CC: leveldb

Differential Revision: https://reviews.facebook.net/D14427
2013-12-03 11:17:58 -08:00
Dhruba Borthakur 98968ba937 Free obsolete memtables outside the dbmutex had a memory leak.
Summary:
The commit at 27bbef1180 had a memory leak
that was detected by valgrind. The memtable that has a refcount decrement
in MemTableList::InstallMemtableFlushResults was not freed.

Test Plan: valgrind ./db_test --leak-check=full

Reviewers: igor

Reviewed By: igor

CC: leveldb

Differential Revision: https://reviews.facebook.net/D14391
2013-11-28 10:25:22 -08:00
Kai Liu 1966b63137 Merge branch 'master' into perf 2013-11-27 11:47:40 -08:00
Dhruba Borthakur 27bbef1180 Free obsolete memtables outside the dbmutex.
Summary:
Large memory allocations and frees are costly and best done outside the
db-mutex. The memtables are already allocated outside the db-mutex but
they were being freed while holding the db-mutex.
This patch frees obsolete memtables outside the db-mutex.

Test Plan:
make check
db_stress

Unit tests pass, I am in the process of running stress tests.

Reviewers: haobo, igor, emayanke

Reviewed By: haobo

CC: reconnect.grayhat, leveldb

Differential Revision: https://reviews.facebook.net/D14319
2013-11-25 21:04:48 -08:00
Igor Canadi 3ce3658411 DB::GetOptions()
Summary: We need access to options for BackupableDB

Test Plan: make check

Reviewers: dhruba

Reviewed By: dhruba

CC: leveldb, reconnect.grayhat

Differential Revision: https://reviews.facebook.net/D14331
2013-11-25 15:51:50 -08:00
Igor Canadi 11c26bd4a4 [RocksDB] Interface changes required for BackupableDB
Summary: This is part of https://reviews.facebook.net/D14295 -- smaller diff that is easier to review

Test Plan: make asan_check

Reviewers: dhruba, haobo, emayanke

Reviewed By: emayanke

CC: leveldb, kailiu, reconnect.grayhat

Differential Revision: https://reviews.facebook.net/D14301
2013-11-25 12:39:23 -08:00
Dhruba Borthakur 299f5c76bb Create new log file outside the dbmutex.
Summary:
All filesystem Io should be done outside the dbmutex. There was one place
when we have to roll the transaction log that we were creating the new log file
while holding the dbmutex.

I rearranged this code so that the act of creating the new transaction log
file is done without holding the dbmutex.  I also allocate the new memtable
outside the dbmutex, this is important because creating the memtable
could be heavyweight.

Test Plan: make check and dbstress

Reviewers: haobo, igor

Reviewed By: haobo

CC: leveldb, reconnect.grayhat

Differential Revision: https://reviews.facebook.net/D14283
2013-11-25 11:23:42 -08:00
Haobo Xu 5b825d6964 [RocksDB] Use raw pointer instead of shared pointer when passing Statistics object internally
Summary: liveness of the statistics object is already ensured by the shared pointer in DB options. There's no reason to pass again shared pointer among internal functions. Raw pointer is sufficient and efficient.

Test Plan: make check

Reviewers: dhruba, MarkCallaghan, igor

Reviewed By: dhruba

CC: leveldb, reconnect.grayhat

Differential Revision: https://reviews.facebook.net/D14289
2013-11-25 10:38:15 -08:00
Siying Dong 3e35aa6412 Revert "Allow users to profile a query and see bottleneck of the query"
This reverts commit 3d8ac31d71.
2013-11-21 17:40:39 -08:00
Siying Dong b135d01e7b Allow users to profile a query and see bottleneck of the query
Summary:
Provide a framework to profile a query in detail to figure out latency bottleneck. Currently, in Get(), Put() and iterators, 2-3 simple timing is used. We can easily add more profile counters to the framework later.

Test Plan: Enable this profiling in seveal existing tests.

Reviewers: haobo, dhruba, kailiu, emayanke, vamsi, igor

CC: leveldb

Differential Revision: https://reviews.facebook.net/D14001

Conflicts:
	table/merger.cc
2013-11-21 17:39:19 -08:00
Siying Dong 3d8ac31d71 Allow users to profile a query and see bottleneck of the query
Summary:
Provide a framework to profile a query in detail to figure out latency bottleneck. Currently, in Get(), Put() and iterators, 2-3 simple timing is used. We can easily add more profile counters to the framework later.

Test Plan: Enable this profiling in seveal existing tests.

Reviewers: haobo, dhruba, kailiu, emayanke, vamsi, igor

CC: leveldb

Differential Revision: https://reviews.facebook.net/D14001
2013-11-21 16:29:57 -08:00
kailiu 6eb5649800 Move flush_block_policy from Options to TableFactory
Summary:
Previously we introduce a `flush_block_policy_factory` in Options, however, that options is strongly releated to Table based tables.
It will make more sense to move it to block based table's own factory class.

Test Plan: make check to pass existing tests

Reviewers: dhruba, haobo

Reviewed By: dhruba

CC: leveldb

Differential Revision: https://reviews.facebook.net/D14211
2013-11-19 22:00:48 -08:00
kailiu 1415f8820d Improve the "table stats"
Summary:
The primary motivation of the changes is to make it easier to figure out the inside of the tables.

* rename "table stats" to "table properties" since now we have more than "integers" to store in the property block.
* Add filter block size to the basic table properties.
* Whenever a table is built, we'll log the table properties (the sample output is in Test Plan).
* Make an api to expose deleted keys.

Test Plan:
Passed all existing test. and the sample output of table stats:

    ==================================================================
        Basic Properties
    ------------------------------------------------------------------
                  # data blocks: 1
                      # entries: 1

                   raw key size: 9
           raw average key size: 9
                 raw value size: 9
         raw average value size: 0

                data block size: 25
               index block size: 27
              filter block size: 18
         (estimated) table size: 70

                  filter policy: rocksdb.BuiltinBloomFilter
    ==================================================================
        User collected properties: InternalKeyPropertiesCollector
    ------------------------------------------------------------------
                    kDeletedKeys: 1
    ==================================================================

Reviewers: dhruba, haobo

Reviewed By: dhruba

CC: leveldb

Differential Revision: https://reviews.facebook.net/D14187
2013-11-19 16:29:42 -08:00
Kai Liu 75df72f2a5 Change the logic in KeyMayExist()
Summary:
Previously in KeyMayExist(), if DB::Get() returns non-Status::OK(), we assumes key may not exist.
However, as if index block is not in block cache, Status::Incomplete() will return. Worse still, if
options::filter_delete is enabled, we may falsely ignore the "delete" operation:

  https://github.com/facebook/rocksdb/blob/master/db/write_batch.cc#L217-L220

This diff fixes this bug and will let crash-test pass.

Test Plan:
Ran:

  ./db_stress --test_batches_snapshots=1 --ops_per_thread=1000000 --threads=32 --write_buffer_size=4194304 --destroy_db_initially=1 --reopen=0 --readpercent=5 --prefixpercent=45 --writepercent=35 --delpercent=5 --iterpercent=10 --db=/home/kailiu/local/newer --max_key=100000000 --disable_seek_compaction=0 --mmap_read=0 --block_size=16384 --cache_size=1048576 --open_files=500000 --verify_checksum=1 --sync=0 --disable_wal=0 --disable_data_sync=0 --target_file_size_base=2097152
--target_file_size_multiplier=2 --max_write_buffer_number=3 --max_background_compactions=20 --max_bytes_for_level_base=10485760 --filter_deletes=1

Previously we'll see crash happens very soon.

Reviewers: igor, dhruba

CC: leveldb

Differential Revision: https://reviews.facebook.net/D14115
2013-11-17 01:00:34 -08:00
Pascal Borreli 443e04e62d Fixed typos 2013-11-16 11:21:34 +00:00
Igor Canadi 29c931f70b Avoid populating live set if we don't need to
Summary: Also changed some comments

Test Plan: ./deletefile_test

Reviewers: haobo

Reviewed By: haobo

CC: leveldb

Differential Revision: https://reviews.facebook.net/D14091
2013-11-14 22:42:02 -08:00
Igor Canadi a0ce3fd00a PurgeObsoleteFiles() unittest
Summary:
Created a unittest that verifies that automatic deletion performed by PurgeObsoleteFiles() works correctly.

Also, few small fixes on the logic part -- call version_set_->GetObsoleteFiles() in FindObsoleteFiles() instead of on some arbitrary positions.

Test Plan: Created a unit test

Reviewers: dhruba, haobo, nkg-

Reviewed By: haobo

CC: leveldb

Differential Revision: https://reviews.facebook.net/D14079
2013-11-14 18:03:57 -08:00
Igor Canadi fda8142f29 Delete log files in the correct dir
Summary: Log files are stored in wal_dir, not dbname_

Test Plan: deletfile_test

Reviewers: nkg-

Reviewed By: nkg-

CC: leveldb

Differential Revision: https://reviews.facebook.net/D14067
2013-11-13 14:54:54 -08:00
Kai Liu 35460ccb53 Fix the string format issue
Summary:

mac and our dev server has totally differnt definition of uint64_t, therefore fixing the warning in mac has actually made code in linux uncompileable.

Test Plan:

make clean && make -j32
2013-11-12 21:05:39 -08:00
Igor Canadi d88d8ecf80 Fix deleting files
Summary: One more fix! In some cases, our filenames start with "/". Apparently, env_ can't handle filenames with double //

Test Plan:
deletefile_test does not include this line in the LOG anymore:
2013/11/12-18:11:43.150149 7fe4a6fff700 RenameFile logfile #3 FAILED -- IO error: /tmp/rocksdbtest-3574/deletefile_test//000003.log: No such file or directory

Reviewers: dhruba, haobo

Reviewed By: haobo

CC: leveldb

Differential Revision: https://reviews.facebook.net/D14055
2013-11-12 20:32:07 -08:00
kailiu 21587760b9 Fixing the warning messages captured under mac os # Consider using git commit -m 'One line title' && arc diff. # You will save time by running lint and unit in the background.
Summary: The work to make sure mac os compiles rocksdb is not completed yet. But at least we can start cleaning some warnings captured only by g++ from mac os..

Test Plan: ran make in mac os

Reviewers: dhruba

Reviewed By: dhruba

CC: leveldb

Differential Revision: https://reviews.facebook.net/D14049
2013-11-12 20:05:28 -08:00
Igor Canadi 9bc4a26f56 Small changes in Deleting obsolete files
Summary:
@haobo's suggestions from https://reviews.facebook.net/D13827

Renaming some variables, deprecating purge_log_after_flush, changing for loop into auto for loop.

I have not implemented deleting objects outside of mutex yet because it would require a big code change - we would delete object in db_impl, which currently does not know anything about object because it's defined in version_edit.h (FileMetaData). We should do it at some point, though.

Test Plan: Ran deletefile_test

Reviewers: haobo

Reviewed By: haobo

CC: leveldb, haobo

Differential Revision: https://reviews.facebook.net/D14025
2013-11-12 11:53:26 -08:00
Igor Canadi dad425562f Move the comment
Summary: Moving the comment per @haobo suggestion.

Test Plan: No

Reviewers: haobo

Reviewed By: haobo

CC: leveldb, haobo

Differential Revision: https://reviews.facebook.net/D14019
2013-11-12 10:07:55 -08:00
Igor Canadi 4abd219cfc Combine two FindObsoleteFiles()
Summary: We don't need to call FindObsoleteFiles() twice

Test Plan: deletefile_test

Reviewers: dhruba

Reviewed By: dhruba

CC: leveldb

Differential Revision: https://reviews.facebook.net/D14007
2013-11-11 21:41:32 -08:00
Igor Canadi 94e139f94d Fixing failed delete file test
Summary: FindObsoleteFiles() has to be called before PurgeObsoleteFiles() because FindObsoleteFiles() sets manifest_file_number, log_number and prev_log_number to valid values.

Test Plan: deletefile_test now works

Reviewers: dhruba, emayanke, kailiu

Reviewed By: kailiu

CC: leveldb

Differential Revision: https://reviews.facebook.net/D13995
2013-11-11 21:03:41 -08:00
Igor Canadi 1510339e52 Speed up FindObsoleteFiles
Summary:
Here's one solution we discussed on speeding up FindObsoleteFiles. Keep a set of all files in DBImpl and update the set every time we create a file. I probably missed few other spots where we create a file.

It might speed things up a bit, but makes code uglier. I don't really like it.

Much better approach would be to abstract all file handling to a separate class. Think of it as layer between DBImpl and Env. Having a separate class deal with file namings and deletion would benefit both code cleanliness (especially with huge DBImpl) and speed things up. It will take a huge effort to do this, though.

Let's discuss offline today.

Test Plan: Ran ./db_stress, verified that files are getting deleted

Reviewers: dhruba, haobo, kailiu, emayanke

Reviewed By: dhruba

Differential Revision: https://reviews.facebook.net/D13827
2013-11-08 15:23:46 -08:00
Kai Liu fd075d6edd Provide mechanism to configure when to flush the block
Summary: Allow block based table to configure the way flushing the blocks. This feature will allow us to add support for prefix-aligned block.

Test Plan: make check

Reviewers: dhruba, haobo, sdong, igor

Reviewed By: sdong

CC: leveldb

Differential Revision: https://reviews.facebook.net/D13875
2013-11-07 21:27:21 -08:00
Igor Canadi 444cf88a56 Flush the log outside of lock
Summary:
Added a new call LogFlush() that flushes the log contents to the OS buffers. We never call it with lock held.

We call it once for every Read/Write and often in compaction/flush process so the frequency should not be a problem.

Test Plan: db_test

Reviewers: dhruba, haobo, kailiu, emayanke

Reviewed By: dhruba

CC: leveldb

Differential Revision: https://reviews.facebook.net/D13935
2013-11-07 11:31:56 -08:00
Haobo Xu fd2044883a [RocksDB] Generalize prefix-aware iterator to be used for more than one Seek
Summary: Added a prefix_seek flag in ReadOptions to indicate that Seek is prefix aware(might not return data with different prefix), and also not bound to a specific prefix. Multiple Seeks and range scans can be invoked on the same iterator. If a specific prefix is specified, this flag will be ignored. Just a quick prototype that works for PrefixHashRep, the new lockless memtable could be easily extended with this support too.

Test Plan: test it on Leaf

Reviewers: dhruba, kailiu, sdong, igor

Reviewed By: igor

CC: leveldb

Differential Revision: https://reviews.facebook.net/D13929
2013-11-06 20:45:49 -08:00
shamdor c2be2cba04 WAL log retention policy based on archive size.
Summary:
Archive cleaning will still happen every WAL_ttl seconds
but archived logs will be deleted only if archive size
is greater then a WAL_size_limit value.
Empty archived logs will be deleted evety WAL_ttl.

Test Plan:
1. Unit tests pass.
2. Benchmark.

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

Reviewed By: emayanke

CC: leveldb

Differential Revision: https://reviews.facebook.net/D13869
2013-11-06 18:46:28 -08:00
Mayank Agarwal f837f5b1c9 Making the transaction log iterator more robust
Summary:
strict essentially means that we MUST find the startsequence. Thus we should return if starteSequence is not found in the first file in case strict is set. This will take care of ending the iterator in case of permanent gaps due to corruptions in the log files
Also created NextImpl function that will have internal variable to distinguish whether Next is being called from StartSequence or by application.
Set NotFoudn::gaps status to give an indication of gaps happeneing.
Polished the inline documentation at various places

Test Plan:
* db_repl_stress test
* db_test relating to transaction log iterator
* fbcode/wormhole/rocksdb/rocks_log_iterator
* sigma production machine sigmafio032.prn1

Reviewers: dhruba

Reviewed By: dhruba

CC: leveldb

Differential Revision: https://reviews.facebook.net/D13689
2013-11-04 20:49:03 -08:00
Dhruba Borthakur b4ad5e89ae Implement a compressed block cache.
Summary:
Rocksdb can now support a uncompressed block cache, or a compressed
block cache or both. Lookups first look for a block in the
uncompressed cache, if it is not found only then it is looked up
in the compressed cache. If it is found in the compressed cache,
then it is uncompressed and inserted into the uncompressed cache.

It is possible that the same block resides in the compressed cache
as well as the uncompressed cache at the same time. Both caches
have their own individual LRU policy.

Test Plan: Unit test case attached.

Reviewers: kailiu, sdong, haobo, leveldb

Reviewed By: haobo

CC: xjin, haobo

Differential Revision: https://reviews.facebook.net/D12675
2013-11-01 14:31:35 -07:00
Haobo Xu 8cbe5bb56b [RocksDB] Add OnCompactionStart to CompactionFilter class
Summary: This is to give application compaction filter a chance to access context information of a specific compaction run. For example, depending on whether a compaction goes through all data files, the application could do things differently.

Test Plan: make check

Reviewers: dhruba, kailiu, sdong

Reviewed By: dhruba

CC: leveldb

Differential Revision: https://reviews.facebook.net/D13683
2013-10-31 13:36:43 -07:00
Siying Dong f03b2df010 Follow-up Cleaning-up After D13521
Summary:
This patch is to address @haobo's comments on D13521:
1. rename Table to be TableReader and make its factory function to be GetTableReader
2. move the compression type selection logic out of TableBuilder but to compaction logic
3. more accurate comments
4. Move stat name constants into BlockBasedTable implementation.
5. remove some uncleaned codes in simple_table_db_test

Test Plan: pass test suites.

Reviewers: haobo, dhruba, kailiu

Reviewed By: haobo

CC: leveldb

Differential Revision: https://reviews.facebook.net/D13785
2013-10-30 10:52:33 -07:00
Siying Dong d4eec30ed0 Make "Table" pluggable
Summary: This patch makes Table and TableBuilder a abstract class and make all the implementation of the current table into BlockedBasedTable and BlockedBasedTable Builder.

Test Plan: Make db_test.cc to work with block based table. Add a new test simple_table_db_test.cc where a different simple table format is implemented.

Reviewers: dhruba, haobo, kailiu, emayanke, vamsi

Reviewed By: dhruba

CC: leveldb

Differential Revision: https://reviews.facebook.net/D13521
2013-10-28 17:54:09 -07:00
Kai Liu 994575c134 Support user-defined table stats collector
Summary:
1. Added a new option that support user-defined table stats collection.
2. Added a deleted key stats collector in `utilities`

Test Plan:
Added a unit test for newly added code.
Also ran make check to make sure other tests are not broken.

Reviewers: dhruba, haobo

Reviewed By: dhruba

CC: leveldb

Differential Revision: https://reviews.facebook.net/D13491
2013-10-28 15:45:14 -07:00
Igor Canadi 100fa8e013 If a Put fails, fail all other puts
Summary:
When a Put fails, it can leave database in a messy state. We don't want to pretend that everything is OK when it may not be. We fail every write following the failed one.

I added checks for corruption to DBImpl::Write(). Is there anywhere else I need to add them?

Test Plan: Corruption unit test.

Reviewers: dhruba, haobo, kailiu

Reviewed By: dhruba

CC: leveldb

Differential Revision: https://reviews.facebook.net/D13671
2013-10-28 12:36:02 -07:00
Mayank Agarwal 56305221c4 Unify DeleteFile and DeleteWalFiles
Summary:
This is to simplify rocksdb public APIs and improve the code quality.
Created an additional parameter to ParseFileName for log sub type and improved the code for deleting a wal file.
Wrote exhaustive unit-tests in delete_file_test
Unification of other redundant APIs can be taken up in a separate diff

Test Plan: Expanded delete_file test

Reviewers: dhruba, haobo, kailiu, sdong

Reviewed By: dhruba

CC: leveldb

Differential Revision: https://reviews.facebook.net/D13647
2013-10-25 08:32:14 -07:00
Kai Liu c17607a251 Fix the log number bug when updating MANIFEST file
Summary:
Crash may occur during the flushes of more than two mem tables.

As the info log suggested, even when both were successfully flushed,
the recovery process still pick up one of the memtable's log for recovery.

This diff fix the problem by setting the correct "log number" in MANIFEST.

Test Plan: make test; deployed to leaf4 and make sure it doesn't result in crashes of this type.

Reviewers: haobo, dhruba

CC: leveldb

Differential Revision: https://reviews.facebook.net/D13659
2013-10-24 21:05:33 -07:00
Haobo Xu 2fb361ad98 [RocksDB] Add perf_context.wal_write_time to track time spent on writing the recovery log.
Summary: as title

Test Plan: make check; ./perf_context_test

Reviewers: dhruba

Reviewed By: dhruba

CC: leveldb

Differential Revision: https://reviews.facebook.net/D13629
2013-10-23 13:38:39 -07:00
Mayank Agarwal 9b50106f9a Dbid feature
Summary:
Create a new type of file on startup if it doesn't already exist called DBID.
This will store a unique number generated from boost library's uuid header file.
The use-case is to identify the case of a db losing all its data and coming back up either empty or from an image(backup/live replica's recovery)
the key point to note is that DBID is not stored in a backup or db snapshot
It's preferable to use Boost for uuid because:
1) A non-standard way of generating uuid is not good
2) /proc/sys/kernel/random/uuid generates a uuid but only on linux environments and the solution would not be clean
3) c++ doesn't have any direct way to get a uuid
4) Boost is a very good library that was already having linkage in rocksdb from third-party
Note: I had to update the TOOLCHAIN_REV in build files to get latest verison of boost from third-party as the older version had a bug.
I had to put Wno-uninitialized in Makefile because boost-1.51 has an unitialized variable and rocksdb would not comiple otherwise. Latet open-source for boost is 1.54 but is not there in third-party. I have notified the concerned people in fbcode about it.
@kailiu : While releasing to third-party, an additional dependency will need to be created for boost in TARGETS file. I can help identify.

Test Plan:
Expand db_test to test 2 cases
1) Restarting db with Id file present - verify that no change to Id
2)Restarting db with Id file deleted - verify that a different Id is there after reopen
Also run make all check

Reviewers: dhruba, haobo, kailiu, sdong

Reviewed By: dhruba

CC: leveldb

Differential Revision: https://reviews.facebook.net/D13587
2013-10-22 12:23:34 -07:00
Siying Dong 9edda37027 Universal Compaction to Have a Size Percentage Threshold To Decide Whether to Compress
Summary:
This patch adds a option for universal compaction to allow us to only compress output files if the files compacted previously did not yet reach a specified ratio, to save CPU costs in some cases.

Compression is always skipped for flushing. This is because the size information is not easy to evaluate for flushing case. We can improve it later.

Test Plan:
add test
DBTest.UniversalCompactionCompressRatio1 and DBTest.UniversalCompactionCompressRatio12

Reviewers: dhruba, haobo

Reviewed By: dhruba

CC: leveldb

Differential Revision: https://reviews.facebook.net/D13467
2013-10-17 13:33:39 -07:00
Dhruba Borthakur 9cd221094c Add appropriate LICENSE and Copyright message.
Summary:
Add appropriate LICENSE and Copyright message.

Test Plan:
make check

Reviewers:

CC:

Task ID: #

Blame Rev:
2013-10-16 17:48:41 -07:00
Siying Dong 073cbfc8f0 Enable background flush thread by default and fix issues related to it
Summary:
Enable background flush thread in this patch and fix unit tests with:
(1) After background flush, schedule a background compaction if condition satisfied;
(2) Fix a bug that if universal compaction is enabled and number of levels are set to be 0, compaction will not be automatically triggered
(3) Fix unit tests to wait for compaction to finish instead of flush, before checking the compaction results.

Test Plan: pass all unit tests

Reviewers: haobo, xjin, dhruba

Reviewed By: haobo

CC: leveldb

Differential Revision: https://reviews.facebook.net/D13461
2013-10-16 13:32:53 -07:00
Mayank Agarwal fe3713961e Features in Transaction log iterator
Summary:
* Logstore requests a valid change of reutrning an empty iterator and not an error in case of no log files.
* Changed the code to return the writebatch containing the sequence number requested from GetupdatesSince even if it lies in the middle. Earlier we used to return the next writebatch,. This also allows me oto guarantee that no files played upon by the iterator are redundant. I mean the starting log file has at least a sequence number >= the sequence number requested form GetupdatesSince.
* Cleaned up redundant logic in Iterator::Next and made a new function SeekToStartSequence for greater readability and maintainibilty.
* Modified a test in db_test accordingly
Please check the logic carefully and suggest improvements. I have a separate patch out for more improvements like restricting reader to read till written sequences.

Test Plan:
* transaction log iterator tests in db_test,
* db_repl_stress.
* rocks_log_iterator_test in fbcode/wormhole/rocksdb/test - 2 tests thriving on hacks till now can get simplified
* testing on the shadow setup for sigma with replication

Reviewers: dhruba, haobo, kailiu, sdong

Reviewed By: dhruba

CC: leveldb

Differential Revision: https://reviews.facebook.net/D13437
2013-10-14 18:16:21 -07:00
Kai Liu 86ef6c3f74 Add statistics to sst file
Summary:
So far we only have key/value pairs as well as bloom filter stored in the
sst file.  It will be great if we are able to store more metadata about
this table itself, for example, the entry size, bloom filter name, etc.

This diff is the first step of this effort. It allows table to keep the
basic statistics mentioned in http://fburl.com/14995441, as well as
allowing writing user-collected stats to stats block.

After this diff, we will figure out the interface of how to allow user to collect their interested statistics.

Test Plan:
1. Added several unit tests.
2. Ran `make check` to ensure it doesn't break other tests.

Reviewers: dhruba, haobo

CC: leveldb

Differential Revision: https://reviews.facebook.net/D13419
2013-10-14 15:56:13 -07:00
Siying Dong 88f2f89068 Change Function names from Compaction->Flush When they really mean Flush
Summary: When I debug the unit test failures when enabling background flush thread, I feel the function names can be made clearer for people to understand. Also, if the names are fixed, in many places, some tests' bugs are obvious (and some of those tests are failing). This patch is to clean it up for future maintenance.

Test Plan: Run test suites.

Reviewers: haobo, dhruba, xjin

Reviewed By: dhruba

CC: leveldb

Differential Revision: https://reviews.facebook.net/D13431
2013-10-14 15:12:15 -07:00
Mayank Agarwal a8b4a69de0 Fixing error in ParseFileName causing DestroyDB to fail on archive directory
Summary:
This careless error was causing ASSERT_OK(DestroyDB) to fail in db_test.
Basically .. was being returned as a child of db/archive and ParseFileName returned false on that,
but 'type' was set to LogFile from earlier and not reset. The return of ParseFileName was not being checked to delete the log file or not.

Test Plan: make all check

Reviewers: dhruba, haobo, xjin, kailiu, nkg-

Reviewed By: nkg-

CC: leveldb

Differential Revision: https://reviews.facebook.net/D13413
2013-10-10 18:18:31 -07:00
Naman Gupta cbf4a06427 Add option for storing transaction logs in a separate dir
Summary: In some cases, you might not want to store the data log (write ahead log) files in the same dir as the sst files. An example use case is leaf, which stores sst files in tmpfs. And would like to save the log files in a separate dir (disk) to save memory.

Test Plan: make all. Ran db_test test. A few test failing. P2785018. If you guys don't see an obvious problem with the code, maybe somebody from the rocksdb team could help me debug the issue here. Running this on leaf worked well. I could see logs stored on disk, and deleted appropriately after compactions. Obviously this is only one set of options. The unit tests cover different options. Seems like I'm missing some edge cases.

Reviewers: dhruba, haobo, leveldb

CC: xinyaohu, sumeet

Differential Revision: https://reviews.facebook.net/D13239
2013-10-08 17:40:27 -07:00
Dhruba Borthakur 4463b11cad Migrate names of properties from 'leveldb' prefix to 'rocksdb' prefix.
Summary: Migrate names of properties from 'leveldb' prefix to 'rocksdb' prefix.

Test Plan: make check

Reviewers: emayanke, haobo

Reviewed By: haobo

CC: leveldb

Differential Revision: https://reviews.facebook.net/D13311
2013-10-06 00:14:26 -07:00
Haobo Xu bf89edf78b [RocksDB] Added a property "leveldb.num-immutable-mem-table" so that Flush can be called without blocking, and application still has a way to check when it's done also without blocking.
Summary: as title

Test Plan: DBTest.NumImmutableMemTable

Reviewers: dhruba

Reviewed By: dhruba

CC: leveldb

Differential Revision: https://reviews.facebook.net/D13305
2013-10-05 11:54:08 -07:00
Dhruba Borthakur 0a9f873f4b Removed scribe, thrift and java modules.
Summary: Removed scribe, thrift and java modules.

Test Plan:
make release
make check

Reviewers: emayanke

Reviewed By: emayanke

CC: leveldb

Differential Revision: https://reviews.facebook.net/D13293
2013-10-04 15:36:00 -07:00
Dhruba Borthakur a143ef9b38 Change namespace from leveldb to rocksdb
Summary:
Change namespace from leveldb to rocksdb. This allows a single
application to link in open-source leveldb code as well as
rocksdb code into the same process.

Test Plan: compile rocksdb

Reviewers: emayanke

Reviewed By: emayanke

CC: leveldb

Differential Revision: https://reviews.facebook.net/D13287
2013-10-04 11:59:26 -07:00
Mayank Agarwal b3ed08129b Add a statistic to count the number of calls to GetUpdatesSince
Summary: This is useful to keep track of refreshes in transaction log iterator

Test Plan: make; db_stress --statistics=1 shows it

Reviewers: dhruba, haobo

Reviewed By: dhruba

CC: leveldb

Differential Revision: https://reviews.facebook.net/D13281
2013-10-04 10:47:20 -07:00
Haobo Xu 200c05a23f [RocksDB] Still honor DisableFileDeletions when purge_log_after_memtable_flush is on
Summary: as title

Test Plan: make check

Reviewers: emayanke

Reviewed By: emayanke

CC: leveldb

Differential Revision: https://reviews.facebook.net/D13263
2013-10-03 16:12:43 -07:00
Haobo Xu fa798e9e28 [Rocksdb] Submit mem table flush job in a different thread pool
Summary: As title. This is just a quick hack and not ready for commit. fails a lot of unit test. I will test/debug it directly in ViewState shadow .

Test Plan: Try it in shadow test.

Reviewers: dhruba, xjin

CC: leveldb

Differential Revision: https://reviews.facebook.net/D12933
2013-10-03 14:37:19 -07:00
Xing Jin 658a3ce2fa Fix SIGSEGV issue in universal compaction
Summary:
We saw SIGSEGV when set options.num_levels=1 in universal compaction
style. Dug into this issue for a while, and finally found the root cause (thank Haobo for discussion).

Test Plan: Add new unit test. It throws SIGSEGV without this change. Also run "make all check".

Reviewers: haobo, dhruba

CC: leveldb

Differential Revision: https://reviews.facebook.net/D13251
2013-10-02 17:33:31 -07:00
Xing Jin 8eb552bf4d New unit test for iterator with snapshot
Summary:
I played with the reported bug about iterator with snapshot:
https://code.google.com/p/leveldb/issues/detail?id=200.

I turned the original test program
(https://code.google.com/p/leveldb/issues/attachmentText?id=200&aid=2000000000&name=test.cc&token=7uOUQW-HFlbAFMUm7EqtaAEy7Tw%3A1378320724136)
into a new unit test, but I cannot reproduce the problem. Notice lines
31-34 in above link. I have ran the new test with and without such Put()
operations. Both succeed.

So this diff simply adds the test, without changing any source codes.

Test Plan: run new test.

Reviewers: dhruba, haobo, emayanke

Reviewed By: dhruba

CC: leveldb

Differential Revision: https://reviews.facebook.net/D12735
2013-09-28 11:39:08 -07:00
Haobo Xu 0c4040681a [RocksDB] Move last_sequence and last_flushed_sequence_ update back into lock protected area
Summary: A previous diff moved these outside of lock protected area. Moved back in now. Also moved tmp_batch_ update outside of lock protected area, as only the single write thread can access it.

Test Plan: make check

Reviewers: dhruba

Reviewed By: dhruba

CC: leveldb

Differential Revision: https://reviews.facebook.net/D13137
2013-09-26 20:43:11 -07:00
Haobo Xu 0e422308aa [RocksDB] Remove Log file immediately after memtable flush
Summary: As title. The DB log file life cycle is tied up with the memtable it backs. Once the memtable is flushed to sst and committed, we should be able to delete the log file, without holding the mutex. This is part of the bigger change to avoid FindObsoleteFiles at runtime. It deals with log files. sst files will be dealt with later.

Test Plan: make check; db_bench

Reviewers: dhruba

CC: leveldb

Differential Revision: https://reviews.facebook.net/D11709
2013-09-12 11:54:44 -07:00
Dhruba Borthakur 32c965d417 Flush was hanging because the configured options specified that more than 1 memtable need to be merged.
Summary:
There is an config option called Options.min_write_buffer_number_to_merge
that specifies the minimum number of write buffers to merge in memory
before flushing to a file in L0. But in the the case when the db is
being closed, we should not be using this config, instead we should
flush whatever write buffers were available at that time.

Test Plan: Unit test attached.

Reviewers: haobo, emayanke

Reviewed By: haobo

CC: leveldb

Differential Revision: https://reviews.facebook.net/D12717
2013-09-06 16:28:33 -07:00
Mayank Agarwal aa5c897d42 Return pathname relative to db dir in LogFile and cleanup AppendSortedWalsOfType
Summary: So that replication can just download from wherever LogFile.Pathname is pointing them.

Test Plan: make all check;./db_repl_stress

Reviewers: dhruba, haobo

Reviewed By: dhruba

CC: leveldb

Differential Revision: https://reviews.facebook.net/D12609
2013-09-04 13:44:43 -07:00
Xing Jin 42c109cc2e New ldb command to convert compaction style
Summary:
Add new command "change_compaction_style" to ldb tool. For
universal->level, it shows "nothing to do". For level->universal, it
compacts all files into a single one and moves the file to level 0.

Also add check for number of files at level 1+ when opening db with
universal compaction style.

Test Plan:
'make all check'. New unit test for internal convertion function. Also manully test various
cmd like:

./ldb change_compaction_style --old_compaction_style=0
--new_compaction_style=1 --db=/tmp/leveldbtest-3088/db_test

Reviewers: haobo, dhruba

Reviewed By: haobo

CC: vamsi, emayanke

Differential Revision: https://reviews.facebook.net/D12603
2013-09-04 13:13:08 -07:00
Mayank Agarwal c34271a5a5 Fix bug in Counters and record Sequencenumber using only TickerCount
Summary:
The way counters/statistics are implemented in rocksdb demands that enum Tickers and TickerNameMap follow the same order, otherwise statistics exposed from fbcode/rocks get out-of-sync. 2 counters for prefix had violated this order and when I built counters for fbcode/mcrocksdb, statistics for sequence number were appearing out-of-sync.
The other change is to record sequence-number using setTickerCount only and not recordTick. This is because of difference in statistics as understood by rocks/utils which uses ServiceData::statistics function and rocksdb statistics. In rocksdb there is just 1 counter for a countername. But in ServiceData there are 4 independent buckets for every countername-Count, Sum, Average and Rate. SetTickerCount and RecordTick update the same variable in rocksdb but different buckets in ServiceData. Therefore, I had to choose one consistent function from RecordTick or SetTickerCount for sequence number in rocksdb. I chose SetTickerCount because the statistics object in options passed during rocksdb-open is user-dependent and SetTickerCount makes sense there.
There will be a corresponding diff to mcorcksdb in fbcode shortly.

Test Plan: make all check; check ticker value using fprintfs

Reviewers: dhruba

Reviewed By: dhruba

CC: leveldb

Differential Revision: https://reviews.facebook.net/D12669
2013-09-01 17:59:32 -07:00
Mayank Agarwal ab5c5c28fe Fix build caused by DeleteFile not tolerating / at the beginning
Summary: db->DeleteFile calls ParseFileName to check name that was returned for sst file. Now, sst filename is returned using TableFileName which uses MakeFileName. This puts a / at the front of the name and ParseFileName doesn't like that. Changed ParseFileName to tolerate /s at the beginning. The test delet_file_test used to pass earlier because this behaviour of MakeFileName had been changed a while back to not return a / during which delete_file_test was checked in. But MakeFileName had to be reverted to add / at the front because GetLiveFiles used at many places outside rocksdb used the previous behaviour of MakeFileName.

Test Plan: make;./delete_filetest;make all check

Reviewers: dhruba, haobo, vamsi

Reviewed By: dhruba

CC: leveldb

Differential Revision: https://reviews.facebook.net/D12663
2013-09-01 17:59:13 -07:00
Dhruba Borthakur 59de2dbad7 Cleanup DeleteFile API
Summary:
The DeleteFile API was removing files inside the db-lock. This
is now changed to remove files outside the db-lock.
The GetLiveFilesMetadata() returns the smallest and largest
seqnuence number of each file as well.

Test Plan: deletefile_test

Reviewers: emayanke, haobo

Reviewed By: haobo

CC: leveldb

Maniphest Tasks: T63

Differential Revision: https://reviews.facebook.net/D12567
2013-08-28 21:18:58 -07:00
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
Haobo Xu 43eef52001 [RocksDB] move stats counting outside of mutex protected region for DB::Get()
Summary:
As title. This is possible as tickers are atomic now.
db_bench on high qps in-memory muti-thread random get workload, showed ~5% throughput improvement.

Test Plan: make check; db_bench; db_stress

Reviewers: dhruba

Reviewed By: dhruba

CC: leveldb

Differential Revision: https://reviews.facebook.net/D12555
2013-08-27 13:36:10 -07:00
Deon Nicholas 573844807c Fix for no_io
Summary: Oops. My bad.

Test Plan: Make all check

Reviewers: emayanke

Reviewed By: emayanke

CC: haobo, leveldb, dhruba

Differential Revision: https://reviews.facebook.net/D12525
2013-08-23 16:36:01 -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
Xing Jin 17dc128048 Pull from https://reviews.facebook.net/D10917
Summary: Pull Mark's patch and slightly revise it. I revised another place in db_impl.cc with similar new formula.

Test Plan:
make all check. Also run "time ./db_bench --num=2500000000 --numdistinct=2200000000". It has run for 20+ hours and hasn't finished. Looks good so far:

Installed stack trace handler for SIGILL SIGSEGV SIGBUS SIGABRT
LevelDB:    version 2.0
Date:       Tue Aug 20 23:11:55 2013
CPU:        32 * Intel(R) Xeon(R) CPU E5-2660 0 @ 2.20GHz
CPUCache:   20480 KB
Keys:       16 bytes each
Values:     100 bytes each (50 bytes after compression)
Entries:    2500000000
RawSize:    276565.6 MB (estimated)
FileSize:   157356.3 MB (estimated)
Write rate limit: 0
Compression: snappy
WARNING: Assertions are enabled; benchmarks unnecessarily slow
------------------------------------------------
DB path: [/tmp/leveldbtest-3088/dbbench]
fillseq      :    7202.000 micros/op 138 ops/sec;
DB path: [/tmp/leveldbtest-3088/dbbench]
fillsync     :    7148.000 micros/op 139 ops/sec; (2500000 ops)
DB path: [/tmp/leveldbtest-3088/dbbench]
fillrandom   :    7105.000 micros/op 140 ops/sec;
DB path: [/tmp/leveldbtest-3088/dbbench]
overwrite    :    6930.000 micros/op 144 ops/sec;
DB path: [/tmp/leveldbtest-3088/dbbench]
readrandom   :       1.020 micros/op 980507 ops/sec; (0 of 2500000000 found)
DB path: [/tmp/leveldbtest-3088/dbbench]
readrandom   :       1.021 micros/op 979620 ops/sec; (0 of 2500000000 found)
DB path: [/tmp/leveldbtest-3088/dbbench]
readseq      :     113.000 micros/op 8849 ops/sec;
DB path: [/tmp/leveldbtest-3088/dbbench]
readreverse  :     102.000 micros/op 9803 ops/sec;
DB path: [/tmp/leveldbtest-3088/dbbench]
Created bg thread 0x7f0ac17f7700
compact      :  111701.000 micros/op 8 ops/sec;
DB path: [/tmp/leveldbtest-3088/dbbench]
readrandom   :       1.020 micros/op 980376 ops/sec; (0 of 2500000000 found)
DB path: [/tmp/leveldbtest-3088/dbbench]
readseq      :     120.000 micros/op 8333 ops/sec;
DB path: [/tmp/leveldbtest-3088/dbbench]
readreverse  :      29.000 micros/op 34482 ops/sec;
DB path: [/tmp/leveldbtest-3088/dbbench]
... finished 618100000 ops

Reviewers: MarkCallaghan, haobo, dhruba, chip

Reviewed By: dhruba

Differential Revision: https://reviews.facebook.net/D12441
2013-08-22 22:37:13 -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
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 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
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
Xing Jin 0a5afd1afc Minor fix to current codes
Summary:
Minor fix to current codes, including: coding style, output format,
comments. No major logic change. There are only 2 real changes, please see my inline comments.

Test Plan: make all check

Reviewers: haobo, dhruba, emayanke

Differential Revision: https://reviews.facebook.net/D12297
2013-08-14 23:03:57 -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 93d77a27d2 Universal Compaction should keep DeleteMarkers unless it is the earliest file.
Summary:
The pre-existing code was purging a DeleteMarker if thay key did not
exist in deeper levels.  But in the Universal Compaction Style, all
files are in Level0. For compaction runs that did not include the
earliest file, we were erroneously purging the DeleteMarkers.

The fix is to purge DeleteMarkers only if the compaction includes
the earlist file.

Test Plan: DBTest.Randomized triggers this code path.

Differential Revision: https://reviews.facebook.net/D12081
2013-08-09 14:03:57 -07:00
Xing Jin 8ae905ed63 Fix unit tests for universal compaction (step 2)
Summary:
Continue fixing existing unit tests for universal compaction. I have
tried to apply universal compaction to all unit tests those haven't
called ChangeOptions(). I left a few which are either apparently not
applicable to universal compaction (because they check files/keys/values
at level 1 or above levels), or apparently not related to compaction
(e.g., open a file, open a db).

I also add a new unit test for universal compaction.

Good news is I didn't see any bugs during this round.

Test Plan: Ran "make all check" yesterday. Has rebased and is rerunning

Reviewers: haobo, dhruba

Differential Revision: https://reviews.facebook.net/D12135
2013-08-09 13:35:44 -07:00
Xing Jin 17b8f786a3 Fix unit tests/bugs for universal compaction (first step)
Summary:
This is the first step to fix unit tests and bugs for universal
compactiion. I added universal compaction option to ChangeOptions(), and
fixed all unit tests calling ChangeOptions(). Some of these tests
obviously assume more than 1 level and check file number/values in level
1 or above levels. I set kSkipUniversalCompaction for these tests.

The major bug I found is manual compaction with universal compaction never stops. I have put a fix for
it.

I have also set universal compaction as the default compaction and found
at least 20+ unit tests failing. I haven't looked into the details. The
next step is to check all unit tests without calling ChangeOptions().

Test Plan: make all check

Reviewers: dhruba, haobo

Differential Revision: https://reviews.facebook.net/D12051
2013-08-07 14:05:44 -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
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
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 6db52b525a Don't use redundant Env::NowMicros() calls
Summary: After my patch for stall histograms, there are redundant calls to NowMicros() by both the stop watches and DBImpl::MakeRoomForWrites. So I removed the redundant calls such that the information is gotten from the stopwatch.

Test Plan:
make clean
make -j32 check

Reviewers: dhruba, haobo, MarkCallaghan

Reviewed By: dhruba

CC: leveldb

Differential Revision: https://reviews.facebook.net/D11883
2013-07-29 15:46:36 -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
Dhruba Borthakur d7ba5bce37 Revert 6fbe4e981a: If disable wal is set, then batch commits are avoided
Summary:
Revert "If disable wal is set, then batch commits are avoided" because
keeping the mutex while inserting into the skiplist means that readers
and writes are all serialized on the mutex.

Test Plan:

Reviewers:

CC:

Task ID: #

Blame Rev:
2013-07-24 10:01:13 -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
Dhruba Borthakur 6fbe4e981a If disable wal is set, then batch commits are avoided.
Summary:
rocksdb uses batch commit to write to transaction log. But if
disable wal is set, then writes to transaction log are anyways
avoided. In this case, there is not much value-add to batch things,
batching can cause unnecessary delays to Puts().
This patch avoids batching when disableWal is set.

Test Plan:
make check.

I am running db_stress now.

Reviewers: haobo

Reviewed By: haobo

CC: leveldb

Differential Revision: https://reviews.facebook.net/D11763
2013-07-23 14:22:57 -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 d364eea1fc [RocksDB] Fix FindMinimumEmptyLevelFitting
Summary: as title

Test Plan: make check;

Reviewers: xjin

CC: leveldb

Differential Revision: https://reviews.facebook.net/D11751
2013-07-22 12:31:43 -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
Haobo Xu 9ba82786ce [RocksDB] Provide contiguous sequence number even in case of write failure
Summary: Replication logic would be simplifeid if we can guarantee that write sequence number is always contiguous, even if write failure occurs. Dhruba and I looked at the sequence number generation part of the code. It seems fixable. Note that if WAL was successful and insert into memtable was not, we would be in an unfortunate state. The approach in this diff is : IO error is expected and error status will be returned to client, sequence number will not be advanced; In-mem error is not expected and we panic.

Test Plan: make check; db_stress

Reviewers: dhruba, sheki

CC: leveldb

Differential Revision: https://reviews.facebook.net/D11439
2013-07-08 15:31:09 -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
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
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
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
Haobo Xu 1afdf28701 [RocksDB] Compaction Filter Cleanup
Summary: This hopefully gives the right semantics to compaction filter. Will write a small wiki to explain the ideas.

Test Plan: make check; db_stress

Reviewers: dhruba

CC: leveldb

Differential Revision: https://reviews.facebook.net/D11121
2013-06-14 14:23:08 -07:00
Deon Nicholas 4985a9f73b [Rocksdb] [Multiget] Introduced multiget into db_bench
Summary:
Preliminary! Introduced the --use_multiget=1 and --keys_per_multiget=n
flags for db_bench. Also updated and tested the ReadRandom() method
to include an option to use multiget. By default,
keys_per_multiget=100.

Preliminary tests imply that multiget is at least 1.25x faster per
key than regular get.

Will continue adding Multiget for ReadMissing, ReadHot,
RandomWithVerify, ReadRandomWriteRandom; soon. Will also think
about ways to better verify benchmarks.

Test Plan:
1. make db_bench
2. ./db_bench --benchmarks=fillrandom
3. ./db_bench --benchmarks=readrandom --use_existing_db=1
	      --use_multiget=1 --threads=4 --keys_per_multiget=100
4. ./db_bench --benchmarks=readrandom --use_existing_db=1
	      --threads=4
5. Verify ops/sec (and 1000000 of 1000000 keys found)

Reviewers: haobo, MarkCallaghan, dhruba

Reviewed By: MarkCallaghan

CC: leveldb

Differential Revision: https://reviews.facebook.net/D11127
2013-06-12 12:42:21 -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
Mayank Agarwal 184343a061 Max_mem_compaction_level can have maximum value of num_levels-1
Summary:
Without this files could be written out to a level greater than the maximum level possible and is the source of the segfaults that wormhole awas getting. The sequence of steps that was followed:
1. WriteLevel0Table was called when memtable was to be flushed for a file.
2. PickLevelForMemTableOutput was called to determine the level to which this file should be pushed.
3. PickLevelForMemTableOutput returned a wrong result because max_mem_compaction_level was equal to 2 even when num_levels was equal to 0.
The fix to re-initialize max_mem_compaction_level based on num_levels passed seems correct.

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

Reviewers: dhruba, haobo

Reviewed By: dhruba

CC: leveldb

Differential Revision: https://reviews.facebook.net/D11157
2013-06-09 10:38:55 -07:00
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
Mark Callaghan d9f538e1a9 Improve output for GetProperty('leveldb.stats')
Summary:
Display separate values for read, write & total compaction IO.
Display compaction amplification and write amplification.
Add similar values for the period since the last call to GetProperty. Results since the server started
are reported as "cumulative" stats. Results since the last call to GetProperty are reported as
"interval" stats.

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

Task ID: #

Blame Rev:

Test Plan:
make check, run db_bench

Revert Plan:

Database Impact:

Memcache Impact:

Other Notes:

EImportant:

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

Reviewers: haobo

Reviewed By: haobo

CC: leveldb

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

Test Plan: make check; db_bench

Reviewers: dhruba

CC: leveldb, MarkCallaghan

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

Test Plan: make check; db_bench; db_stress

Reviewers: dhruba

CC: MarkCallaghan, leveldb

Differential Revision: https://reviews.facebook.net/D11031
2013-06-01 23:11:34 -07:00