510 Commits (daceb85c51ca191d32b5e07c6401021032a41264)

Author	SHA1	Message	Date
akankshamahajan	0e7b27bfcf	Refactor block cache tracing APIs (#10811) ... Summary: Refactor the classes, APIs and data structures for block cache tracing to allow a user provided trace writer to be used. Currently, only a TraceWriter is supported, with a default built-in implementation of FileTraceWriter. The TraceWriter, however, takes a flat trace record and is thus only suitable for file tracing. This PR introduces an abstract BlockCacheTraceWriter class that takes a structured BlockCacheTraceRecord. The BlockCacheTraceWriter implementation can then format and log the record in whatever way it sees fit. The default BlockCacheTraceWriterImpl does file tracing using a user provided TraceWriter. `DB::StartBlockTrace` will internally redirect to changed `BlockCacheTrace::StartBlockCacheTrace`. New API `DB::StartBlockTrace` is also added that directly takes `BlockCacheTraceWriter` pointer. This same philosophy can be applied to KV and IO tracing as well. Pull Request resolved: https://github.com/facebook/rocksdb/pull/10811 Test Plan: existing unit tests Old API DB::StartBlockTrace checked with db_bench tool create database ``` ./db_bench --benchmarks="fillseq" \ --key_size=20 --prefix_size=20 --keys_per_prefix=0 --value_size=100 \ --cache_index_and_filter_blocks --cache_size=1048576 \ --disable_auto_compactions=1 --disable_wal=1 --compression_type=none \ --min_level_to_compress=-1 --compression_ratio=1 --num=10000000 ``` To trace block cache accesses when running readrandom benchmark: ``` ./db_bench --benchmarks="readrandom" --use_existing_db --duration=60 \ --key_size=20 --prefix_size=20 --keys_per_prefix=0 --value_size=100 \ --cache_index_and_filter_blocks --cache_size=1048576 \ --disable_auto_compactions=1 --disable_wal=1 --compression_type=none \ --min_level_to_compress=-1 --compression_ratio=1 --num=10000000 \ --threads=16 \ -block_cache_trace_file="/tmp/binary_trace_test_example" \ -block_cache_trace_max_trace_file_size_in_bytes=1073741824 \ -block_cache_trace_sampling_frequency=1 ``` Reviewed By: anand1976 Differential Revision: D40435289 Pulled By: akankshamahajan15 fbshipit-source-id: fa2755f4788185e19f4605e731641cfd21ab3282	2 years ago
Jay Zhuang	1663f77d2a	Fix no internal time recorded for small preclude_last_level (#10829) ... Summary: When the `preclude_last_level_data_seconds` or `preserve_internal_time_seconds` is smaller than 100 (seconds), no seqno->time information was recorded. Also make sure all data will be compacted to the last level even if there's no write to record the time information. Pull Request resolved: https://github.com/facebook/rocksdb/pull/10829 Test Plan: added unittest Reviewed By: siying Differential Revision: D40443934 Pulled By: jay-zhuang fbshipit-source-id: 2ecf1361daf9f3e5c3385aee6dc924fa59e2813a	2 years ago
Yueh-Hsuan Chiang	e267909ecf	Enable a multi-level db to smoothly migrate to FIFO via DB::Open (#10348) ... Summary: FIFO compaction can theoretically open a DB with any compaction style. However, the current code only allows FIFO compaction to open a DB with a single level. This PR relaxes the limitation of FIFO compaction and allows it to open a DB with multiple levels. Below is the read / write / compaction behavior: * The read behavior is untouched, and it works like a regular rocksdb instance. * The write behavior is untouched as well. When a FIFO compacted DB is opened with multiple levels, all new files will still be in level 0, and no files will be moved to a different level. * Compaction logic is extended. It will first identify the bottom-most non-empty level. Then, it will delete the oldest file in that level. Pull Request resolved: https://github.com/facebook/rocksdb/pull/10348 Test Plan: Added a new test to verify the migration from level to FIFO where the db has multiple levels. Extended existing test cases in db_test and db_basic_test to also verify all entries of a key after reopening the DB with FIFO compaction. Reviewed By: jay-zhuang Differential Revision: D40233744 fbshipit-source-id: 6cc011d6c3467e6bfb9b6a4054b87619e69815e1	2 years ago
Hui Xiao	f6a0065d54	Allow Flush(sync=true) not supported in DB::Open() and db_stress (#10784) ... Summary: **Context:** https://github.com/facebook/rocksdb/pull/10698 made `Flush(sync=true)` required for` DB::Open()` (to pass the original but now deleted assertion `impl->TEST_WALBufferIsEmpty()` under `manual_wal_flush=true`, see https://github.com/facebook/rocksdb/pull/10698 summary for more ) as well as db_stress to pass. However RocksDB users may not implement SyncWAL() (used inFlush(sync=true)). Therefore we replace such in DB::Open and db_stress in this PR and align with https://github.com/facebook/rocksdb/blob/main/db/db_impl/db_impl_open.cc#L1883-L1887 and https://github.com/facebook/rocksdb/blob/main/db_stress_tool/db_stress_test_base.cc#L847-L849 Pull Request resolved: https://github.com/facebook/rocksdb/pull/10784 Test Plan: make check Reviewed By: anand1976 Differential Revision: D40193354 Pulled By: anand1976 fbshipit-source-id: e80d53880799ae01bdd717641d07997d3bfe2b54	2 years ago
Qingping Wang	a45e6878f3	fix issue 10751 (#10765) ... Summary: Fix https://github.com/facebook/rocksdb/issues/10751 where a stalled write could be blocked forever when DB shutdown. Pull Request resolved: https://github.com/facebook/rocksdb/pull/10765 Reviewed By: ajkr Differential Revision: D40110069 Pulled By: ajkr fbshipit-source-id: 598c05777db9be85913a0a85e421b3295ecdff5e	2 years ago
Jay Zhuang	c401f285c3	Add option `preserve_internal_time_seconds` to preserve the time info (#10747) ... Summary: Add option `preserve_internal_time_seconds` to preserve the internal time information. It's mostly for the migration of the existing data to tiered storage ( `preclude_last_level_data_seconds`). When the tiering feature is just enabled, the existing data won't have the time information to decide if it's hot or cold. Enabling this feature will start collect and preserve the time information for the new data. Pull Request resolved: https://github.com/facebook/rocksdb/pull/10747 Reviewed By: siying Differential Revision: D39910141 Pulled By: siying fbshipit-source-id: 25c21638e37b1a7c44006f636b7d714fe7242138	2 years ago
Changyu Bi	eca47fb696	Ignore kBottommostFiles compaction logic when allow_ingest_behind (#10767) ... Summary: fix for https://github.com/facebook/rocksdb/issues/10752 where RocksDB could be in an infinite compaction loop (with compaction reason kBottommostFiles) if allow_ingest_behind is enabled and the bottommost level is unfilled. Pull Request resolved: https://github.com/facebook/rocksdb/pull/10767 Test Plan: Added a unit test to reproduce the compaction loop. Reviewed By: ajkr Differential Revision: D40031861 Pulled By: ajkr fbshipit-source-id: 71c4b02931fbe507a847632905404c9b8fa8c96b	2 years ago
Yanqin Jin	edda219fc3	Manual flush with `wait=false` should not stall when writes stopped (#10001) ... Summary: When `FlushOptions::wait` is set to false, manual flush should not stall forever. If the database has already stopped writes, then the thread calling `DB::Flush()` with `FlushOptions::wait=false` should not enter the `DBImpl::write_thread_`. To prevent this, we should do a check at the beginning and return `TryAgain()` Resolves: https://github.com/facebook/rocksdb/issues/9892 Pull Request resolved: https://github.com/facebook/rocksdb/pull/10001 Reviewed By: siying Differential Revision: D36422303 Pulled By: siying fbshipit-source-id: 723bd3065e8edc4f17c82449d0d6b95a2381ac0a	2 years ago
akankshamahajan	ae0f9c3339	Add new property in IOOptions to skip recursing through directories and list only files during GetChildren. (#10668) ... Summary: Add new property "do_not_recurse" in IOOptions for underlying file system to skip iteration of directories during DB::Open if there are no sub directories and list only files. By default this property is set to false. This property is set true currently in the code where RocksDB is sure only files are needed during DB::Open. Provided support in PosixFileSystem to use "do_not_recurse". TestPlan: - Existing tests Pull Request resolved: https://github.com/facebook/rocksdb/pull/10668 Reviewed By: anand1976 Differential Revision: D39471683 Pulled By: akankshamahajan15 fbshipit-source-id: 90e32f0b86d5346d53bc2714d3a0e7002590527f	2 years ago
Changyu Bi	9f2363f4c4	User-defined timestamp support for `DeleteRange()` (#10661) ... Summary: Add user-defined timestamp support for range deletion. The new API is `DeleteRange(opt, cf, begin_key, end_key, ts)`. Most of the change is to update the comparator to compare without timestamp. Other than that, major changes are - internal range tombstone data structures (`FragmentedRangeTombstoneList`, `RangeTombstone`, etc.) to store timestamps. - Garbage collection of range tombstones and range tombstone covered keys during compaction. - Get()/MultiGet() to return the timestamp of a range tombstone when needed. - Get/Iterator with range tombstones bounded by readoptions.timestamp. - timestamp crash test now issues DeleteRange by default. Pull Request resolved: https://github.com/facebook/rocksdb/pull/10661 Test Plan: - Added unit test: `make check` - Stress test: `python3 tools/db_crashtest.py --enable_ts whitebox --readpercent=57 --prefixpercent=4 --writepercent=25 -delpercent=5 --iterpercent=5 --delrangepercent=4` - Ran `db_bench` to measure regression when timestamp is not enabled. The tests are for write (with some range deletion) and iterate with DB fitting in memory: `./db_bench--benchmarks=fillrandom,seekrandom --writes_per_range_tombstone=200 --max_write_buffer_number=100 --min_write_buffer_number_to_merge=100 --writes=500000 --reads=500000 --seek_nexts=10 --disable_auto_compactions -disable_wal=true --max_num_range_tombstones=1000`. Did not see consistent regression in no timestamp case. | micros/op | fillrandom | seekrandom | | --- | --- | --- | |main| 2.58 |10.96| |PR 10661| 2.68 |10.63| Reviewed By: riversand963 Differential Revision: D39441192 Pulled By: cbi42 fbshipit-source-id: f05aca3c41605caf110daf0ff405919f300ddec2	2 years ago
Hui Xiao	3b8164912e	Add manual_wal_flush, FlushWAL() to stress/crash test (#10698) ... Summary: **Context/Summary:** Introduce `manual_wal_flush_one_in` as titled. - When `manual_wal_flush_one_in > 0`, we also need tracing to correctly verify recovery because WAL data can be lost in this case when `FlushWAL()` is not explicitly called by users of RocksDB (in our case, db stress) and the recovery from such potential WAL data loss is a prefix recovery that requires tracing to verify. As another consequence, we need to disable features can't run under unsync data loss with `manual_wal_flush_one_in` Incompatibilities fixed along the way: ``` db_stress: db/db_impl/db_impl_open.cc:2063: static rocksdb::Status rocksdb::DBImpl::Open(const rocksdb::DBOptions&, const string&, const std::vector<rocksdb::ColumnFamilyDescriptor>&, std::vector<rocksdb::ColumnFamilyHandle*>*, rocksdb::DB**, bool, bool): Assertion `impl->TEST_WALBufferIsEmpty()' failed. ``` - It turns out that `Writer::AddCompressionTypeRecord` before this assertion `EmitPhysicalRecord(kSetCompressionType, encode.data(), encode.size());` but do not trigger flush if `manual_wal_flush` is set . This leads to `impl->TEST_WALBufferIsEmpty()' is false. - As suggested, assertion is removed and violation case is handled by `FlushWAL(sync=true)` along with refactoring `TEST_WALBufferIsEmpty()` to be `WALBufferIsEmpty()` since it is used in prod code now. Pull Request resolved: https://github.com/facebook/rocksdb/pull/10698 Test Plan: - Locally running `python3 tools/db_crashtest.py blackbox --manual_wal_flush_one_in=1 --manual_wal_flush=1 --sync_wal_one_in=100 --atomic_flush=1 --flush_one_in=100 --column_families=3` - Joined https://github.com/facebook/rocksdb/pull/10624 in auto CI testings with all RocksDB stress/crash test jobs Reviewed By: ajkr Differential Revision: D39593752 Pulled By: ajkr fbshipit-source-id: 3a2135bb792c52d2ffa60257d4fbc557fb04d2ce	2 years ago
anand76	fb9a025892	Fix platform 10 build with folly (#10708) ... Summary: Change the library order in PLATFORM_LDFLAGS to enable fbcode platform 10 build with folly. This PR also has a few fixes for platform 10 compiler errors. Pull Request resolved: https://github.com/facebook/rocksdb/pull/10708 Test Plan: ROCKSDB_FBCODE_BUILD_WITH_PLATFORM010=1 USE_COROUTINES=1 make -j64 check ROCKSDB_FBCODE_BUILD_WITH_PLATFORM010=1 USE_FOLLY=1 make -j64 check Reviewed By: ajkr Differential Revision: D39666590 Pulled By: anand1976 fbshipit-source-id: 256a1127ef561399cd6299a6a392ca29bd68ca44	2 years ago
Changyu Bi	749b849a34	Fix memtable-only iterator regression (#10705) ... Summary: when there is a single memtable without range tombstones and no SST files in the database, DBIter should wrap memtable iterator directly. Currently we create a merging iterator on top of the memtable iterator, and have DBIter wrap around it. This causes iterator regression and this PR fixes this issue. Pull Request resolved: https://github.com/facebook/rocksdb/pull/10705 Test Plan: - `make check` - Performance: - Set up: `./db_bench -benchmarks=filluniquerandom -write_buffer_size=$((1 << 30)) -num=10000` - Benchmark: `./db_bench -benchmarks=seekrandom -use_existing_db=true -avoid_flush_during_recovery=true -write_buffer_size=$((1 << 30)) -num=10000 -threads=16 -duration=60 -seek_nexts=$seek_nexts` ``` seek_nexts main op/sec https://github.com/facebook/rocksdb/issues/10705 RocksDB v7.6 0 5746568 5749033 5786180 30 2411690 3006466 2837699 1000 102556 128902 124667 ``` Reviewed By: ajkr Differential Revision: D39644221 Pulled By: cbi42 fbshipit-source-id: 8063ff611ba31b0e5670041da3927c8c54b2097d	2 years ago
Hui Xiao	f79b3d19a7	Inject spurious wakeup and sleep before acquiring db mutex to expose race condition (#10291) ... Summary: **Context/Summary:** Previous experience with bugs and flaky tests taught us there exist features in RocksDB vulnerable to race condition caused by acquiring db mutex at a particular timing. This PR aggressively exposes those vulnerable features by injecting spurious wakeup and sleep to cause acquiring db mutex at various timing in order to expose such race condition **Testing:** - `COERCE_CONTEXT_SWITCH=1 make -j56 check / make -j56 db_stress` should reveal - flaky tests caused by db mutex related race condition - Reverted https://github.com/facebook/rocksdb/pull/9528 - A/B testing on `COMPILE_WITH_TSAN=1 make -j56 listener_test` w/ and w/o `COERCE_CONTEXT_SWITCH=1` followed by `./listener_test --gtest_filter=EventListenerTest.MultiCF --gtest_repeat=10` - `COERCE_CONTEXT_SWITCH=1` can cause expected test failure (i.e, expose target TSAN data race error) within 10 run while the other couldn't. - This proves our injection can expose flaky tests caused by db mutex related race condition faster. - known or new race-condition-type of internal bug by continuously running this PR - Performance - High ops-threads time: COERCE_CONTEXT_SWITCH=1 regressed by 4 times slower (2:01.16 vs 0:22.10 elapsed ). This PR will be run as a separate CI job so this regression won't affect any existing job. ``` TEST_TMPDIR=$db /usr/bin/time ./db_stress \ --ops_per_thread=100000 --expected_values_dir=$exp --clear_column_family_one_in=0 \ --write_buffer_size=524288 —target_file_size_base=524288 —ingest_external_file_one_in=100 —compact_files_one_in=1000 —compact_range_one_in=1000 ``` - Start-up time: COERCE_CONTEXT_SWITCH=1 didn't regress by 25% (0:01.51 vs 0:01.29 elapsed) ``` TEST_TMPDIR=$db ./db_stress -ops_per_thread=100000000 -expected_values_dir=$exp --clear_column_family_one_in=0 & sleep 120; pkill -9 db_stress TEST_TMPDIR=$db /usr/bin/time ./db_stress \ --ops_per_thread=1 -reopen=0 --expected_values_dir=$exp --clear_column_family_one_in=0 --destroy_db_initially=0 ``` Pull Request resolved: https://github.com/facebook/rocksdb/pull/10291 Reviewed By: ajkr Differential Revision: D39231182 Pulled By: hx235 fbshipit-source-id: 7ab6695430460e0826727fd8c66679b32b3e44b6	2 years ago
Peter Dillinger	6de7081cf3	Always verify SST unique IDs on SST file open (#10532) ... Summary: Although we've been tracking SST unique IDs in the DB manifest unconditionally, checking has been opt-in and with an extra pass at DB::Open time. This changes the behavior of `verify_sst_unique_id_in_manifest` to check unique ID against manifest every time an SST file is opened through table cache (normal DB operations), replacing the explicit pass over files at DB::Open time. This change also enables the option by default and removes the "EXPERIMENTAL" designation. One possible criticism is that the option no longer ensures the integrity of a DB at Open time. This is far from an all-or-nothing issue. Verifying the IDs of all SST files hardly ensures all the data in the DB is readable. (VerifyChecksum is supposed to do that.) Also, with max_open_files=-1 (default, extremely common), all SST files are opened at DB::Open time anyway. Implementation details: * `VerifySstUniqueIdInManifest()` functions are the extra/explicit pass that is now removed. * Unit tests that manipulate/corrupt table properties have to opt out of this check, because that corrupts the "actual" unique id. (And even for testing we don't currently have a mechanism to set "no unique id" in the in-memory file metadata for new files.) * A lot of other unit test churn relates to (a) default checking on, and (b) checking on SST open even without DB::Open (e.g. on flush) * Use `FileMetaData` for more `TableCache` operations (in place of `FileDescriptor`) so that we have access to the unique_id whenever we might need to open an SST file. **There is the possibility of performance impact because we can no longer use the more localized `fd` part of an `FdWithKeyRange` but instead follow the `file_metadata` pointer. However, this change (possible regression) is only done for `GetMemoryUsageByTableReaders`.** * Removed a completely unnecessary constructor overload of `TableReaderOptions` Possible follow-up: * Verification only happens when opening through table cache. Are there more places where this should happen? * Improve error message when there is a file size mismatch vs. manifest (FIXME added in the appropriate place). * I'm not sure there's a justification for `FileDescriptor` to be distinct from `FileMetaData`. * I'm skeptical that `FdWithKeyRange` really still makes sense for optimizing some data locality by duplicating some data in memory, but I could be wrong. * An unnecessary overload of NewTableReader was recently added, in the public API nonetheless (though unusable there). It should be cleaned up to put most things under `TableReaderOptions`. Pull Request resolved: https://github.com/facebook/rocksdb/pull/10532 Test Plan: updated unit tests Performance test showing no significant difference (just noise I think): `./db_bench -benchmarks=readwhilewriting[-X10] -num=3000000 -disable_wal=1 -bloom_bits=8 -write_buffer_size=1000000 -target_file_size_base=1000000` Before: readwhilewriting [AVG 10 runs] : 68702 (± 6932) ops/sec After: readwhilewriting [AVG 10 runs] : 68239 (± 7198) ops/sec Reviewed By: jay-zhuang Differential Revision: D38765551 Pulled By: pdillinger fbshipit-source-id: a827a708155f12344ab2a5c16e7701c7636da4c2	2 years ago
Changyu Bi	30bc495c03	Skip swaths of range tombstone covered keys in merging iterator (2022 edition) (#10449) ... Summary: Delete range logic is moved from `DBIter` to `MergingIterator`, and `MergingIterator` will seek to the end of a range deletion if possible instead of scanning through each key and check with `RangeDelAggregator`. With the invariant that a key in level L (consider memtable as the first level, each immutable and L0 as a separate level) has a larger sequence number than all keys in any level >L, a range tombstone `[start, end)` from level L covers all keys in its range in any level >L. This property motivates optimizations in iterator: - in `Seek(target)`, if level L has a range tombstone `[start, end)` that covers `target.UserKey`, then for all levels > L, we can do Seek() on `end` instead of `target` to skip some range tombstone covered keys. - in `Next()/Prev()`, if the current key is covered by a range tombstone `[start, end)` from level L, we can do `Seek` to `end` for all levels > L. This PR implements the above optimizations in `MergingIterator`. As all range tombstone covered keys are now skipped in `MergingIterator`, the range tombstone logic is removed from `DBIter`. The idea in this PR is similar to https://github.com/facebook/rocksdb/issues/7317, but this PR leaves `InternalIterator` interface mostly unchanged. **Credit**: the cascading seek optimization and the sentinel key (discussed below) are inspired by [Pebble](https://github.com/cockroachdb/pebble/blob/master/merging_iter.go) and suggested by ajkr in https://github.com/facebook/rocksdb/issues/7317. The two optimizations are mostly implemented in `SeekImpl()/SeekForPrevImpl()` and `IsNextDeleted()/IsPrevDeleted()` in `merging_iterator.cc`. See comments for each method for more detail. One notable change is that the minHeap/maxHeap used by `MergingIterator` now contains range tombstone end keys besides point key iterators. This helps to reduce the number of key comparisons. For example, for a range tombstone `[start, end)`, a `start` and an `end` `HeapItem` are inserted into the heap. When a `HeapItem` for range tombstone start key is popped from the minHeap, we know this range tombstone becomes "active" in the sense that, before the range tombstone's end key is popped from the minHeap, all the keys popped from this heap is covered by the range tombstone's internal key range `[start, end)`. Another major change, *delete range sentinel key*, is made to `LevelIterator`. Before this PR, when all point keys in an SST file are iterated through in `MergingIterator`, a level iterator would advance to the next SST file in its level. In the case when an SST file has a range tombstone that covers keys beyond the SST file's last point key, advancing to the next SST file would lose this range tombstone. Consequently, `MergingIterator` could return keys that should have been deleted by some range tombstone. We prevent this by pretending that file boundaries in each SST file are sentinel keys. A `LevelIterator` now only advance the file iterator once the sentinel key is processed. Pull Request resolved: https://github.com/facebook/rocksdb/pull/10449 Test Plan: - Added many unit tests in db_range_del_test - Stress test: `./db_stress --readpercent=5 --prefixpercent=19 --writepercent=20 -delpercent=10 --iterpercent=44 --delrangepercent=2` - Additional iterator stress test is added to verify against iterators against expected state: https://github.com/facebook/rocksdb/issues/10538. This is based on ajkr's previous attempt https://github.com/facebook/rocksdb/pull/5506#issuecomment-506021913. ``` python3 ./tools/db_crashtest.py blackbox --simple --write_buffer_size=524288 --target_file_size_base=524288 --max_bytes_for_level_base=2097152 --compression_type=none --max_background_compactions=8 --value_size_mult=33 --max_key=5000000 --interval=10 --duration=7200 --delrangepercent=3 --delpercent=9 --iterpercent=25 --writepercent=60 --readpercent=3 --prefixpercent=0 --num_iterations=1000 --range_deletion_width=100 --verify_iterator_with_expected_state_one_in=1 ``` - Performance benchmark: I used a similar setup as in the blog [post](http://rocksdb.org/blog/2018/11/21/delete-range.html) that introduced DeleteRange, "a database with 5 million data keys, and 10000 range tombstones (ignoring those dropped during compaction) that were written in regular intervals after 4.5 million data keys were written". As expected, the performance with this PR depends on the range tombstone width. ``` # Setup: TEST_TMPDIR=/dev/shm ./db_bench_main --benchmarks=fillrandom --writes=4500000 --num=5000000 TEST_TMPDIR=/dev/shm ./db_bench_main --benchmarks=overwrite --writes=500000 --num=5000000 --use_existing_db=true --writes_per_range_tombstone=50 # Scan entire DB TEST_TMPDIR=/dev/shm ./db_bench_main --benchmarks=readseq[-X5] --use_existing_db=true --num=5000000 --disable_auto_compactions=true # Short range scan (10 Next()) TEST_TMPDIR=/dev/shm/width-100/ ./db_bench_main --benchmarks=seekrandom[-X5] --use_existing_db=true --num=500000 --reads=100000 --seek_nexts=10 --disable_auto_compactions=true # Long range scan(1000 Next()) TEST_TMPDIR=/dev/shm/width-100/ ./db_bench_main --benchmarks=seekrandom[-X5] --use_existing_db=true --num=500000 --reads=2500 --seek_nexts=1000 --disable_auto_compactions=true ``` Avg over of 10 runs (some slower tests had fews runs): For the first column (tombstone), 0 means no range tombstone, 100-10000 means width of the 10k range tombstones, and 1 means there is a single range tombstone in the entire DB (width is 1000). The 1 tombstone case is to test regression when there's very few range tombstones in the DB, as no range tombstone is likely to take a different code path than with range tombstones. - Scan entire DB | tombstone width | Pre-PR ops/sec | Post-PR ops/sec | ±% | | ------------- | ------------- | ------------- | ------------- | | 0 range tombstone |2525600 (± 43564) |2486917 (± 33698) |-1.53% | | 100 |1853835 (± 24736) |2073884 (± 32176) |+11.87% | | 1000 |422415 (± 7466) |1115801 (± 22781) |+164.15% | | 10000 |22384 (± 227) |227919 (± 6647) |+918.22% | | 1 range tombstone |2176540 (± 39050) |2434954 (± 24563) |+11.87% | - Short range scan | tombstone width | Pre-PR ops/sec | Post-PR ops/sec | ±% | | ------------- | ------------- | ------------- | ------------- | | 0 range tombstone |35398 (± 533) |35338 (± 569) |-0.17% | | 100 |28276 (± 664) |31684 (± 331) |+12.05% | | 1000 |7637 (± 77) |25422 (± 277) |+232.88% | | 10000 |1367 |28667 |+1997.07% | | 1 range tombstone |32618 (± 581) |32748 (± 506) |+0.4% | - Long range scan | tombstone width | Pre-PR ops/sec | Post-PR ops/sec | ±% | | ------------- | ------------- | ------------- | ------------- | | 0 range tombstone |2262 (± 33) |2353 (± 20) |+4.02% | | 100 |1696 (± 26) |1926 (± 18) |+13.56% | | 1000 |410 (± 6) |1255 (± 29) |+206.1% | | 10000 |25 |414 |+1556.0% | | 1 range tombstone |1957 (± 30) |2185 (± 44) |+11.65% | - Microbench does not show significant regression: https://gist.github.com/cbi42/59f280f85a59b678e7e5d8561e693b61 Reviewed By: ajkr Differential Revision: D38450331 Pulled By: cbi42 fbshipit-source-id: b5ef12e8d8c289ed2e163ccdf277f5039b511fca	2 years ago
Hui Xiao	e484b81eee	Sync dir containing CURRENT after RenameFile on CURRENT as much as possible (#10573) ... Summary: **Context:** Below crash test revealed a bug that directory containing CURRENT file (short for `dir_contains_current_file` below) was not always get synced after a new CURRENT is created and being called with `RenameFile` as part of the creation. This bug exposes a risk that such un-synced directory containing the updated CURRENT can’t survive a host crash (e.g, power loss) hence get corrupted. This then will be followed by a recovery from a corrupted CURRENT that we don't want. The root-cause is that a nullptr `FSDirectory* dir_contains_current_file` sometimes gets passed-down to `SetCurrentFile()` hence in those case `dir_contains_current_file->FSDirectory::FsyncWithDirOptions()` will be skipped (which otherwise will internally call`Env/FS::SyncDic()` ) ``` ./db_stress --acquire_snapshot_one_in=10000 --adaptive_readahead=1 --allow_data_in_errors=True --avoid_unnecessary_blocking_io=0 --backup_max_size=104857600 --backup_one_in=100000 --batch_protection_bytes_per_key=8 --block_size=16384 --bloom_bits=134.8015470676662 --bottommost_compression_type=disable --cache_size=8388608 --checkpoint_one_in=1000000 --checksum_type=kCRC32c --clear_column_family_one_in=0 --compact_files_one_in=1000000 --compact_range_one_in=1000000 --compaction_pri=2 --compaction_ttl=100 --compression_max_dict_buffer_bytes=511 --compression_max_dict_bytes=16384 --compression_type=zstd --compression_use_zstd_dict_trainer=1 --compression_zstd_max_train_bytes=65536 --continuous_verification_interval=0 --data_block_index_type=0 --db=$db --db_write_buffer_size=1048576 --delpercent=5 --delrangepercent=0 --destroy_db_initially=0 --disable_wal=0 --enable_compaction_filter=0 --enable_pipelined_write=1 --expected_values_dir=$exp --fail_if_options_file_error=1 --file_checksum_impl=none --flush_one_in=1000000 --get_current_wal_file_one_in=0 --get_live_files_one_in=1000000 --get_property_one_in=1000000 --get_sorted_wal_files_one_in=0 --index_block_restart_interval=4 --ingest_external_file_one_in=0 --iterpercent=10 --key_len_percent_dist=1,30,69 --level_compaction_dynamic_level_bytes=True --mark_for_compaction_one_file_in=10 --max_background_compactions=20 --max_bytes_for_level_base=10485760 --max_key=10000 --max_key_len=3 --max_manifest_file_size=16384 --max_write_batch_group_size_bytes=64 --max_write_buffer_number=3 --max_write_buffer_size_to_maintain=0 --memtable_prefix_bloom_size_ratio=0.001 --memtable_protection_bytes_per_key=1 --memtable_whole_key_filtering=1 --mmap_read=1 --nooverwritepercent=1 --open_metadata_write_fault_one_in=0 --open_read_fault_one_in=0 --open_write_fault_one_in=0 --ops_per_thread=100000000 --optimize_filters_for_memory=1 --paranoid_file_checks=1 --partition_pinning=2 --pause_background_one_in=1000000 --periodic_compaction_seconds=0 --prefix_size=5 --prefixpercent=5 --prepopulate_block_cache=1 --progress_reports=0 --read_fault_one_in=1000 --readpercent=45 --recycle_log_file_num=0 --reopen=0 --ribbon_starting_level=999 --secondary_cache_fault_one_in=32 --secondary_cache_uri=compressed_secondary_cache://capacity=8388608 --set_options_one_in=10000 --snapshot_hold_ops=100000 --sst_file_manager_bytes_per_sec=0 --sst_file_manager_bytes_per_truncate=0 --subcompactions=3 --sync_fault_injection=1 --target_file_size_base=2097 --target_file_size_multiplier=2 --test_batches_snapshots=1 --top_level_index_pinning=1 --use_full_merge_v1=1 --use_merge=1 --value_size_mult=32 --verify_checksum=1 --verify_checksum_one_in=1000000 --verify_db_one_in=100000 --verify_sst_unique_id_in_manifest=1 --wal_bytes_per_sync=524288 --write_buffer_size=4194 --writepercent=35 ``` ``` stderr: WARNING: prefix_size is non-zero but memtablerep != prefix_hash db_stress: utilities/fault_injection_fs.cc:748: virtual rocksdb::IOStatus rocksdb::FaultInjectionTestFS::RenameFile(const std::string &, const std::string &, const rocksdb::IOOptions &, rocksdb::IODebugContext *): Assertion `tlist.find(tdn.second) == tlist.end()' failed.` ``` **Summary:** The PR ensured the non-test path pass down a non-null dir containing CURRENT (which is by current RocksDB assumption just db_dir) by doing the following: - Renamed `directory_to_fsync` as `dir_contains_current_file` in `SetCurrentFile()` to tighten the association between this directory and CURRENT file - Changed `SetCurrentFile()` API to require `dir_contains_current_file` being passed-in, instead of making it by default nullptr. - Because `SetCurrentFile()`'s `dir_contains_current_file` is passed down from `VersionSet::LogAndApply()` then `VersionSet::ProcessManifestWrites()` (i.e, think about this as a chain of 3 functions related to MANIFEST update), these 2 functions also got refactored to require `dir_contains_current_file` - Updated the non-test-path callers of these 3 functions to obtain and pass in non-nullptr `dir_contains_current_file`, which by current assumption of RocksDB, is the `FSDirectory* db_dir`. - `db_impl` path will obtain `DBImpl::directories_.getDbDir()` while others with no access to such `directories_` are obtained on the fly by creating such object `FileSystem::NewDirectory(..)` and manage it by unique pointers to ensure short life time. Pull Request resolved: https://github.com/facebook/rocksdb/pull/10573 Test Plan: - `make check` - Passed the repro db_stress command - For future improvement, since we currently don't assert dir containing CURRENT to be non-nullptr due to https://github.com/facebook/rocksdb/pull/10573#pullrequestreview-1087698899, there is still chances that future developers mistakenly pass down nullptr dir containing CURRENT thus resulting skipped sync dir and cause the bug again. Therefore a smarter test (e.g, such as quoted from ajkr "(make) unsynced data loss to be dropping files corresponding to unsynced directory entries") is still needed. Reviewed By: ajkr Differential Revision: D39005886 Pulled By: hx235 fbshipit-source-id: 336fb9090d0cfa6ca3dd580db86268007dde7f5a	2 years ago
Peter Dillinger	c5afbbfe4b	Don't wait for indirect flush in read-only DB (#10569) ... Summary: Some APIs for getting live files, which are used by Checkpoint and BackupEngine, can optionally trigger and wait for a flush. These would deadlock when used on a read-only DB. Here we fix that by assuming the user wants the overall operation to succeed and is OK without flushing (because the DB is read-only). Follow-up work: the same or other issues can be hit by directly invoking some DB functions that are clearly not appropriate for read-only instance, but are not covered by overrides in DBImplReadOnly and CompactedDBImpl. These should be fixed to avoid similar problems on accidental misuse. (Long term, it would be nice to have a DBReadOnly class without those members, like BackupEngineReadOnly.) Pull Request resolved: https://github.com/facebook/rocksdb/pull/10569 Test Plan: tests updated to catch regression (hang before the fix) Reviewed By: riversand963 Differential Revision: D38995759 Pulled By: pdillinger fbshipit-source-id: f5f8bc7123e13cb45bd393dd974d7d6eda20bc68	2 years ago
Jay Zhuang	d9e71fb2c5	Fix periodic_task unable to re-register the same task type (#10379) ... Summary: Timer has a limitation that it cannot re-register a task with the same name, because the cancel only mark the task as invalid and wait for the Timer thread to clean it up later, before the task is cleaned up, the same task name cannot be added. Which makes the task option update likely to fail, which basically cancel and re-register the same task name. Change the periodic task name to a random unique id and store it in periodic_task_scheduler. Also refactor the `periodic_work` to `periodic_task` to make each job function as a `task`. Pull Request resolved: https://github.com/facebook/rocksdb/pull/10379 Test Plan: unittests Reviewed By: ajkr Differential Revision: D38000615 Pulled By: jay-zhuang fbshipit-source-id: e4135f9422e3b53aaec8eda54f4e18ce633a279e	2 years ago
Andrew Kryczka	7ad4b38617	Ensure writes to WAL tail during `FlushWAL(true /* sync */)` will be synced (#10560) ... Summary: WAL append and switch can both happen between `FlushWAL(true /* sync */)`'s sync operations and its call to `MarkLogsSynced()`. We permit this since locks need to be released for the sync operations. Such an appended/switched WAL is both inactive and incompletely synced at the time `MarkLogsSynced()` processes it. Prior to this PR, `MarkLogsSynced()` assumed all inactive WALs were fully synced and removed them from consideration for future syncs. That was wrong in the scenario described above and led to the latest append(s) never being synced. This PR changes `MarkLogsSynced()` to only remove inactive WALs from consideration for which all flushed data has been synced. Pull Request resolved: https://github.com/facebook/rocksdb/pull/10560 Test Plan: repro unit test for the scenario described above. Without this PR, it fails on "key2" not found Reviewed By: riversand963 Differential Revision: D38957391 Pulled By: ajkr fbshipit-source-id: da77175eba97ff251a4219b227b3bb2d4843ed26	2 years ago
Levi Tamasi	81388b36e0	Add support for wide-column point lookups (#10540) ... Summary: The patch adds a new API `GetEntity` that can be used to perform wide-column point lookups. It also extends the `Get` code path and the `MemTable` / `MemTableList` and `Version` / `GetContext` logic accordingly so that wide-column entities can be served from both memtables and SSTs. If the result of a lookup is a wide-column entity (`kTypeWideColumnEntity`), it is passed to the application in deserialized form; if it is a plain old key-value (`kTypeValue`), it is presented as a wide-column entity with a single default (anonymous) column. (In contrast, regular `Get` returns plain old key-values as-is, and returns the value of the default column for wide-column entities, see https://github.com/facebook/rocksdb/issues/10483 .) The result of `GetEntity` is a self-contained `PinnableWideColumns` object. `PinnableWideColumns` contains a `PinnableSlice`, which either stores the underlying data in its own buffer or holds on to a cache handle. It also contains a `WideColumns` instance, which indexes the contents of the `PinnableSlice`, so applications can access the values of columns efficiently. There are several pieces of functionality which are currently not supported for wide-column entities: there is currently no `MultiGetEntity` or wide-column iterator; also, `Merge` and `GetMergeOperands` are not supported, and there is no `GetEntity` implementation for read-only and secondary instances. We plan to implement these in future PRs. Pull Request resolved: https://github.com/facebook/rocksdb/pull/10540 Test Plan: `make check` Reviewed By: akankshamahajan15 Differential Revision: D38847474 Pulled By: ltamasi fbshipit-source-id: 42311a34ccdfe88b3775e847a5e2a5296e002b5b	2 years ago
Andrew Kryczka	91166012c8	Prevent a case of WriteBufferManager flush thrashing (#6364) ... Summary: Previously, the flushes triggered by `WriteBufferManager` could affect the same CF repeatedly if it happens to get consecutive writes. Such flushes are not particularly useful for reducing memory usage since they switch nearly-empty memtables to immutable while they've just begun filling their first arena block. In fact they may not even reduce the mutable memory count if they involve replacing one mutable memtable containing one arena block with a new mutable memtable containing one arena block. Further, if such switches happen even a few times before a flush finishes, the immutable memtable limit will be reached and writes will stall. This PR adds a heuristic to not switch memtables to immutable for CFs that already have one or more immutable memtables awaiting flush. There is a memory usage regression if the user continues writing to the same CF, that DB does not have any CFs eligible for switching, flushes are not finishing, and the `WriteBufferManager` was constructed with `allow_stall=false`. Before, it would grow by switching nearly empty memtables until writes stall. Now, it would grow by filling memtables until writes stall. This feels like an acceptable behavior change because users who prefer to stall over violate the memory limit should be using `allow_stall=true`, which is unaffected by this PR. Pull Request resolved: https://github.com/facebook/rocksdb/pull/6364 Test Plan: - Command: `rm -rf /dev/shm/dbbench/ && TEST_TMPDIR=/dev/shm ./db_bench -benchmarks=fillrandom -num_multi_db=8 -num_column_families=2 -write_buffer_size=4194304 -db_write_buffer_size=16777216 -compression_type=none -statistics=true -target_file_size_base=4194304 -max_bytes_for_level_base=16777216` - `rocksdb.db.write.stall` count before this PR: 175 - `rocksdb.db.write.stall` count after this PR: 0 Reviewed By: jay-zhuang Differential Revision: D20167197 Pulled By: ajkr fbshipit-source-id: 4a64064e9bc33d57c0a35f15547542d0191d0cb7	2 years ago
sdong	911c0208b9	WritableFileWriter tries to skip operations after failure (#10489) ... Summary: A flag in WritableFileWriter is introduced to remember error has happened. Subsequent operations will fail with an assertion. Those operations, except Close() are not supposed to be called anyway. This change will help catch bug in tests and stress tests and limit damage of a potential bug of continue writing to a file after a failure. Pull Request resolved: https://github.com/facebook/rocksdb/pull/10489 Test Plan: Fix existing unit tests and watch crash tests for a while. Reviewed By: anand1976 Differential Revision: D38473277 fbshipit-source-id: 09aafb971e56cfd7f9ef92ad15b883f54acf1366	2 years ago
Changyu Bi	9d77bf8f7b	Fragment memtable range tombstone in the write path (#10380) ... Summary: - Right now each read fragments the memtable range tombstones https://github.com/facebook/rocksdb/issues/4808. This PR explores the idea of fragmenting memtable range tombstones in the write path and reads can just read this cached fragmented tombstone without any fragmenting cost. This PR only does the caching for immutable memtable, and does so right before a memtable is added to an immutable memtable list. The fragmentation is done without holding mutex to minimize its performance impact. - db_bench is updated to print out the number of range deletions executed if there is any. Pull Request resolved: https://github.com/facebook/rocksdb/pull/10380 Test Plan: - CI, added asserts in various places to check whether a fragmented range tombstone list should have been constructed. - Benchmark: as this PR only optimizes immutable memtable path, the number of writes in the benchmark is chosen such an immutable memtable is created and range tombstones are in that memtable. ``` single thread: ./db_bench --benchmarks=fillrandom,readrandom --writes_per_range_tombstone=1 --max_write_buffer_number=100 --min_write_buffer_number_to_merge=100 --writes=500000 --reads=100000 --max_num_range_tombstones=100 multi_thread ./db_bench --benchmarks=fillrandom,readrandom --writes_per_range_tombstone=1 --max_write_buffer_number=100 --min_write_buffer_number_to_merge=100 --writes=15000 --reads=20000 --threads=32 --max_num_range_tombstones=100 ``` Commit 99cdf16464a057ca44de2f747541dedf651bae9e is included in benchmark result. It was an earlier attempt where tombstones are fragmented for each write operation. Reader threads share it using a shared_ptr which would slow down multi-thread read performance as seen in benchmark results. Results are averaged over 5 runs. Single thread result: | Max # tombstones | main fillrandom micros/op | 99cdf16464a057ca44de2f747541dedf651bae9e | Post PR | main readrandom micros/op | 99cdf16464a057ca44de2f747541dedf651bae9e | Post PR | | ------------- | ------------- |------------- |------------- |------------- |------------- |------------- | | 0 |6.68 |6.57 |6.72 |4.72 |4.79 |4.54 | | 1 |6.67 |6.58 |6.62 |5.41 |4.74 |4.72 | | 10 |6.59 |6.5 |6.56 |7.83 |4.69 |4.59 | | 100 |6.62 |6.75 |6.58 |29.57 |5.04 |5.09 | | 1000 |6.54 |6.82 |6.61 |320.33 |5.22 |5.21 | 32-thread result: note that "Max # tombstones" is per thread. | Max # tombstones | main fillrandom micros/op | 99cdf16464a057ca44de2f747541dedf651bae9e | Post PR | main readrandom micros/op | 99cdf16464a057ca44de2f747541dedf651bae9e | Post PR | | ------------- | ------------- |------------- |------------- |------------- |------------- |------------- | | 0 |234.52 |260.25 |239.42 |5.06 |5.38 |5.09 | | 1 |236.46 |262.0 |231.1 |19.57 |22.14 |5.45 | | 10 |236.95 |263.84 |251.49 |151.73 |21.61 |5.73 | | 100 |268.16 |296.8 |280.13 |2308.52 |22.27 |6.57 | Reviewed By: ajkr Differential Revision: D37916564 Pulled By: cbi42 fbshipit-source-id: 05d6d2e16df26c374c57ddcca13a5bfe9d5b731e	2 years ago
Yanqin Jin	538df26fcc	Deflake DBWALTest.RaceInstallFlushResultsWithWalObsoletion (#10456) ... Summary: Existing DBWALTest.RaceInstallFlushResultsWithWalObsoletion test relies on a specific interleaving of two background flush threads. We call them bg1 and bg2, and assume bg1 starts to install flush results ahead of bg2. After bg1 enters `ProcessManifestWrites`, bg1 waits for bg2 to also enter `MemTableList::TryInstallMemtableFlushResults()` before bg1 can proceed with MANIFEST write. However, if bg2 called `SyncClosedLogs()` and needed to commit to the MANIFEST but falls behind bg1, then bg2 needs to wait for bg1 to finish writing to MANIFEST. This is a circular dependency. Fix this by allowing bg2 to start only after bg1 grabs the chance to sync the WAL and commit to MANIFEST. Pull Request resolved: https://github.com/facebook/rocksdb/pull/10456 Test Plan: 1. make check 2. export TEST_TMPDIR=/dev/shm && gtest-parallel -r 1000 -w 32 ./db_wal_test --gtest_filter=DBWALTest.RaceInstallFlushResultsWithWalObsoletion Reviewed By: ltamasi Differential Revision: D38391856 Pulled By: riversand963 fbshipit-source-id: 55f647d5b94e534c008a4dd2fb082675ddf58c96	2 years ago
Andrew Kryczka	504fe4de80	Avoid allocations/copies for large `GetMergeOperands()` results (#10458) ... Summary: This PR avoids allocations and copies for the result of `GetMergeOperands()` when the average operand size is at least 256 bytes and the total operands size is at least 32KB. The `GetMergeOperands()` already included `PinnableSlice` but was calling `PinSelf()` (i.e., allocating and copying) for each operand. When this optimization takes effect, we instead call `PinSlice()` to skip that allocation and copy. Resources are pinned in order for the `PinnableSlice` to point to valid memory even after `GetMergeOperands()` returns. The pinned resources include a referenced `SuperVersion`, a `MergingContext`, and a `PinnedIteratorsManager`. They are bundled into a `GetMergeOperandsState`. We use `SharedCleanablePtr` to share that bundle among all `PinnableSlice`s populated by `GetMergeOperands()`. That way, the last `PinnableSlice` to be `Reset()` will cleanup the bundle, including unreferencing the `SuperVersion`. Pull Request resolved: https://github.com/facebook/rocksdb/pull/10458 Test Plan: - new DB level test - measured benefit/regression in a number of memtable scenarios Setup command: ``` $ ./db_bench -benchmarks=mergerandom -merge_operator=StringAppendOperator -num=$num -writes=16384 -key_size=16 -value_size=$value_sz -compression_type=none -write_buffer_size=1048576000 ``` Benchmark command: ``` ./db_bench -threads=$threads -use_existing_db=true -avoid_flush_during_recovery=true -write_buffer_size=1048576000 -benchmarks=readrandomoperands -merge_operator=StringAppendOperator -num=$num -duration=10 ``` Worst regression is when a key has many tiny operands: - Parameters: num=1 (implying 16384 operands per key), value_sz=8, threads=1 - `GetMergeOperands()` latency increases 682 micros -> 800 micros (+17%) The regression disappears into the noise (<1% difference) if we remove the `Reset()` loop and the size counting loop. The former is arguably needed regardless of this PR as the convention in `Get()` and `MultiGet()` is to `Reset()` the input `PinnableSlice`s at the start. The latter could be optimized to count the size as we accumulate operands rather than after the fact. Best improvement is when a key has large operands and high concurrency: - Parameters: num=4 (implying 4096 operands per key), value_sz=2KB, threads=32 - `GetMergeOperands()` latency decreases 11492 micros -> 437 micros (-96%). Reviewed By: cbi42 Differential Revision: D38336578 Pulled By: ajkr fbshipit-source-id: 48146d127e04cb7f2d4d2939a2b9dff3aba18258	2 years ago
Peter Dillinger	27f3af5966	Fix serious FSDirectory use-after-Close bug (missing fsync) (#10460) ... Summary: TL;DR: due to a recent change, if you drop a column family, often that DB will no longer fsync after writing new SST files to remaining or new column families, which could lead to data loss on power loss. More bug detail: The intent of https://github.com/facebook/rocksdb/issues/10049 was to Close FSDirectory objects at DB::Close time rather than waiting for DB object destruction. Unfortunately, it also closes shared FSDirectory objects on DropColumnFamily (& destroy remaining handles), which can lead to use-after-Close on FSDirectory shared with remaining column families. Those "uses" are only Fsyncs (or redundant Closes). In the default Posix filesystem, an Fsync on a closed FSDirectory is a quiet no-op. Consequently (under most configurations), if you drop a column family, that DB will no longer fsync after writing new SST files to column families sharing the same directory (true under most configurations). More fix detail: Basically, this removes unnecessary Close ops on destroying ColumnFamilyData. We let `shared_ptr` take care of calling the destructor at the right time. If the intent was to require Close be called before destroying FSDirectory, that was not made clear by the author of FileSystem and was not at all enforced by https://github.com/facebook/rocksdb/issues/10049, which could have added `assert(fd_ == -1)` to `~PosixDirectory()` but did not. To keep this fix simple, we relax the unit test for https://github.com/facebook/rocksdb/issues/10049 to allow timely destruction of FSDirectory to suffice as Close (in CountedFileSystem). Added a TODO to revisit that. Also in this PR: * Added a TODO to share FSDirectory instances between DB and its column families. (Already shared among column families.) * Made DB::Close attempt to close all its open FSDirectory objects even if there is a failure in closing one. Also code clean-up around this logic. Pull Request resolved: https://github.com/facebook/rocksdb/pull/10460 Test Plan: add an assert to check for use-after-Close. With that existing tests can detect the misuse. With fix, tests pass (except noted relaxing of unit test for https://github.com/facebook/rocksdb/issues/10049) Reviewed By: ajkr Differential Revision: D38357922 Pulled By: pdillinger fbshipit-source-id: d42079cadbedf0a969f03389bf586b3b4e1f9137	2 years ago
Yanqin Jin	fbfcf5cbcd	Remove unused fields from FileMetaData (temporarily) (#10443) ... Summary: FileMetaData::[min|max]_timestamp are not currently being used or tracked by RocksDB, even when user-defined timestamp is enabled. Each of them is a std::string which can occupy 32 bytes. Remove them for now. They may be added back when we have a pressing need for them. When we do add them back, consider store them in a more compact way, e.g. one boolean flag and a byte array of size 16. Per file min/max timestamp bounds are available as table properties. Pull Request resolved: https://github.com/facebook/rocksdb/pull/10443 Test Plan: make check Reviewed By: pdillinger Differential Revision: D38292275 Pulled By: riversand963 fbshipit-source-id: 841dc4e855ad8f8481c80cb020603de9607c9c94	2 years ago
Andrew Kryczka	c7ccbb33a6	Allow manual compactions to run in parallel by default (#10317) ... Summary: This PR changes the default value of `CompactRangeOptions::exclusive_manual_compaction` from true to false so manual `CompactRange()`s can run in parallel with other compactions. I believe no artificial parallelism restriction is the intuitive behavior so feel the old default value is a trap, which I have fallen into several times, including yesterday. `CompactRangeOptions::exclusive_manual_compaction == false` has been used in both our correctness test and in production for years so should be reasonably safe. Pull Request resolved: https://github.com/facebook/rocksdb/pull/10317 Reviewed By: jay-zhuang Differential Revision: D37659392 Pulled By: ajkr fbshipit-source-id: 504915e978bbe300b79483d064070c75e93d91e5	2 years ago
Jay Zhuang	87649d3288	Best efforts recovery to skip empty MANIFEST (#10416) ... Summary: Skip empty MANIFEST fie during best_efforts_recovery. Pull Request resolved: https://github.com/facebook/rocksdb/pull/10416 Test Plan: make failed db_stress test pass Reviewed By: riversand963 Differential Revision: D38126273 Pulled By: jay-zhuang fbshipit-source-id: 4498d322b09eaa194dd2cbf9c683d62ab54bfb01	2 years ago
Zichen Zhu	8860fc902a	Support subcmpct using reserved resources for round-robin priority (#10341) ... Summary: Earlier implementation of round-robin priority can only pick one file at a time and disallows parallel compactions within the same level. In this PR, round-robin compaction policy will expand towards more input files with respecting some additional constraints, which are summarized as follows: * Constraint 1: We can only pick consecutive files - Constraint 1a: When a file is being compacted (or some input files are being compacted after expanding), we cannot choose it and have to stop choosing more files - Constraint 1b: When we reach the last file (with the largest keys), we cannot choose more files (the next file will be the first one with small keys) * Constraint 2: We should ensure the total compaction bytes (including the overlapped files from the next level) is no more than `mutable_cf_options_.max_compaction_bytes` * Constraint 3: We try our best to pick as many files as possible so that the post-compaction level size can be just less than `MaxBytesForLevel(start_level_)` * Constraint 4: If trivial move is allowed, we reuse the logic of `TryNonL0TrivialMove()` instead of expanding files with Constraint 3 More details can be found in `LevelCompactionBuilder::SetupOtherFilesWithRoundRobinExpansion()`. The above optimization accelerates the process of moving the compaction cursor, in which the write-amp can be further reduced. While a large compaction may lead to high write stall, we break this large compaction into several subcompactions **regardless of** the `max_subcompactions` limit. The number of subcompactions for round-robin compaction priority is determined through the following steps: * Step 1: Initialized against `max_output_file_limit`, the number of input files in the start level, and also the range size limit `ranges.size()` * Step 2: Call `AcquireSubcompactionResources()`when max subcompactions is not sufficient, but we may or may not obtain desired resources, additional number of resources is stored in `extra_num_subcompaction_threads_reserved_`). Subcompaction limit is changed and update `num_planned_subcompactions` with `GetSubcompactionLimit()` * Step 3: Call `ShrinkSubcompactionResources()` to ensure extra resources can be released (extra resources may exist for round-robin compaction when the number of actual number of subcompactions is less than the number of planned subcompactions) More details can be found in `CompactionJob::AcquireSubcompactionResources()`,`CompactionJob::ShrinkSubcompactionResources()`, and `CompactionJob::ReleaseSubcompactionResources()`. Pull Request resolved: https://github.com/facebook/rocksdb/pull/10341 Test Plan: Add `CompactionPriMultipleFilesRoundRobin[1-3]` unit test in `compaction_picker_test.cc` and `RoundRobinSubcompactionsAgainstResources.SubcompactionsUsingResources/[0-4]`, `RoundRobinSubcompactionsAgainstPressureToken.PressureTokenTest/[0-1]` in `db_compaction_test.cc` Reviewed By: ajkr, hx235 Differential Revision: D37792644 Pulled By: littlepig2013 fbshipit-source-id: 7fecb7c4ffd97b34bbf6e3b760b2c35a772a0657	2 years ago
Wallace	1e9bf25f61	Do not hold mutex when write keys if not necessary (#7516) ... Summary: ## Problem Summary RocksDB will acquire the global mutex of db instance for every time when user calls `Write`. When RocksDB schedules a lot of compaction jobs, it will compete the mutex with write thread and it will hurt the write performance. ## Problem Solution: I want to use log_write_mutex to replace the global mutex in most case so that we do not acquire it in write-thread unless there is a write-stall event or a write-buffer-full event occur. Pull Request resolved: https://github.com/facebook/rocksdb/pull/7516 Test Plan: 1. make check 2. CI 3. COMPILE_WITH_TSAN=1 make db_stress make crash_test make crash_test_with_multiops_wp_txn make crash_test_with_multiops_wc_txn make crash_test_with_atomic_flush Reviewed By: siying Differential Revision: D36908702 Pulled By: riversand963 fbshipit-source-id: 59b13881f4f5c0a58fd3ca79128a396d9cd98efe	2 years ago
Jay Zhuang	18a61a1734	Fix seqno->time worker not scheduled with multi DB instances (#10383) ... Summary: `PeriodicWorkScheduler` is a global singleton, which were used to store per-instance setting `record_seqno_time_cadence_`. Move that to db_impl.h which is per-instance. Pull Request resolved: https://github.com/facebook/rocksdb/pull/10383 Reviewed By: siying Differential Revision: D37928009 Pulled By: jay-zhuang fbshipit-source-id: e517754f4a9db98798ac04f72033d4b517f734e9	2 years ago
Jay Zhuang	faa0f9723c	Tiered compaction: integrate Seqno time mapping with per key placement (#10370) ... Summary: Using the Sequence number to time mapping to decide if a key is hot or not in compaction and place it in the corresponding level. Note: the feature is not complete, level compaction will run indefinitely until all penultimate level data is cold and small enough to not trigger compaction. Pull Request resolved: https://github.com/facebook/rocksdb/pull/10370 Test Plan: CI * Run basic db_bench for universal compaction manually Reviewed By: siying Differential Revision: D37892338 Pulled By: jay-zhuang fbshipit-source-id: 792bbd91b1ccc2f62b5d14c53118434bcaac4bbe	2 years ago
Jay Zhuang	fb579a221c	Remove fixed TODO (#10241) ... Summary: Pull Request resolved: https://github.com/facebook/rocksdb/pull/10241 Reviewed By: gitbw95 Differential Revision: D37369726 Pulled By: jay-zhuang fbshipit-source-id: 1e94f0e2433aee42e9871043fa434291ce948eac	2 years ago
Jay Zhuang	69a18b9bad	VerifySstUniqueIds status is overrided for multi CFs (#10247) ... Summary: There's bug that basically we only report the last CF's VerifySstUniqueIds() result: https://github.com/facebook/rocksdb/pull/9990#discussion_r877268810 Pull Request resolved: https://github.com/facebook/rocksdb/pull/10247 Test Plan: CI Reviewed By: pdillinger Differential Revision: D37384265 Pulled By: jay-zhuang fbshipit-source-id: d462ad0eab39c9145c45a3db9c45539d5d76f7dd	2 years ago
Jay Zhuang	a3acf2ef87	Add seqno to time mapping (#10338) ... Summary: Which will be used for tiered storage to preclude hot data from compacting to the cold tier (the last level). Internally, adding seqno to time mapping. A periodic_task is scheduled to record the current_seqno -> current_time in certain cadence. When memtable flush, the mapping informaiton is stored in sstable property. During compaction, the mapping information are merged and get the approximate time of sequence number, which is used to determine if a key is recently inserted or not and preclude it from the last level if it's recently inserted (within the `preclude_last_level_data_seconds`). Pull Request resolved: https://github.com/facebook/rocksdb/pull/10338 Test Plan: CI Reviewed By: siying Differential Revision: D37810187 Pulled By: jay-zhuang fbshipit-source-id: 6953be7a18a99de8b1cb3b162d712f79c2b4899f	2 years ago
Yanqin Jin	b283f041f5	Stop tracking syncing live WAL for performance (#10330) ... Summary: With https://github.com/facebook/rocksdb/issues/10087, applications calling `SyncWAL()` or writing with `WriteOptions::sync=true` can suffer from performance regression. This PR reverts to original behavior of tracking the syncing of closed WALs. After we revert back to old behavior, recovery, whether kPointInTime or kAbsoluteConsistency, may fail to detect corruption in synced WALs if the corruption is in the live WAL. Pull Request resolved: https://github.com/facebook/rocksdb/pull/10330 Test Plan: make check Before https://github.com/facebook/rocksdb/issues/10087 ```bash fillsync : 750.269 micros/op 1332 ops/sec 75.027 seconds 100000 operations; 0.1 MB/s (100 ops) fillsync : 776.492 micros/op 1287 ops/sec 77.649 seconds 100000 operations; 0.1 MB/s (100 ops) fillsync [AVG 2 runs] : 1310 (± 44) ops/sec; 0.1 (± 0.0) MB/sec fillsync : 805.625 micros/op 1241 ops/sec 80.563 seconds 100000 operations; 0.1 MB/s (100 ops) fillsync [AVG 3 runs] : 1287 (± 51) ops/sec; 0.1 (± 0.0) MB/sec fillsync [AVG 3 runs] : 1287 (± 51) ops/sec; 0.1 (± 0.0) MB/sec fillsync [MEDIAN 3 runs] : 1287 ops/sec; 0.1 MB/sec ``` Before this PR and after https://github.com/facebook/rocksdb/issues/10087 ```bash fillsync : 1479.601 micros/op 675 ops/sec 147.960 seconds 100000 operations; 0.1 MB/s (100 ops) fillsync : 1626.080 micros/op 614 ops/sec 162.608 seconds 100000 operations; 0.1 MB/s (100 ops) fillsync [AVG 2 runs] : 645 (± 59) ops/sec; 0.1 (± 0.0) MB/sec fillsync : 1588.402 micros/op 629 ops/sec 158.840 seconds 100000 operations; 0.1 MB/s (100 ops) fillsync [AVG 3 runs] : 640 (± 35) ops/sec; 0.1 (± 0.0) MB/sec fillsync [AVG 3 runs] : 640 (± 35) ops/sec; 0.1 (± 0.0) MB/sec fillsync [MEDIAN 3 runs] : 629 ops/sec; 0.1 MB/sec ``` After this PR ```bash fillsync : 749.621 micros/op 1334 ops/sec 74.962 seconds 100000 operations; 0.1 MB/s (100 ops) fillsync : 865.577 micros/op 1155 ops/sec 86.558 seconds 100000 operations; 0.1 MB/s (100 ops) fillsync [AVG 2 runs] : 1244 (± 175) ops/sec; 0.1 (± 0.0) MB/sec fillsync : 845.837 micros/op 1182 ops/sec 84.584 seconds 100000 operations; 0.1 MB/s (100 ops) fillsync [AVG 3 runs] : 1223 (± 109) ops/sec; 0.1 (± 0.0) MB/sec fillsync [AVG 3 runs] : 1223 (± 109) ops/sec; 0.1 (± 0.0) MB/sec fillsync [MEDIAN 3 runs] : 1182 ops/sec; 0.1 MB/sec ``` Reviewed By: ajkr Differential Revision: D37725212 Pulled By: riversand963 fbshipit-source-id: 8fa7d13b3c7662be5d56351c42caf3266af937ae	2 years ago
Yanqin Jin	7e2004a123	Remove unused variables (#10327) ... Summary: As title. Pull Request resolved: https://github.com/facebook/rocksdb/pull/10327 Test Plan: make check Reviewed By: gitbw95 Differential Revision: D37699040 Pulled By: riversand963 fbshipit-source-id: 305a88628907a47dea53c4d9aec9c2f5bb9b58df	2 years ago
Changyu Bi	0ff7713112	Handoff checksum during WAL replay (#10212) ... Summary: Added checksum protection for write batch content read from WAL to when per key-value checksum is computed on the write batch. This gives full coverage on write batch integrity of WAL replay to memtable. Pull Request resolved: https://github.com/facebook/rocksdb/pull/10212 Test Plan: - Added unit test and the existing tests (replay code path covers the change in this PR): `make -j32 check` - Stress test: ran `db_stress` for 30min. - Perf regression: ``` # setup TEST_TMPDIR=/dev/shm/100MB_WAL_DB/ ./db_bench -benchmarks=fillrandom -write_buffer_size=1048576000 # benchmark db open time TEST_TMPDIR=/dev/shm/100MB_WAL_DB/ /usr/bin/time ./db_bench -use_existing_db=true -benchmarks=overwrite -write_buffer_size=1048576000 -writes=1 -report_open_timing=true For 20 runs, pre-PR avg: 3734.31ms, post-PR avg: 3790.06 ms (~1.5% regression). Pre-PR OpenDb: 3714.36 milliseconds OpenDb: 3622.71 milliseconds OpenDb: 3591.17 milliseconds OpenDb: 3674.7 milliseconds OpenDb: 3615.79 milliseconds OpenDb: 3982.83 milliseconds OpenDb: 3650.6 milliseconds OpenDb: 3809.26 milliseconds OpenDb: 3576.44 milliseconds OpenDb: 3638.12 milliseconds OpenDb: 3845.68 milliseconds OpenDb: 3677.32 milliseconds OpenDb: 3659.64 milliseconds OpenDb: 3837.55 milliseconds OpenDb: 3899.64 milliseconds OpenDb: 3840.72 milliseconds OpenDb: 3802.71 milliseconds OpenDb: 3573.27 milliseconds OpenDb: 3895.76 milliseconds OpenDb: 3778.02 milliseconds Post-PR: OpenDb: 3880.46 milliseconds OpenDb: 3709.02 milliseconds OpenDb: 3954.67 milliseconds OpenDb: 3955.64 milliseconds OpenDb: 3958.64 milliseconds OpenDb: 3631.28 milliseconds OpenDb: 3721 milliseconds OpenDb: 3729.89 milliseconds OpenDb: 3730.55 milliseconds OpenDb: 3966.32 milliseconds OpenDb: 3685.54 milliseconds OpenDb: 3573.17 milliseconds OpenDb: 3703.75 milliseconds OpenDb: 3873.62 milliseconds OpenDb: 3704.4 milliseconds OpenDb: 3820.98 milliseconds OpenDb: 3721.62 milliseconds OpenDb: 3770.86 milliseconds OpenDb: 3949.78 milliseconds OpenDb: 3760.07 milliseconds ``` Reviewed By: ajkr Differential Revision: D37302092 Pulled By: cbi42 fbshipit-source-id: 7346e625f453ce4c0e5d708776cd1fb2af6b068b	2 years ago
Yanqin Jin	d6b9c4ae26	Update code comment and logging for secondary instance (#10260) ... Summary: Before this PR, it is required that application open RocksDB secondary instance with `max_open_files = -1`. This is a hacky workaround that prevents IOErrors on the seconary instance during point-lookup or range scan caused by primary instance deleting the table files. This is not necessary if the application can coordinate the primary and secondaries so that primary does not delete files that are still being used by the secondaries. Or users can provide a custom Env/FS implementation that deletes the files only after all primary and secondary instances indicate files are obsolete and deleted. Pull Request resolved: https://github.com/facebook/rocksdb/pull/10260 Test Plan: make check Reviewed By: jay-zhuang Differential Revision: D37462633 Pulled By: riversand963 fbshipit-source-id: 9c2fc939f49663efa61e3d60c8f1e01d64b9d72c	2 years ago
Levi Tamasi	c73d2a9d18	Add API for writing wide-column entities (#10242) ... Summary: The patch builds on https://github.com/facebook/rocksdb/pull/9915 and adds a new API called `PutEntity` that can be used to write a wide-column entity to the database. The new API is added to both `DB` and `WriteBatch`. Note that currently there is no way to retrieve these entities; more precisely, all read APIs (`Get`, `MultiGet`, and iterator) return `NotSupported` when they encounter a wide-column entity that is required to answer a query. Read-side support (as well as other missing functionality like `Merge`, compaction filter, and timestamp support) will be added in later PRs. Pull Request resolved: https://github.com/facebook/rocksdb/pull/10242 Test Plan: `make check` Reviewed By: riversand963 Differential Revision: D37369748 Pulled By: ltamasi fbshipit-source-id: 7f5e412359ed7a400fd80b897dae5599dbcd685d	2 years ago
Yanqin Jin	725df120e9	Fix race condition between file purge and backup/checkpoint (#10187) ... Summary: Resolves https://github.com/facebook/rocksdb/issues/10129 I extracted this fix from https://github.com/facebook/rocksdb/issues/7516 since it's also already a bug in main branch, and we want to separate it from the main part of the PR. There can be a race condition between two threads. Thread 1 executes `DBImpl::FindObsoleteFiles()` while thread 2 executes `GetSortedWals()`. ``` Time thread 1 thread 2 | mutex_.lock | read disable_delete_obsolete_files_ | ... | wait on log_sync_cv and release mutex_ | mutex_.lock | ++disable_delete_obsolete_files_ | mutex_.unlock | mutex_.lock | while (pending_purge_obsolete_files > 0) { bg_cv.wait;} | wake up with mutex_ locked | compute WALs tracked by MANIFEST | mutex_.unlock | wake up with mutex_ locked | ++pending_purge_obsolete_files_ | mutex_.unlock | | delete obsolete WAL | WAL missing but tracked in MANIFEST. V ``` The fix proposed eliminates the possibility of the above by increasing `pending_purge_obsolete_files_` before `FindObsoleteFiles()` can possibly release the mutex. Pull Request resolved: https://github.com/facebook/rocksdb/pull/10187 Test Plan: make check Reviewed By: ltamasi Differential Revision: D37214235 Pulled By: riversand963 fbshipit-source-id: 556ab1b58ae6d19150169dfac4db08195c797184	2 years ago
Baptiste Lemaire	5879053fd0	Dynamically changeable `MemPurge` option (#10011) ... Summary: **Summary** Make the mempurge option flag a Mutable Column Family option flag. Therefore, the mempurge feature can be dynamically toggled. **Motivation** RocksDB users prefer having the ability to switch features on and off without having to close and reopen the DB. This is particularly important if the feature causes issues and needs to be turned off. Dynamically changing a DB option flag does not seem currently possible. Moreover, with this new change, the MemPurge feature can be toggled on or off independently between column families, which we see as a major improvement. **Content of this PR** This PR includes removal of the `experimental_mempurge_threshold` flag as a DB option flag, and its re-introduction as a `MutableCFOption` flag. I updated the code to handle dynamic changes of the flag (in particular inside the `FlushJob` file). Additionally, this PR includes a new test to demonstrate the capacity of the code to toggle the MemPurge feature on and off, as well as the addition in the `db_stress` module of 2 different mempurge threshold values (0.0 and 1.0) that can be randomly changed with the `set_option_one_in` flag. This is useful to stress test the dynamic changes. **Benchmarking** I will add numbers to prove that there is no performance impact within the next 12 hours. Pull Request resolved: https://github.com/facebook/rocksdb/pull/10011 Reviewed By: pdillinger Differential Revision: D36462357 Pulled By: bjlemaire fbshipit-source-id: 5e3d63bdadf085c0572ecc2349e7dd9729ce1802	2 years ago
Bo Wang	c073ed7601	Fix typo in comments and code (#10233) ... Summary: Fix typo in comments and code. Pull Request resolved: https://github.com/facebook/rocksdb/pull/10233 Test Plan: Existing unit tests should pass. Reviewed By: jay-zhuang, anand1976 Differential Revision: D37356702 Pulled By: gitbw95 fbshipit-source-id: 32c019adcc6dcc95a9882b38147a310091368e51	2 years ago
Yanqin Jin	9586dcf1ce	Expose the initial logger creation error (#10223) ... Summary: https://github.com/facebook/rocksdb/issues/9984 changes the behavior of RocksDB: if logger creation failed during `SanitizeOptions()`, `DB::Open()` will fail. However, since `SanitizeOptions()` is called in `DBImpl::DBImpl()`, we cannot directly expose the error to caller without some additional work. This is a first version proposal which: - Adds a new member `init_logger_creation_s` to `DBImpl` to store the result of init logger creation - Checks the error during `DB::Open()` and return it to caller if non-ok This is not very ideal. We can alternatively move the logger creation logic out of the `SanitizeOptions()`. Since `SanitizeOptions()` is used in other places, we need to check whether this change breaks anything in case other callers of `SanitizeOptions()` assumes that a logger should be created. Pull Request resolved: https://github.com/facebook/rocksdb/pull/10223 Test Plan: make check Reviewed By: pdillinger Differential Revision: D37321717 Pulled By: riversand963 fbshipit-source-id: 58042358a86369d606549dd9938933dd47591c4b	2 years ago
Yanqin Jin	d654888b8f	Refactor wal filter processing during recovery (#10214) ... Summary: So that DBImpl::RecoverLogFiles do not have to deal with implementation details of WalFilter. Pull Request resolved: https://github.com/facebook/rocksdb/pull/10214 Test Plan: make check Reviewed By: ajkr Differential Revision: D37299122 Pulled By: riversand963 fbshipit-source-id: acf1a80f1ef75da393d375f55968b2f3ac189816	2 years ago
zczhu	30141461f9	Add basic kRoundRobin compaction policy (#10107) ... Summary: Add `kRoundRobin` as a compaction priority. The implementation is as follows. - Define a cursor as the smallest Internal key in the successor of the selected file. Add `vector<InternalKey> compact_cursor_` into `VersionStorageInfo` where each element (`InternalKey`) in `compact_cursor_` represents a cursor. In round-robin compaction policy, we just need to select the first file (assuming files are sorted) and also has the smallest InternalKey larger than/equal to the cursor. After a file is chosen, we create a new `Fsize` vector which puts the selected file is placed at the first position in `temp`, the next cursor is then updated as the smallest InternalKey in successor of the selected file (the above logic is implemented in `SortFileByRoundRobin`). - After a compaction succeeds, typically `InstallCompactionResults()`, we choose the next cursor for the input level and save it to `edit`. When calling `LogAndApply`, we save the next cursor with its level into some local variable and finally apply the change to `vstorage` in `SaveTo` function. - Cursors are persist pair by pair (<level, InternalKey>) in `EncodeTo` so that they can be reconstructed when reopening. An empty cursor will not be encoded to MANIFEST Pull Request resolved: https://github.com/facebook/rocksdb/pull/10107 Test Plan: add unit test (`CompactionPriRoundRobin`) in `compaction_picker_test`, add `kRoundRobin` priority in `CompactionPriTest` from `db_compaction_test`, and add `PersistRoundRobinCompactCursor` in `db_compaction_test` Reviewed By: ajkr Differential Revision: D37316037 Pulled By: littlepig2013 fbshipit-source-id: 9f481748190ace416079139044e00df2968fb1ee	2 years ago
Gang Liao	deff48bcef	Add blob source to retrieve blobs in RocksDB (#10198) ... Summary: There is currently no caching mechanism for blobs, which is not ideal especially when the database resides on remote storage (where we cannot rely on the OS page cache). As part of this task, we would like to make it possible for the application to configure a blob cache. In this task, we formally introduced the blob source to RocksDB. BlobSource is a new abstraction layer that provides universal access to blobs, regardless of whether they are in the blob cache, secondary cache, or (remote) storage. Depending on user settings, it always fetch blobs from multi-tier cache and storage with minimal cost. Note: The new `MultiGetBlob()` implementation is not included in the current PR. To go faster, we aim to create a separate PR for it in parallel! This PR is a part of https://github.com/facebook/rocksdb/issues/10156 Pull Request resolved: https://github.com/facebook/rocksdb/pull/10198 Reviewed By: ltamasi Differential Revision: D37294735 Pulled By: gangliao fbshipit-source-id: 9cb50422d9dd1bc03798501c2778b6c7520c7a1e	2 years ago
Andrew Kryczka	d5d8920f2c	Fix race condition with WAL tracking and `FlushWAL(true /* sync */)` (#10185) ... Summary: `FlushWAL(true /* sync */)` is used internally and for manual WAL sync. It had a bug when used together with `track_and_verify_wals_in_manifest` where the synced size tracked in MANIFEST was larger than the number of bytes actually synced. The bug could be repro'd almost immediately with the following crash test command: `python3 tools/db_crashtest.py blackbox --simple --write_buffer_size=524288 --max_bytes_for_level_base=2097152 --target_file_size_base=524288 --duration=3600 --interval=10 --sync_fault_injection=1 --disable_wal=0 --checkpoint_one_in=1000 --max_key=10000 --value_size_mult=33`. An example error message produced by the above command is shown below. The error sometimes arose from the checkpoint and other times arose from the main stress test DB. ``` Corruption: Size mismatch: WAL (log number: 119) in MANIFEST is 27938 bytes , but actually is 27859 bytes on disk. ``` Pull Request resolved: https://github.com/facebook/rocksdb/pull/10185 Test Plan: - repro unit test - the above crash test command no longer finds the error. It does find a different error after a while longer such as "Corruption: WAL file 481 required by manifest but not in directory list" Reviewed By: riversand963 Differential Revision: D37200993 Pulled By: ajkr fbshipit-source-id: 98e0071c1a89f4d009888512ed89f9219779ae5f	2 years ago