Summary:
So far, we benchmarked RocksDB by writing as fast as possible. With this change, we're able to limit our write throughput, which should help us better understand how RocksDB performes under varying write workloads.
Specifically, I'm currently interested in the shape of the graph that has write throughput on one axis and write rate on another. This should help us with designing our stall system, as we have started to do with D36351.
Test Plan:
$ ./db_bench --benchmarks=fillrandom --benchmark_write_rate_limit=1000000
fillrandom : 118.523 micros/op 8437 ops/sec; 0.9 MB/s
$ ./db_bench --benchmarks=fillrandom --benchmark_write_rate_limit=2000000
fillrandom : 59.136 micros/op 16910 ops/sec; 1.9 MB/s
Reviewers: MarkCallaghan, sdong
Reviewed By: sdong
Subscribers: dhruba, leveldb
Differential Revision: https://reviews.facebook.net/D39759
Summary:
This diff update DB::CompactRange to use RangeCompactionOptions instead of using multiple parameters
Old CompactRange is still available but deprecated
Test Plan:
make all check
make rocksdbjava
USE_CLANG=1 make all
OPT=-DROCKSDB_LITE make release
Reviewers: sdong, yhchiang, igor
Reviewed By: igor
Subscribers: dhruba
Differential Revision: https://reviews.facebook.net/D40209
Summary:
We go to great lengths to make sure MaybeScheduleFlushOrCompaction() is called outside of write thread. But anyway, it's still called in the mutex, so it's not that much cheaper.
This diff removes the "optimization" and cleans up the code a bit.
Test Plan: make check
Reviewers: rven, sdong
Reviewed By: sdong
Subscribers: dhruba, leveldb
Differential Revision: https://reviews.facebook.net/D40113
Summary: Block c_test in ROCKSDB_LITE as it's not supported in ROCKSDB_LITE.
Test Plan: c_test
Reviewers: sdong, rven, anthony, kradhakrishnan, IslamAbdelRahman, igor
Reviewed By: igor
Subscribers: dhruba, leveldb
Differential Revision: https://reviews.facebook.net/D40257
Summary:
Add an option in GetApproximateSize() so that the result will include estimated sizes in mem tables.
To implement it, implement an estimated count from the beginning to a key in skip list. The approach is to count to find the entry, how many Next() is issued from each level, and sum them with a weight that is <branching factor> ^ <level>.
Test Plan: Add a test case
Subscribers: leveldb, dhruba
Differential Revision: https://reviews.facebook.net/D40119
Summary:
This is part of an effort to better understand and optimize RocksDB stalls under high load. I added a feature to db_bench to periodically write QPS to CSV files. That way we can nicely see how our QPS changes in time (especially when DB is stalled) and can do a better job of evaluating our stall system (i.e. we want the QPS to be as constant as possible, as opposed to having bunch of stalls)
Cool part of CSV files is that we can easily graph them -- there are a bunch of tools available.
Test Plan:
Ran ./db_bench --report_interval_seconds=10 --benchmarks=fillrandom --num=10000000
and observed this in report.csv:
secs_elapsed,interval_qps
10,2725860
20,1980480
30,1863456
40,1454359
50,1460389
Reviewers: sdong, MarkCallaghan, rven, yhchiang
Reviewed By: yhchiang
Subscribers: dhruba, leveldb
Differential Revision: https://reviews.facebook.net/D40047
Summary: Fixed false alarm of size comparison in compaction_job_stats_test
Test Plan: compaction_job_stats_test
Reviewers: igor
Reviewed By: igor
Subscribers: dhruba, leveldb
Differential Revision: https://reviews.facebook.net/D39921
Summary:
Reverting this diff https://reviews.facebook.net/D39999
Will add an option to force bottom most level compaction and then re submit it
Test Plan: make check
Reviewers: igor, sdong
Reviewed By: sdong
Subscribers: dhruba
Differential Revision: https://reviews.facebook.net/D40041
Summary: If we don't have a compaction filter then we can skip compacting the bottom most level
Test Plan:
make check
added unit tests
Reviewers: yhchiang, sdong, igor
Reviewed By: sdong
Subscribers: dhruba
Differential Revision: https://reviews.facebook.net/D39999
Summary:
We slow down data into the database to the rate of options.delayed_write_rate (a new option) with this patch.
The thread synchronization approach I take is to still synchronize write controller by DB mutex and GetDelay() is inside DB mutex. Try to minimize the frequency of getting time in GetDelay(). I verified it through db_bench and it seems to work
hard_rate_limit is deprecated.
options.delayed_write_rate is still not dynamically changeable. Need to work on it as a follow-up.
Test Plan: Add new unit tests in db_test
Reviewers: yhchiang, rven, kradhakrishnan, anthony, MarkCallaghan, igor
Reviewed By: igor
Subscribers: ikabiljo, leveldb, dhruba
Differential Revision: https://reviews.facebook.net/D36351
Summary: With experimental feature SuggestCompactRange() we don't restrict running two L0->L1 compactions in parallel. This diff fixes this.
Test Plan: added a unit test to reproduce the failure. fixed the unit test
Reviewers: yhchiang, rven, sdong
Reviewed By: sdong
Subscribers: dhruba, leveldb
Differential Revision: https://reviews.facebook.net/D39981
Summary:
Adding largest sequence number to FlushJobInfo
and passing flushed file metadata to NotifyOnFlushCompleted which include alot of other values that we may want to expose in FlushJobInfo
Test Plan: make check
Reviewers: igor, sdong
Reviewed By: sdong
Subscribers: dhruba
Differential Revision: https://reviews.facebook.net/D39927
Summary:
Add Env::GetThreadID(), which returns the ID of the current thread.
In addition, make GetThreadList() and InfoLog use same unique ID for the same thread.
Test Plan:
db_test
listener_test
Reviewers: igor, rven, IslamAbdelRahman, kradhakrishnan, sdong
Reviewed By: sdong
Subscribers: dhruba
Differential Revision: https://reviews.facebook.net/D39735
Summary:
Right now the level we pass to ReFitLevel is the maximum level with files (before compaction), there are multiple cases where this maximum level have changed after compaction
- all files where in L0 (now maximum level is L1)
- using kCompactionStyleUniversal (now maximum level in the last level)
- level_compaction_dynamic_level_bytes ??
We can handle each of these cases individually, but I felt it's safer to calculate max_level_with_files again if we want to do a ReFitLevel
Test Plan:
adding some tests
make -j64 check
Reviewers: igor, sdong
Reviewed By: sdong
Subscribers: ott, dhruba
Differential Revision: https://reviews.facebook.net/D39663
Summary: Some test and benchmark codes don't build for CYGWIN. Fix it.
Test Plan: Build "make all" with TARGET_OS=Cygwin on cygwin and make sure it passes.
Reviewers: rven, yhchiang, anthony, igor, kradhakrishnan
Reviewed By: igor, kradhakrishnan
Subscribers: leveldb, dhruba
Differential Revision: https://reviews.facebook.net/D39711
Summary:
When there are files marked for compaction after compactions, print extra messages to help debugging. Example:
2015/06/08-23:12:55.212855 7ff5013ff700 [default] [JOB 121] Generated table #75: 54 keys, 4807 bytes (need compaction)
2015/06/08-23:12:55.556194 7ff5013ff700 (Original Log Time 2015/06/08-23:12:55.556160) [default] compacted to: base level 1 max bytes base
10240 files[0 1 9 32 12 0 0 0] max score 0.96 (2 files need compaction), MB/sec: 0.0 rd, 0.1 wr, level 2, files in(1, 3) out(5) MB in(0.0,
0.0) out(0.0), read-write-amplify(11.3) write-amplify(5.7) OK, records in: 40, records dropped: 0
Test Plan:
Run test and see LOG files.
valgrind test DBTest.TablePropertiesNeedCompactTest
Reviewers: rven, yhchiang, kradhakrishnan, IslamAbdelRahman, igor
Reviewed By: igor
Subscribers: yoshinorim, maykov, leveldb, dhruba
Differential Revision: https://reviews.facebook.net/D39771
Summary:
There is a hang during DB close in the following scenario:
a) a load with WAL disabled was done,
b) CancelAllBackgroundWork was called,
c) DB Close was called
This was because in that we will wait for a flush but we cannot do a
background flush because we have called CancelAllBackgroundWork which
marks the DB as shutting downn.
Test Plan: Added DBTest FlushOnDestroy
Reviewers: sdong
Reviewed By: sdong
Subscribers: yoshinorim, hermanlee4, dhruba, leveldb
Differential Revision: https://reviews.facebook.net/D39747
Summary: We currently issue malloc and free inside DB mutex in GetSnapshot() and ReleaseSnapshot(). Move them out.
Test Plan:
Go through all tests
make valgrind_check
Reviewers: yhchiang, rven, IslamAbdelRahman, anthony, igor
Reviewed By: igor
Subscribers: maykov, hermanlee4, MarkCallaghan, yoshinorim, leveldb, dhruba
Differential Revision: https://reviews.facebook.net/D39753
Summary:
Replacing the default value for compaction_filter_factory and compaction_filter_factory_v2 to be nullptr instead of DefaultCompactionFilterFactory / DefaultCompactionFilterFactoryV2
The reason for this is to be able to determine easily if we have compaction filter factory or not without depending on RTTI
Test Plan: make check
Reviewers: yoshinorim, ott, igor, sdong
Reviewed By: sdong
Subscribers: dhruba
Differential Revision: https://reviews.facebook.net/D39693
Summary: key_sizes claims that 3rd key is of length 8, but it's really only 3. This diff makes it length 8.
Test Plan: asan c_test works again.
Reviewers: sdong, yhchiang
Subscribers: dhruba, leveldb
Differential Revision: https://reviews.facebook.net/D39699
Summary:
It is experimental. Allow users to return from a call back function TablePropertiesCollector::NeedCompact(), based on the data in the file.
It can be used to allow users to suggest DB to clear up delete tombstones faster.
Test Plan: Add a unit test.
Reviewers: igor, yhchiang, kradhakrishnan, rven
Reviewed By: rven
Subscribers: yoshinorim, MarkCallaghan, maykov, leveldb, dhruba
Differential Revision: https://reviews.facebook.net/D39585
Summary:
EventListener::OnFlushCompleted() now passes a structure instead
of a list of parameters. This minimizes the API change in the
future.
Test Plan:
listener_test
compact_files_test
example/compact_files_example
Reviewers: kradhakrishnan, sdong, IslamAbdelRahman, rven, igor
Reviewed By: rven, igor
Subscribers: IslamAbdelRahman, rven, dhruba, leveldb
Differential Revision: https://reviews.facebook.net/D39543
Summary: I encountered an issue where the database hang, it looks like the mutex is not unlocked on return in ReFitLevel function
Test Plan: make -j64 check
Reviewers: yhchiang, sdong
Reviewed By: sdong
Subscribers: dhruba
Differential Revision: https://reviews.facebook.net/D39609
Summary:
The type of smallest_output_key_prefix and largest_output_key_prefix
have been changed to std::string in https://reviews.facebook.net/D39537.
As a result, we shouldn't do smallest_output_key_prefix[0] = 0 in the
initialization.
Test Plan: compile db_test with tsan enabled and repeat DBTest.CompactionDeletionTrigger test to verify the tsan issue has been gone.
Reviewers: igor, sdong
Reviewed By: sdong
Subscribers: dhruba, leveldb
Differential Revision: https://reviews.facebook.net/D39645
Summary:
This diff updates the logic of how we do trivial move, now trivial move can run on any number of files in input level as long as they are not overlapping
The conditions for trivial move have been updated
Introduced conditions:
- Trivial move cannot happen if we have a compaction filter (except if the compaction is not manual)
- Input level files cannot be overlapping
Removed conditions:
- Trivial move only run when the compaction is not manual
- Input level should can contain only 1 file
More context on what tests failed because of Trivial move
```
DBTest.CompactionsGenerateMultipleFiles
This test is expecting compaction on a file in L0 to generate multiple files in L1, this test will fail with trivial move because we end up with one file in L1
```
```
DBTest.NoSpaceCompactRange
This test expect compaction to fail when we force environment to report running out of space, of course this is not valid in trivial move situation
because trivial move does not need any extra space, and did not check for that
```
```
DBTest.DropWrites
Similar to DBTest.NoSpaceCompactRange
```
```
DBTest.DeleteObsoleteFilesPendingOutputs
This test expect that a file in L2 is deleted after it's moved to L3, this is not valid with trivial move because although the file was moved it is now used by L3
```
```
CuckooTableDBTest.CompactionIntoMultipleFiles
Same as DBTest.CompactionsGenerateMultipleFiles
```
This diff is based on a work by @sdonghttps://reviews.facebook.net/D34149
Test Plan: make -j64 check
Reviewers: rven, sdong, igor
Reviewed By: igor
Subscribers: yhchiang, ott, march, dhruba, sdong
Differential Revision: https://reviews.facebook.net/D34797
Summary:
Keys in RocksDB can be arbitrary byte strings. However, in the current
CompactionJobStats, smallest_output_key_prefix and largest_output_key_prefix
are of type char[] without having a length, which is insufficient to handle
non-null terminated strings.
This patch change their type to std::string.
Test Plan: compaction_job_stats_test
Reviewers: igor, rven, IslamAbdelRahman, kradhakrishnan, sdong
Reviewed By: sdong
Subscribers: dhruba, leveldb
Differential Revision: https://reviews.facebook.net/D39537
Summary:
Add EventListener::OnTableFileDeletion(), which will be
called when a table file is deleted.
Test Plan: Extend three existing tests in db_test to verify the deleted files.
Reviewers: rven, anthony, kradhakrishnan, igor, sdong
Reviewed By: sdong
Subscribers: dhruba, leveldb
Differential Revision: https://reviews.facebook.net/D38931
Summary: We need to start doing some CI on Macs.
Test Plan: works now
Reviewers: yhchiang
Subscribers: dhruba, leveldb
Differential Revision: https://reviews.facebook.net/D39489
Summary:
DBTest.MigrateToDynamicLevelMaxBytesBase with valgrind test is
extremely slow. Work it around by not having both threads running
everything non-stop.
Test Plan: Run the test with valgrind which used to take too long to finish and see it finish in reasonable time.
Reviewers: yhchiang, anthony, rven, kradhakrishnan, igor
Reviewed By: igor
Subscribers: leveldb, dhruba
Differential Revision: https://reviews.facebook.net/D39477
Summary: Remove a TODO that has been done
Test Plan: make
Reviewers: sdong, igor
Subscribers: dhruba, leveldb
Differential Revision: https://reviews.facebook.net/D39429
Summary:
Allow EventListener::OnCompactionCompleted to return CompactionJobStats,
which contains useful information about a compaction.
Example CompactionJobStats returned by OnCompactionCompleted():
smallest_output_key_prefix 05000000
largest_output_key_prefix 06990000
elapsed_time 42419
num_input_records 300
num_input_files 3
num_input_files_at_output_level 2
num_output_records 200
num_output_files 1
actual_bytes_input 167200
actual_bytes_output 110688
total_input_raw_key_bytes 5400
total_input_raw_value_bytes 300000
num_records_replaced 100
is_manual_compaction 1
Test Plan: Developed a mega test in db_test which covers 20 variables in CompactionJobStats.
Reviewers: rven, igor, anthony, sdong
Reviewed By: sdong
Subscribers: tnovak, dhruba, leveldb
Differential Revision: https://reviews.facebook.net/D38463
Summary:
Fixed the following compile warning in listener_test.cc:
db/listener_test.cc:214:8: error: 'OnTableFileCreated' overrides a member function but is not marked 'override' [-Werror,-Winconsistent-missing-override]
14:16:46 void OnTableFileCreated(
Test Plan:
make listener_test
Reviewers: sdong, igor
Subscribers: leveldb
Summary:
Add EventListener::OnTableFileCreated(), which will be called
when a table file is created. This patch is part of the
EventLogger and EventListener integration.
Test Plan: Augment existing test in db/listener_test.cc
Reviewers: anthony, kradhakrishnan, rven, igor, sdong
Reviewed By: sdong
Subscribers: dhruba, leveldb
Differential Revision: https://reviews.facebook.net/D38865
Summary: Add a stats counter for DB_WRITE back which was mistakenly removed.
Test Plan: augment GroupCommitTest
Reviewers: sdong
Reviewed By: sdong
Subscribers: dhruba, leveldb
Differential Revision: https://reviews.facebook.net/D39399
Summary:
We occasionally get write stalls (>1s Write() calls) on HDD under read load. The following timers explain almost all of the stalls:
- perf_context.db_mutex_lock_nanos
- perf_context.db_condition_wait_nanos
- iostats_context.open_time
- iostats_context.allocate_time
- iostats_context.write_time
- iostats_context.range_sync_time
- iostats_context.logger_time
In my experiments each of these occasionally takes >1s on write path under some workload. There are rare cases when Write() takes long but none of these takes long.
Test Plan: Added code to our application to write the listed timings to log for slow writes. They usually add up to almost exactly the time Write() call took.
Reviewers: rven, yhchiang, sdong
Reviewed By: sdong
Subscribers: march, dhruba, tnovak
Differential Revision: https://reviews.facebook.net/D39177
Summary: In DB::CompactRange(), change parameter "reduce_level" to "change_level". Users can compact all data to the last level if needed. By doing it, users can migrate the DB to options.level_compaction_dynamic_level_bytes=true.
Test Plan: Add a unit test for it.
Reviewers: yhchiang, anthony, kradhakrishnan, igor, rven
Reviewed By: rven
Subscribers: leveldb, dhruba
Differential Revision: https://reviews.facebook.net/D39099
Summary:
DBImpl::notifying_events_ is a internal counter in DBImpl which is
used to prevent DB close when DB is notifying events. However, as
the current events all rely on either compaction or flush which
already have similar counters to prevent DB close, it is safe to
remove notifying_events_.
Test Plan:
listener_test
examples/compact_files_example
Reviewers: igor, anthony, kradhakrishnan, rven, sdong
Reviewed By: sdong
Subscribers: dhruba, leveldb
Differential Revision: https://reviews.facebook.net/D39315
Summary: Broken by optimistic transaction diff. (I only built 'release' not 'static_lib' when testing).
Test Plan: build
Reviewers: yhchiang, sdong, igor
Reviewed By: igor
Subscribers: dhruba, leveldb
Differential Revision: https://reviews.facebook.net/D39219
Summary: Optimistic transactions supporting begin/commit/rollback semantics. Currently relies on checking the memtable to determine if there are any collisions at commit time. Not yet implemented would be a way of enuring the memtable has some minimum amount of history so that we won't fail to commit when the memtable is empty. You should probably start with transaction.h to get an overview of what is currently supported.
Test Plan: Added a new test, but still need to look into stress testing.
Reviewers: yhchiang, igor, rven, sdong
Reviewed By: sdong
Subscribers: adamretter, MarkCallaghan, leveldb, dhruba
Differential Revision: https://reviews.facebook.net/D33435
Igor Canadi