mirror of https://github.com/facebook/rocksdb.git
302 Commits
Author | SHA1 | Message | Date |
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Yu Zhang | 4ea7b796b7 |
Respect cutoff timestamp during flush (#11599)
Summary: Make flush respect the cutoff timestamp `full_history_ts_low` as much as possible for the user-defined timestamps in Memtables only feature. We achieve this by not proceeding with the actual flushing but instead reschedule the same `FlushRequest` so a follow up flush job can continue with the check after some interval. This approach doesn't work well for atomic flush, so this feature currently is not supported in combination with atomic flush. Furthermore, this approach also requires a customized method to get the next immediately bigger user-defined timestamp. So currently it's limited to comparator that use uint64_t as the user-defined timestamp format. This support can be extended when we add such a customized method to `AdvancedColumnFamilyOptions`. For non atomic flush request, at any single time, a column family can only have as many as one FlushRequest for it in the `flush_queue_`. There is deduplication done at `FlushRequest` enqueueing(`SchedulePendingFlush`) and dequeueing time (`PopFirstFromFlushQueue`). We hold the db mutex between when a `FlushRequest` is popped from the queue and the same FlushRequest get rescheduled, so no other `FlushRequest` with a higher `max_memtable_id` can be added to the `flush_queue_` blocking us from re-enqueueing the same `FlushRequest`. Flush is continued nevertheless if there is risk of entering write stall mode had the flush being postponed, e.g. due to accumulation of write buffers, exceeding the `max_write_buffer_number` setting. When this happens, the newest user-defined timestamp in the involved Memtables need to be tracked and we use it to increase the `full_history_ts_low`, which is an inclusive cutoff timestamp for which RocksDB promises to keep all user-defined timestamps equal to and newer than it. Tet plan: ``` ./column_family_test --gtest_filter="*RetainUDT*" ./memtable_list_test --gtest_filter="*WithTimestamp*" ./flush_job_test --gtest_filter="*WithTimestamp*" ``` Pull Request resolved: https://github.com/facebook/rocksdb/pull/11599 Reviewed By: ajkr Differential Revision: D47561586 Pulled By: jowlyzhang fbshipit-source-id: 9400445f983dd6eac489e9dd0fb5d9b99637fe89 |
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Changyu Bi | 5c2a063c49 |
Clarify usage for options `ttl` and `periodic_compaction_seconds` for universal compaction (#11552)
Summary: this is stacked on https://github.com/facebook/rocksdb/issues/11550 to further clarify usage of these two options for universal compaction. Similar to FIFO, the two options have the same meaning for universal compaction, which can be confusing to use. For example, for universal compaction, dynamically changing the value of `ttl` has no impact on periodic compactions. Users should dynamically change `periodic_compaction_seconds` instead. From feature matrix (https://fburl.com/daiquery/5s647hwh), there are instances where users set `ttl` to non-zero value and `periodic_compaction_seconds` to 0. For backward compatibility reason, instead of deprecating `ttl`, comments are added to mention that `periodic_compaction_seconds` are preferred. In `SanitizeOptions()`, we update the value of `periodic_compaction_seconds` to take into account value of `ttl`. The logic is documented in relevant option comment. Pull Request resolved: https://github.com/facebook/rocksdb/pull/11552 Test Plan: * updated existing unit test `DBTestUniversalCompaction2.PeriodicCompactionDefault` Reviewed By: ajkr Differential Revision: D47381434 Pulled By: cbi42 fbshipit-source-id: bc41f29f77318bae9a96be84dd89bf5617c7fd57 |
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Changyu Bi | df082c8d1d |
Deprecate option `periodic_compaction_seconds` for FIFO compaction (#11550)
Summary: both options `ttl` and `periodic_compaction_seconds` have the same meaning for FIFO compaction, which is redundant and can be confusing to use. For example, setting TTL to 0 does not disable TTL: user needs to also set periodic_compaction_seconds to 0. Another example is that dynamically setting `periodic_compaction_seconds` (surprisingly) has no effect on TTL compaction. This is because FIFO compaction picker internally only looks at value of `ttl`. The value of `ttl` is in `SanitizeOptions()` which take into account the value of `periodic_compaction_seconds`, but dynamically setting an option does not invoke this method. This PR clarifies the usage of both options for FIFO compaction: only `ttl` should be used, `periodic_compaction_seconds` will not have any effect on FIFO compaction. Pull Request resolved: https://github.com/facebook/rocksdb/pull/11550 Test Plan: - updated existing unit test `DBOptionsTest.SanitizeFIFOPeriodicCompaction` - checked existing values of both options in feature matrix: https://fburl.com/daiquery/xxd0gs9w. All current uses cases either have `periodic_compaction_seconds = 0` or have `periodic_compaction_seconds > ttl`, so should not cause change of behavior. Reviewed By: ajkr Differential Revision: D46902959 Pulled By: cbi42 fbshipit-source-id: a9ede235b276783b4906aaec443551fa62ceff4c |
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Yu Zhang | 56ca9e3106 |
Logging timestamp size record in WAL and use it during recovery (#11471)
Summary: Start logging the timestamp size record in WAL and use the record during recovery. Currently, user comparator cannot be different from what was used to create a column family, so the timestamp size record is just used to confirm it's consistent with the timestamp size the running user comparator indicates. Pull Request resolved: https://github.com/facebook/rocksdb/pull/11471 Test Plan: ``` make all check ./db_secondary_test ./db_wal_test --gtest_filter="*WithTimestamp*" ./repair_test --gtest_filter="*WithTimestamp*" ``` Reviewed By: ltamasi Differential Revision: D46236769 Pulled By: jowlyzhang fbshipit-source-id: f6c60b5c8defdb05021c63df302ccc0be1275ad0 |
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rogertyang | 28bf7ba77d |
remove unnecessary code in super version getter (#11452)
Summary: Do not bother comparing the version of the local super version handle with the global one. An inequality comparison result indicates nothing but a spurious obsoleteness. It only happens when the writer has increased the `ColumnFamilyData::super_version_number_`( |
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Changyu Bi | 8827cd0618 |
Support compacting files to different temperatures in FIFO compaction (#11428)
Summary: - Add a new option `CompactionOptionsFIFO::file_temperature_age_thresholds` that allows user to specify age thresholds for compacting files to different temperatures. File temperature can be used to store files in different storage media. The new options allows specifying multiple temperature-age pairs. The option uses struct for a temperature-age pair to use the existing parsing functionality to make the option dynamically settable. - Deprecate the old option `age_for_warm` that was added for a similar purpose. - Compaction score calculation logic is updated to check if a file needs to be compacted to change its temperature. - Some refactoring is done in `FIFOCompactionPicker::PickTemperatureChangeCompaction`. Pull Request resolved: https://github.com/facebook/rocksdb/pull/11428 Test Plan: adapted unit tests that were for `age_for_warm` to this new option. Reviewed By: ajkr Differential Revision: D45611412 Pulled By: cbi42 fbshipit-source-id: 2dc384841f61cc04abb9681e31aa2de0f0b06106 |
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Changyu Bi | 62fc15f009 |
Block per key-value checksum (#11287)
Summary: add option `block_protection_bytes_per_key` and implementation for block per key-value checksum. The main changes are 1. checksum construction and verification in block.cc/h 2. pass the option `block_protection_bytes_per_key` around (mainly for methods defined in table_cache.h) 3. unit tests/crash test updates Tests: * Added unit tests * Crash test: `python3 tools/db_crashtest.py blackbox --simple --block_protection_bytes_per_key=1 --write_buffer_size=1048576` Follow up (maybe as a separate PR): make sure corruption status returned from BlockIters are correctly handled. Performance: Turning on block per KV protection has a non-trivial negative impact on read performance and costs additional memory. For memory, each block includes additional 24 bytes for checksum-related states beside checksum itself. For CPU, I set up a DB of size ~1.2GB with 5M keys (32 bytes key and 200 bytes value) which compacts to ~5 SST files (target file size 256 MB) in L6 without compression. I tested readrandom performance with various block cache size (to mimic various cache hit rates): ``` SETUP make OPTIMIZE_LEVEL="-O3" USE_LTO=1 DEBUG_LEVEL=0 -j32 db_bench ./db_bench -benchmarks=fillseq,compact0,waitforcompaction,compact,waitforcompaction -write_buffer_size=33554432 -level_compaction_dynamic_level_bytes=true -max_background_jobs=8 -target_file_size_base=268435456 --num=5000000 --key_size=32 --value_size=200 --compression_type=none BENCHMARK ./db_bench --use_existing_db -benchmarks=readtocache,readrandom[-X10] --num=5000000 --key_size=32 --disable_auto_compactions --reads=1000000 --block_protection_bytes_per_key=[0|1] --cache_size=$CACHESIZE The readrandom ops/sec looks like the following: Block cache size: 2GB 1.2GB * 0.9 1.2GB * 0.8 1.2GB * 0.5 8MB Main 240805 223604 198176 161653 139040 PR prot_bytes=0 238691 226693 200127 161082 141153 PR prot_bytes=1 214983 193199 178532 137013 108211 prot_bytes=1 vs -10% -15% -10.8% -15% -23% prot_bytes=0 ``` The benchmark has a lot of variance, but there was a 5% to 25% regression in this benchmark with different cache hit rates. Pull Request resolved: https://github.com/facebook/rocksdb/pull/11287 Reviewed By: ajkr Differential Revision: D43970708 Pulled By: cbi42 fbshipit-source-id: ef98d898b71779846fa74212b9ec9e08b7183940 |
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Hui Xiao | 151242ce46 |
Group rocksdb.sst.read.micros stat by IOActivity flush and compaction (#11288)
Summary: **Context:** The existing stat rocksdb.sst.read.micros does not reflect each of compaction and flush cases but aggregate them, which is not so helpful for us to understand IO read behavior of each of them. **Summary** - Update `StopWatch` and `RandomAccessFileReader` to record `rocksdb.sst.read.micros` and `rocksdb.file.{flush/compaction}.read.micros` - Fixed the default histogram in `RandomAccessFileReader` - New field `ReadOptions/IOOptions::io_activity`; Pass `ReadOptions` through paths under db open, flush and compaction to where we can prepare `IOOptions` and pass it to `RandomAccessFileReader` - Use `thread_status_util` for assertion in `DbStressFSWrapper` for continuous testing on we are passing correct `io_activity` under db open, flush and compaction Pull Request resolved: https://github.com/facebook/rocksdb/pull/11288 Test Plan: - **Stress test** - **Db bench 1: rocksdb.sst.read.micros COUNT ≈ sum of rocksdb.file.read.flush.micros's and rocksdb.file.read.compaction.micros's.** (without blob) - May not be exactly the same due to `HistogramStat::Add` only guarantees atomic not accuracy across threads. ``` ./db_bench -db=/dev/shm/testdb/ -statistics=true -benchmarks="fillseq" -key_size=32 -value_size=512 -num=50000 -write_buffer_size=655 -target_file_size_base=655 -disable_auto_compactions=false -compression_type=none -bloom_bits=3 (-use_plain_table=1 -prefix_size=10) ``` ``` // BlockBasedTable rocksdb.sst.read.micros P50 : 2.009374 P95 : 4.968548 P99 : 8.110362 P100 : 43.000000 COUNT : 40456 SUM : 114805 rocksdb.file.read.flush.micros P50 : 1.871841 P95 : 3.872407 P99 : 5.540541 P100 : 43.000000 COUNT : 2250 SUM : 6116 rocksdb.file.read.compaction.micros P50 : 2.023109 P95 : 5.029149 P99 : 8.196910 P100 : 26.000000 COUNT : 38206 SUM : 108689 // PlainTable Does not apply ``` - **Db bench 2: performance** **Read** SETUP: db with 900 files ``` ./db_bench -db=/dev/shm/testdb/ -benchmarks="fillseq" -key_size=32 -value_size=512 -num=50000 -write_buffer_size=655 -disable_auto_compactions=true -target_file_size_base=655 -compression_type=none ```run till convergence ``` ./db_bench -seed=1678564177044286 -use_existing_db=true -db=/dev/shm/testdb -benchmarks=readrandom[-X60] -statistics=true -num=1000000 -disable_auto_compactions=true -compression_type=none -bloom_bits=3 ``` Pre-change `readrandom [AVG 60 runs] : 21568 (± 248) ops/sec` Post-change (no regression, -0.3%) `readrandom [AVG 60 runs] : 21486 (± 236) ops/sec` **Compaction/Flush**run till convergence ``` ./db_bench -db=/dev/shm/testdb2/ -seed=1678564177044286 -benchmarks="fillseq[-X60]" -key_size=32 -value_size=512 -num=50000 -write_buffer_size=655 -disable_auto_compactions=false -target_file_size_base=655 -compression_type=none rocksdb.sst.read.micros COUNT : 33820 rocksdb.sst.read.flush.micros COUNT : 1800 rocksdb.sst.read.compaction.micros COUNT : 32020 ``` Pre-change `fillseq [AVG 46 runs] : 1391 (± 214) ops/sec; 0.7 (± 0.1) MB/sec` Post-change (no regression, ~-0.4%) `fillseq [AVG 46 runs] : 1385 (± 216) ops/sec; 0.7 (± 0.1) MB/sec` Reviewed By: ajkr Differential Revision: D44007011 Pulled By: hx235 fbshipit-source-id: a54c89e4846dfc9a135389edf3f3eedfea257132 |
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Hui Xiao | cb58477185 |
New stat rocksdb.{cf|db}-write-stall-stats exposed in a structural way (#11300)
Summary: **Context/Summary:** Users are interested in figuring out what has caused write stall. - Refactor write stall related stats from property `kCFStats` into its own db property `rocksdb.cf-write-stall-stats` as a map or string. For now, this only contains count of different combination of (CF-scope `WriteStallCause`) + (`WriteStallCondition`) - Add new `WriteStallCause::kWriteBufferManagerLimit` to reflect write stall caused by write buffer manager - Add new `rocksdb.db-write-stall-stats`. For now, this only contains `WriteStallCause::kWriteBufferManagerLimit` + `WriteStallCondition::kStopped` - Expose functions in new class `WriteStallStatsMapKeys` for examining the above two properties returned as map - Misc: rename/comment some write stall InternalStats for clarity Pull Request resolved: https://github.com/facebook/rocksdb/pull/11300 Test Plan: - New UT - Stress test `python3 tools/db_crashtest.py blackbox --simple --get_property_one_in=1` - Perf test: Both converge very slowly at similar rates but post-change has higher average ops/sec than pre-change even though they are run at the same time. ``` ./db_bench -seed=1679014417652004 -db=/dev/shm/testdb/ -statistics=false -benchmarks="fillseq[-X60]" -key_size=32 -value_size=512 -num=100000 -db_write_buffer_size=655 -target_file_size_base=655 -disable_auto_compactions=false -compression_type=none -bloom_bits=3 ``` pre-change: ``` fillseq [AVG 15 runs] : 1176 (± 732) ops/sec; 0.6 (± 0.4) MB/sec fillseq : 1052.671 micros/op 949 ops/sec 105.267 seconds 100000 operations; 0.5 MB/s fillseq [AVG 16 runs] : 1162 (± 685) ops/sec; 0.6 (± 0.4) MB/sec fillseq : 1387.330 micros/op 720 ops/sec 138.733 seconds 100000 operations; 0.4 MB/s fillseq [AVG 17 runs] : 1136 (± 646) ops/sec; 0.6 (± 0.3) MB/sec fillseq : 1232.011 micros/op 811 ops/sec 123.201 seconds 100000 operations; 0.4 MB/s fillseq [AVG 18 runs] : 1118 (± 610) ops/sec; 0.6 (± 0.3) MB/sec fillseq : 1282.567 micros/op 779 ops/sec 128.257 seconds 100000 operations; 0.4 MB/s fillseq [AVG 19 runs] : 1100 (± 578) ops/sec; 0.6 (± 0.3) MB/sec fillseq : 1914.336 micros/op 522 ops/sec 191.434 seconds 100000 operations; 0.3 MB/s fillseq [AVG 20 runs] : 1071 (± 551) ops/sec; 0.6 (± 0.3) MB/sec fillseq : 1227.510 micros/op 814 ops/sec 122.751 seconds 100000 operations; 0.4 MB/s fillseq [AVG 21 runs] : 1059 (± 525) ops/sec; 0.5 (± 0.3) MB/sec ``` post-change: ``` fillseq [AVG 15 runs] : 1226 (± 732) ops/sec; 0.6 (± 0.4) MB/sec fillseq : 1323.825 micros/op 755 ops/sec 132.383 seconds 100000 operations; 0.4 MB/s fillseq [AVG 16 runs] : 1196 (± 687) ops/sec; 0.6 (± 0.4) MB/sec fillseq : 1223.905 micros/op 817 ops/sec 122.391 seconds 100000 operations; 0.4 MB/s fillseq [AVG 17 runs] : 1174 (± 647) ops/sec; 0.6 (± 0.3) MB/sec fillseq : 1168.996 micros/op 855 ops/sec 116.900 seconds 100000 operations; 0.4 MB/s fillseq [AVG 18 runs] : 1156 (± 611) ops/sec; 0.6 (± 0.3) MB/sec fillseq : 1348.729 micros/op 741 ops/sec 134.873 seconds 100000 operations; 0.4 MB/s fillseq [AVG 19 runs] : 1134 (± 579) ops/sec; 0.6 (± 0.3) MB/sec fillseq : 1196.887 micros/op 835 ops/sec 119.689 seconds 100000 operations; 0.4 MB/s fillseq [AVG 20 runs] : 1119 (± 550) ops/sec; 0.6 (± 0.3) MB/sec fillseq : 1193.697 micros/op 837 ops/sec 119.370 seconds 100000 operations; 0.4 MB/s fillseq [AVG 21 runs] : 1106 (± 524) ops/sec; 0.6 (± 0.3) MB/sec ``` Reviewed By: ajkr Differential Revision: D44159541 Pulled By: hx235 fbshipit-source-id: 8d29efb70001fdc52d34535eeb3364fc3e71e40b |
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sdong | 4720ba4391 |
Remove RocksDB LITE (#11147)
Summary: We haven't been actively mantaining RocksDB LITE recently and the size must have been gone up significantly. We are removing the support. Most of changes were done through following comments: unifdef -m -UROCKSDB_LITE `git grep -l ROCKSDB_LITE | egrep '[.](cc|h)'` by Peter Dillinger. Others changes were manually applied to build scripts, CircleCI manifests, ROCKSDB_LITE is used in an expression and file db_stress_test_base.cc. Pull Request resolved: https://github.com/facebook/rocksdb/pull/11147 Test Plan: See CI Reviewed By: pdillinger Differential Revision: D42796341 fbshipit-source-id: 4920e15fc2060c2cd2221330a6d0e5e65d4b7fe2 |
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Hui Xiao | 86fa2592be |
Fix data race on `ColumnFamilyData::flush_reason` by letting FlushRequest/Job owns flush_reason instead of CFD (#11111)
Summary: **Context:** Concurrent flushes on the same CF can set on `ColumnFamilyData::flush_reason` before each other flush finishes. An symptom is one CF has different flush_reason with others though all of them are in an atomic flush `db_stress: db/db_impl/db_impl_compaction_flush.cc:423: rocksdb::Status rocksdb::DBImpl::AtomicFlushMemTablesToOutputFiles(const rocksdb::autovector<rocksdb::DBImpl::BGFlushArg>&, bool*, rocksdb::JobContext*, rocksdb::LogBuffer*, rocksdb::Env::Priority): Assertion cfd->GetFlushReason() == cfds[0]->GetFlushReason() failed. ` **Summary:** Suggested by ltamasi, we now refactor and let FlushRequest/Job to own flush_reason as there is no good way to define `ColumnFamilyData::flush_reason` in face of concurrent flushes on the same CF (which wasn't the case a long time ago when `ColumnFamilyData::flush_reason ` first introduced`) **Tets:** - new unit test - make check - aggressive crash test rehearsal Pull Request resolved: https://github.com/facebook/rocksdb/pull/11111 Reviewed By: ajkr Differential Revision: D42644600 Pulled By: hx235 fbshipit-source-id: 8589c8184869d3415e5b780c887f877818a5ebaf |
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Hui Xiao | 9502856edd |
Add missing range conflict check between file ingestion and RefitLevel() (#10988)
Summary: **Context:** File ingestion never checks whether the key range it acts on overlaps with an ongoing RefitLevel() (used in `CompactRange()` with `change_level=true`). That's because RefitLevel() doesn't register and make its key range known to file ingestion. Though it checks overlapping with other compactions by https://github.com/facebook/rocksdb/blob/7.8.fb/db/external_sst_file_ingestion_job.cc#L998. RefitLevel() (used in `CompactRange()` with `change_level=true`) doesn't check whether the key range it acts on overlaps with an ongoing file ingestion. That's because file ingestion does not register and make its key range known to other compactions. - Note that non-refitlevel-compaction (e.g, manual compaction w/o RefitLevel() or general compaction) also does not check key range overlap with ongoing file ingestion for the same reason. - But it's fine. Credited to cbi42's discovery, `WaitForIngestFile` was called by background and foreground compactions. They were introduced in |
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Hui Xiao | 98d5db5c2e |
Sort L0 files by newly introduced epoch_num (#10922)
Summary:
**Context:**
Sorting L0 files by `largest_seqno` has at least two inconvenience:
- File ingestion and compaction involving ingested files can create files of overlapping seqno range with the existing files. `force_consistency_check=true` will catch such overlap seqno range even those harmless overlap.
- For example, consider the following sequence of events ("key@n" indicates key at seqno "n")
- insert k1@1 to memtable m1
- ingest file s1 with k2@2, ingest file s2 with k3@3
- insert k4@4 to m1
- compact files s1, s2 and result in new file s3 of seqno range [2, 3]
- flush m1 and result in new file s4 of seqno range [1, 4]. And `force_consistency_check=true` will think s4 and s3 has file reordering corruption that might cause retuning an old value of k1
- However such caught corruption is a false positive since s1, s2 will not have overlapped keys with k1 or whatever inserted into m1 before ingest file s1 by the requirement of file ingestion (otherwise the m1 will be flushed first before any of the file ingestion completes). Therefore there in fact isn't any file reordering corruption.
- Single delete can decrease a file's largest seqno and ordering by `largest_seqno` can introduce a wrong ordering hence file reordering corruption
- For example, consider the following sequence of events ("key@n" indicates key at seqno "n", Credit to ajkr for this example)
- an existing SST s1 contains only k1@1
- insert k1@2 to memtable m1
- ingest file s2 with k3@3, ingest file s3 with k4@4
- insert single delete k5@5 in m1
- flush m1 and result in new file s4 of seqno range [2, 5]
- compact s1, s2, s3 and result in new file s5 of seqno range [1, 4]
- compact s4 and result in new file s6 of seqno range [2] due to single delete
- By the last step, we have file ordering by largest seqno (">" means "newer") : s5 > s6 while s6 contains a newer version of the k1's value (i.e, k1@2) than s5, which is a real reordering corruption. While this can be caught by `force_consistency_check=true`, there isn't a good way to prevent this from happening if ordering by `largest_seqno`
Therefore, we are redesigning the sorting criteria of L0 files and avoid above inconvenience. Credit to ajkr , we now introduce `epoch_num` which describes the order of a file being flushed or ingested/imported (compaction output file will has the minimum `epoch_num` among input files'). This will avoid the above inconvenience in the following ways:
- In the first case above, there will no longer be overlap seqno range check in `force_consistency_check=true` but `epoch_number` ordering check. This will result in file ordering s1 < s2 < s4 (pre-compaction) and s3 < s4 (post-compaction) which won't trigger false positive corruption. See test class `DBCompactionTestL0FilesMisorderCorruption*` for more.
- In the second case above, this will result in file ordering s1 < s2 < s3 < s4 (pre-compacting s1, s2, s3), s5 < s4 (post-compacting s1, s2, s3), s5 < s6 (post-compacting s4), which are correct file ordering without causing any corruption.
**Summary:**
- Introduce `epoch_number` stored per `ColumnFamilyData` and sort CF's L0 files by their assigned `epoch_number` instead of `largest_seqno`.
- `epoch_number` is increased and assigned upon `VersionEdit::AddFile()` for flush (or similarly for WriteLevel0TableForRecovery) and file ingestion (except for allow_behind_true, which will always get assigned as the `kReservedEpochNumberForFileIngestedBehind`)
- Compaction output file is assigned with the minimum `epoch_number` among input files'
- Refit level: reuse refitted file's epoch_number
- Other paths needing `epoch_number` treatment:
- Import column families: reuse file's epoch_number if exists. If not, assign one based on `NewestFirstBySeqNo`
- Repair: reuse file's epoch_number if exists. If not, assign one based on `NewestFirstBySeqNo`.
- Assigning new epoch_number to a file and adding this file to LSM tree should be atomic. This is guaranteed by us assigning epoch_number right upon `VersionEdit::AddFile()` where this version edit will be apply to LSM tree shape right after by holding the db mutex (e.g, flush, file ingestion, import column family) or by there is only 1 ongoing edit per CF (e.g, WriteLevel0TableForRecovery, Repair).
- Assigning the minimum input epoch number to compaction output file won't misorder L0 files (even through later `Refit(target_level=0)`). It's due to for every key "k" in the input range, a legit compaction will cover a continuous epoch number range of that key. As long as we assign the key "k" the minimum input epoch number, it won't become newer or older than the versions of this key that aren't included in this compaction hence no misorder.
- Persist `epoch_number` of each file in manifest and recover `epoch_number` on db recovery
- Backward compatibility with old db without `epoch_number` support is guaranteed by assigning `epoch_number` to recovered files by `NewestFirstBySeqno` order. See `VersionStorageInfo::RecoverEpochNumbers()` for more
- Forward compatibility with manifest is guaranteed by flexibility of `NewFileCustomTag`
- Replace `force_consistent_check` on L0 with `epoch_number` and remove false positive check like case 1 with `largest_seqno` above
- Due to backward compatibility issue, we might encounter files with missing epoch number at the beginning of db recovery. We will still use old L0 sorting mechanism (`NewestFirstBySeqno`) to check/sort them till we infer their epoch number. See usages of `EpochNumberRequirement`.
- Remove fix https://github.com/facebook/rocksdb/pull/5958#issue-511150930 and their outdated tests to file reordering corruption because such fix can be replaced by this PR.
- Misc:
- update existing tests with `epoch_number` so make check will pass
- update https://github.com/facebook/rocksdb/pull/5958#issue-511150930 tests to verify corruption is fixed using `epoch_number` and cover universal/fifo compaction/CompactRange/CompactFile cases
- assert db_mutex is held for a few places before calling ColumnFamilyData::NewEpochNumber()
Pull Request resolved: https://github.com/facebook/rocksdb/pull/10922
Test Plan:
- `make check`
- New unit tests under `db/db_compaction_test.cc`, `db/db_test2.cc`, `db/version_builder_test.cc`, `db/repair_test.cc`
- Updated tests (i.e, `DBCompactionTestL0FilesMisorderCorruption*`) under https://github.com/facebook/rocksdb/pull/5958#issue-511150930
- [Ongoing] Compatibility test: manually run
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Hui Xiao | f1574a20ff |
Revert PR 10777 "Fix FIFO causing overlapping seqnos in L0 files due to overla…" (#10999)
Summary:
**Context/Summary:**
This reverts commit
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Andrew Kryczka | 5cf6ab6f31 |
Ran clang-format on db/ directory (#10910)
Summary: Ran `find ./db/ -type f | xargs clang-format -i`. Excluded minor changes it tried to make on db/db_impl/. Everything else it changed was directly under db/ directory. Included minor manual touchups mentioned in PR commit history. Pull Request resolved: https://github.com/facebook/rocksdb/pull/10910 Reviewed By: riversand963 Differential Revision: D40880683 Pulled By: ajkr fbshipit-source-id: cfe26cda05b3fb9a72e3cb82c286e21d8c5c4174 |
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Hui Xiao | fc74abb436 |
Fix FIFO causing overlapping seqnos in L0 files due to overlapped seqnos between ingested files and memtable's (#10777)
Summary: **Context:** Same as https://github.com/facebook/rocksdb/pull/5958#issue-511150930 but apply the fix to FIFO Compaction case Repro: ``` COERCE_CONTEXT_SWICH=1 make -j56 db_stress ./db_stress --acquire_snapshot_one_in=0 --adaptive_readahead=0 --allow_data_in_errors=True --async_io=1 --avoid_flush_during_recovery=0 --avoid_unnecessary_blocking_io=0 --backup_max_size=104857600 --backup_one_in=0 --batch_protection_bytes_per_key=0 --block_size=16384 --bloom_bits=18 --bottommost_compression_type=disable --bytes_per_sync=262144 --cache_index_and_filter_blocks=0 --cache_size=8388608 --cache_type=lru_cache --charge_compression_dictionary_building_buffer=0 --charge_file_metadata=1 --charge_filter_construction=1 --charge_table_reader=1 --checkpoint_one_in=0 --checksum_type=kCRC32c --clear_column_family_one_in=0 --column_families=1 --compact_files_one_in=0 --compact_range_one_in=1000 --compaction_pri=3 --open_files=-1 --compaction_style=2 --fifo_allow_compaction=1 --compaction_ttl=0 --compression_max_dict_buffer_bytes=8388607 --compression_max_dict_bytes=16384 --compression_parallel_threads=1 --compression_type=zlib --compression_use_zstd_dict_trainer=1 --compression_zstd_max_train_bytes=0 --continuous_verification_interval=0 --data_block_index_type=0 --db=/dev/shm/rocksdb_test0/rocksdb_crashtest_whitebox --db_write_buffer_size=8388608 --delpercent=4 --delrangepercent=1 --destroy_db_initially=1 --detect_filter_construct_corruption=0 --disable_wal=0 --enable_compaction_filter=0 --enable_pipelined_write=1 --fail_if_options_file_error=1 --file_checksum_impl=none --flush_one_in=1000 --format_version=5 --get_current_wal_file_one_in=0 --get_live_files_one_in=0 --get_property_one_in=0 --get_sorted_wal_files_one_in=0 --index_block_restart_interval=15 --index_type=3 --ingest_external_file_one_in=100 --initial_auto_readahead_size=0 --iterpercent=10 --key_len_percent_dist=1,30,69 --level_compaction_dynamic_level_bytes=True --log2_keys_per_lock=10 --long_running_snapshots=0 --mark_for_compaction_one_file_in=10 --max_auto_readahead_size=16384 --max_background_compactions=20 --max_bytes_for_level_base=10485760 --max_key=100000 --max_key_len=3 --max_manifest_file_size=1073741824 --max_write_batch_group_size_bytes=1048576 --max_write_buffer_number=3 --max_write_buffer_size_to_maintain=4194304 --memtable_prefix_bloom_size_ratio=0.5 --memtable_protection_bytes_per_key=1 --memtable_whole_key_filtering=1 --memtablerep=skip_list --mmap_read=1 --mock_direct_io=False --nooverwritepercent=1 --num_file_reads_for_auto_readahead=0 --num_levels=1 --open_metadata_write_fault_one_in=0 --open_read_fault_one_in=32 --open_write_fault_one_in=0 --ops_per_thread=200000 --optimize_filters_for_memory=0 --paranoid_file_checks=1 --partition_filters=0 --partition_pinning=1 --pause_background_one_in=0 --periodic_compaction_seconds=0 --prefix_size=8 --prefixpercent=5 --prepopulate_block_cache=0 --progress_reports=0 --read_fault_one_in=0 --readahead_size=16384 --readpercent=45 --recycle_log_file_num=1 --reopen=20 --ribbon_starting_level=999 --snapshot_hold_ops=1000 --sst_file_manager_bytes_per_sec=0 --sst_file_manager_bytes_per_truncate=0 --subcompactions=2 --sync=0 --sync_fault_injection=0 --target_file_size_base=524288 --target_file_size_multiplier=2 --test_batches_snapshots=0 --top_level_index_pinning=3 --unpartitioned_pinning=0 --use_direct_io_for_flush_and_compaction=0 --use_direct_reads=0 --use_full_merge_v1=1 --use_merge=0 --use_multiget=1 --user_timestamp_size=0 --value_size_mult=32 --verify_checksum=1 --verify_checksum_one_in=0 --verify_db_one_in=1000 --verify_sst_unique_id_in_manifest=1 --wal_bytes_per_sync=0 --wal_compression=zstd --write_buffer_size=524288 --write_dbid_to_manifest=0 --writepercent=35 put or merge error: Corruption: force_consistency_checks(DEBUG): VersionBuilder: L0 file https://github.com/facebook/rocksdb/issues/479 with seqno 23711 29070 vs. file https://github.com/facebook/rocksdb/issues/482 with seqno 27138 29049 ``` **Summary:** FIFO only does intra-L0 compaction in the following four cases. For other cases, FIFO drops data instead of compacting on data, which is irrelevant to the overlapping seqno issue we are solving. - [FIFOCompactionPicker::PickSizeCompaction](https://github.com/facebook/rocksdb/blob/7.6.fb/db/compaction/compaction_picker_fifo.cc#L155) when `total size < compaction_options_fifo.max_table_files_size` and `compaction_options_fifo.allow_compaction == true` - For this path, we simply reuse the fix in `FindIntraL0Compaction` https://github.com/facebook/rocksdb/pull/5958/files#diff-c261f77d6dd2134333c4a955c311cf4a196a08d3c2bb6ce24fd6801407877c89R56 - This path was not stress-tested at all. Therefore we covered `fifo.allow_compaction` in stress test to surface the overlapping seqno issue we are fixing here. - [FIFOCompactionPicker::PickCompactionToWarm](https://github.com/facebook/rocksdb/blob/7.6.fb/db/compaction/compaction_picker_fifo.cc#L313) when `compaction_options_fifo.age_for_warm > 0` - For this path, we simply replicate the idea in https://github.com/facebook/rocksdb/pull/5958#issue-511150930 and skip files of largest seqno greater than `earliest_mem_seqno` - This path was not stress-tested at all. However covering `age_for_warm` option worths a separate PR to deal with db stress compatibility. Therefore we manually tested this path for this PR - [FIFOCompactionPicker::CompactRange](https://github.com/facebook/rocksdb/blob/7.6.fb/db/compaction/compaction_picker_fifo.cc#L365) that ends up picking one of the above two compactions - [CompactionPicker::CompactFiles](https://github.com/facebook/rocksdb/blob/7.6.fb/db/compaction/compaction_picker.cc#L378) - Since `SanitizeCompactionInputFiles()` will be called [before](https://github.com/facebook/rocksdb/blob/7.6.fb/db/compaction/compaction_picker.h#L111-L113) `CompactionPicker::CompactFiles` , we simply replicate the idea in https://github.com/facebook/rocksdb/pull/5958#issue-511150930 in `SanitizeCompactionInputFiles()`. To simplify implementation, we return `Stats::Abort()` on encountering seqno-overlapped file when doing compaction to L0 instead of skipping the file and proceed with the compaction. Some additional clean-up included in this PR: - Renamed `earliest_memtable_seqno` to `earliest_mem_seqno` for consistent naming - Added comment about `earliest_memtable_seqno` in related APIs - Made parameter `earliest_memtable_seqno` constant and required Pull Request resolved: https://github.com/facebook/rocksdb/pull/10777 Test Plan: - make check - New unit test `TEST_P(DBCompactionTestFIFOCheckConsistencyWithParam, FlushAfterIntraL0CompactionWithIngestedFile)`corresponding to the above 4 cases, which will fail accordingly without the fix - Regular CI stress run on this PR + stress test with aggressive value https://github.com/facebook/rocksdb/pull/10761 and on FIFO compaction only Reviewed By: ajkr Differential Revision: D40090485 Pulled By: hx235 fbshipit-source-id: 52624186952ee7109117788741aeeac86b624a4f |
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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 |
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Yanqin Jin | 4d82b94896 |
Sanitize min_write_buffer_number_to_merge to 1 with atomic_flush (#10773)
Summary: With current implementation, within the same RocksDB instance, all column families with non-empty memtables will be scheduled for flush if RocksDB determines that any column family needs to be flushed, e.g. memtable full, write buffer manager, etc., if atomic flush is enabled. Not doing so can lead to data loss and inconsistency when WAL is disabled, which is a common setting when atomic flush is enabled. Therefore, setting a per-column-family knob, min_write_buffer_number_to_merge to a value greater than 1 is not compatible with atomic flush, and should be sanitized during column family creation and db open. Pull Request resolved: https://github.com/facebook/rocksdb/pull/10773 Test Plan: Reproduce: D39993203 has detailed steps. Run the test with and without the fix. Reviewed By: cbi42 Differential Revision: D40077955 Pulled By: cbi42 fbshipit-source-id: 451a9179eb531ac42eaccf40b451b9dec4085240 |
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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 |
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Changyu Bi | 3a75219e5d |
Validate option `memtable_protection_bytes_per_key` (#10621)
Summary: sanity check value for option `memtable_protection_bytes_per_key` in `ColumnFamilyData::ValidateOptions()`. Pull Request resolved: https://github.com/facebook/rocksdb/pull/10621 Test Plan: `make check`, added unit test in ColumnFamilyTest. Reviewed By: ajkr Differential Revision: D39180133 Pulled By: cbi42 fbshipit-source-id: 009e0da3ccb332d1c9e14d20193304610bd4eb8a |
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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 |
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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 |
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Yu Zhao 00540916 | bfc737da21 |
fix typos in some code and comment (#10139)
Summary: Minor issue, I just found a few typos on db_test and column_family while reading the code. And I have this PR opened to contribute. :) Pull Request resolved: https://github.com/facebook/rocksdb/pull/10139 Reviewed By: ajkr Differential Revision: D38007098 Pulled By: jay-zhuang fbshipit-source-id: 511947b32424c34348184691216640f32c410fb1 |
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sdong | 6115254416 |
Fix A Bug Where Concurrent Compactions Cause Further Slowing Down (#10270)
Summary: Currently, when installing a new super version, when stalling condition triggers, we compare estimated compaction bytes to previously, and if the new value is larger or equal to the previous one, we reduce the slowdown write rate. However, if concurrent compactions happen, the same value might be used. The result is that, although some compactions reduce estimated compaction bytes, we treat them as a signal for further slowing down. In some cases, it causes slowdown rate drops all the way to the minimum, far lower than needed. Fix the bug by not triggering a re-calculation if a new super version doesn't have Version or a memtable change. With this fix, number of compaction finishes are still undercounted in this algorithm, but it is still better than the current bug where they are negatively counted. Pull Request resolved: https://github.com/facebook/rocksdb/pull/10270 Test Plan: Run a benchmark where the slowdown rate is dropped to minimal unnessarily and see it is back to a normal value. Reviewed By: ajkr Differential Revision: D37497327 fbshipit-source-id: 9bca961cc38fed965c3af0fa6c9ca0efaa7637c4 |
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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 |
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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 |
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Hui Xiao | d665afdbf3 |
Account memory of FileMetaData in global memory limit (#9924)
Summary: **Context/Summary:** As revealed by heap profiling, allocation of `FileMetaData` for [newly created file added to a Version](https://github.com/facebook/rocksdb/pull/9924/files#diff-a6aa385940793f95a2c5b39cc670bd440c4547fa54fd44622f756382d5e47e43R774) can consume significant heap memory. This PR is to account that toward our global memory limit based on block cache capacity. Pull Request resolved: https://github.com/facebook/rocksdb/pull/9924 Test Plan: - Previous `make check` verified there are only 2 places where the memory of the allocated `FileMetaData` can be released - New unit test `TEST_P(ChargeFileMetadataTestWithParam, Basic)` - db bench (CPU cost of `charge_file_metadata` in write and compact) - **write micros/op: -0.24%** : `TEST_TMPDIR=/dev/shm/testdb ./db_bench -benchmarks=fillseq -db=$TEST_TMPDIR -charge_file_metadata=1 (remove this option for pre-PR) -disable_auto_compactions=1 -write_buffer_size=100000 -num=4000000 | egrep 'fillseq'` - **compact micros/op -0.87%** : `TEST_TMPDIR=/dev/shm/testdb ./db_bench -benchmarks=fillseq -db=$TEST_TMPDIR -charge_file_metadata=1 -disable_auto_compactions=1 -write_buffer_size=100000 -num=4000000 -numdistinct=1000 && ./db_bench -benchmarks=compact -db=$TEST_TMPDIR -use_existing_db=1 -charge_file_metadata=1 -disable_auto_compactions=1 | egrep 'compact'` table 1 - write #-run | (pre-PR) avg micros/op | std micros/op | (post-PR) micros/op | std micros/op | change (%) -- | -- | -- | -- | -- | -- 10 | 3.9711 | 0.264408 | 3.9914 | 0.254563 | 0.5111933721 20 | 3.83905 | 0.0664488 | 3.8251 | 0.0695456 | -0.3633711465 40 | 3.86625 | 0.136669 | 3.8867 | 0.143765 | 0.5289363078 80 | 3.87828 | 0.119007 | 3.86791 | 0.115674 | **-0.2673865734** 160 | 3.87677 | 0.162231 | 3.86739 | 0.16663 | **-0.2419539978** table 2 - compact #-run | (pre-PR) avg micros/op | std micros/op | (post-PR) micros/op | std micros/op | change (%) -- | -- | -- | -- | -- | -- 10 | 2,399,650.00 | 96,375.80 | 2,359,537.00 | 53,243.60 | -1.67 20 | 2,410,480.00 | 89,988.00 | 2,433,580.00 | 91,121.20 | 0.96 40 | 2.41E+06 | 121811 | 2.39E+06 | 131525 | **-0.96** 80 | 2.40E+06 | 134503 | 2.39E+06 | 108799 | **-0.78** - stress test: `python3 tools/db_crashtest.py blackbox --charge_file_metadata=1 --cache_size=1` killed as normal Reviewed By: ajkr Differential Revision: D36055583 Pulled By: hx235 fbshipit-source-id: b60eab94707103cb1322cf815f05810ef0232625 |
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zczhu | b6de139df5 |
Handle "NotSupported" status by default implementation of Close() in … (#10127)
Summary: The default implementation of Close() function in Directory/FSDirectory classes returns `NotSupported` status. However, we don't want operations that worked in older versions to begin failing after upgrading when run on FileSystems that have not implemented Directory::Close() yet. So we require the upper level that calls Close() function should properly handle "NotSupported" status instead of treating it as an error status. Pull Request resolved: https://github.com/facebook/rocksdb/pull/10127 Reviewed By: ajkr Differential Revision: D36971112 Pulled By: littlepig2013 fbshipit-source-id: 100f0e6ad1191e1acc1ba6458c566a11724cf466 |
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zczhu | e88d8935ae |
Add comments/permit unchecked error to close_db_dir pull requests (#10093)
Summary: In [close_db_dir](https://github.com/facebook/rocksdb/pull/10049) pull request, some merging conflicts occurred (some comments and one line `s.PermitUncheckedError()` are missing). This pull request aims to put them back. Pull Request resolved: https://github.com/facebook/rocksdb/pull/10093 Reviewed By: ajkr Differential Revision: D36884117 Pulled By: littlepig2013 fbshipit-source-id: 8c0e2a8793fc52804067c511843bd1ff4912c1c3 |
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Zichen Zhu | 65893ad959 |
Explicitly closing all directory file descriptors (#10049)
Summary: Currently, the DB directory file descriptor is left open until the deconstruction process (`DB::Close()` does not close the file descriptor). To verify this, comment out the lines between `db_ = nullptr` and `db_->Close()` (line 512, 513, 514, 515 in ldb_cmd.cc) to leak the ``db_'' object, build `ldb` tool and run ``` strace --trace=open,openat,close ./ldb --db=$TEST_TMPDIR --ignore_unknown_options put K1 V1 --create_if_missing ``` There is one directory file descriptor that is not closed in the strace log. Pull Request resolved: https://github.com/facebook/rocksdb/pull/10049 Test Plan: Add a new unit test DBBasicTest.DBCloseAllDirectoryFDs: Open a database with different WAL directory and three different data directories, and all directory file descriptors should be closed after calling Close(). Explicitly call Close() after a directory file descriptor is not used so that the counter of directory open and close should be equivalent. Reviewed By: ajkr, hx235 Differential Revision: D36722135 Pulled By: littlepig2013 fbshipit-source-id: 07bdc2abc417c6b30997b9bbef1f79aa757b21ff |
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Changyu Bi | cc23b46da1 |
Support using ZDICT_finalizeDictionary to generate zstd dictionary (#9857)
Summary:
An untrained dictionary is currently simply the concatenation of several samples. The ZSTD API, ZDICT_finalizeDictionary(), can improve such a dictionary's effectiveness at low cost. This PR changes how dictionary is created by calling the ZSTD ZDICT_finalizeDictionary() API instead of creating raw content dictionary (when max_dict_buffer_bytes > 0), and pass in all buffered uncompressed data blocks as samples.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/9857
Test Plan:
#### db_bench test for cpu/memory of compression+decompression and space saving on synthetic data:
Set up: change the parameter [here](
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sdong | 49628c9a83 |
Use std::numeric_limits<> (#9954)
Summary: Right now we still don't fully use std::numeric_limits but use a macro, mainly for supporting VS 2013. Right now we only support VS 2017 and up so it is not a problem. The code comment claims that MinGW still needs it. We don't have a CI running MinGW so it's hard to validate. since we now require C++17, it's hard to imagine MinGW would still build RocksDB but doesn't support std::numeric_limits<>. Pull Request resolved: https://github.com/facebook/rocksdb/pull/9954 Test Plan: See CI Runs. Reviewed By: riversand963 Differential Revision: D36173954 fbshipit-source-id: a35a73af17cdcae20e258cdef57fcf29a50b49e0 |
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Peter Dillinger | cad809978a |
Fix heap use-after-free race with DropColumnFamily (#9730)
Summary: Although ColumnFamilySet comments say that DB mutex can be freed during iteration, as long as you hold a ref while releasing DB mutex, this is not quite true because UnrefAndTryDelete might delete cfd right before it is needed to get ->next_ for the next iteration of the loop. This change solves the problem by making a wrapper class that makes such iteration easier while handling the tricky details of UnrefAndTryDelete on the previous cfd only after getting next_ in operator++. FreeDeadColumnFamilies should already have been obsolete; this removes it for good. Similarly, ColumnFamilySet::iterator doesn't need to check for cfd with 0 refs, because those are immediately deleted. Pull Request resolved: https://github.com/facebook/rocksdb/pull/9730 Test Plan: was reported with ASAN on unit tests like DBLogicalBlockSizeCacheTest.CreateColumnFamily (very rare); keep watching Reviewed By: ltamasi Differential Revision: D35038143 Pulled By: pdillinger fbshipit-source-id: 0a5478d5be96c135343a00603711b7df43ae19c9 |
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Jay Zhuang | 4dff279b19 |
DisableManualCompaction may fail to cancel an unscheduled task (#9659)
Summary: https://github.com/facebook/rocksdb/issues/9625 didn't change the unschedule condition which was waiting for the background thread to clean-up the compaction. make sure we only unschedule the task when it's scheduled. Pull Request resolved: https://github.com/facebook/rocksdb/pull/9659 Reviewed By: ajkr Differential Revision: D34651820 Pulled By: jay-zhuang fbshipit-source-id: 23f42081b15ec8886cd81cbf131b116e0c74dc2f |
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Jay Zhuang | 09b0e8f2c7 |
Fix a timer crash caused by invalid memory management (#9656)
Summary: Timer crash when multiple DB instances doing heavy DB open and close operations concurrently. Which is caused by adding a timer task with smaller timestamp than the current running task. Fix it by moving the getting new task timestamp part within timer mutex protection. And other fixes: - Disallow adding duplicated function name to timer - Fix a minor memory leak in timer when a running task is cancelled Pull Request resolved: https://github.com/facebook/rocksdb/pull/9656 Reviewed By: ajkr Differential Revision: D34626296 Pulled By: jay-zhuang fbshipit-source-id: 6b6d96a5149746bf503546244912a9e41a0c5f6b |
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slk | 95305c44a1 |
Add OpenAndTrimHistory API to support trimming data with specified timestamp (#9410)
Summary: As disscussed in (https://github.com/facebook/rocksdb/issues/9223), Here added a new API named DB::OpenAndTrimHistory, this API will open DB and trim data to the timestamp specofied by **trim_ts** (The data with newer timestamp than specified trim bound will be removed). This API should only be used at a timestamp-enabled db instance recovery. And this PR implemented a new iterator named HistoryTrimmingIterator to support trimming history with a new API named DB::OpenAndTrimHistory. HistoryTrimmingIterator wrapped around the underlying InternalITerator such that keys whose timestamps newer than **trim_ts** should not be returned to the compaction iterator while **trim_ts** is not null. Pull Request resolved: https://github.com/facebook/rocksdb/pull/9410 Reviewed By: ltamasi Differential Revision: D34410207 Pulled By: riversand963 fbshipit-source-id: e54049dc234eccd673244c566b15df58df5a6236 |
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Peter Dillinger | 2a67d475f1 |
Fix bug affecting GetSortedWalFiles, Backups, Checkpoint (#9208)
Summary: Saw error like this: `Backup failed -- IO error: No such file or directory: While opening a file for sequentially reading: /dev/shm/rocksdb/rocksdb_crashtest_blackbox/004426.log: No such file or directory` Unfortunately, GetSortedWalFiles (used by Backups, Checkpoint, etc.) relies on no file deletions happening while its operating, which means not only disabling (more) deletions, but ensuring any pending deletions are completed. Two fixes related to this: * There was a gap in several places between decrementing pending_purge_obsolete_files_ and incrementing bg_purge_scheduled_ where the db mutex would be released and GetSortedWalFiles (and others) could get false information that no deletions are pending. * The fix to https://github.com/facebook/rocksdb/issues/8591 (disabling deletions in GetSortedWalFiles) seems incomplete because it doesn't prevent pending deletions from occuring during the operation (if deletions not already disabled, the case that was to be fixed by the change). Pull Request resolved: https://github.com/facebook/rocksdb/pull/9208 Test Plan: existing tests (it's hard to write a test for interleavings that are now excluded - this is what stress test is for) Reviewed By: ajkr Differential Revision: D32630675 Pulled By: pdillinger fbshipit-source-id: a121e3da648de130cd24d44c524232f4eb22f178 |
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Yanqin Jin | 2035798834 |
Update TransactionUtil::CheckKeyForConflict to also use timestamps (#9162)
Summary: Pull Request resolved: https://github.com/facebook/rocksdb/pull/9162 Existing TransactionUtil::CheckKeyForConflict() performs only seq-based conflict checking. If user-defined timestamp is enabled, it should perform conflict checking based on timestamps too. Update TransactionUtil::CheckKey-related methods to verify the timestamp of the latest version of a key is smaller than the read timestamp. Note that CheckKeysForConflict() is not updated since it's used only by optimistic transaction, and we do not plan to update it in this upcoming batch of diffs. Existing GetLatestSequenceForKey() returns the sequence of the latest version of a specific user key. Since we support user-defined timestamp, we need to update this method to also return the timestamp (if enabled) of the latest version of the key. This will be needed for snapshot validation. Reviewed By: ltamasi Differential Revision: D31567960 fbshipit-source-id: 2e4a14aed267435a9aa91bc632d2411c01946d44 |
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Levi Tamasi | 3e1bf771a3 |
Make it possible to force the garbage collection of the oldest blob files (#8994)
Summary: The current BlobDB garbage collection logic works by relocating the valid blobs from the oldest blob files as they are encountered during compaction, and cleaning up blob files once they contain nothing but garbage. However, with sufficiently skewed workloads, it is theoretically possible to end up in a situation when few or no compactions get scheduled for the SST files that contain references to the oldest blob files, which can lead to increased space amp due to the lack of GC. In order to efficiently handle such workloads, the patch adds a new BlobDB configuration option called `blob_garbage_collection_force_threshold`, which signals to BlobDB to schedule targeted compactions for the SST files that keep alive the oldest batch of blob files if the overall ratio of garbage in the given blob files meets the threshold *and* all the given blob files are eligible for GC based on `blob_garbage_collection_age_cutoff`. (For example, if the new option is set to 0.9, targeted compactions will get scheduled if the sum of garbage bytes meets or exceeds 90% of the sum of total bytes in the oldest blob files, assuming all affected blob files are below the age-based cutoff.) The net result of these targeted compactions is that the valid blobs in the oldest blob files are relocated and the oldest blob files themselves cleaned up (since *all* SST files that rely on them get compacted away). These targeted compactions are similar to periodic compactions in the sense that they force certain SST files that otherwise would not get picked up to undergo compaction and also in the sense that instead of merging files from multiple levels, they target a single file. (Note: such compactions might still include neighboring files from the same level due to the need of having a "clean cut" boundary but they never include any files from any other level.) This functionality is currently only supported with the leveled compaction style and is inactive by default (since the default value is set to 1.0, i.e. 100%). Pull Request resolved: https://github.com/facebook/rocksdb/pull/8994 Test Plan: Ran `make check` and tested using `db_bench` and the stress/crash tests. Reviewed By: riversand963 Differential Revision: D31489850 Pulled By: ltamasi fbshipit-source-id: 44057d511726a0e2a03c5d9313d7511b3f0c4eab |
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Kajetan Janiak | 8717c26823 |
Warning about incompatible options with level_compaction_dynamic_level_bytes (#8329)
Summary: This change introduces warnings instead of a silent override when trying to use level_compaction_dynamic_level_bytes with multiple cf_paths/db_paths. I have completed the CLA. Pull Request resolved: https://github.com/facebook/rocksdb/pull/8329 Reviewed By: hx235 Differential Revision: D31399713 Pulled By: ajkr fbshipit-source-id: 29c6fe5258d1f739b4590ecd44aee44f55415595 |
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mrambacher | 13ae16c315 |
Cleanup includes in dbformat.h (#8930)
Summary: This header file was including everything and the kitchen sink when it did not need to. This resulted in many places including this header when they needed other pieces instead. Cleaned up this header to only include what was needed and fixed up the remaining code to include what was now missing. Hopefully, this sort of code hygiene cleanup will speed up the builds... Pull Request resolved: https://github.com/facebook/rocksdb/pull/8930 Reviewed By: pdillinger Differential Revision: D31142788 Pulled By: mrambacher fbshipit-source-id: 6b45de3f300750c79f751f6227dece9cfd44085d |
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Zhiyi Zhang | 0cb0fc6fd3 |
Add DB properties for BlobDB (#8734)
Summary: RocksDB exposes certain internal statistics via the DB property interface. However, there are currently no properties related to BlobDB. For starters, we would like to add the following BlobDB properties: `rocksdb.num-blob-files`: number of blob files in the current Version (kind of like `num-files-at-level` but note this is not per level, since blob files are not part of the LSM tree). `rocksdb.blob-stats`: this could return the total number and size of all blob files, and potentially also the total amount of garbage (in bytes) in the blob files in the current Version. `rocksdb.total-blob-file-size`: the total size of all blob files (as a blob counterpart for `total-sst-file-size`) of all Versions. `rocksdb.live-blob-file-size`: the total size of all blob files in the current Version. `rocksdb.estimate-live-data-size`: this is actually an existing property that we can extend so it considers blob files as well. When it comes to blobs, we actually have an exact value for live bytes. Namely, live bytes can be computed simply as total bytes minus garbage bytes, summed over the entire set of blob files in the Version. Pull Request resolved: https://github.com/facebook/rocksdb/pull/8734 Test Plan: ``` ➜ rocksdb git:(new_feature_blobDB_properties) ./db_blob_basic_test [==========] Running 16 tests from 2 test cases. [----------] Global test environment set-up. [----------] 10 tests from DBBlobBasicTest [ RUN ] DBBlobBasicTest.GetBlob [ OK ] DBBlobBasicTest.GetBlob (12 ms) [ RUN ] DBBlobBasicTest.MultiGetBlobs [ OK ] DBBlobBasicTest.MultiGetBlobs (11 ms) [ RUN ] DBBlobBasicTest.GetBlob_CorruptIndex [ OK ] DBBlobBasicTest.GetBlob_CorruptIndex (10 ms) [ RUN ] DBBlobBasicTest.GetBlob_InlinedTTLIndex [ OK ] DBBlobBasicTest.GetBlob_InlinedTTLIndex (12 ms) [ RUN ] DBBlobBasicTest.GetBlob_IndexWithInvalidFileNumber [ OK ] DBBlobBasicTest.GetBlob_IndexWithInvalidFileNumber (9 ms) [ RUN ] DBBlobBasicTest.GenerateIOTracing [ OK ] DBBlobBasicTest.GenerateIOTracing (11 ms) [ RUN ] DBBlobBasicTest.BestEffortsRecovery_MissingNewestBlobFile [ OK ] DBBlobBasicTest.BestEffortsRecovery_MissingNewestBlobFile (13 ms) [ RUN ] DBBlobBasicTest.GetMergeBlobWithPut [ OK ] DBBlobBasicTest.GetMergeBlobWithPut (11 ms) [ RUN ] DBBlobBasicTest.MultiGetMergeBlobWithPut [ OK ] DBBlobBasicTest.MultiGetMergeBlobWithPut (14 ms) [ RUN ] DBBlobBasicTest.BlobDBProperties [ OK ] DBBlobBasicTest.BlobDBProperties (21 ms) [----------] 10 tests from DBBlobBasicTest (124 ms total) [----------] 6 tests from DBBlobBasicTest/DBBlobBasicIOErrorTest [ RUN ] DBBlobBasicTest/DBBlobBasicIOErrorTest.GetBlob_IOError/0 [ OK ] DBBlobBasicTest/DBBlobBasicIOErrorTest.GetBlob_IOError/0 (12 ms) [ RUN ] DBBlobBasicTest/DBBlobBasicIOErrorTest.GetBlob_IOError/1 [ OK ] DBBlobBasicTest/DBBlobBasicIOErrorTest.GetBlob_IOError/1 (10 ms) [ RUN ] DBBlobBasicTest/DBBlobBasicIOErrorTest.MultiGetBlobs_IOError/0 [ OK ] DBBlobBasicTest/DBBlobBasicIOErrorTest.MultiGetBlobs_IOError/0 (10 ms) [ RUN ] DBBlobBasicTest/DBBlobBasicIOErrorTest.MultiGetBlobs_IOError/1 [ OK ] DBBlobBasicTest/DBBlobBasicIOErrorTest.MultiGetBlobs_IOError/1 (10 ms) [ RUN ] DBBlobBasicTest/DBBlobBasicIOErrorTest.CompactionFilterReadBlob_IOError/0 [ OK ] DBBlobBasicTest/DBBlobBasicIOErrorTest.CompactionFilterReadBlob_IOError/0 (1011 ms) [ RUN ] DBBlobBasicTest/DBBlobBasicIOErrorTest.CompactionFilterReadBlob_IOError/1 [ OK ] DBBlobBasicTest/DBBlobBasicIOErrorTest.CompactionFilterReadBlob_IOError/1 (1013 ms) [----------] 6 tests from DBBlobBasicTest/DBBlobBasicIOErrorTest (2066 ms total) [----------] Global test environment tear-down [==========] 16 tests from 2 test cases ran. (2190 ms total) [ PASSED ] 16 tests. ``` Reviewed By: ltamasi Differential Revision: D30690849 Pulled By: Zhiyi-Zhang fbshipit-source-id: a7567319487ad76bd1a2e24bf143afdbbd9e4346 |
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mrambacher | beed86473a |
Make MemTableRepFactory into a Customizable class (#8419)
Summary: This PR does the following: -> Makes the MemTableRepFactory into a Customizable class and creatable/configurable via CreateFromString -> Makes the existing implementations compatible with configurations -> Moves the "SpecialRepFactory" test class into testutil, accessible via the ObjectRegistry or a NewSpecial API New tests were added to validate the functionality and all existing tests pass. db_bench and memtablerep_bench were hand-tested to verify the functionality in those tools. Pull Request resolved: https://github.com/facebook/rocksdb/pull/8419 Reviewed By: zhichao-cao Differential Revision: D29558961 Pulled By: mrambacher fbshipit-source-id: 81b7229636e4e649a0c914e73ac7b0f8454c931c |
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Peter Dillinger | c9cd5d25a8 |
Remove some unneeded code (#8736)
Summary: * FullKey and ParseFullKey appear to serve no purpose in the public API (or anything else) so removed. Only use in one test updated. * NumberToString serves no purpose vs. ToString so removed, numerous calls updated * Remove unnecessary forward declarations in metadata.h by re-arranging class definitions. * Remove some unneeded semicolons Pull Request resolved: https://github.com/facebook/rocksdb/pull/8736 Test Plan: existing tests Reviewed By: mrambacher Differential Revision: D30700039 Pulled By: pdillinger fbshipit-source-id: 1e436a576f511a6ed8b4d97af7cc8216bc729af2 |
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Levi Tamasi | 3f7e929865 |
Fix a race in ColumnFamilyData::UnrefAndTryDelete (#8605)
Summary: The `ColumnFamilyData::UnrefAndTryDelete` code currently on the trunk unlocks the DB mutex before destroying the `ThreadLocalPtr` holding the per-thread `SuperVersion` pointers when the only remaining reference is the back reference from `super_version_`. The idea behind this was to break the circular dependency between `ColumnFamilyData` and `SuperVersion`: when the penultimate reference goes away, `ColumnFamilyData` can clean up the `SuperVersion`, which can in turn clean up `ColumnFamilyData`. (Assuming there is a `SuperVersion` and it is not referenced by anything else.) However, unlocking the mutex throws a wrench in this plan by making it possible for another thread to jump in and take another reference to the `ColumnFamilyData`, keeping the object alive in a zombie `ThreadLocalPtr`-less state. This can cause issues like https://github.com/facebook/rocksdb/issues/8440 , https://github.com/facebook/rocksdb/issues/8382 , and might also explain the `was_last_ref` assertion failures from the `ColumnFamilySet` destructor we sometimes observe during close in our stress tests. Digging through the archives, this unlocking goes way back to 2014 (or earlier). The original rationale was that `SuperVersionUnrefHandle` used to lock the mutex so it can call `SuperVersion::Cleanup`; however, this logic turned out to be deadlock-prone. https://github.com/facebook/rocksdb/pull/3510 fixed the deadlock but left the unlocking in place. https://github.com/facebook/rocksdb/pull/6147 then introduced the circular dependency and associated cleanup logic described above (in order to enable iterators to keep the `ColumnFamilyData` for dropped column families alive), and moved the unlocking-relocking snippet to its present location in `UnrefAndTryDelete`. Finally, https://github.com/facebook/rocksdb/pull/7749 fixed a memory leak but apparently exacerbated the race by (otherwise correctly) switching to `UnrefAndTryDelete` in `SuperVersion::Cleanup`. The patch simply eliminates the unlocking and relocking, which has been unnecessary ever since https://github.com/facebook/rocksdb/issues/3510 made `SuperVersionUnrefHandle` lock-free. This closes the window during which another thread could increase the reference count, and hopefully fixes the issues above. Pull Request resolved: https://github.com/facebook/rocksdb/pull/8605 Test Plan: Ran `make check` and stress tests locally. Reviewed By: pdillinger Differential Revision: D30051035 Pulled By: ltamasi fbshipit-source-id: 8fe559e4b4ad69fc142579f8bc393ef525918528 |
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Peter Dillinger | 74b7c0d249 |
Fix use-after-free on implicit temporary FileOptions (#8571)
Summary: FileOptions has an implicit conversion from EnvOptions and some internal APIs take `const FileOptions&` and save the reference, which is counter to Google C++ guidelines, > Avoid defining functions that require a const reference parameter to outlive the call, because const reference parameters bind to temporaries. Instead, find a way to eliminate the lifetime requirement (for example, by copying the parameter), or pass it by const pointer and document the lifetime and non-null requirements. This is at least a problem for repair.cc, which passes an EnvOptions to TableCache(), which would save a reference to the temporary copy as FileOptions. This was unfortunately only caught as a side effect of changes in https://github.com/facebook/rocksdb/issues/8544. This change fixes the repair.cc case and updates the involved internal APIs that save a reference to use `const FileOptions*` instead. Unfortunately, I don't know how to get any of our sanitizers to reliably report bugs like this, so I can't rule out more existing in our codebase. Pull Request resolved: https://github.com/facebook/rocksdb/pull/8571 Test Plan: Test that issues seen with https://github.com/facebook/rocksdb/issues/8544 are fixed (can reproduce on AWS EC2) Reviewed By: ajkr Differential Revision: D29943890 Pulled By: pdillinger fbshipit-source-id: 95f9c5251548777b4dc994c1a083dd2add5799c9 |
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Baptiste Lemaire | c521a9ab2b |
Retire superfluous functions introduced in earlier mempurge PRs. (#8558)
Summary: The main challenge to make the memtable garbage collection prototype (nicknamed `mempurge`) was to not get rid of WAL files that contain unflushed (but mempurged) data. That was successfully guaranteed by not writing the VersionEdit to the MANIFEST file after a successful mempurge. By not writing VersionEdits to the `MANIFEST` file after a succesful mempurge operation, we do not change the earliest log file number that contains unflushed data: `cfd->GetLogNumber()` (`cfd->SetLogNumber()` is only called in `VersionSet::ProcessManifestWrites`). As a result, a number of functions introduced earlier just for the mempurge operation are not obscolete/redundant. (e.g.: `FlushJob::ExtractEarliestLogFileNumber`), and this PR aims at cleaning up all these now-unnecessary functions. In particular, we no longer need to store the earliest log file number in the `MemTable` struct itself. This PR therefore also reverts the `MemTable` struct to its original form. Pull Request resolved: https://github.com/facebook/rocksdb/pull/8558 Test Plan: Already included in `db_flush_test.cc`. Reviewed By: anand1976 Differential Revision: D29764351 Pulled By: bjlemaire fbshipit-source-id: 0f43b260fa270251862512f397d3f24ee62e8437 |
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Baptiste Lemaire | 206845c057 |
Mempurge support for wal (#8528)
Summary: In this PR, `mempurge` is made compatible with the Write Ahead Log: in case of recovery, the DB is now capable of recovering the data that was "mempurged" and kept in the `imm()` list of immutable memtables. The twist was to add a uint64_t to the `memtable` struct to store the number of the earliest log file containing entries from the `memtable`. When a `Flush` operation is replaced with a `MemPurge`, the `VersionEdit` (which usually contains the new min log file number to pick up for recovery and the level 0 file path of the newly created SST file) is no longer appended to the manifest log, and every time the `deleteWal` method is called, a check is made on the list of immutable memtables. This PR also includes a unit test that verifies that no data is lost upon Reopening of the database when the mempurge feature is activated. This extensive unit test includes two column families, with valid data contained in the imm() at time of "crash"/reopening (recovery). Pull Request resolved: https://github.com/facebook/rocksdb/pull/8528 Reviewed By: pdillinger Differential Revision: D29701097 Pulled By: bjlemaire fbshipit-source-id: 072a900fb6ccc1edcf5eef6caf88f3060238edf9 |
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Baptiste Lemaire | 837705ad80 |
Make mempurge a background process (equivalent to in-memory compaction). (#8505)
Summary: In https://github.com/facebook/rocksdb/issues/8454, I introduced a new process baptized `MemPurge` (memtable garbage collection). This new PR is built upon this past mempurge prototype. In this PR, I made the `mempurge` process a background task, which provides superior performance since the mempurge process does not cling on the db_mutex anymore, and addresses severe restrictions from the past iteration (including a scenario where the past mempurge was failling, when a memtable was mempurged but was still referred to by an iterator/snapshot/...). Now the mempurge process ressembles an in-memory compaction process: the stack of immutable memtables is filtered out, and the useful payload is used to populate an output memtable. If the output memtable is filled at more than 60% capacity (arbitrary heuristic) the mempurge process is aborted and a regular flush process takes place, else the output memtable is kept in the immutable memtable stack. Note that adding this output memtable to the `imm()` memtable stack does not trigger another flush process, so that the flush thread can go to sleep at the end of a successful mempurge. MemPurge is activated by making the `experimental_allow_mempurge` flag `true`. When activated, the `MemPurge` process will always happen when the flush reason is `kWriteBufferFull`. The 3 unit tests confirm that this process supports `Put`, `Get`, `Delete`, `DeleteRange` operators and is compatible with `Iterators` and `CompactionFilters`. Pull Request resolved: https://github.com/facebook/rocksdb/pull/8505 Reviewed By: pdillinger Differential Revision: D29619283 Pulled By: bjlemaire fbshipit-source-id: 8a99bee76b63a8211bff1a00e0ae32360aaece95 |
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Baptiste Lemaire | 9dc887ece0 |
Memtable "MemPurge" prototype (#8454)
Summary: Implement an experimental feature called "MemPurge", which consists in purging "garbage" bytes out of a memtable and reuse the memtable struct instead of making it immutable and eventually flushing its content to storage. The prototype is by default deactivated and is not intended for use. It is intended for correctness and validation testing. At the moment, the "MemPurge" feature can be switched on by using the `options.experimental_allow_mempurge` flag. For this early stage, when the allow_mempurge flag is set to `true`, all the flush operations will be rerouted to perform a MemPurge. This is a temporary design decision that will give us the time to explore meaningful heuristics to use MemPurge at the right time for relevant workloads . Moreover, the current MemPurge operation only supports `Puts`, `Deletes`, `DeleteRange` operations, and handles `Iterators` as well as `CompactionFilter`s that are invoked at flush time . Three unit tests are added to `db_flush_test.cc` to test if MemPurge works correctly (and checks that the previously mentioned operations are fully supported thoroughly tested). One noticeable design decision is the timing of the MemPurge operation in the memtable workflow: for this prototype, the mempurge happens when the memtable is switched (and usually made immutable). This is an inefficient process because it implies that the entirety of the MemPurge operation happens while holding the db_mutex. Future commits will make the MemPurge operation a background task (akin to the regular flush operation) and aim at drastically enhancing the performance of this operation. The MemPurge is also not fully "WAL-compatible" yet, but when the WAL is full, or when the regular MemPurge operation fails (or when the purged memtable still needs to be flushed), a regular flush operation takes place. Later commits will also correct these behaviors. Pull Request resolved: https://github.com/facebook/rocksdb/pull/8454 Reviewed By: anand1976 Differential Revision: D29433971 Pulled By: bjlemaire fbshipit-source-id: 6af48213554e35048a7e03816955100a80a26dc5 |