Summary: In previous change https://reviews.facebook.net/D39099 , while renaming parameters, use a wrong parameter, causing CompactRange() to compact not wrong level.
Test Plan: Run "DBTest.MigrateToDynamicLevelMaxBytesBase" which failed with the patch.
Reviewers: rven, yhchiang, kradhakrishnan, igor, anthony
Subscribers: leveldb, dhruba
Differential Revision: https://reviews.facebook.net/D39393
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: It used to be no good (known to me) non-intrusive way to wrap WritableFile - you can't call protected virtual methods of the wrapped pointer to WritableFile. This diff adds a convenience class WritableFileWrapper that makes wrapping WritableFile both possible and easy.
Test Plan: `make clean; make -j release`, `make clean; OPT=-DROCKSDB_LITE make release`, `make clean; USE_CLANG=1 make -j all`.
Reviewers: sdong, yhchiang, rven
Reviewed By: rven
Subscribers: dhruba, tnovak, march
Differential Revision: https://reviews.facebook.net/D39147
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
Summary: Fixed a compile error in ROCKSDB_LITE
Test Plan: make db_stress OPT=-DROCKSDB_LITE -j32
Reviewers: sdong, igor, anthony
Subscribers: dhruba, leveldb
Differential Revision: https://reviews.facebook.net/D39201
Summary:
For transactions, we are using the memtables to validate that there are no write conflicts. But after flushing, we don't have any memtables, and transactions could fail to commit. So we want to someone keep around some extra history to use for conflict checking. In addition, we want to provide a way to increase the size of this history if too many transactions fail to commit.
After chatting with people, it seems like everyone prefers just using Memtables to store this history (instead of a separate history structure). It seems like the best place for this is abstracted inside the memtable_list. I decide to create a separate list in MemtableListVersion as using the same list complicated the flush/installalflushresults logic too much.
This diff adds a new parameter to control how much memtable history to keep around after flushing. However, it sounds like people aren't too fond of adding new parameters. So I am making the default size of flushed+not-flushed memtables be set to max_write_buffers. This should not change the maximum amount of memory used, but make it more likely we're using closer the the limit. (We are now postponing deleting flushed memtables until the max_write_buffer limit is reached). So while we might use more memory on average, we are still obeying the limit set (and you could argue it's better to go ahead and use up memory now instead of waiting for a write stall to happen to test this limit).
However, if people are opposed to this default behavior, we can easily set it to 0 and require this parameter be set in order to use transactions.
Test Plan: Added a xfunc test to play around with setting different values of this parameter in all tests. Added testing in memtablelist_test and planning on adding more testing here.
Reviewers: sdong, rven, igor
Reviewed By: igor
Subscribers: dhruba, leveldb
Differential Revision: https://reviews.facebook.net/D37443
Summary: Having stats in our LOG more often will help a lot with perf debugging.
Test Plan: none
Reviewers: sdong, MarkCallaghan
Reviewed By: MarkCallaghan
Subscribers: dhruba, leveldb
Differential Revision: https://reviews.facebook.net/D38781
Summary:
sync_file_range is not always asyncronous and thus can block writes if we do this for WAL in the foreground thread. See more here: http://yoshinorimatsunobu.blogspot.com/2014/03/how-syncfilerange-really-works.html
Some users don't want us to call sync_file_range on WALs. Some other do.
Thus, I'm adding a separate option wal_bytes_per_sync to control calling
sync_file_range on WAL files. bytes_per_sync will apply only to table
files now.
Test Plan: no more sync_file_range for WAL as evidenced by strace
Reviewers: yhchiang, rven, sdong
Reviewed By: sdong
Subscribers: dhruba, leveldb
Differential Revision: https://reviews.facebook.net/D38253
Summary: CompactRange() now is much more expensive for dynamic level base size as it goes through all the levels. Skip those not used levels between level 0 an base level.
Test Plan: Run all unit tests
Reviewers: yhchiang, rven, anthony, kradhakrishnan, igor
Reviewed By: igor
Subscribers: leveldb, dhruba
Differential Revision: https://reviews.facebook.net/D37125
Summary:
Allow GetThreadList to report Flush properties, which includes:
* job id
* number of bytes that has been written since flush started.
* total size of input mem-tables
Test Plan:
./db_bench --threads=30 --num=1000000 --benchmarks=fillrandom --thread_status_per_interval=100 --value_size=1000
Sample output from db_bench which tracks same flush job
ThreadID ThreadType cfName Operation ElapsedTime Stage State OperationProperties
140213879898240 High Pri default Flush 5789 us FlushJob::WriteLevel0Table BytesMemtables 4112835 | BytesWritten 577104 | JobID 8 |
ThreadID ThreadType cfName Operation ElapsedTime Stage State OperationProperties
140213879898240 High Pri default Flush 30.634 ms FlushJob::WriteLevel0Table BytesMemtables 4112835 | BytesWritten 1734865 | JobID 8 |
Reviewers: rven, igor, sdong
Reviewed By: sdong
Subscribers: dhruba, leveldb
Differential Revision: https://reviews.facebook.net/D38505
Summary: Use a better way to initialize ThreadStatus::kNumOperationProperties.
Test Plan: make
Reviewers: sdong, rven, anthony, krishnanm86, igor
Reviewed By: igor
Subscribers: dhruba, leveldb
Differential Revision: https://reviews.facebook.net/D38547
Summary: Universal compactions with multiple levels should use file preallocation size based on file size if output level is not level 0
Test Plan: Run all tests.
Reviewers: igor
Reviewed By: igor
Subscribers: leveldb, dhruba
Differential Revision: https://reviews.facebook.net/D38439
Summary: Make ThreadStatus::InterpretOperationProperties take const uint64_t*
Test Plan:
make
make OPT=-DROCKSDB_LITE shared_lib
Reviewers: igor
Reviewed By: igor
Subscribers: dhruba, leveldb
Differential Revision: https://reviews.facebook.net/D38445
Summary:
Fixed a bug in EventListener::OnCompactionCompleted() that returns
incorrect list of input / output file names.
Test Plan: Extend existing test in listener_test.cc
Reviewers: sdong, rven, igor
Reviewed By: igor
Subscribers: dhruba, leveldb
Differential Revision: https://reviews.facebook.net/D38349
Summary:
Added a couple functions to WriteBatchWithIndex to make it easier to query the value of a key including reading pending writes from a batch. (This is needed for transactions).
I created write_batch_with_index_internal.h to use to store an internal-only helper function since there wasn't a good place in the existing class hierarchy to store this function (and it didn't seem right to stick this function inside WriteBatchInternal::Rep).
Since I needed to access the WriteBatchEntryComparator, I moved some helper classes from write_batch_with_index.cc into write_batch_with_index_internal.h/.cc. WriteBatchIndexEntry, ReadableWriteBatch, and WriteBatchEntryComparator are all unchanged (just moved to a different file(s)).
Test Plan: Added new unit tests.
Reviewers: rven, yhchiang, sdong, igor
Reviewed By: igor
Subscribers: dhruba, leveldb
Differential Revision: https://reviews.facebook.net/D38037
Summary:
When new capacity is larger than existing capacity, simply update the capacity to the new valie
When new capacity is less than existing capacity, but more than the usage, simply update the capacity to new value
When new capacity is less than the existing capacity and existing usage both, try to purge entries in LRU if feasible to make usage < capacity
Test Plan: Created unit tests in cache_test.cc
Reviewers: sdong, rven, yhchiang, igor
Reviewed By: igor
Subscribers: dhruba
Differential Revision: https://reviews.facebook.net/D37527
Summary:
Make it build for CYGWIN.
Need to define "-std=gnu++11" instead of "-std=c++11" and use some replacement functions.
Test Plan: Build it and run some unit tests in CYGWIN
Reviewers: yhchiang, rven, anthony, kradhakrishnan, igor
Reviewed By: igor
Subscribers: leveldb, dhruba
Differential Revision: https://reviews.facebook.net/D37605
Summary:
This diff implements a new `DB` method `PromoteL0` which moves all files in L0
to a given level skipping compaction, provided that the files have disjoint
ranges and all levels up to the target level are empty.
This method provides finer-grain control for trivial compactions, and it is
useful for bulk-loading pre-sorted keys. Compared to D34797, it does not change
the semantics of an existing operation, which can impact existing code.
PromoteL0 is designed to work well in combination with the proposed
`GetSstFileWriter`/`AddFile` interface, enabling to "design" the level structure
by populating one level at a time. Such fine-grained control can be very useful
for static or mostly-static databases.
Test Plan: `make check`
Reviewers: IslamAbdelRahman, philipp, MarkCallaghan, yhchiang, igor, sdong
Reviewed By: sdong
Subscribers: dhruba
Differential Revision: https://reviews.facebook.net/D37107
Summary: To further distinguish the corruption cases were caused by storage media or in memory states when writing it, add a paranoid check after writing the file to iterate all the rows.
Test Plan: Add a new unit test for it
Reviewers: rven, igor
Subscribers: leveldb, dhruba
Differential Revision: https://reviews.facebook.net/D37335
Summary:
Some Mongo+Rocks datasets in Parse's environment are not doing compactions very frequently. During the quiet period (with no IO), we'd like to schedule compactions so that our reads become faster. Also, aggressively compacting during quiet periods helps when write bursts happen. In addition, we also want to compact files that are containing deleted key ranges (like old oplog keys).
All of this is currently not possible with CompactRange() because it's single-threaded and blocks all other compactions from happening. Running CompactRange() risks an issue of blocking writes because we generate too much Level 0 files before the compaction is over. Stopping writes is very dangerous because they hold transaction locks. We tried running manual compaction once on Mongo+Rocks and everything fell apart.
MarkForCompaction() solves all of those problems. This is very light-weight manual compaction. It is lower priority than automatic compactions, which means it shouldn't interfere with background process keeping the LSM tree clean. However, if no automatic compactions need to be run (or we have extra background threads available), we will start compacting files that are marked for compaction.
Test Plan: added a new unit test
Reviewers: yhchiang, rven, MarkCallaghan, sdong
Reviewed By: sdong
Subscribers: yoshinorim, dhruba, leveldb
Differential Revision: https://reviews.facebook.net/D37083
Summary: Other than making some class members private, this is a documentation-only change
Test Plan: unit tests
Reviewers: sdong, yhchiang, igor
Reviewed By: igor
Subscribers: dhruba, leveldb
Differential Revision: https://reviews.facebook.net/D36567
Summary:
There are some cases when flachcache file descriptor was
already allocated (i.e. fb-MySQL). Then NewFlashcacheAwareEnv returns an
error at open() because fd was already assigned. This diff adds another
function to instantiate FlashcacheAwareEnv, with pre-allocated fd cachedev_fd.
Test Plan: Tested with MyRocks using this function, then worked
Reviewers: sdong, igor
Reviewed By: igor
Subscribers: dhruba, MarkCallaghan, rven
Differential Revision: https://reviews.facebook.net/D36447
Summary: Now we add warnings when user configures compression and the compression is not supported.
Test Plan:
Configured compression to non-supported values. Observed messages in my log:
2015/03/26-12:17:57.586341 7ffb8a496840 [WARN] Compression type chosen for level 2 is not supported: LZ4. RocksDB will not compress data on level 2.
2015/03/26-12:19:10.768045 7f36f15c5840 [WARN] Compression type chosen is not supported: LZ4. RocksDB will not compress data.
Reviewers: rven, sdong, yhchiang
Reviewed By: sdong
Subscribers: dhruba, leveldb
Differential Revision: https://reviews.facebook.net/D35979
Summary:
Currently users have no idea a key is add, delete or merge from TablePropertiesCollector call back. Add a new function to add it.
Also refactor the codes so that
(1) make table property collector and internal table property collector two separate data structures with the later one now exposed
(2) table builders only receive internal table properties
Test Plan: Add cases in table_properties_collector_test to cover both of old and new ways of using TablePropertiesCollector.
Reviewers: yhchiang, igor.sugak, rven, igor
Reviewed By: rven, igor
Subscribers: meyering, yoshinorim, maykov, leveldb, dhruba
Differential Revision: https://reviews.facebook.net/D35373
Summary: Most of the approach is copied from WebSQL's MySQL branch. It's nice that we can do this without touching core RocksDB code.
Test Plan: Compiles and runs. Didn't test flashback code, as I don't have flashback device and most if it is c/p
Reviewers: MarkCallaghan, sdong
Reviewed By: sdong
Subscribers: rven, lgalanis, kradhakrishnan, dhruba, leveldb
Differential Revision: https://reviews.facebook.net/D35391
Summary:
Assign the string properties to const string variables under the
DB::Properties namespace. This helps catch typos during compilation and
also consolidates the property definition in one place.
Test Plan: Run rocksdb unit tests
Reviewers: sdong, yoshinorim, igor
Subscribers: dhruba
Differential Revision: https://reviews.facebook.net/D35991
Summary:
We have addded new stats and perf_context for measuring the merge and filter operation time consumption.
We have bounded all the merge operations within the GUARD statment and collected the total time for these operations in the DB.
Test Plan: WIP
Reviewers: rven, yhchiang, kradhakrishnan, igor, sdong
Reviewed By: sdong
Subscribers: dhruba
Differential Revision: https://reviews.facebook.net/D34377
Summary:
Report elapsed time of a thread operation in micros in ThreadStatus
instead of start time of a thread operation in seconds since the
Epoch, 1970-01-01 00:00:00 (UTC).
Test Plan:
./db_bench --benchmarks=fillrandom --num=100000 --threads=40 \
--max_background_compactions=10 --max_background_flushes=3 \
--thread_status_per_interval=1000 --key_size=16 --value_size=1000 \
--num_column_families=10
Sample Output:
ThreadID ThreadType cfName Operation ElapsedTime Stage State
140667724562496 High Pri column_family_name_000002 Flush 772.419 ms FlushJob::WriteLevel0Table
140667728756800 High Pri default Flush 617.845 ms FlushJob::WriteLevel0Table
140667732951104 High Pri column_family_name_000005 Flush 772.078 ms FlushJob::WriteLevel0Table
140667875557440 Low Pri column_family_name_000008 Compaction 1409.216 ms CompactionJob::Install
140667737145408 Low Pri
140667749728320 Low Pri
140667816837184 Low Pri column_family_name_000007 Compaction 1071.815 ms CompactionJob::ProcessKeyValueCompaction
140667787477056 Low Pri column_family_name_000009 Compaction 772.516 ms CompactionJob::ProcessKeyValueCompaction
140667741339712 Low Pri
140667758116928 Low Pri column_family_name_000004 Compaction 620.739 ms CompactionJob::ProcessKeyValueCompaction
140667753922624 Low Pri
140667842003008 Low Pri column_family_name_000006 Compaction 1260.079 ms CompactionJob::ProcessKeyValueCompaction
140667745534016 Low Pri
Reviewers: sdong, igor, rven
Subscribers: dhruba, leveldb
Differential Revision: https://reviews.facebook.net/D35769
Summary: There is no alternative to GetLiveFiles() function
Test Plan: none
Reviewers: sdong
Reviewed By: sdong
Subscribers: dhruba, leveldb
Differential Revision: https://reviews.facebook.net/D35805
Summary: Add a DB property for number of deletions in memtables. It can sometimes help people debug slowness because of too many deletes.
Test Plan: Add test cases.
Reviewers: rven, yhchiang, kradhakrishnan, igor
Reviewed By: igor
Subscribers: leveldb, dhruba, yoshinorim
Differential Revision: https://reviews.facebook.net/D35247
Summary: This feature is going to be useful for mongodb+rocksdb. I'll expose it through mongo's API.
Test Plan: added new unit test. also will run TSAN on the new unit test
Reviewers: meyering, sdong
Reviewed By: meyering, sdong
Subscribers: meyering, dhruba, leveldb
Differential Revision: https://reviews.facebook.net/D35307
Summary: WriteBatch and WriteBatchWithIndex now both inherit from a common abstract base class. This makes it easier to write code that is agnostic toward the implementation of the particular write batch. In particular, I plan on utilizing this abstraction to allow transactions to support using either implementation of a write batch.
Test Plan: modified existing WriteBatchWithIndex tests to test new functions. Running all tests.
Reviewers: igor, rven, yhchiang, sdong
Reviewed By: sdong
Subscribers: dhruba, leveldb
Differential Revision: https://reviews.facebook.net/D34017
Summary: It is no longer used by the implementation, so we should also remove it from the public API.
Test Plan: make check
Reviewers: sdong
Reviewed By: sdong
Subscribers: dhruba, leveldb
Differential Revision: https://reviews.facebook.net/D34971
Summary: Mark function as override.
Test Plan: USE_CLANG=1 make -j32 check
Reviewers: sdong, yhchiang, igor
Reviewed By: igor
Subscribers: dhruba, leveldb
Differential Revision: https://reviews.facebook.net/D35163
Summary:
On RocksDB, when there are multiple instances doing
flushes/compactions in the background, the close call takes a long time
because the flushes/compactions need to complete before the database can
shut down. If another instance is using the background threads and the compaction for this instance is in the queue since it has been scheduled, we still cannot shutdown. We now remove the scheduled background tasks which have not yet started running, so that shutdown is speeded up.
Test Plan: DB Test added.
Reviewers: yhchiang, igor, sdong
Reviewed By: sdong
Subscribers: dhruba, leveldb
Differential Revision: https://reviews.facebook.net/D33741
Summary:
Change the way options.compression_per_level is used when options.level_compaction_dynamic_level_bytes=true so that options.compression_per_level[1] determines compression for the level L0 is merged to, options.compression_per_level[2] to the level after that, etc.
Test Plan: run all tests
Reviewers: rven, yhchiang, kradhakrishnan, igor
Reviewed By: igor
Subscribers: yoshinorim, leveldb, dhruba
Differential Revision: https://reviews.facebook.net/D34431
sdong