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| Author | SHA1 | Message | Date | |
|---|---|---|---|---|
 Xingbo Wang
|
de7b8e8f7d |
Add RocksDB flush reason and atomic flush request metrics (#14898)
Summary:
This PR adds flush observability for debugging write stalls and flush bottlenecks.
Changes include:
- Add flush reason tickers for physical flush jobs:
- rocksdb.flush.reason.write_buffer_full
- rocksdb.flush.reason.write_buffer_manager
- rocksdb.flush.reason.memtable_max_range_deletions
- Add flush memtable size histograms:
- rocksdb.flush.memtable.memory.bytes
- rocksdb.flush.memtable.total.data.size.bytes
- rocksdb.flush.write_buffer_full.memtable.memory.bytes
- rocksdb.flush.write_buffer_manager.memtable.memory.bytes
- Add FlushReason::kMemtableMaxRangeDeletions and propagate it from memtables when memtable_max_range_deletions triggers a flush.
- Preserve atomic flush as a single request-level reason. For atomic flush, the reason is derived only from CFs that scheduled the flush, not every CF selected into the atomic flush cut.
- Add atomic flush request-level counters:
- rocksdb.atomic_flush.request.reason.write_buffer_full
- rocksdb.atomic_flush.request.reason.write_buffer_manager
- rocksdb.atomic_flush.request.reason.memtable_max_range_deletions
- rocksdb.atomic_flush.request.reason.other
- Keep existing per-CF flush job reason counters unchanged. Under atomic flush, rocksdb.flush.reason.* still counts physical CF flush jobs, while rocksdb.atomic_flush.request.reason.* counts one logical atomic flush request.
- Wire the new flush reason, ticker, and histogram types through Java and JNI bindings.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/14898
Test Plan: CI
Reviewed By: anand1976
Differential Revision: D110214337
Pulled By: xingbowang
fbshipit-source-id: 4a445c4175d2e09ff5edbe66fde81fa00bb9e8da
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Xingbo Wang
|
76b8cce2f7 |
Fix spelling of memtable_verify_per_key_checksum_on_seek (#14811)
Summary: - Rename the misspelled `memtable_veirfy_per_key_checksum_on_seek` option and related flags/config keys to `memtable_verify_per_key_checksum_on_seek`. - Update memtable option plumbing, options serialization/logging, db_bench/db_stress/crash-test flags, tests, and the option-addition guide to use the corrected name. - Keep the checksum-on-seek behavior unchanged. Pull Request resolved: https://github.com/facebook/rocksdb/pull/14811 Test Plan: CI Reviewed By: pdillinger Differential Revision: D107382276 Pulled By: xingbowang fbshipit-source-id: 7621dc718d61503b982a7e3f65cc9293a1ad085b |
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Xingbo Wang
|
4707775ae9 |
Fix GetContext status propagation and blob-backed wide-column merge operands (#14640)
Summary: - propagate lower-level read and merge failures through `GetContext` via `read_status`, so `Get` and `GetEntity` preserve the original error instead of synthesizing `Corruption` when blob-backed reads or merge resolution fail - teach `GetMergeOperands` to resolve blob-backed default columns from wide-column entities, covering both the direct base-value path and the merge-plus-base path - add regression coverage for blob-read IO errors during `Get`/`GetEntity` merge resolution and for `GetMergeOperands` on blob-backed wide-column entities - fix the `DBFlushTest.MemPurgeCorrectLogNumberAndSSTFileCreation` test race by waiting for flush callbacks and cleaning up sync points ## Testing - `make db_blob_basic_test -j14` - `/usr/bin/perl -e 'alarm shift; exec ARGV' 60 ./db_blob_basic_test --gtest_filter='DBBlobBasicTest/DBBlobBasicIOErrorTest.GetBlob_IOError/*:DBBlobBasicTest/DBBlobBasicIOErrorTest.GetEntityMergeWithBlobBaseIOError/*'` ## Task T265824017, T265415808 Pull Request resolved: https://github.com/facebook/rocksdb/pull/14640 Reviewed By: anand1976 Differential Revision: D101690700 Pulled By: xingbowang fbshipit-source-id: 2b6fc357b37a01efa72a2d54dcff55be8992f42a |
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Josh Kang
|
03e5a0b9a8 |
Fix range tombstone conversion + ingest sst and re-enable crash tests (#14654)
Summary:
Fixes a correctness bug in read-path range-tombstone synthesis when it races with `IngestExternalFile`. The synthesis path could insert a tombstone into the active memtable at a snapshot's sequence number, while ingestion installed an L0 SST at `LastSequence + 1` — a higher seqno than the synthesized tombstone. This breaks the main assumption of range tombstone reads that all lower levels have lower seqno.
The fix introduces a per-CF `port::RWMutex` (`ColumnFamilyData::ingest_sst_lock_`) plus a per-memtable `ingest_seqno_barrier_`. Ingestion takes the read lock and range tombstone synthesis **tries** to take a write lock.
If iterator lock is successful, then we have a new updated barrier seqno that we can validate the iterator seqno against. An added benefit is we no longer need to gate against empty memtable. This was originally added as an easy fix to prevent memtables from being inserted into while ingestion was happening.
## The bug, by example
`ReadPathRangeTombstoneTest.NewerPointInOlderFileStillVisible` (`db/db_iterator_test.cc:6929`):
1. L0 file `b@1, c@2, d@3`, then L0 file `Delete(b)4, Delete(c)5`.
2. Active memtable: `Put(z)6`. Snapshot taken at seq 6.
3. `IngestExternalFile({c → "vc_live"})` → installed at L0 with seq 7.
4. Iterator at snap 6 walks the deletion run and synthesizes `[b, d) @ seq 6` into the active memtable via `MemTable::AddLogicallyRedundantRangeTombstone`.
5. `Get("c")` at the latest snapshot: memtable returns covering tombstone (seq 6), `Version::Get` short-circuits, **never reads `c@7`** — returns `NotFound` instead of `"vc_live"`.
The invariant `Version::Get` relies on (memtable seqs ≥ any L0 seq for the same key) is broken because synthesis writes at the *snapshot's* seq while ingestion writes at `LastSequence + 1`.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/14654
Test Plan:
- Updated regression test
- Re-enable crashtests and manually run
| Flavor | Jobs |
|---|---:|
| `fbcode_blackbox_crash_test` | 200 |
| `fbcode_whitebox_crash_test` | 30 |
| `fbcode_asan_blackbox_crash_test` | 30 |
| `fbcode_tsan_blackbox_crash_test` | 30 |
| `fbcode_crash_test_with_atomic_flush` | 30 |
| `fbcode_crash_test_with_wc_txn` | 30 |
| `fbcode_crash_test_with_ts` | 30 |
| **Total** | **380** |
Reviewed By: xingbowang
Differential Revision: D102044512
Pulled By: joshkang97
fbshipit-source-id: 0c69187595edc5a5fa80be24bffdba710a92e56e
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Xingbo Wang
|
3070f73e97 |
Wide-column blob separation: lazy resolution through read, compaction, and write paths (#14386)
Summary: Wide-column blob separation: lazy resolution through read, compaction, and write paths Extend blob direct write to support wide-column entities (PutEntity), and add lazy blob resolution for wide-column values across all read and compaction paths. **Write path -- PutEntity blob separation:** - BlobWriteBatchTransformer::PutEntityCF now extracts large column values (>= min_blob_size) to blob files and serializes V2 entities with BlobIndex references, matching the existing Put behavior. - Add MaybePreprocessWideColumns() static helper to share blob extraction logic between the WriteBatch transformer and the new PutEntity fast path. - Add PutEntityFastPath() in DBImpl that preprocesses columns (sort, blob extract, serialize) before calling WriteImpl, skipping the redundant WriteBatch transformation pass. Trace batch preserves the original columns. **Read path -- blob resolution for Get/MultiGet/Iterator:** - GetContext::SaveValue resolves V2 entity blob columns eagerly: for value (Get), resolves the default column's blob reference; for columns (GetEntity), resolves all blob columns and re-serializes as V1. - DBIter::SetValueAndColumnsFromEntity detects V2 entities, deserializes with DeserializeV2, and eagerly resolves all blob columns via a new ReadPathBlobResolver. Resolved values are cached in the resolver and wide_columns_ Slices point into the cache, avoiding copies. - Add ReadPathBlobResolver (new file) -- on-demand blob fetcher for the read path with per-column caching, used by both DBIter and GetContext. - BlobFetcher gains allow_write_path_fallback to read from in-flight direct-write blob files not yet visible through Version (pre-flush reads). - Memtable lookups for Get(key) on V2 entities with a blob default column now return the blob index with is_blob_index=true, triggering the existing BDW resolution in MaybeResolveWritePathValue. - MaybeResolveWritePathValue (renamed from MaybeResolveDirectWriteBlobIndex) now also resolves V2 entity blob columns for GetEntity/MultiGetEntity, re-serializing as V1 after resolution. **Compaction path -- filter, GC, and extraction:** - CompactionIterator::InvokeFilterIfNeeded handles V2 entities: FilterV3 gets eagerly-resolved column values for backward compatibility; FilterV4 gets a CompactionBlobResolver for lazy on-demand resolution. - Add CompactionFilter::FilterV4 with WideColumnBlobResolver* parameter and SupportsFilterV4() opt-in. Default delegates to FilterV3. - CompactionBlobResolver (new class) implements WideColumnBlobResolver for the compaction path with stats tracking. - ExtractLargeColumnValuesIfNeeded extracts inline columns to blob files during compaction (entities without existing blob columns only). - GarbageCollectEntityBlobsIfNeeded relocates blob values from old blob files to new ones during compaction GC, with helpers FetchBlobsNeedingGC, RelocateBlobValues, and SerializeEntityAfterGC. - PrepareOutput unified entity deserialization: single DeserializeV2 call reused by both filter and GC/extraction paths via entity_deserialized_ flag, avoiding redundant parsing. **Merge path -- V2 entity base value resolution:** - MergeHelper::MergeUntil, GetContext::MergeWithWideColumnBaseValue, and DBIter::MergeWithWideColumnBaseValue resolve V2 blob columns before calling TimedFullMerge, using ResolveEntityForMerge. **Blob garbage accounting:** - BlobGarbageMeter tracks blob file in/out flow for V2 entity blob columns via ForEachBlobFileNumber, used for accurate GC decisions. - FileMetaData::UpdateBoundaries tracks oldest_blob_file_number for V2 entities, ensuring blob files referenced by entities are not prematurely deleted. **Serialization improvements:** - WideColumnSerialization::SerializeV2Impl allocates serialized_blob_indices only for actual blob columns (not all columns) and uses autovector for name/value sizes. - Add ForEachBlobFileNumber for lightweight blob file number extraction without full deserialization. - Add ResolveEntityForMerge helper for merge-path resolution. - Add section-size validation in DeserializeV2Impl. - Add empty blob index and column type validation. - blob_column_resolver_util.h -- shared helpers (FindBlobColumn, FindInCache, CacheInlinedBlob) used by both ReadPathBlobResolver and CompactionBlobResolver. **Testing:** - db_blob_direct_write_test: end-to-end PutEntity with BDW before/after flush, verifying Get, GetEntity, MultiGetEntity, and Iterator. - db_blob_index_test: ~1550 lines covering V2 entity blob resolution through Get, GetEntity, MultiGet, Iterator, compaction filter (V3 compat and V4 lazy), merge with blob base, and compaction GC/extraction. - compaction_iterator_test: ~950 lines testing entity blob GC, extraction, filter interaction, and combined GC+filter scenarios. - db_wide_basic_test: ~1200 lines for wide-column lazy blob resolution through all read paths plus compaction round-trips. - db_open_with_config_test: ~450 lines for BDW entity config validation. Pull Request resolved: https://github.com/facebook/rocksdb/pull/14386 Reviewed By: anand1976 Differential Revision: D99739701 Pulled By: xingbowang fbshipit-source-id: 6badd89b577f3054802eaaa654738468efb9dbdb |
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Josh Kang
|
3f51c0a185 |
Convert sequential single deletes into range tombstones (#14448)
Summary:
Add a read-path optimization that converts contiguous point tombstones into range tombstones during forward/reverse iteration. When a configurable threshold of consecutive point deletions (kTypeDeletion, kTypeDeletionWithTimestamp, kTypeSingleDeletion — with no live keys between them) is detected, a range tombstone covering `[first_tombstone_key, next_live_key)` is inserted into the active mutable memtable. This benefits future iterators by enabling efficient skipping via range tombstone fragmentation.
If there is a memtable switch during the read iteration, then the range deletion entry is discarded.
The inserted range tombstones are logically redundant (they don't delete anything that isn't already deleted by point tombstones), skip WAL (they're a derived optimization regenerated by future reads on crash), and use the max tombstone sequence number so they don't interfere with newer writes.
## Key changes
- **New option `min_tombstones_for_range_conversion`** (`AdvancedColumnFamilyOptions`): Threshold of contiguous point tombstones before converting to a range tombstone. Default 0 (disabled). Dynamically changeable via `SetOptions()`.
- **`DBIter` tracking logic** (`db/db_iter.cc`): Tracks contiguous tombstones during `FindNextUserEntryInternal()` (forward) and `PrevInternal()` (reverse). When a live key terminates a run that meets the threshold, `MaybeInsertRangeTombstone()` inserts `[first_tombstone, live_key)` into the active memtable.
- **`FindValueForCurrentKey` `found_visible` output** (`db/db_iter.cc`): Distinguishes "key deleted at this snapshot" from "no visible entries" so reverse tracking doesn't treat post-snapshot keys as tombstones.
- **`IterKey::Swap()`** (`db/dbformat.h`): Efficiently tracks reverse tombstone run end keys without extra allocations.
- **`MemTable::AddLogicallyRedundantRangeTombstone()`** (`db/memtable.cc`): Concurrent-safe range tombstone insertion into the active memtable. Range tombstone skiplist always uses concurrent inserts.
- **`ConstructFragmentedRangeTombstones` race fix** (`db/db_impl/db_impl_write.cc`): Moved after `MarkImmutable()` to prevent lost entries.
- **`MarkImmutable` ordering fix** (`db/memtable_list.cc`): Called before `current_->Add()` to close a race window.
- **Prefix filter awareness** (`db/db_iter.cc`): Tombstone tracking scoped to the seek prefix when prefix filtering is active. See dedicated section below.
- **Transaction awareness** (`db/db_iter.cc`): Tombstones with `seq > snapshot` excluded from tracking. `min_uncommitted` guard uses `insert_seq` (which may be bumped to `earliest_seq`) instead of `range_tomb_max_seq_`. See dedicated section below.
- **Duplicate range check**: Skips insertion if the memtable already covers `[start, end)`.
- **New statistics**: `READ_PATH_RANGE_TOMBSTONES_INSERTED` and `READ_PATH_RANGE_TOMBSTONES_DISCARDED`.
- **Memtable MultiGet batch lookup** (`memtable/inlineskiplist.h`, `db/memtable.cc`): `InlineSkipList::MultiGet()` with cached search path ("finger") for sorted key lookups.
- **New option `memtable_batch_lookup_optimization`** (`AdvancedColumnFamilyOptions`): Enables batch lookup for memtable MultiGet. Default false. Immutable.
## Deciding Range Tombstone Seqno
- The range tombstone is inserted with `insert_seq = max(range_tomb_max_seq_, earliest_seq)` where `range_tomb_max_seq_` is the maximum sequence number across all point tombstones in the contiguous run, and `earliest_seq` is the memtable's earliest sequence number. This preserves the memtable's `earliest_seqno_` invariant.
- If the iterator's snapshot sequence (`sequence_`) predates the memtable's `earliest_seq`, insertion is skipped entirely to avoid unintentionally covering entries between `sequence_` and `earliest_seq`.
## ConstructFragmentedRangeTombstones Race Fix
- `MarkImmutable()` and `ConstructFragmentedRangeTombstones()` are now called before `mutex_.Lock()` in `SwitchMemtable`, keeping this work outside the DB mutex. `MarkImmutable()` blocks concurrent `AddLogicallyRedundantRangeTombstone()` calls via `immutable_mutex_`, ensuring no range tombstones are inserted after the fragmented list is built. `MarkImmutable()` is idempotent, so `MemTableList::Add()` calling it again inside the mutex is harmless.
## Prefix Filter Safety
- When prefix filtering is active, the BBTI bloom filter may reject SST files outside the seek prefix, but the memtable (no bloom filter) returns keys across prefix boundaries. Tombstone tracking is scoped to the seek prefix so that converted range tombstones cannot cover live keys hidden in filtered files.
- `total_order_seek=true` disables prefix filtering — all files are visible, so tombstones safely span prefix boundaries.
- **Behavior change**: Seeking to an out-of-domain key with `total_order_seek=false` now treats it as total-order (prefix_ not set). When `prefix_same_as_start=true`, iterating past an out-of-domain key cleanly invalidates the iterator instead of calling `Transform()` on it (which was UB in release builds with `FixedPrefixTransform`). This is a requirement because an incorrect iterator scan could lead to a range tombstone covering a live key.
## Transaction Support
- Tombstones written by the transaction's own uncommitted writes (sequence > snapshot) are now excluded from contiguous tombstone tracking entirely at the tracking site in `FindNextUserEntryInternal()` and `PrevInternal()`. Previously, tracking relied on a `min_uncommitted` check at insertion time, but this was insufficient — a transaction's own Delete with `seq > snapshot` could extend a run of committed tombstones, and the resulting range tombstone would cover data visible to other snapshots.
- The fix skips any tombstone with `ikey_.sequence > sequence_` during tracking. If a transaction-owned tombstone appears mid-run, it flushes the accumulated committed run first, then resets tracking. This ensures only tombstones visible to the current snapshot are ever converted.
- Both WritePrepared and WriteUnprepared transactions are supported with dedicated test coverage:
- **WritePrepared**: When tombstones are committed before `Prepare()`, their seqnos are below `min_uncommitted` and insertion proceeds safely. When `Prepare()` happens first, tombstone seqnos exceed `min_uncommitted` and insertion is blocked.
- **WriteUnprepared**: Multiple unprepared batches with different seqno ranges are handled correctly. Own transaction Deletes that extend a committed tombstone run block insertion of the entire run. After rollback, data correctness is verified.
## UDT support
- When user-defined timestamps (UDT) are enabled, keys include an 8-byte timestamp suffix. The comparator, Put/Delete APIs, and ReadOptions all require timestamps.
- Forward exhaustion with UDT: `iterate_upper_bound_` is a plain user key without a timestamp suffix. It is padded with min timestamp via `AppendKeyWithMinTimestamp()` so it sorts after all entries with this user key, preserving the exclusive bound semantics.
- Reverse exhaustion with UDT: The end key comes from either the previous live key (which already has a proper timestamp suffix) or the seek target set by `SetSavedKeyToSeekForPrevTarget()` (which appends a timestamp via `SetInternalKey(..., timestamp_ub_)` and `UpdateInternalKey(..., ts)`). In both cases, the end key is already properly timestamped, so no additional padding is needed unlike forward exhaustion.
- Contiguous tombstone detection works correctly with UDT because the underlying `kTypeDeletionWithTimestamp` entries are tracked the same way as `kTypeDeletion`.
## Concurrent Iterators
- Should concurrent iterators happen to read the range at the same time, both will produce the same range and seqno entry. Only one will be accepted by the skip list and the others will be rejected. Future iterators will read the range and not even attempt to insert the range.
- There is nothing preventing similar ranges from being inserted however. Two iterators can produce overlapping ranges, but this protection would be complicated to implement and there is no evidence that it is a likely scenario yet.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/14448
Test Plan:
- **Unit tests** (`db/db_iterator_test.cc`): `ReadPathRangeTombstoneTest` parameterized by forward/reverse with cases for basic insertion, non-contiguous (below threshold), memtable switch, exhausted iterator with/without bounds, direction change, mixed Delete/SingleDelete, single-delete-only runs, snapshot predating memtable, block cache tier incomplete, skip when covered by existing range, UDT basic scan, UDT exhaustion, prefix filter cross-prefix scan (`PrefixFilterCrossPrefixScanCoversLiveKey` with default/total_order_seek/prefix_same_as_start variants), stale ikey from forward-then-reverse scan (`StaleIkeyFromForwardThenReverse`), and reseek stale ikey (`ReseekStaleIkey`).
- **Concurrency test** (`db/db_test2.cc`): `DBTestConcurrentRangeTombstoneConversions` parameterized by `(allow_concurrent_memtable_write, min_tombstones_for_range_conversion)` with mixed writers, deleters, range deleters, and concurrent forward/reverse readers.
- **Transaction tests** (`utilities/transactions/write_prepared_transaction_test.cc`, `write_unprepared_transaction_test.cc`): Tests for WritePrepared (insertion allowed when tombstones committed before prepare, blocked when after; seqno bump shadowing prepared writes `RangeTombstoneSeqnoBumpShadowsPreparedWrite`) and WriteUnprepared (multiple batches, extended visibility with CalcMaxVisibleSeq, own deletions with rollback).
- **IterKey::Swap tests** (`db/dbformat_test.cc`): `IterKeySwapTest` parameterized over `(key_len, copy, use_secondary)` × 2 covering all inline/heap/pinned/secondary combinations.
- **InlineSkipList MultiGet tests** (`memtable/inlineskiplist_test.cc`): Basic, exact matches, empty, single key, randomized validation against `std::set::lower_bound`, duplicate keys with callback walk, and concurrent MultiGet with read-after-write consistency.
- **Memtable MultiGet tests** (`db/db_basic_test.cc`): Batch lookup, overwrite, flush, merge, disabled by default, paranoid checks, and snapshot tests.
- **Stress test coverage**: `min_tombstones_for_range_conversion` and `memtable_batch_lookup_optimization` options added to `db_crashtest.py` and `db_stress` flags.
- `make check` passes all tests.
### Benchmark results
Tombstones scattered randomly in clusters via `seek_nexts_to_delete` for realistic workloads.
**DB Setup A (scattered deletes, 100 per seek)**:
```
# Step 1: Create and compact
./db_bench --benchmarks=fillseq,compact --seed=1 --compression_type=none --num=1000000 --db=<DB>
# Step 2: Scatter tombstones (5000 seeks × 100 deletes ≈ 500k tombstones)
./db_bench --benchmarks=seekrandom,flush --seed=1 --compression_type=none --num=2000 \
--seek_nexts=0 --seek_nexts_to_delete=100 --use_existing_db=1 --threads=1 --db=<DB>
```
**DB Setup A2 (scattered deletes, 8 per seek)**:
```
# Step 1: Create and compact
./db_bench --benchmarks=fillseq,compact --seed=1 --compression_type=none --num=1000000 --db=<DB>
# Step 2: Scatter tombstones (5000 seeks × 8 deletes ≈ 40k tombstones)
./db_bench --benchmarks=seekrandom,flush --seed=1 --compression_type=none --num=2000 \
--seek_nexts=0 --seek_nexts_to_delete=8 --use_existing_db=1 --threads=1 --db=<DB>
```
**DB Setup B (no deletes)**:
```
./db_bench --benchmarks=fillseq,compact --seed=1 --compression_type=none --num=1000000 \
[--key_size=100] --db=<DB>
```
**Read workload** (same for all):
```
./db_bench --benchmarks=seekrandom --seek_nexts=100 --threads=8 \
--reverse_iterator={true,false} --seed=1 --use_existing_db=1 \
--compression_type=none --num=1000000 --duration=10 \
--disable_auto_compactions \
[--key_size=100] [--min_tombstones_for_range_conversion=X] --db=<DB_COPY>
```
Each workload averaged over 3 runs.
**Table 1: seekrandom forward, scattered deletes (2000 seeks × 100 deletes/seek)**
| Variant | avg ops/s | % vs main |
|---------|-----------|-----------|
| main | 2,895 | - |
| threshold=0 | 2,869 | -0.9% |
| threshold=8 | 287,334 | +9,824% |
**Table 2: seekrandom reverse, scattered deletes (2000 seeks × 100 deletes/seek)**
| Variant | avg ops/s | % vs main |
|---------|-----------|-----------|
| main | 544 | - |
| threshold=0 | 548 | +0.7% |
| threshold=8 | 206,491 | +37,860% |
**Table 3: seekrandom forward, scattered deletes (2000 seeks × 8 deletes/seek)**
| Variant | avg ops/s | % vs main |
|---------|-----------|-----------|
| main | 194,049 | - |
| threshold=0 | 195,703 | +0.9% |
| threshold=8 | 310,740 | +60.1% |
**Table 4: seekrandom reverse, scattered deletes (2000 seeks × 8 deletes/seek)**
| Variant | avg ops/s | % vs main |
|---------|-----------|-----------|
| main | 63,854 | - |
| threshold=0 | 69,266 | +8.5% |
| threshold=8 | 218,101 | +241.6% |
**Table 5: seekrandom forward, no deletes (regression check)**
| Variant | key=16B avg ops/s | % vs main | key=100B avg ops/s | % vs main |
|---------|-------------------|-----------|---------------------|-----------|
| main | 330,901 | - | 236,048 | - |
| threshold=0 | 328,398 | -0.8% | 238,055 | +0.9% |
| threshold=8 | 332,539 | +0.5% | 233,776 | -1.0% |
**Table 6: seekrandom reverse, no deletes (regression check)**
| Variant | key=16B avg ops/s | % vs main | key=100B avg ops/s | % vs main |
|---------|-------------------|-----------|---------------------|-----------|
| main | 261,445 | - | 192,177 | - |
| threshold=0 | 265,020 | +1.4% | 191,616 | -0.3% |
| threshold=8 | 250,881 | -4.0% | 189,239 | -1.5% |
Reviewed By: xingbowang
Differential Revision: D96203950
Pulled By: joshkang97
fbshipit-source-id: 06ba66ebde3c355f04671d1e681f1b1586e8751d
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Xingbo Wang
|
af4e32945b |
Blob direct write v1: write-path blob separation with partitioned files (reduced scope) (#14535)
Summary: This PR introduces **blob direct write v1**, a reduced-scope write-path optimization where large values (>= `min_blob_size`) are written directly to blob files during `Put()` and replaced in the memtable with compact `BlobIndex` references. This avoids holding full values in memory until flush time. ### Motivation In the existing BlobDB architecture, values are written to the WAL and memtable in their full form and separated into blob files only at flush time. This means: - Large values are held in memory twice (raw in memtable + blob file at flush) - Blob I/O is serialized through a single flush thread per column family Blob direct write addresses both: values leave the write path as small `BlobIndex` references, and multiple **partitions** (configurable via `blob_direct_write_partitions`) allow concurrent blob writes with independent locks. ### Design (v1 — single-writer, WAL-disabled, reduced scope) The v1 design intentionally keeps scope narrow for correctness and reviewability: - **Single writer thread assumption**: no concurrent writes to the same partition file. One logical writer serializes the batch. - **WAL-disabled**: direct-write blob files are only registered in MANIFEST at flush time. WAL replay cannot recover unregistered blob references, so WAL is disabled for this v1. - **Flush-on-write**: each `AddRecord` call flushes to the OS immediately. - **FIFO generation batching**: each memtable switch creates one generation batch. Direct-write files for that memtable are sealed and registered atomically when the batch is flushed to MANIFEST. - **Round-robin partitions**: blob writes are distributed across `blob_direct_write_partitions` files using an atomic counter. ### New components | Component | Description | |---|---| | `BlobFilePartitionManager` | Owns N partition files per CF. Manages open/seal/register lifecycle tied to memtable generations. | | `BlobWriteBatchTransformer` | A `WriteBatch::Handler` that rewrites qualifying `Put` values as `BlobIndex` entries before the batch enters the write group. | ### Write path integration 1. `DBImpl::WriteImpl` calls `BlobWriteBatchTransformer::TransformBatch` before entering the writer group (for default write path), or before joining the batch group (for pipelined/unordered write). 2. Values >= `min_blob_size` are written to a partition file; the key is stored with a `BlobIndex` in the transformed batch. A rollback guard marks blob bytes as initial garbage if the write fails. 3. On `SwitchMemtable`, `RotateCurrentGeneration` moves active partitions into the next immutable batch. 4. `FlushMemTableToOutputFile` / `AtomicFlushMemTablesToOutputFiles` call `PrepareFlushAdditions` to seal partition files and collect `BlobFileAddition` + `BlobFileGarbage` entries registered to MANIFEST alongside the flush. 5. Shutdown paths (`CancelAllBackgroundWork`, `WaitForCompact` with `close_db=true`) force-flush all CFs with active direct-write managers to ensure blob files are registered before close. ### Read path - **Get/MultiGet**: `MaybeResolveBlobForWritePath` resolves `BlobIndex` references found in memtable or immutable memtable via `BlobFilePartitionManager::ResolveBlobDirectWriteIndex`, which first checks manifest-visible state and falls back to direct blob-file reads via `BlobFileCache`. - **Iterator**: `DBIter::BlobReader` is extended with a `BlobFilePartitionManager*` to resolve direct-write blob indexes during iteration. The unified `ResolveBlobDirectWriteIndex` path handles both manifest-visible and not-yet-flushed files. ### New options | Option | Default | Description | |---|---|---| | `enable_blob_direct_write` | `false` | Enable write-path blob separation for this CF. Requires `enable_blob_files = true`. Not dynamically changeable. | | `blob_direct_write_partitions` | `1` | Number of parallel partition files per CF. Not dynamically changeable. | ### Feature incompatibilities (reduced v1 scope) The following features are *not supported* when `enable_blob_direct_write = true`, and are enforced both in `db_stress_tool` validation and `db_crashtest.py` sanitization: **Write model constraints:** - `threads` must be 1 (single writer assumption) - `allow_concurrent_memtable_write` = 0 - `enable_pipelined_write` = 0 (transformation done before batch group, but pipelined path supported with pre-transform) - `two_write_queues` = 0 - `unordered_write` = 0 (transformation done before batch group, but unordered path supported with pre-transform) **WAL and recovery:** - `disable_wal` = 1 (required — WAL replay of unregistered blob files is out of v1 scope) - `best_efforts_recovery` = 0 - `reopen` = 0 (no crash-restart with WAL replay) - All WAL-related stress features disabled: `manual_wal_flush_one_in`, `sync_wal_one_in`, `lock_wal_one_in`, `get_sorted_wal_files_one_in`, `get_current_wal_file_one_in`, `track_and_verify_wals`, `rate_limit_auto_wal_flush`, `recycle_log_file_num` **Blob GC and dynamic options:** - `use_blob_db` = 0 (stacked BlobDB not supported) - `allow_setting_blob_options_dynamically` = 0 - `enable_blob_garbage_collection` = 0 - `blob_compaction_readahead_size` = 0 - `blob_file_starting_level` = 0 **Unsupported value types and APIs:** - Merge (`use_merge`, `use_full_merge_v1`) — merge values pass through untransformed - Entity APIs (`use_put_entity_one_in`, `use_get_entity`, `use_multi_get_entity`, `use_attribute_group`) - `use_timed_put_one_in` - User-defined timestamps (`user_timestamp_size`, `persist_user_defined_timestamps`, `create_timestamped_snapshot_one_in`) - Transactions (`use_txn`, `use_optimistic_txn`, `test_multi_ops_txns`, `commit_bypass_memtable_one_in`) — though `WriteCommittedTxn::CommitInternal` falls back from bypass-memtable to normal path when BDW is active - `IngestWriteBatchWithIndex` returns `NotSupported` - `inplace_update_support` = 0 **Fault injection:** - All write/read/metadata fault injection disabled (`sync_fault_injection`, `write_fault_one_in`, `metadata_write_fault_one_in`, `read_fault_one_in`, `metadata_read_fault_one_in`, `open_*_fault_one_in`) **Infrastructure/snapshot APIs:** - `remote_compaction_worker_threads` = 0 - `test_secondary` = 0 - `backup_one_in` = 0 - `checkpoint_one_in` = 0 - `get_live_files_apis_one_in` = 0 - `ingest_external_file_one_in` = 0 - `ingest_wbwi_one_in` = 0 ### Tests - `db/blob/db_blob_basic_test.cc`: ~660 lines of new direct-write unit tests covering basic put/get, multi-partition, flush/compaction, recovery, and error injection. - `db/blob/blob_file_cache_test.cc`: ~96 lines of new tests for direct-write blob file cache behavior. - `db/write_batch_test.cc`: ~96 lines of tests for WriteBatch with blob index entries. - `utilities/transactions/transaction_test.cc`: verifies transaction commit path falls back correctly with direct write enabled. - `db_stress_tool/`: full stress test support with `--enable_blob_direct_write` and `--blob_direct_write_partitions` flags, integrated into `db_crashtest.py` with 10% random selection alongside regular blob params. Pull Request resolved: https://github.com/facebook/rocksdb/pull/14535 Test Plan: ``` make -j128 db_blob_basic_test && ./db_blob_basic_test make -j128 blob_file_cache_test && ./blob_file_cache_test make -j128 write_batch_test && ./write_batch_test make -j128 transaction_test && ./transaction_test make -j128 check ``` Stress test: ``` python3 tools/db_crashtest.py blackbox --enable_blob_direct_write=1 \ --enable_blob_files=1 --blob_direct_write_partitions=4 \ --disable_wal=1 --threads=1 ``` Reviewed By: pdillinger Differential Revision: D98766843 Pulled By: xingbowang fbshipit-source-id: 1577653826913a59d05680a87bce5534ac5a5e69 |
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Josh Kang
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dcf3db95a6 |
Make concurrent Memtable stats more robust (#14506)
Summary: Fix thread-safety issues in memtable stats tracking and `MaybeUpdateNewestUDT` to prepare for PR https://github.com/facebook/rocksdb/issues/14448, which introduces concurrent range tombstone insertion from the read path into the mutable memtable. Currently the non-concurrent write path updates memtable counters (`num_entries_`, `num_deletes_`, `num_range_deletes_`, `data_size_`) using non-atomic load/store pairs. While this is safe today PR https://github.com/facebook/rocksdb/issues/14448 will make range_tombstone memtable concurrent, but the main write path can still be non-concurrent. This fix ensures stats are tracked correctly. Similarly, `MaybeUpdateNewestUDT` was not thread-safe and was not called in the concurrent write path at all. This PR also fixes the `post_process_info` delete counter which missed `kTypeSingleDeletion` and `kTypeDeletionWithTimestamp`. ## Key changes - Switch non-concurrent counter updates from `LoadRelaxed`/`StoreRelaxed` pairs to `FetchAddRelaxed` to avoid races with concurrent range tombstone inserts (e.g. `AddLogicallyRedundantRangeTombstone` calling `BatchPostProcess`). - Make `MaybeUpdateNewestUDT` thread-safe by replacing `Slice newest_udt_` with `RelaxedAtomic<const char*> newest_udt_data_` and using a CAS loop. The pointed-to memory lives in the arena and remains valid for the memtable's lifetime. - Call `MaybeUpdateNewestUDT` in the concurrent write path (was previously skipped with a TODO). - Fix `post_process_info->num_deletes++` to also count `kTypeSingleDeletion` and `kTypeDeletionWithTimestamp`, matching the non-concurrent path. - Change `GetNewestUDT()` return type from `const Slice&` to `Slice` (returning by value) to avoid dangling reference issues with the new atomic pointer storage. Updated across `MemTable`, `ReadOnlyMemTable`, `MemTableListVersion`, and `WBWIMemTable`. - Remove unused `Slice newest_udt_` member from `WBWIMemTable`. Pull Request resolved: https://github.com/facebook/rocksdb/pull/14506 Test Plan: - Added `ConcurrentWriteMemTableProperties` test in `db_properties_test.cc`: 4 threads writing puts, deletes, and single deletes concurrently, then verifying `rocksdb.num-entries-active-mem-table` and `rocksdb.num-deletes-active-mem-table` properties are correct. Flush with `flush_verify_memtable_count=true` validates integrity. - Added `ConcurrentGetTableNewestUDT` test in `memtable_list_test.cc`: 4 threads concurrently inserting entries with UDTs via `allow_concurrent=true`, verifying the newest UDT is correctly tracked. - Extended `DuplicateSeq` and `ConcurrentMergeWrite` tests in `db_memtable_test.cc` to verify stat counters after `BatchPostProcess`. - Benchmark results show no performance regression (3 runs each, averaged): **Workload 1: fillrandom** (pure Put workload) ``` ./db_bench -benchmarks=fillrandom -seed=1 -compression_type=none -threads=8 -db=<DB> ``` **Workload 2: readrandomwriterandom** (mixed read/write/delete) ``` # Setup: fillrandom,compact to populate DB (single-threaded) ./db_bench -benchmarks=readrandomwriterandom -seed=1 -compression_type=none \ -use_existing_db=1 -readwritepercent=50 -deletepercent=20 -threads=8 -db=<DB> ``` **Workload 3: fillrandom with range tombstones** (puts interleaved with range deletes) ``` ./db_bench -benchmarks=fillrandom -seed=1 -compression_type=none \ -writes_per_range_tombstone=100 -range_tombstone_width=10 \ -max_num_range_tombstones=1000 -threads=8 -db=<DB> ``` ``` | Benchmark | avg ops/s (main) | avg ops/s (feature) | % change | |------------------------------------|-----------------|--------------------:|----------| | fillrandom | 531,986 | 532,099 | +0.02% | | readrandomwriterandom (50r/30w/20d)| 786,400 | 815,143 | +3.65% | | fillrandom (range tombstones) | 541,656 | 531,008 | -1.97% | ``` Reviewed By: xingbowang Differential Revision: D97974456 Pulled By: joshkang97 fbshipit-source-id: ea95f23953fe37771a599aed61ece1a504b12c2e |
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anand76
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c66c14258f |
Add memtable MultiGet finger search optimization (#14428)
Summary: Add memtable batch lookup optimization with finger search Optimize memtable MultiGet by using a finger search on the skip list. After finding key[i], the search path (Splice) is retained as a "finger" for key[i+1]. The next search walks up the finger until the forward pointer overshoots, then descends -- costing O(log d) where d is the distance between consecutive sorted keys, rather than O(log N) from the head each time. Controlled by the new `memtable_batch_lookup_optimization` column family option (default: false). ## Changes - Add `FindGreaterOrEqualWithFinger()` and `MultiGet()` to `InlineSkipList` with optional paranoid validation support (key ordering checks and per-key checksum verification via default parameters) - Add virtual `MultiGet()` to `MemTableRep`, override in `SkipListRep` - Add `memtable_batch_lookup_optimization` CF option - Integrate finger search into `MemTable::MultiGet` -- sorts keys, performs batched finger search, then unscrambles results - Add `db_bench`, `db_stress`, and crash test support - Add unit tests for `InlineSkipList::MultiGet` (5 tests) and integration tests at the DB level (25 `BatchLookup` tests), including paranoid validation tests ## Benchmark Results Setup: 2M keys in memtable, release build (`DEBUG_LEVEL=0`). ### Single-threaded `multireadrandom` | Batch Size | Baseline | BatchOpt | vs Base | |:---:|---:|---:|---:| | 2 | 363,593 | 376,562 | **+3.6%** | | 8 | 385,204 | 386,082 | **+0.2%** | | 32 | 360,339 | 375,105 | **+4.1%** | | 64 | 352,696 | 378,497 | **+7.3%** | ### Multithreaded `multireadrandom` (batch_size=64) | Threads | Baseline | BatchOpt | vs Base | |:---:|---:|---:|---:| | 4 | 171,356 | 185,633 | **+8.3%** | | 8 | 161,478 | 171,392 | **+6.1%** | ### `multireadwhilewriting` (batch_size=64) | Threads | Baseline | BatchOpt | vs Base | |:---:|---:|---:|---:| | 1 | 163,938 | 175,068 | **+6.8%** | | 4 | 109,698 | 120,790 | **+10.1%** | | 8 | 116,623 | 123,658 | **+6.0%** | No regression at any batch size or thread count. The finger is stack-allocated per `MultiGet` call, so there is no shared state or cache-line contention between threads. Concurrent writes don't invalidate the finger's bracket since it only reads via acquire-load `Next()` pointers. Small Batch Size Regression Check: memtable_batch_lookup_optimization ===================================================================== All values are ops/sec. Measured with db_bench (release build). 2M keys in memtable, value_size=100, duration=30s per run. Multithreaded multireadrandom — small batch sizes -------------------------------------------------- Threads | Batch Size | Baseline | BatchOpt | Change 4 | 2 | 532,302 | 540,682 | +1.6% 8 | 2 | 1,044,046 | 1,046,920 | +0.3% 4 | 8 | 633,733 | 630,039 | -0.6% 8 | 8 | 1,260,818 | 1,241,792 | -1.5% multireadwhilewriting — small batch sizes ----------------------------------------- Threads | Batch Size | Baseline | BatchOpt | Change 1 | 2 | 107,284 | 105,217 | -1.9% 4 | 2 | 428,508 | 423,747 | -1.1% 8 | 2 | 854,654 | 864,923 | +1.2% 1 | 8 | 114,788 | 118,496 | +3.2% 4 | 8 | 467,995 | 473,437 | +1.2% 8 | 8 | 935,636 | 960,791 | +2.7% No regression at small batch sizes. Variations at batch_size=2 are within noise (~1-2%). At batch_size=8, modest positive trend (+1-3% in read-while-writing). Pull Request resolved: https://github.com/facebook/rocksdb/pull/14428 Test Plan: - `make check` -- all tests pass - `ASSERT_STATUS_CHECKED=1 make check` -- all tests pass - 2-hour `db_crashtest.py blackbox` with `--memtable_batch_lookup_optimization=1` -- passed - 2-hour `db_crashtest.py blackbox` with `--memtable_batch_lookup_optimization=1 --paranoid_memory_checks=1` -- passed Reviewed By: pdillinger Differential Revision: D95813786 Pulled By: anand1976 fbshipit-source-id: b182a023e1026021f1b9682d1cc024c7729326c7 |
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Xingbo Wang
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94e65a2e0b |
Add option to validate key during seek in SkipList Memtable (#13902)
Summary: Add a new CF immutable option `paranoid_memory_check_key_checksum_on_seek` that allows additional data integrity validations during seek on SkipList Memtable. When this option is enabled and memtable_protection_bytes_per_key is non zero, skiplist-based memtable will validate the checksum of each key visited during seek operation. The option is opt-in due to performance overhead. This is an enhancement on top of paranoid_memory_checks option. Pull Request resolved: https://github.com/facebook/rocksdb/pull/13902 Test Plan: * new unit test added for paranoid_memory_check_key_checksum_on_seek=true. * existing unit test for paranoid_memory_check_key_checksum_on_seek=false. * enable in stress test. Performance Benchmark: we check for performance regression in read path where data is in memtable only. For each benchmark, the script was run at the same time for main and this PR: ### Memtable-only randomread ops/sec: * Value size = 100 Bytes ``` for B in 0 1 2 4 8; do (for I in $(seq 1 50);do ./db_bench --benchmarks=fillseq,readrandom --write_buffer_size=268435456 --writes=250000 --value_size=100 --num=250000 --reads=500000 --seed=1723056275 --paranoid_memory_check_key_checksum_on_seek=true --memtable_protection_bytes_per_key=$B 2>&1 | grep "readrandom"; done;) | awk '{ t += $5; c++; print } END { print 1.0 * t / c }'; done; ``` 1. Main: 928999 2. PR with paranoid_memory_check_key_checksum_on_seek=false: 930993 (+0.2%) 3. PR with paranoid_memory_check_key_checksum_on_seek=true: 3.1 memtable_protection_bytes_per_key=1: 464577 (-50%) 3.2 memtable_protection_bytes_per_key=2: 470319 (-49%) 3.3 memtable_protection_bytes_per_key=4: 468457 (-50%) 3.4 memtable_protection_bytes_per_key=8: 465061 (-50%) * Value size = 1000 Bytes ``` for B in 0 1 2 4 8; do (for I in $(seq 1 50);do ./db_bench --benchmarks=fillseq,readrandom --write_buffer_size=268435456 --writes=250000 --value_size=1000 --num=250000 --reads=500000 --seed=1723056275 --paranoid_memory_check_key_checksum_on_seek=true --memtable_protection_bytes_per_key=$B 2>&1 | grep "readrandom"; done;) | awk '{ t += $5; c++; print } END { print 1.0 * t / c }'; done; ``` 1. Main: 601321 2. PR with paranoid_memory_check_key_checksum_on_seek=false: 607885 (+1.1%) 3. PR with paranoid_memory_check_key_checksum_on_seek=true: 3.1 memtable_protection_bytes_per_key=1: 185742 (-69%) 3.2 memtable_protection_bytes_per_key=2: 177167 (-71%) 3.3 memtable_protection_bytes_per_key=4: 185908 (-69%) 3.4 memtable_protection_bytes_per_key=8: 183639 (-69%) Reviewed By: pdillinger Differential Revision: D81199245 Pulled By: xingbowang fbshipit-source-id: e3c29552ab92f2c5f360361366a293fa26934913 |
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Peter Dillinger
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b3fdb9b3cc |
Use safer atomic APIs for some memtable code (#13844)
Summary: Two instances of change that are not just cosmetic: * InlineSkipList<>::Node::CASNext() was implicitly using memory_order_seq_cst to access `next_` while it's intended to be accessed with acquire/release. This is probably not a correctness issue for compare_exchange_strong but potentially a previously missed optimization. * Similar for `max_height_` in Insert which is otherwise accessed with relaxed memory order. * One non-relaxed access to `is_range_del_table_empty_` in a function only used in assertions. Access to this atomic is otherwise relaxed (and should be - comment added) Didn't do all of memtable.h because some of them are more complicated changes and I should probably add FetchMin and FetchMax functions to simplify and take advantage of C++27 functions where available (intended follow-up). Pull Request resolved: https://github.com/facebook/rocksdb/pull/13844 Test Plan: existing tests Reviewed By: xingbowang Differential Revision: D79742552 Pulled By: pdillinger fbshipit-source-id: d97ce72ba9af6c105694b7d40622db9e994720cd |
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RROP
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6ae1cb8837 |
Switch fragmented range tombstone cache to C++20 atomic<shared_ptr> API (#13744)
Summary: • Guard on __cpp_lib_atomic_shared_ptr to use std::atomic<std::shared_ptr<T>>::load()/store() • Fallback to std::atomic_load_explicit()/store_explicit() under C++17 When attempting to build with CXX 20 using clang in a Linux environment, the build fails due to deprecation of atomic_load_explicit. Pull Request resolved: https://github.com/facebook/rocksdb/pull/13744 Reviewed By: xingbowang Differential Revision: D78997919 Pulled By: cbi42 fbshipit-source-id: f829c282cba878f072d4b0ad44192a87f73b8a90 |
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Changyu Bi
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c8aafdba33 |
Support concurrent write for vector memtable (#13675)
Summary: Some usage of vector memtable is bottlenecked in the memtable insertion path when using multiple writers. This PR adds support for concurrent writes for the vector memtable. The updates from each concurrent writer are buffered in a thread local vector. When a writer is done, MemTable::BatchPostProcess() is called to flush the thread local updates to the main vector. TSAN test and function comment suggest that ApproximateMemoryUsage() needs to be thread-safe, so its implementation is updated to provide thread-safe access. Together with unordered_write, benchmark shows much improved insertion throughput. Pull Request resolved: https://github.com/facebook/rocksdb/pull/13675 Test Plan: - new unit test - enabled some coverage of vector memtable in stress test - Performance benchmark: benchmarked memtable insertion performance with by running fillrandom 20 times - Compare branch and main performance with one thread and write batch size 100: - main: 4896888.950 ops/sec - branch: 4923366.350 ops/sec - Benchmark this branch by configuring different threads, allow_concurrent_memtable_write, and unordered_write. Performance ratio is computed as current ops/sec divided by ops/sec at 1 thread with the same options. allow_concurrent | unordered_write | Threads | ops/sec | Performance Ratio -- | -- | -- | -- | -- 0 | 0 | 1 | 4923367 | 1.0 0 | 0 | 2 | 5215640 | 1.1 0 | 0 | 4 | 5588510 | 1.1 0 | 0 | 8 | 6077525 | 1.2 1 | 0 | 1 | 4919060 | 1.0 1 | 0 | 2 | 5821922 | 1.2 1 | 0 | 4 | 7850395 | 1.6 1 | 0 | 8 | 10516600 | 2.1 1 | 1 | 1 | 5050004 | 1.0 1 | 1 | 2 | 8489834 | 1.7 1 | 1 | 4 | 14439513 | 2.9 1 | 1 | 8 | 21538098 | 4.3 ``` mkdir -p /tmp/bench_$1 export TEST_TMPDIR=/tmp/bench_$1 memtablerep_value=${6:-vector} (for I in $(seq 1 $2) do /data/users/changyubi/vscode-root/rocksdb/$1 --benchmarks=fillrandom --seed=1722808058 --write_buffer_size=67108864 --min_write_buffer_number_to_merge=1000 --max_write_buffer_number=1000 --enable_pipelined_write=0 --memtablerep=$memtablerep_value --disable_auto_compactions=1 --disable_wal=1 --avoid_flush_during_shutdown=1 --allow_concurrent_memtable_write=${5:-0} --unordered_write=$4 --batch_size=1 --threads=$3 2>&1 | grep "fillrandom" done;) | awk '{ t += $5; c++; print } END { printf ("%9.3f\n", 1.0 * t / c) }'; ``` Reviewed By: pdillinger Differential Revision: D76641755 Pulled By: cbi42 fbshipit-source-id: c107ba42749855ad4fd1f52491eb93900757542e |
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Yu Zhang
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476a98ca30 |
Add a new GetNewestUserDefinedTimestamp API (#13547)
Summary: This PR adds a DB::GetNewestUserDefinedTimestamp API to get the newest timestamp of the column family. This is only for when the column family enables user defined timestamp. It checks the mutable memtable, the immutable memtable and the SST files, and returns the first newest user defined timestamp found. When user defined timestamp is not persisted in SST files, there is metadata in MANIFEST tracking upperbound of flushed timestamps, so the newest timestamp in SST files can be found. If user defined timestamps are persisted in SST files, currently no timestamp metadata info is persisted. A NotSupported status will be returned if SST files need to be checked in that case. Pull Request resolved: https://github.com/facebook/rocksdb/pull/13547 Test Plan: Added tests Reviewed By: cbi42 Differential Revision: D73123575 Pulled By: jowlyzhang fbshipit-source-id: 460ac4f9c96926d3c8fcf7944edab8dc0feae1dd |
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Changyu Bi
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56359da691 |
Trigger memtable flush based on number of hidden entries scanned (#13523)
Summary: Introduce a mutable CF option `memtable_op_scan_flush_trigger`. When a DB iterator scans this number of hidden entries (tombstones, overwritten puts) from the active memtable in a Seek() or Next() operation, it marks the memtable to be eligible for flush. Subsequent write operations will schedule the marked memtable for flush. The main change is small and is in db_iter.cc. Some refactoring is done to consolidate and simplify creation of `ArenaWrappedDBIter` and `DBIter`. Pull Request resolved: https://github.com/facebook/rocksdb/pull/13523 Test Plan: - new unit tests added. - added `memtable_op_scan_flush_trigger` in crash test - benchmark: The following benchmark was done with a previous version of the PR where the option was `memtable_tombstone_scan_limit` and it concerns tombstone only. The results should still be applicable for the case when there's no overwritten puts. Tests that when memtable has many tombstones, the option helps to improve scan performance: ``` TEST_TMPDIR=/dev/shm ./db_bench --benchmarks=seekrandomwhilewriting --expand_range_tombstones=true --writes_per_range_tombstone=1 --max_num_range_tombstones=10000000 --perf_level=2 --range_tombstone_width=100 --memtable_tombstone_scan_limit= memtable_tombstone_scan_limit = 10000 seekrandomwhilewriting : 18.527 micros/op 53973 ops/sec 18.527 seconds 1000000 operations; (7348 of 1000000 found) next_on_memtable_count = 122305248 grep "flush_started" /dev/shm/dbbench/LOG | wc 8 200 2417 memtable_tombstone_scan_limit=200 seekrandomwhilewriting : 4.918 micros/op 203315 ops/sec 4.918 seconds 1000000 operations; (4510 of 1000000 found) next_on_memtable_count = 1853167 grep "flush_started" /dev/shm/dbbench/LOG | wc 184 4600 54121 When memtable_tombstone_scan_limit=200, more flush is trigged to drop tombstones sooner and improve scan performance. ``` Tests that the new option does not introduce noticeable regression: ``` TEST_TMPDIR=/dev/shm ./db_bench --benchmarks=seekrandomwhilewriting[-X5] --expand_range_tombstones=true --writes_per_range_tombstone=1 --max_num_range_tombstones=10000000 --perf_level=2 --range_tombstone_width=100 --seed=123 Main: seekrandomwhilewriting [AVG 5 runs] : 46049 (± 4512) ops/sec PR: seekrandomwhilewriting [AVG 5 runs] : 46100 (± 4470) ops/sec The results are noisy with this PR performing better and worse in different runs, with no noticeable regression. ``` Reviewed By: pdillinger Differential Revision: D72596434 Pulled By: cbi42 fbshipit-source-id: 2d51a0221dc20dac844aeba2ad3999d075a4cf91 |
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Changyu Bi
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3c2c2689b9 |
Merge support in WBWIMemTable (#13410)
Summary: added merge support for WBWIMemTable. Most of the preparation work is done in https://github.com/facebook/rocksdb/issues/13387 and https://github.com/facebook/rocksdb/issues/13400. The main code change to support merge is in wbwi_memtable.cc to support reading the Merge value type. The rest of the changes are mostly comment change and tests. Pull Request resolved: https://github.com/facebook/rocksdb/pull/13410 Test Plan: - new unit test - ran `python3 ./tools/db_crashtest.py --txn blackbox --txn_write_policy=0 --commit_bypass_memtable_one_in=100 --test_batches_snapshots=0 --use_merge=1` for several runs. Reviewed By: jowlyzhang Differential Revision: D69885868 Pulled By: cbi42 fbshipit-source-id: b127d95a3027dc35910f6e5d65f3409ba27e2b6b |
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Changyu Bi
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dd01f73e26 |
Fix a bug in GetMergeOperands() with continue_cb set (#13383)
Summary: Noticed this while I was working on memtable code. Wrong status (MergeInProgress()) and wrong number of merge operands can be returned if the `continue_cb` stop at an immutable memtable. This is due to 1. Get from memtable sets MergeInProress() status https://github.com/facebook/rocksdb/blob/302254d928402c80ecabb0cf2b76d18be35a87b9/db/memtable.cc#L1461 2. Get from immutable memtable does not update status but stops the get: https://github.com/facebook/rocksdb/blob/302254d928402c80ecabb0cf2b76d18be35a87b9/db/memtable.cc#L1364 3. GetImpl() only returns merge_operands for OK status: https://github.com/facebook/rocksdb/blob/302254d928402c80ecabb0cf2b76d18be35a87b9/db/db_impl/db_impl.cc#L2552 Also updated some comments for GetMergeOperands(). Pull Request resolved: https://github.com/facebook/rocksdb/pull/13383 Test Plan: added a unit test that fails GetMergeOperands() with MergeInProgress() status before this fix. Reviewed By: jowlyzhang Differential Revision: D69322133 Pulled By: cbi42 fbshipit-source-id: aebfccd8446e9640cff02877915076e2d10f7a5b |
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Peter Dillinger
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c72e79a262 |
Standardize on clang-format version 18 (#13233)
Summary: ... which is the default for CentOS 9 and Ubuntu 24, the latter of which is now available in GitHub Actions. Relevant CI job updated. Re-formatted all cc|c|h files except in third-party/, using ``` clang-format -i `git ls-files | grep -E '[.](cc|c|h)$' | grep -v third-party/` ``` Pull Request resolved: https://github.com/facebook/rocksdb/pull/13233 Test Plan: CI Reviewed By: jaykorean, archang19 Differential Revision: D67461638 Pulled By: pdillinger fbshipit-source-id: 0c9ac21a3f5eea6f5ade68bb6af7b6ba16c8b301 |
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Changyu Bi
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d5345a8ff7 |
Introduce a transaction option to skip memtable write during commit (#13144)
Summary: add a new transaction option `TransactionOptions::commit_bypass_memtable` that will ingest the transaction into a DB as an immutable memtables, skipping memtable writes during transaction commit. This helps to reduce the blocking time of committing a large transaction, which is mostly spent on memtable writes. The ingestion is done by creating WBWIMemTable using transaction's underlying WBWI, and ingest it as the latest immutable memtable. The feature will be experimental. Major changes are: 1. write path change to ingest the transaction, mostly in WriteImpl() and IngestWBWI() in db_impl_write.cc. 2. WBWI changes to track some per CF stats like entry count and overwritten single deletion count, and track which keys have overwritten single deletions (see 3.). Per CF stat is used to precompute the number of entries in each WBWIMemTable. 3. WBWIMemTable Iterator changes to emit overwritten single deletions. The motivation is explained in the comment above class WBWIMemTable definition. The rest of the changes in WBWIMemTable are moving the iterator definition around. Some intended follow ups: 1. support for merge operations 2. stats/logging around this option 3. tests improvement, including stress test support for the more comprehensive no_batched_op_stress. Pull Request resolved: https://github.com/facebook/rocksdb/pull/13144 Test Plan: * added new unit tests * enabled in multi_ops_txns_stress test * Benchmark: applying the change in 8222c0cafc4c6eb3a0d05807f7014b44998acb7a, I tested txn size of 10k and check perf context for write_memtable_time, write_wal_time and key_lock_wait_time(repurposed for transaction unlock time). Though the benchmark result number can be flaky, this shows memtable write time improved a lot (more than 100 times). The benchmark also shows that the remaining commit latency is from transaction unlock. ``` ./db_bench --benchmarks=fillrandom --seed=1727376962 --threads=1 --disable_auto_compactions=1 --max_write_buffer_number=100 --min_write_buffer_number_to_merge=100 --writes=100000 --batch_size=10000 --transaction_db=1 --perf_level=4 --enable_pipelined_write=false --commit_bypass_memtable=1 commit_bypass_memtable = false fillrandom : 3.982 micros/op 251119 ops/sec 0.398 seconds 100000 operations; 27.8 MB/s PERF_CONTEXT: write_memtable_time = 116950422 write_wal_time = 8535565 txn unlock time = 32979883 commit_bypass_memtable = true fillrandom : 2.627 micros/op 380559 ops/sec 0.263 seconds 100000 operations; 42.1 MB/s PERF_CONTEXT: write_memtable_time = 740784 write_wal_time = 11993119 txn unlock time = 21735685 ``` Reviewed By: jowlyzhang Differential Revision: D66307632 Pulled By: cbi42 fbshipit-source-id: 6619af58c4c537aed1f76c4a7e869fb3f5098999 |
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Changyu Bi
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1c7652fcef |
Introduce a WriteBatchWithIndex-based implementation of ReadOnlyMemTable (#13123)
Summary: introduce the class WBWIMemTable that implements ReadOnlyMemTable interface with data stored in a WriteBatchWithIndex object. This PR implements the main read path: Get, MultiGet and Iterator. It only supports Put, Delete and SingleDelete operations for now. All the keys in the WBWIMemTable will be assigned a global sequence number through WBWIMemTable::SetGlobalSequenceNumber(). Planned follow up PRs: - Create WBWIMemTable with a transaction's WBWI and ingest it into a DB during Transaction::Commit() - Support for Merge. This will be more complicated since we can have multiple updates with the same user key for Merge. - Support for other operations like WideColumn and other ReadOnlyMemTable methods. Pull Request resolved: https://github.com/facebook/rocksdb/pull/13123 Test Plan: * A mini-stress test for the read path is added as a new unit test Reviewed By: jowlyzhang Differential Revision: D65633419 Pulled By: cbi42 fbshipit-source-id: 0684fe47260b41f51ca39c300eb72ca5bc9c5a3b |
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changyubi
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2ce6902cf5 |
Introduce an interface ReadOnlyMemTable for immutable memtables (#13107)
Summary: This PR sets up follow-up changes for large transaction support. It introduces an interface that allows custom implementations of immutable memtables. Since transactions use a WriteBatchWithIndex to index their operations, I plan to add a ReadOnlyMemTable implementation backed by WriteBatchWithIndex. This will enable direct ingestion of WriteBatchWithIndex into the DB as an immutable memtable, bypassing memtable writes for transactions. The changes mostly involve moving required methods for immutable memtables into the ReadOnlyMemTable class. Pull Request resolved: https://github.com/facebook/rocksdb/pull/13107 Test Plan: * Existing unit test and stress test. * Performance: I do not expect this change to cause noticeable performance regressions with LTO and devirtualization. The memtable-only readrandom benchmark shows no consistent performance difference: ``` USE_LTO=1 OPTIMIZE_LEVEL="-O3" DEBUG_LEVEL=0 make -j160 db_bench (for I in $(seq 1 50);do ./db_bench --benchmarks=fillseq,readrandom --write_buffer_size=268435456 --writes=250000 --num=250000 --reads=500000 --seed=1723056275 2>&1 | grep "readrandom"; done;) | awk '{ t += $5; c++; print } END { print 1.0 * t / c }'; 3 runs: main: 760728, 752727, 739600 PR: 763036, 750696, 739022 ``` Reviewed By: jowlyzhang Differential Revision: D65365062 Pulled By: cbi42 fbshipit-source-id: 40c673ab856b91c65001ef6d6ac04b65286f2882 |
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Yu Zhang
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8592517c89 |
Remove stale entries from L0 files when UDT is not persisted (#13035)
Summary: When user-defined timestamps are not persisted, currently we replace the actual timestamp with min timestamp after an entry is output from compaction iterator. Compaction iterator won't be able to help with removing stale entries this way. This PR adds a wrapper iterator `TimestampStrippingIterator` for `MemTableIterator` that does the min timestamp replacement at the memtable iteration step. It is used by flush and can help remove stale entries from landing in L0 files. Pull Request resolved: https://github.com/facebook/rocksdb/pull/13035 Test Plan: Added unit test Reviewed By: pdillinger, cbi42 Differential Revision: D63423682 Pulled By: jowlyzhang fbshipit-source-id: 087dcc9cee97b9ea51b8d2b88dc91c2984d54e55 |
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Peter Dillinger
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a1a102ffce |
Steps toward deprecating implicit prefix seek, related fixes (#13026)
Summary: With some new use cases onboarding to prefix extractors/seek/filters, one of the risks is existing iterator code, e.g. for maintenance tasks, being unintentionally subject to prefix seek semantics. This is a longstanding known design flaw with prefix seek, and `prefix_same_as_start` and `auto_prefix_mode` were steps in the direction of making that obsolete. However, we can't just immediately set `total_order_seek` to true by default, because that would impact so much code instantly. Here we add a new DB option, `prefix_seek_opt_in_only` that basically allows users to transition to the future behavior when they are ready. When set to true, all iterators will be treated as if `total_order_seek=true` and then the only ways to get prefix seek semantics are with `prefix_same_as_start` or `auto_prefix_mode`. Related fixes / changes: * Make sure that `prefix_same_as_start` and `auto_prefix_mode` are compatible with (or override) `total_order_seek` (depending on your interpretation). * Fix a bug in which a new iterator after dynamically changing the prefix extractor might mix different prefix semantics between memtable and SSTs. Both should use the latest extractor semantics, which means iterators ignoring memtable prefix filters with an old extractor. And that means passing the latest prefix extractor to new memtable iterators that might use prefix seek. (Without the fix, the test added for this fails in many ways.) Suggested follow-up: * Investigate a FIXME where a MergeIteratorBuilder is created in db_impl.cc. No unit test detects a change in value that should impact correctness. * Make memtable prefix bloom compatible with `auto_prefix_mode`, which might require involving the memtablereps because we don't know at iterator creation time (only seek time) whether an auto_prefix_mode seek will be a prefix seek. * Add `prefix_same_as_start` testing to db_stress Pull Request resolved: https://github.com/facebook/rocksdb/pull/13026 Test Plan: tests updated, added. Add combination of `total_order_seek=true` and `auto_prefix_mode=true` to stress test. Ran `make blackbox_crash_test` for a long while. Manually ran tests with `prefix_seek_opt_in_only=true` as default, looking for unexpected issues. I inspected most of the results and migrated many tests to be ready for such a change (but not all). Reviewed By: ltamasi Differential Revision: D63147378 Pulled By: pdillinger fbshipit-source-id: 1f4477b730683d43b4be7e933338583702d3c25e |
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Changyu Bi
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defd97bc9d |
Add an option to verify memtable key order during reads (#12889)
Summary: add a new CF option `paranoid_memory_checks` that allows additional data integrity validations during read/scan. Currently, skiplist-based memtable will validate the order of keys visited. Further data validation can be added in different layers. The option will be opt-in due to performance overhead. The motivation for this feature is for services where data correctness is critical and want to detect in-memory corruption earlier. For a corrupted memtable key, this feature can help to detect it during during reads instead of during flush with existing protections (OutputValidator that verifies key order or per kv checksum). See internally linked task for more context. Pull Request resolved: https://github.com/facebook/rocksdb/pull/12889 Test Plan: * new unit test added for paranoid_memory_checks=true. * existing unit test for paranoid_memory_checks=false. * enable in stress test. Performance Benchmark: we check for performance regression in read path where data is in memtable only. For each benchmark, the script was run at the same time for main and this PR: * Memtable-only randomread ops/sec: ``` (for I in $(seq 1 50);do ./db_bench --benchmarks=fillseq,readrandom --write_buffer_size=268435456 --writes=250000 --num=250000 --reads=500000 --seed=1723056275 2>&1 | grep "readrandom"; done;) | awk '{ t += $5; c++; print } END { print 1.0 * t / c }'; Main: 608146 PR with paranoid_memory_checks=false: 607727 (- %0.07) PR with paranoid_memory_checks=true: 521889 (-%14.2) ``` * Memtable-only sequential scan ops/sec: ``` (for I in $(seq 1 50); do ./db_bench--benchmarks=fillseq,readseq[-X10] --write_buffer_size=268435456 --num=1000000 --seed=1723056275 2>1 | grep "\[AVG 10 runs\]"; done;) | awk '{ t += $6; c++; print; } END { printf "%.0f\n", 1.0 * t / c }'; Main: 9180077 PR with paranoid_memory_checks=false: 9536241 (+%3.8) PR with paranoid_memory_checks=true: 7653934 (-%16.6) ``` * Memtable-only reverse scan ops/sec: ``` (for I in $(seq 1 20); do ./db_bench --benchmarks=fillseq,readreverse[-X10] --write_buffer_size=268435456 --num=1000000 --seed=1723056275 2>1 | grep "\[AVG 10 runs\]"; done;) | awk '{ t += $6; c++; print; } END { printf "%.0f\n", 1.0 * t / c }'; Main: 1285719 PR with integrity_checks=false: 1431626 (+%11.3) PR with integrity_checks=true: 811031 (-%36.9) ``` The `readrandom` benchmark shows no regression. The scanning benchmarks show improvement that I can't explain. Reviewed By: pdillinger Differential Revision: D60414267 Pulled By: cbi42 fbshipit-source-id: a70b0cbeea131f1a249a5f78f9dc3a62dacfaa91 |
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Changyu Bi
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b32d899482 |
Fix MultiGet dropping memtable kv checksum corruption (#12842)
Summary: Corruption status returned by `GetFromTable()` could be overwritten here: https://github.com/facebook/rocksdb/blob/b6c3495a7183f01901d3be01dc68f7e40a1a2e9b/db/version_set.cc#L2614 This PR fixes this issue by setting `*(s->found_final_value) = true;` in SaveValue. Also makes the handling of the return value of `GetFromTable()` more robust and added asserts in a couple places. Pull Request resolved: https://github.com/facebook/rocksdb/pull/12842 Test Plan: Updated an existing unit test to cover MultiGet. It fails the assertion here before this PR: https://github.com/facebook/rocksdb/blob/b6c3495a7183f01901d3be01dc68f7e40a1a2e9b/db/version_set.cc#L2601 Reviewed By: anand1976 Differential Revision: D59498203 Pulled By: cbi42 fbshipit-source-id: 1f071c1b2c5b66fb71264b547a9e670d1cf592f0 |
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Changyu Bi
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b4a84efb4e |
Fix assertion failure in ConstructFragmentedRangeTombstones() (#12796)
Summary: the assertion `assert(!IsFragmentedRangeTombstonesConstructed(false));` assumes ConstructFragmentedRangeTombstones() is called only once for a memtable. This is not true since SwitchMemtable() can be called multiple times on the same live memtable, if a previous attempt fails. So remove the assertion in this PR and simplify relevant code. Pull Request resolved: https://github.com/facebook/rocksdb/pull/12796 Test Plan: the exact condition to trigger manifest write in SwitchMemtable() is complicated. Will monitor crash test to see if there's no more failure. Reviewed By: hx235 Differential Revision: D58913310 Pulled By: cbi42 fbshipit-source-id: 458bb9eebcf6743e9001186fcb757e4b50e8a5d2 |
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Daniel Vasquez Lopez
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7c6c632ea9 |
Use std::optional instead of std::unique_ptr to conditionally create a read lock. (#12704)
Summary: This change replaces the use of `std::unique_ptr` with `std::optional` for conditionally constructing a `ReadLock` object. The read lock object was recently introduced in PR https://github.com/facebook/rocksdb/issues/12624. This change makes the code more concise and clarifies that the lock is not meant to be transferred (as `std::unique_ptr` is movable). It also avoids a heap allocation. There are no functional changes. Pull Request resolved: https://github.com/facebook/rocksdb/pull/12704 Reviewed By: cbi42 Differential Revision: D57848192 Pulled By: ajkr fbshipit-source-id: da48c77aac33b51ba5dcc238f98fc48ccf234a21 |
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Andrew Kryczka
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933ac0e05c |
Fix locking for ColumnFamilyOptions::inplace_update_support (#12624)
Summary: In `SaveValue()`, the read lock needs to be obtained before `VerifyEntryChecksum()` because the KV checksum verification reads the entire value metadata+data, which is all mutable when `ColumnFamilyOptions::inplace_update_support == true`. In `MemTable::Update()`, the write lock needs to be obtained before mutating the value metadata (changing the value size) because it can be read concurrently. Pull Request resolved: https://github.com/facebook/rocksdb/pull/12624 Test Plan: ``` $ make COMPILE_WITH_TSAN=1 -j56 db_stress ... $ python3 tools/db_crashtest.py blackbox --simple --max_key=10 --inplace_update_support=1 --interval=10 --allow_concurrent_memtable_write=0 ``` Reviewed By: cbi42 Differential Revision: D57034571 Pulled By: ajkr fbshipit-source-id: 3dddf881ad87923143acdf6bfec12ce47bb13a48 |
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Andrew Kryczka
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3f3045a405 |
fix DeleteRange+memtable_insert_with_hint_prefix_extractor interaction (#12558)
Summary: Previously `insert_hints_` was used for both point key table (`table_`) and range deletion table (`range_del_table_`). Hints include pointers to table data, so mixing hints for different tables together without tracking which hint corresponds to which table was problematic. We can just make the hints dedicated to the point key table only. Pull Request resolved: https://github.com/facebook/rocksdb/pull/12558 Reviewed By: hx235 Differential Revision: D56279019 Pulled By: ajkr fbshipit-source-id: 00fe5ce72f9f11a1c1cba5f1977b908b2d518f29 |
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Andrew Kryczka
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7027265417 |
Fix max_successive_merges counting CPU overhead regression (#12546)
Summary: In https://github.com/facebook/rocksdb/issues/12365 we made `max_successive_merges` non-strict by default. Before https://github.com/facebook/rocksdb/issues/12365, `CountSuccessiveMergeEntries()`'s scan was implicitly limited to `max_successive_merges` entries for a given key, because after that the merge operator would be invoked and the merge chain would be collapsed. After https://github.com/facebook/rocksdb/issues/12365, the merge chain will not be collapsed no matter how long it is when the chain's operands are not all in memory. Since `CountSuccessiveMergeEntries()` scanned the whole merge chain, https://github.com/facebook/rocksdb/issues/12365 had a side effect that it would scan more memtable entries. This PR introduces a limit so it won't scan more entries than it could before. Pull Request resolved: https://github.com/facebook/rocksdb/pull/12546 Reviewed By: jaykorean Differential Revision: D56193693 Pulled By: ajkr fbshipit-source-id: b070ba0703ef733e0ff230f89cd5cca5233b84da |
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Yu Zhang
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13e1c32a18 |
Follow ups for TimedPut and write time property (#12455)
Summary: This PR contains a few follow ups from https://github.com/facebook/rocksdb/issues/12419 and https://github.com/facebook/rocksdb/issues/12428 including: 1) Handle a special case for `WriteBatch::TimedPut`. When the user specified write time is `std::numeric_limits<uint64_t>::max()`, it's not treated as an error, but it instead creates and writes a regular `Put` entry. 2) Update the `InternalIterator::write_unix_time` APIs to handle `kTypeValuePreferredSeqno` entries. 3) FlushJob is updated to use the seqno to time mapping copy in `SuperVersion`. FlushJob currently copy the DB's seqno to time mapping while holding db mutex and only copies the part of interest, a.k.a, the part that only goes back to the earliest sequence number of the to-be-flushed memtables. While updating FlushJob to use the mapping copy in `SuperVersion`, it's given access to the full mapping to help cover the need to convert `kTypeValuePreferredSeqno`'s write time to preferred seqno as much as possible. Test plans: Added unit tests Pull Request resolved: https://github.com/facebook/rocksdb/pull/12455 Reviewed By: pdillinger Differential Revision: D55165422 Pulled By: jowlyzhang fbshipit-source-id: dc022653077f678c24661de5743146a74cce4b47 |
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Yu Zhang
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f2546b6623 |
Support returning write unix time in iterator property (#12428)
Summary: This PR adds support to return data's approximate unix write time in the iterator property API. The general implementation is: 1) If the entry comes from a SST file, the sequence number to time mapping recorded in that file's table properties will be used to deduce the entry's write time from its sequence number. If no such recording is available, `std::numeric_limits<uint64_t>::max()` is returned to indicate the write time is unknown except if the entry's sequence number is zero, in which case, 0 is returned. This also means that even if `preclude_last_level_data_seconds` and `preserve_internal_time_seconds` can be toggled off between DB reopens, as long as the SST file's table property has the mapping available, the entry's write time can be deduced and returned. 2) If the entry comes from memtable, we will use the DB's sequence number to write time mapping to do similar things. A copy of the DB's seqno to write time mapping is kept in SuperVersion to allow iterators to have lock free access. This also means a new `SuperVersion` is installed each time DB's seqno to time mapping updates, which is originally proposed by Peter in https://github.com/facebook/rocksdb/issues/11928 . Similarly, if the feature is not enabled, `std::numeric_limits<uint64_t>::max()` is returned to indicate the write time is unknown. Needed follow up: 1) The write time for `kTypeValuePreferredSeqno` should be special cased, where it's already specified by the user, so we can directly return it. 2) Flush job can be updated to use DB's seqno to time mapping copy in the SuperVersion. 3) Handle the case when `TimedPut` is called with a write time that is `std::numeric_limits<uint64_t>::max()`. We can make it a regular `Put`. Pull Request resolved: https://github.com/facebook/rocksdb/pull/12428 Test Plan: Added unit test Reviewed By: pdillinger Differential Revision: D54967067 Pulled By: jowlyzhang fbshipit-source-id: c795b1b7ec142e09e53f2ed3461cf719833cb37a |
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Andrew Kryczka
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3f5bd46a07 |
Add ContinueCallback to GetMergeOperands() (#12438)
Summary: The use case is similar to `MergeOperator::ShouldMerge()` for `Get()`: preventing reads into LSM components for merge operands that are of no interest to the user. `MergeOperator::ShouldMerge()` cannot be reused here because: - Its name does not make sense in the context of `GetMergeOperands()` since `GetMergeOperands()` never invokes merge - The callback is part of the `MergeOperator`, but an option specific to the read operation makes more sense to me If there are any ideas for an API design that covers both `MergeOperator::ShouldMerge()`'s use cases and `GetMergeOperandsOptions::continue_cb`'s use cases, that would be ideal, but for now this is what I came up with. Pull Request resolved: https://github.com/facebook/rocksdb/pull/12438 Reviewed By: hx235 Differential Revision: D54914669 Pulled By: ajkr fbshipit-source-id: 5f3ff78d3890adc0b1b74bedf3921221930ce63a |
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Yu Zhang
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1104eaa35e |
Add initial support for TimedPut API (#12419)
Summary:
This PR adds support for `TimedPut` API. We introduced a new type `kTypeValuePreferredSeqno` for entries added to the DB via the `TimedPut` API.
The life cycle of such an entry on the write/flush/compaction paths are:
1) It is initially added to memtable as:
`<user_key, seq, kTypeValuePreferredSeqno>: {value, write_unix_time}`
2) When it's flushed to L0 sst files, it's converted to:
`<user_key, seq, kTypeValuePreferredSeqno>: {value, preferred_seqno}`
when we have easy access to the seqno to time mapping.
3) During compaction, if certain conditions are met, we swap in the `preferred_seqno` and the entry will become:
`<user_key, preferred_seqno, kTypeValue>: value`. This step helps fast track these entries to the cold tier if they are eligible after the sequence number swap.
On the read path:
A `kTypeValuePreferredSeqno` entry acts the same as a `kTypeValue` entry, the unix_write_time/preferred seqno part packed in value is completely ignored.
Needed follow ups:
1) The seqno to time mapping accessible in flush needs to be extended to cover the `write_unix_time` for possible `kTypeValuePreferredSeqno` entries. This also means we need to track these `write_unix_time` in memtable.
2) Compaction filter support for the new `kTypeValuePreferredSeqno` type for feature parity with other `kTypeValue` and equivalent types.
3) Stress test coverage for the feature
Pull Request resolved: https://github.com/facebook/rocksdb/pull/12419
Test Plan: Added unit tests
Reviewed By: pdillinger
Differential Revision: D54920296
Pulled By: jowlyzhang
fbshipit-source-id: c8b43f7a7c465e569141770e93c748371ff1da9e
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Andrew Kryczka
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8e29f243c9 |
No filesystem reads during Merge() writes (#12365)
Summary: This occasional filesystem read in the write path has caused user pain. It doesn't seem very useful considering it only limits one component's merge chain length, and only helps merge uncached (i.e., infrequently read) values. This PR proposes allowing `max_successive_merges` to be exceeded when the value cannot be read from in-memory components. I included a rollback flag (`strict_max_successive_merges`) just in case. Pull Request resolved: https://github.com/facebook/rocksdb/pull/12365 Test Plan: "rocksdb.block.cache.data.add" is number of data blocks read from filesystem. Since the benchmark is write-only, compaction is disabled, and flush doesn't read data blocks, any nonzero value means the user write issued the read. ``` $ for s in false true; do echo -n "strict_max_successive_merges=$s: " && ./db_bench -value_size=64 -write_buffer_size=131072 -writes=128 -num=1 -benchmarks=mergerandom,flush,mergerandom -merge_operator=stringappend -disable_auto_compactions=true -compression_type=none -strict_max_successive_merges=$s -max_successive_merges=100 -statistics=true |& grep 'block.cache.data.add COUNT' ; done strict_max_successive_merges=false: rocksdb.block.cache.data.add COUNT : 0 strict_max_successive_merges=true: rocksdb.block.cache.data.add COUNT : 1 ``` Reviewed By: hx235 Differential Revision: D53982520 Pulled By: ajkr fbshipit-source-id: e40f761a60bd601f232417ac0058e4a33ee9c0f4 |
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Peter Dillinger
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54cb9c77d9 |
Prefer static_cast in place of most reinterpret_cast (#12308)
Summary: The following are risks associated with pointer-to-pointer reinterpret_cast: * Can produce the "wrong result" (crash or memory corruption). IIRC, in theory this can happen for any up-cast or down-cast for a non-standard-layout type, though in practice would only happen for multiple inheritance cases (where the base class pointer might be "inside" the derived object). We don't use multiple inheritance a lot, but we do. * Can mask useful compiler errors upon code change, including converting between unrelated pointer types that you are expecting to be related, and converting between pointer and scalar types unintentionally. I can only think of some obscure cases where static_cast could be troublesome when it compiles as a replacement: * Going through `void*` could plausibly cause unnecessary or broken pointer arithmetic. Suppose we have `struct Derived: public Base1, public Base2`. If we have `Derived*` -> `void*` -> `Base2*` -> `Derived*` through reinterpret casts, this could plausibly work (though technical UB) assuming the `Base2*` is not dereferenced. Changing to static cast could introduce breaking pointer arithmetic. * Unnecessary (but safe) pointer arithmetic could arise in a case like `Derived*` -> `Base2*` -> `Derived*` where before the Base2 pointer might not have been dereferenced. This could potentially affect performance. With some light scripting, I tried replacing pointer-to-pointer reinterpret_casts with static_cast and kept the cases that still compile. Most occurrences of reinterpret_cast have successfully been changed (except for java/ and third-party/). 294 changed, 257 remain. A couple of related interventions included here: * Previously Cache::Handle was not actually derived from in the implementations and just used as a `void*` stand-in with reinterpret_cast. Now there is a relationship to allow static_cast. In theory, this could introduce pointer arithmetic (as described above) but is unlikely without multiple inheritance AND non-empty Cache::Handle. * Remove some unnecessary casts to void* as this is allowed to be implicit (for better or worse). Most of the remaining reinterpret_casts are for converting to/from raw bytes of objects. We could consider better idioms for these patterns in follow-up work. I wish there were a way to implement a template variant of static_cast that would only compile if no pointer arithmetic is generated, but best I can tell, this is not possible. AFAIK the best you could do is a dynamic check that the void* conversion after the static cast is unchanged. Pull Request resolved: https://github.com/facebook/rocksdb/pull/12308 Test Plan: existing tests, CI Reviewed By: ltamasi Differential Revision: D53204947 Pulled By: pdillinger fbshipit-source-id: 9de23e618263b0d5b9820f4e15966876888a16e2 |
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Hui Xiao
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06e593376c |
Group SST write in flush, compaction and db open with new stats (#11910)
Summary: ## Context/Summary Similar to https://github.com/facebook/rocksdb/pull/11288, https://github.com/facebook/rocksdb/pull/11444, categorizing SST/blob file write according to different io activities allows more insight into the activity. For that, this PR does the following: - Tag different write IOs by passing down and converting WriteOptions to IOOptions - Add new SST_WRITE_MICROS histogram in WritableFileWriter::Append() and breakdown FILE_WRITE_{FLUSH|COMPACTION|DB_OPEN}_MICROS Some related code refactory to make implementation cleaner: - Blob stats - Replace high-level write measurement with low-level WritableFileWriter::Append() measurement for BLOB_DB_BLOB_FILE_WRITE_MICROS. This is to make FILE_WRITE_{FLUSH|COMPACTION|DB_OPEN}_MICROS include blob file. As a consequence, this introduces some behavioral changes on it, see HISTORY and db bench test plan below for more info. - Fix bugs where BLOB_DB_BLOB_FILE_SYNCED/BLOB_DB_BLOB_FILE_BYTES_WRITTEN include file failed to sync and bytes failed to write. - Refactor WriteOptions constructor for easier construction with io_activity and rate_limiter_priority - Refactor DBImpl::~DBImpl()/BlobDBImpl::Close() to bypass thread op verification - Build table - TableBuilderOptions now includes Read/WriteOpitons so BuildTable() do not need to take these two variables - Replace the io_priority passed into BuildTable() with TableBuilderOptions::WriteOpitons::rate_limiter_priority. Similar for BlobFileBuilder. This parameter is used for dynamically changing file io priority for flush, see https://github.com/facebook/rocksdb/pull/9988?fbclid=IwAR1DtKel6c-bRJAdesGo0jsbztRtciByNlvokbxkV6h_L-AE9MACzqRTT5s for more - Update ThreadStatus::FLUSH_BYTES_WRITTEN to use io_activity to track flush IO in flush job and db open instead of io_priority ## Test ### db bench Flush ``` ./db_bench --statistics=1 --benchmarks=fillseq --num=100000 --write_buffer_size=100 rocksdb.sst.write.micros P50 : 1.830863 P95 : 4.094720 P99 : 6.578947 P100 : 26.000000 COUNT : 7875 SUM : 20377 rocksdb.file.write.flush.micros P50 : 1.830863 P95 : 4.094720 P99 : 6.578947 P100 : 26.000000 COUNT : 7875 SUM : 20377 rocksdb.file.write.compaction.micros P50 : 0.000000 P95 : 0.000000 P99 : 0.000000 P100 : 0.000000 COUNT : 0 SUM : 0 rocksdb.file.write.db.open.micros P50 : 0.000000 P95 : 0.000000 P99 : 0.000000 P100 : 0.000000 COUNT : 0 SUM : 0 ``` compaction, db oopen ``` Setup: ./db_bench --statistics=1 --benchmarks=fillseq --num=10000 --disable_auto_compactions=1 -write_buffer_size=100 --db=../db_bench Run:./db_bench --statistics=1 --benchmarks=compact --db=../db_bench --use_existing_db=1 rocksdb.sst.write.micros P50 : 2.675325 P95 : 9.578788 P99 : 18.780000 P100 : 314.000000 COUNT : 638 SUM : 3279 rocksdb.file.write.flush.micros P50 : 0.000000 P95 : 0.000000 P99 : 0.000000 P100 : 0.000000 COUNT : 0 SUM : 0 rocksdb.file.write.compaction.micros P50 : 2.757353 P95 : 9.610687 P99 : 19.316667 P100 : 314.000000 COUNT : 615 SUM : 3213 rocksdb.file.write.db.open.micros P50 : 2.055556 P95 : 3.925000 P99 : 9.000000 P100 : 9.000000 COUNT : 23 SUM : 66 ``` blob stats - just to make sure they aren't broken by this PR ``` Integrated Blob DB Setup: ./db_bench --enable_blob_files=1 --statistics=1 --benchmarks=fillseq --num=10000 --disable_auto_compactions=1 -write_buffer_size=100 --db=../db_bench Run:./db_bench --enable_blob_files=1 --statistics=1 --benchmarks=compact --db=../db_bench --use_existing_db=1 pre-PR: rocksdb.blobdb.blob.file.write.micros P50 : 7.298246 P95 : 9.771930 P99 : 9.991813 P100 : 16.000000 COUNT : 235 SUM : 1600 rocksdb.blobdb.blob.file.synced COUNT : 1 rocksdb.blobdb.blob.file.bytes.written COUNT : 34842 post-PR: rocksdb.blobdb.blob.file.write.micros P50 : 2.000000 P95 : 2.829360 P99 : 2.993779 P100 : 9.000000 COUNT : 707 SUM : 1614 - COUNT is higher and values are smaller as it includes header and footer write - COUNT is 3X higher due to each Append() count as one post-PR, while in pre-PR, 3 Append()s counts as one. See https://github.com/facebook/rocksdb/pull/11910/files#diff-32b811c0a1c000768cfb2532052b44dc0b3bf82253f3eab078e15ff201a0dabfL157-L164 rocksdb.blobdb.blob.file.synced COUNT : 1 (stay the same) rocksdb.blobdb.blob.file.bytes.written COUNT : 34842 (stay the same) ``` ``` Stacked Blob DB Run: ./db_bench --use_blob_db=1 --statistics=1 --benchmarks=fillseq --num=10000 --disable_auto_compactions=1 -write_buffer_size=100 --db=../db_bench pre-PR: rocksdb.blobdb.blob.file.write.micros P50 : 12.808042 P95 : 19.674497 P99 : 28.539683 P100 : 51.000000 COUNT : 10000 SUM : 140876 rocksdb.blobdb.blob.file.synced COUNT : 8 rocksdb.blobdb.blob.file.bytes.written COUNT : 1043445 post-PR: rocksdb.blobdb.blob.file.write.micros P50 : 1.657370 P95 : 2.952175 P99 : 3.877519 P100 : 24.000000 COUNT : 30001 SUM : 67924 - COUNT is higher and values are smaller as it includes header and footer write - COUNT is 3X higher due to each Append() count as one post-PR, while in pre-PR, 3 Append()s counts as one. See https://github.com/facebook/rocksdb/pull/11910/files#diff-32b811c0a1c000768cfb2532052b44dc0b3bf82253f3eab078e15ff201a0dabfL157-L164 rocksdb.blobdb.blob.file.synced COUNT : 8 (stay the same) rocksdb.blobdb.blob.file.bytes.written COUNT : 1043445 (stay the same) ``` ### Rehearsal CI stress test Trigger 3 full runs of all our CI stress tests ### Performance Flush ``` TEST_TMPDIR=/dev/shm ./db_basic_bench_pre_pr --benchmark_filter=ManualFlush/key_num:524288/per_key_size:256 --benchmark_repetitions=1000 -- default: 1 thread is used to run benchmark; enable_statistics = true Pre-pr: avg 507515519.3 ns 497686074,499444327,500862543,501389862,502994471,503744435,504142123,504224056,505724198,506610393,506837742,506955122,507695561,507929036,508307733,508312691,508999120,509963561,510142147,510698091,510743096,510769317,510957074,511053311,511371367,511409911,511432960,511642385,511691964,511730908, Post-pr: avg 511971266.5 ns, regressed 0.88% 502744835,506502498,507735420,507929724,508313335,509548582,509994942,510107257,510715603,511046955,511352639,511458478,512117521,512317380,512766303,512972652,513059586,513804934,513808980,514059409,514187369,514389494,514447762,514616464,514622882,514641763,514666265,514716377,514990179,515502408, ``` Compaction ``` TEST_TMPDIR=/dev/shm ./db_basic_bench_{pre|post}_pr --benchmark_filter=ManualCompaction/comp_style:0/max_data:134217728/per_key_size:256/enable_statistics:1 --benchmark_repetitions=1000 -- default: 1 thread is used to run benchmark Pre-pr: avg 495346098.30 ns 492118301,493203526,494201411,494336607,495269217,495404950,496402598,497012157,497358370,498153846 Post-pr: avg 504528077.20, regressed 1.85%. "ManualCompaction" include flush so the isolated regression for compaction should be around 1.85-0.88 = 0.97% 502465338,502485945,502541789,502909283,503438601,504143885,506113087,506629423,507160414,507393007 ``` Put with WAL (in case passing WriteOptions slows down this path even without collecting SST write stats) ``` TEST_TMPDIR=/dev/shm ./db_basic_bench_pre_pr --benchmark_filter=DBPut/comp_style:0/max_data:107374182400/per_key_size:256/enable_statistics:1/wal:1 --benchmark_repetitions=1000 -- default: 1 thread is used to run benchmark Pre-pr: avg 3848.10 ns 3814,3838,3839,3848,3854,3854,3854,3860,3860,3860 Post-pr: avg 3874.20 ns, regressed 0.68% 3863,3867,3871,3874,3875,3877,3877,3877,3880,3881 ``` Pull Request resolved: https://github.com/facebook/rocksdb/pull/11910 Reviewed By: ajkr Differential Revision: D49788060 Pulled By: hx235 fbshipit-source-id: 79e73699cda5be3b66461687e5147c2484fc5eff |
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Levi Tamasi
|
0ebe1614cb |
Eliminate some code duplication in MergeHelper (#12121)
Summary: Pull Request resolved: https://github.com/facebook/rocksdb/pull/12121 The patch eliminates some code duplication by unifying the two sets of `MergeHelper::TimedFullMerge` overloads using variadic templates. It also brings the order of parameters into sync when it comes to the various `TimedFullMerge*` methods. Reviewed By: jaykorean Differential Revision: D51862483 fbshipit-source-id: e3f832a6ff89ba34591451655cf11025d0a0d018 |
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Yu Zhang
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ba8fa0f546 |
internal_repo_rocksdb (4372117296613874540) (#12117)
Summary: Pull Request resolved: https://github.com/facebook/rocksdb/pull/12117 Reviewed By: ajkr Differential Revision: D51745846 Pulled By: jowlyzhang fbshipit-source-id: 51c806a484b3b43d174b06d2cfe9499191d09914 |
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Levi Tamasi
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f42e70bf56 |
Integrate FullMergeV3 into the query and compaction paths (#11858)
Summary: Pull Request resolved: https://github.com/facebook/rocksdb/pull/11858 The patch builds on https://github.com/facebook/rocksdb/pull/11807 and integrates the `FullMergeV3` API into the read and compaction code paths by updating and extending the logic in `MergeHelper`. In particular, when it comes to merge inputs, the existing `TimedFullMergeWithEntity` is folded into `TimedFullMerge`, since wide-column base values are now handled the same way as plain base values (or no base values for that matter), e.g. they are passed directly to the `MergeOperator`. On the other hand, there is some new differentiation on the output side. Namely, there are now two sets of `TimedFullMerge` variants: one set for contexts where the complete merge result and its value type are needed (used by iterators and compactions), and another set where the merge result is needed in a form determined by the client (used by the point lookup APIs, where e.g. for `Get` we have to extract the value of the default column of any wide-column results). Implementation-wise, the two sets of overloads use different visitors to process the `std::variant` produced by `FullMergeV3`. This has the benefit of eliminating some repeated code e.g. in the point lookup paths, since `TimedFullMerge` now populates the application's result object (`PinnableSlice`/`string` or `PinnableWideColumns`) directly. Moreover, within each set of variants, there is a separate overload for the no base value/plain base value/wide-column base value cases, which eliminates some repeated branching w/r/t to the type of the base value if any. Reviewed By: jaykorean Differential Revision: D49352562 fbshipit-source-id: c2fb9853dba3fbbc6918665bde4195c4ea150a0c |
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Vardhan
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87a21d08fe |
Add an option to trigger flush when the number of range deletions reach a threshold (#11358)
Summary: Add a mutable column family option `memtable_max_range_deletions`. When non-zero, RocksDB will try to flush the current memtable after it has at least `memtable_max_range_deletions` range deletions. Java API is added and crash test is updated accordingly to randomly enable this option. Pull Request resolved: https://github.com/facebook/rocksdb/pull/11358 Test Plan: * New unit test: `DBRangeDelTest.MemtableMaxRangeDeletions` * Ran crash test `python3 ./tools/db_crashtest.py whitebox --simple --memtable_max_range_deletions=20` and saw logs showing flushed memtables usually with 20 range deletions. Reviewed By: ajkr Differential Revision: D46582680 Pulled By: cbi42 fbshipit-source-id: f23d6fa8d8264ecf0a18d55c113ba03f5e2504da |
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Yu Zhang
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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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leipeng
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25b08eb438 |
MemTable::Add: first_seqno_.compare_exchange_weak to earliest_seqno_ (#11398)
Summary: This should be a benign bug caused by a long lived typo, this PR fix this issue. Pull Request resolved: https://github.com/facebook/rocksdb/pull/11398 Reviewed By: ajkr Differential Revision: D47163379 Pulled By: cbi42 fbshipit-source-id: 531728cae496fd7ac1371bbbd64fc103c3a90dcf |
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Peter Dillinger
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206fdea3d9 |
Change internal headers with duplicate names (#11408)
Summary: In IDE navigation I find it annoying that there are two statistics.h files (etc.) and often land on the wrong one. Here I migrate several headers to use the blah.h <- blah_impl.h <- blah.cc idiom. Although clang-format wants "blah.h" to be the top include for "blah.cc", I think overall this is an improvement. No public API changes. Pull Request resolved: https://github.com/facebook/rocksdb/pull/11408 Test Plan: existing tests Reviewed By: ltamasi Differential Revision: D45456696 Pulled By: pdillinger fbshipit-source-id: 809d931253f3272c908cf5facf7e1d32fc507373 |
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Changyu Bi
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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
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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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Levi Tamasi
|
49881921cd |
Rename a recently added PerfContext counter (#11294)
Summary: The patch renames the counter added in https://github.com/facebook/rocksdb/issues/11284 for better consistency with the existing naming scheme. Pull Request resolved: https://github.com/facebook/rocksdb/pull/11294 Test Plan: `make check` Reviewed By: jowlyzhang Differential Revision: D44035964 Pulled By: ltamasi fbshipit-source-id: 8b1a2a03ee728148365367e0ecc1fcf462f62191 |
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Levi Tamasi
|
1d52438504 |
Add a PerfContext counter for merge operands applied in point lookups (#11284)
Summary: The existing PerfContext counter `internal_merge_count` only tracks the Merge operands applied during range scans. The patch adds a new counter called `internal_merge_count_point_lookups` to track the same metric for point lookups (`Get` / `MultiGet` / `GetEntity` / `MultiGetEntity`), and also fixes a couple of cases in the iterator where the existing counter wasn't updated. Pull Request resolved: https://github.com/facebook/rocksdb/pull/11284 Test Plan: `make check` Reviewed By: jowlyzhang Differential Revision: D43926082 Pulled By: ltamasi fbshipit-source-id: 321566d8b4cf0a3b6c9b73b7a5c984fb9bb492e9 |
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Levi Tamasi
|
3c9eed688e |
Enable moving a string or PinnableSlice into PinnableWideColumns (#11248)
Summary: This makes it possible to eliminate some copies in `GetEntity` / `MultiGetEntity`, in particular when `Merge`s or blobs are involved. Pull Request resolved: https://github.com/facebook/rocksdb/pull/11248 Test Plan: `make check` Reviewed By: akankshamahajan15 Differential Revision: D43544215 Pulled By: ltamasi fbshipit-source-id: bc4c8955a24bbd8bc4ab098e72133ead757f9707 |
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Levi Tamasi
|
9794acb597 |
Add a new MultiGetEntity API (#11222)
Summary: The new `MultiGetEntity` API can be used to get a consistent view of a batch of keys, with the results presented as wide-column entities. Similarly to `GetEntity` and the iterator's `columns` API, if the entry corresponding to the key is a wide-column entity to start with, it is returned as-is, and if it is a plain key-value, it is wrapped into an entity with a single default column. Implementation-wise, the new API shares the logic of the batched `MultiGet` API (via the `MultiGetCommon` methods). Both single-CF and multi-CF `MultiGetEntity` APIs are provided, and blobs are also supported. Pull Request resolved: https://github.com/facebook/rocksdb/pull/11222 Test Plan: `make check` Reviewed By: akankshamahajan15 Differential Revision: D43256950 Pulled By: ltamasi fbshipit-source-id: 47fb2cb7e2d0470e3580f43fdb2fe9e51f0e7005 |