1
0
mirror of https://github.com/facebook/rocksdb.git synced 2026-10-23 08:09:02 +03:00

159 Commits

Author SHA1 Message Date
Josh Kang
4b983da055 Spell out special member functions (rule of five) (#15387)
Summary:
Pull Request resolved: https://github.com/facebook/rocksdb/pull/15387

## Summary

RocksDB's `.clang-tidy` enables `cppcoreguidelines-special-member-functions`,
`cppcoreguidelines-virtual-class-destructor` and the noexcept-move checks,
and clang warns `-Wdeprecated-copy-with-user-provided-dtor`. A full scan
reports 476 findings. In most of them, a class declares a destructor (or
copy operations) but leaves the rest of copy/move implicit. That has two
costs. Readers can't tell whether a class may be copied or moved. And
resource-owning classes keep an implicit copy that would double-free if
anyone ever used it. This diff resolves 453 of the 476.

Approach, picked per class from least to most invasive:
1. An empty user-provided destructor becomes `= default`. This covers most
   interface classes, such as `virtual ~X() {}` -> `= default`. If the
   class is still copied, that would only rename the deprecated-copy
   warning, so the destructor is removed instead when nothing needs it
   (`Customizable`, `TableFactory` and `InternalKeyComparator` inherit a
   virtual one; `IteratorWrapperBase` isn't polymorphic), and
   `MemTableRep::KeyComparator` gets defaulted copy and move.
2. Classes whose copy is already deleted get explicitly deleted move
   operations too. Move was already unavailable, so this only documents
   it.
3. Resource-owning classes that are never copied get deleted copy and move
   operations. Examples: the C API wrapper structs, which run a
   `destructor_` callback (edited in `tools/c_api_gen/c_base.cc` and
   regenerated into `db/c.cc`); `ShardedCache`, which frees its shards;
   iterator wrappers; and RAII handles.
4. Value types that are copied or moved get the missing operations as
   `= default`, which keeps their current behavior.
5. Exception specifications of existing functions are unchanged, except
   for `WriteBatch`'s move assignment (below): no other `noexcept` is
   added or removed. Only the move operations this diff
   newly declares (`Comparator`, `FileSampledStats` and the thread-local
   `Entry`) are `noexcept`; they copy only scalars or atomics.

`WriteBatch`'s copy and move assignment destroyed `*this` and
placement-new'ed a new `WriteBatch` over it. That is undefined behavior
when `*this` is a subclass, and if the copy constructor threw, `*this`
was left destroyed and was later destroyed again. Move assignment now
assigns member-wise and ends in the same state as the move constructor,
which leaves `has_key_with_ts_`, the timestamp-size tracking and the
other fields it doesn't copy at their defaults. `rep_` is swapped through
a temporary, because a plain string move-assignment can keep the old
buffer (e.g. a large batch reset with `batch = WriteBatch()` would keep
its memory). Nothing in it can throw, so it is now `noexcept`. Copy
assignment copies into a temporary and moves it in, so a throwing copy
leaves `*this` unchanged.

Bugs this exposed and fixed:
- `RestoreAfterCopyOrCreateWorkItem` (backup engine): the hand-written
  move constructor and assignment moved only some fields, so `from_file`
  and `to_file` were empty after `push_back(std::move(...))`. A restore
  that hit a checksum mismatch then reported "While restoring  -> : ..."
  without file names. It now uses the compiler-generated moves, which
  are still `noexcept`.
- `ExternalSstFileIngestionJob` lived in a `std::vector`, and its
  destructor frees raw-owned pointers, so the implicit copy used on
  vector reallocation would double-free. Its file batches also point into
  its own inline file storage, so neither a copy nor a move is safe after
  `Prepare()`. Copy and move are now deleted, and `DBImpl` holds jobs
  through `std::unique_ptr`.

Compatibility: no public class loses an operation users can call. Public
interfaces mostly only get `virtual ~X() = default;`.
`WriteBatch`'s move assignment becomes `noexcept`, which is not part of
the mangled name, so the ABI doesn't change.
`SubcompactionJobInfo` and `CompactionJobInfo` intentionally stay C++20
aggregates, so users' aggregate and designated initializers keep
compiling. `Configurable`, `CompareInterface`, `WriteBatchBase`,
`ObjectLibrary::Entry` and `MemTableRep::KeyComparator` declare defaulted
copy and move, and `Customizable` no longer declares a destructor. As a
result, `Configurable` and `Customizable` subclasses that declare no
destructor or copy operations of their own now move their
registered-options list instead of copying it. In-tree, these are the
mutable-options adapters, the table factories, the memory allocators and
test classes; all are held through smart pointers or used in place, and
`Clone()` copies, so none is moved by value.

Not changed (23): `IODebugContext` (custom deep copy plus a
`std::shared_mutex`), `DBWithColumnFamilies` in db_bench (stored in a
`std::vector` with non-movable members), `Snapshot`'s protected virtual
destructor (intended), `ManagedSnapshot`, the `SubcompactionJobInfo` and
`CompactionJobInfo` aggregates, and the 16 noexcept-move-constructor and
noexcept-swap findings on existing functions, including `autovector`'s
move assignment (adding `noexcept` would change their exception
specifications). Copying `ManagedSnapshot` already double-releases the
snapshot. Fixing that needs a real move implementation and is a behavior
change, so it is left for a separate diff.

Reviewed By: rban1

Differential Revision: D123186309

fbshipit-source-id: 6f8e57e233e12199a007407130bb9a1f6d52e8d1
2026-10-12 16:00:09 -07:00
Xingbo Wang
baa4d373a6 Commit authoritative OPTIONS file numbers in MANIFEST (#15305)
Summary:
Pull Request resolved: https://github.com/facebook/rocksdb/pull/15305

Why the change is required:

Column-family topology is durable in MANIFEST, while its operational
configuration snapshot is stored in a separate OPTIONS file.
CreateColumnFamily and DropColumnFamily previously committed MANIFEST first
and wrote OPTIONS afterward. An OPTIONS I/O failure could therefore make the
API report failure after the topology change was already durable.
Persisted-options readers also selected the highest file number and could
consume an orphan left by a failed publication.

Previous behavior:

RocksDB had no durable correspondence between a MANIFEST state and the
OPTIONS snapshot describing it. LoadLatestOptions and
GetLatestOptionsFileName treated the highest-numbered OPTIONS file as
authoritative. Column-family creation and deletion returned the later OPTIONS
persistence error even when their MANIFEST edit had already succeeded.
Multi-column-family operations wrote a complete OPTIONS snapshot after every
successful member, producing quadratic OPTIONS bytes.

Ordinary DB::Open consumes caller-supplied DB and column-family options rather
than loading OPTIONS. This change preserves that contract.

New behavior:

Add the default-disabled experimental DB option
track_options_file_number_in_manifest. Its value is serialized into each
OPTIONS file so the selection rule is self-describing and participates in the
normal DB-options compatibility checks.

When enabled, RocksDB first durably creates and renames OPTIONS-N and then
commits N with one safely ignorable MANIFEST field. A normal OPTIONS rotation
uses one MANIFEST commit. Column-family creation and deletion prewrite the
proposed snapshot and commit its number together with a topology edit in the
same VersionEdit. A failure before the OPTIONS file is durable changes no
topology. A failure after the file is durable but before MANIFEST commit leaves
an orphan that binding-aware readers ignore, while the previous committed
snapshot remains authoritative.

Each multi-CF create or drop writes one proposed snapshot, independent of the
batch size. Create commits the new number with the first successful add; drop
commits it with the last successful drop. Existing partial-success semantics
can therefore leave a committed snapshot with extra CFs, but never one missing
a live MANIFEST CF. Persisted-options APIs filter this safe superset against
recovered MANIFEST membership. A snapshot missing a live CF is corruption.
DB::Open with create_missing_column_families uses the same batched path.

If the newest OPTIONS file has tracking disabled, it retains the legacy
highest-numbered-file behavior, including after an old or disabled writer has
run. If it has tracking enabled, readers use the recovered MANIFEST commit and
reject newer tracked orphans. A missing usable commit falls back to the highest
tracked snapshot for RepairDB and legacy-rewrite recovery. DB open logs that
fallback through its configured logger; logger-less utility APIs remain
silent. Writable open removes rejected tracked orphans when local obsolete-file
deletion is enabled. Read-only open never mutates the DB directory.

A DB with no recovered commit and tracking disabled takes the legacy fast path
without parsing the newest OPTIONS file. When inspection is required, RocksDB
reads only the tracking marker. Marker-read failures used for selection do not
fail DB open; a recovered commit remains authoritative and ambiguous newer
candidates are conservatively retained.

The first topology change after enabling tracking first binds the current
topology, so failure of the proposed change cannot make its orphan
authoritative. MANIFEST failure during an ordinary tracked OPTIONS rotation
also enters the existing manifest-write background-error path.

Implementation:

- Add the safely ignorable CommittedOptionsFileNumber VersionEdit field and
  carry it through recovery, MANIFEST snapshots, rollover, and subset
  checkpoints.
- Persist the tracking marker through C++, C, and Java options, generated
  round-trip coverage, compatibility checking, and db_stress configuration.
- Centralize binding-aware selection for DB open and public persisted-options
  APIs. Reuse RecoveryContext's directory listing, use a narrow marker scan,
  and recover live CF names while replaying MANIFEST.
- Filter manifest-selected safe-superset snapshots to live MANIFEST CFs in
  LoadLatestOptions and compatibility verification without discarding their
  option maps.
- Prevalidate and sanitize CF batches outside the DB mutex, write one complete
  snapshot while options_mutex_ serializes topology changes, and hold the DB
  mutex only for the existing individual MANIFEST commits. Batch missing-CF
  creation during DB open follows the same locking boundary.
- Keep the committed snapshot live in cleanup and live-file APIs, and make
  subset checkpoints write an OPTIONS snapshot and filtered MANIFEST with
  identical membership in tracked and legacy modes.
- Preserve the first partial multi-CF drop error while consuming legacy
  OPTIONS persistence Status, and sync the checkpoint MANIFEST directory after
  replacement.
- Pass checkpoint helper callbacks by reference and group VersionEdit storage
  by alignment so the new paths add neither callback copies nor avoidable
  object padding.

Safety boundaries and unsupported cases:

- Tracking defaults to false. Disabled writers and never-tracked databases
  retain legacy write ordering and highest-numbered selection.
- Older binaries safely ignore the new MANIFEST tag and continue choosing the
  highest OPTIONS number. Downgrade is readable but not crash-atomic: an old
  binary can consume a tracked orphan. That is the same class of
  OPTIONS/MANIFEST inconsistency as the previous behavior.
- A rollback binary must know the serialized option name before the feature is
  enabled. Exact compatibility checks intentionally report a mismatch when the
  caller's tracking setting differs from the persisted snapshot.
- A newer untracked OPTIONS file deliberately supersedes an older committed
  number, allowing an old or disabled writer to become authoritative without
  rewriting MANIFEST.
- Reactive secondary and follower instances do not enforce or repair the
  binding. Ordinary DB::Open still uses caller-supplied options.
- Writable open does not delete rejected tracked or ambiguous files when a
  compaction service owns OPTIONS-file retention. Read-only open performs no
  repair writes.
- Direct consumers that scan OPTIONS filenames themselves are unchanged; the
  binding is enforced by RocksDB's persisted-options APIs.
- If the committed snapshot is missing and only tracked candidates remain,
  selection intentionally falls back to the highest candidate so RepairDB
  output remains usable.

Validation coverage and known limitations:

Focused coverage exercises encoding compatibility, tracked and legacy
selection, the never-tracked open fast path, marker-read failures, exact
tracking-marker compatibility, activation and disable/re-enable transitions,
batched create/drop and create-missing behavior, partial-batch safe supersets,
OPTIONS/MANIFEST failure injection, background-error propagation, orphan
cleanup and retention, read-only non-mutation, subset-checkpoint behavior,
stale OPTIONS recovery, RepairDB option sanitization, and transient
read-corruption reconstruction. The assertion-enabled full executable suite
passes. The repository check-format and check-sources wrappers cannot run
because they invoke Git inside this Sapling checkout; fbsource lint is used
instead. Cross-platform CI is not part of local validation.

Reviewed By: pdillinger

Differential Revision: D123104845

fbshipit-source-id: 77d94c989243c3f3f9fedfa81fa364c166250303
2026-10-11 10:39:30 -07:00
Peter Dillinger
1c490a4a4d Fix "ancester" spelling; deprecate TablePropertiesNames (#15335)
Summary:
Follow-up to https://github.com/facebook/rocksdb/issues/15304, which renamed `TableProperties::creation_time` to `oldest_ancestor_time` but left the long-standing "ancester" misspelling everywhere else, so the same concept was spelled two ways (e.g. `TableProperties::oldest_ancestor_time` vs. `FileMetaData::oldest_ancester_time` and `SstFileMetaData::oldest_ancester_time`). This change makes the spelling consistent and addresses remaining review feedback on https://github.com/facebook/rocksdb/issues/15304.

Change:
* All internal identifiers and comments now use "ancestor": `FileMetaData::oldest_ancestor_time`, `CompactionServiceOutputFile::oldest_ancestor_time`, `kUnknownOldestAncestorTime`, `TryGetOldestAncestorTime()`, `Compaction::MinInputFileOldestAncestorTime()`, the `kOldestAncestorTime` manifest tag enum, and related locals and test sync point names.
* Public API: `SstFileMetaData::oldest_ancestor_time` is the new name; `oldest_ancester_time` remains as a deprecated alias sharing storage via an anonymous union (same approach as `TableProperties::creation_time`, so size, layout, and copy semantics are unchanged).
* Public API: `TablePropertiesNames::kOldestAncestorTime` is the new name; `kCreationTime` remains as a deprecated `static const std::string&` alias. A static reference member has no per-object cost and binds at constant initialization, so it adds no static-init-order exposure.
* `TablePropertiesNames` as a whole is marked DEPRECATED for public use. An fbsource-wide BigGrep found no references outside RocksDB and its vendored copies, and it is only meaningful to table format internals; users should read the corresponding `TableProperties` fields.

Fix:
* The `table_file_creation` event log entry had the `oldest_key_time` and `newest_key_time` values swapped since https://github.com/facebook/rocksdb/issues/13083 (v10.0). Now each label is paired with its own value.

Also: tools/c_api_gen/auto_simple_bindings.py resets the pending anonymous union field list after use and skips unnamed members inside the union (review suggestion); generated C API output is unchanged.

Compatibility: names that are persisted or externally parsed intentionally keep the old spelling: the on-disk property name `rocksdb.creation.time`, the `"oldest_ancester_time"` key in remote compaction serialization, and the `oldest_ancester_time` / `OldestAncesterTime` labels in `VersionEdit` DebugString/DebugJSON (ldb manifest_dump output). The manifest tag value is unchanged. HISTORY.md is left as historical record.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/15335

Test Plan: DBTablePropertiesTest.CreationTimeAliasesOldestAncestorTime now also verifies `TablePropertiesNames::kCreationTime` and `kOldestAncestorTime` refer to the same object, and new DBTablePropertiesTest.SstFileMetaDataOldestAncesterTimeAlias verifies the two `SstFileMetaData` names share an address and that writes through the old name are visible through the new one. Remote compaction serialization through the unchanged `"oldest_ancester_time"` key is covered by compaction_service_test; manifest encode/decode through the renamed field by version_edit_test. `make check-c-api-gen` confirms the generated C API is up to date and backward compatible.

Reviewed By: jaykorean

Differential Revision: D123559299

Pulled By: pdillinger

fbshipit-source-id: 480106e8d539e654f31db210ef6e1de02325d604
2026-10-06 11:59:54 -07:00
Peter Dillinger
c83a84e98c Rename TableProperties::creation_time to oldest_ancestor_time (#15304)
Summary:
The `creation_time` table property has long stored the file's oldest ancestor time (the oldest key time among the file's ancestors, falling back to flush/compaction time), not the file's creation time, which is `file_creation_time`. A TODO in table_properties.h acknowledged the misleading name. This change starts the API migration: `TableProperties::oldest_ancestor_time` is the new name, and `creation_time` remains as a deprecated alias sharing storage via an anonymous union, so existing external reads and writes continue to compile and behave identically.

An anonymous union is used rather than a `uint64_t&` alias member. A reference member would delete TableProperties copy/move assignment, make the implicit copy constructor bind the copy's alias to the source object (dangling), permit writes through a const TableProperties, add 8 bytes, and break the uint64_t-range walk in TEST_SetRandomTableProperties. The union leaves size, layout, copying, constness, and offsetof unchanged. Reading the other union member is formally UB in ISO C++, but both members are uint64_t and this is supported in practice by GCC, Clang, and MSVC.

All in-repo uses of the old name now use `oldest_ancestor_time`. Names that are externally observable or persisted are intentionally unchanged:
* On-disk property name `rocksdb.creation.time` (`TablePropertiesNames::kCreationTime`)
* The `"creation_time"` key in TableProperties serialization (used by remote compaction)
* The event-log JSON key and `TableProperties::ToString()` label
* Java `TableProperties.getCreationTime()` and C `rocksdb_table_properties_creation_time()`

C API: the auto-binding generator (tools/c_api_gen/auto_simple_bindings.py) only considered direct FieldDecls and failed on the anonymous union's implicit unnamed field. It now treats anonymous union members as direct fields. Regenerating adds a new C getter
`rocksdb_table_properties_oldest_ancestor_time()` alongside the existing `rocksdb_table_properties_creation_time()`.

Follow-up: remove the deprecated `creation_time` alias in a future release.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/15304

Test Plan: New unit test DBTablePropertiesTest.CreationTimeAliasesOldestAncestorTime verifies the two names share an address and that a write through the old name is visible through the new one. options_settable_test and compaction_service_test cover TableProperties serialization round trips through the unchanged "creation_time" key, now mapped to the renamed field.

Reviewed By: jaykorean

Differential Revision: D123079083

Pulled By: pdillinger

fbshipit-source-id: 18b07d91f303a8f6de58da0c730f80d8c371505c
2026-10-05 10:34:04 -07:00
Andrew Chang
2b628ccfe5 Preserve fast_sst_open metadata across MANIFEST rotation (#14987)
Summary:
Pull Request resolved: https://github.com/facebook/rocksdb/pull/14987

The `fast_sst_open` optimization speeds up DB open times by persisting file metadata information in the MANIFEST.

When MANIFESTs are rotated however, this metadata is currently getting dropped, since it is not fed through `VersionEdit::AddFile`. There were also a few additional missing `AddFile` call sites.

Fix: Add an optional `file_open_metadata` to `AddFile`. Feed this through wherever we call `AddFile`.

Reviewed By: anand1976

Differential Revision: D113265655

fbshipit-source-id: c8371d66f6555bb9c372eea095bfa30a5f56a88a
2026-07-22 16:01:44 -07:00
Josh Kang
e292aa95b3 Allow skipping lmax index and filter block prefetches for external file ingestion
Summary:
Bulk external file ingestion can spend significant commit time prefetching index/filter blocks for large Lmax files. This adds `IngestExternalFileOptions::prefetch_lmax_index_and_filter_blocks` (default true) so bulk-load callers can defer that metadata prefetch when the cache doesn't need immediate warming. The option threads through `FileMetaData::skip_index_and_filter_blocks_prefetch` to drive the existing `LoadTableHandlers()` prefetch logic. Benchmarks show ~40% commit latency reduction (3459 → 2112 μs) and ~55% lower IO time (2560 → 1145 μs) when disabled.

Benchmarks:

```
db_bench --benchmarks=ingestexternalfile --num=2200000 --ingest_external_file_num_batches=1 --ingest_external_file_batch_size=1 --ingest_external_file_use_file_info=true --ingest_external_file_fill_cache=true --cache_index_and_filter_blocks=true --bloom_bits=10 --statistics=true --stats_level=3 --ingest_external_file_prefetch_lmax_index_and_filter_blocks=<true|false>
```

| `ingest_external_file_prefetch_lmax_index_and_filter_blocks` | `rocksdb.ingest.external.file.run.micros` | `rocksdb.table.open.io.micros` | index/filter cache adds | last-level read bytes |
| `true` | `3459 us` | `2560 us` | `1 / 1` | `3551559` |
| `false` | `2112 us` | `1145 us` | `0 / 0` | `1333` |

Reviewed By: xingbowang

Differential Revision: D108678511

fbshipit-source-id: e8951e3aad36cc0accffb33ecc3cc1b4aeb89459
2026-06-16 11:20:07 -07:00
Peter Dillinger
62f05627be Reduce manifest rotation for foreground metadata ops (#14797)
Summary:
Async WAL precreation in https://github.com/facebook/rocksdb/pull/14738 / D105020559 was motivated by slow file creation time on remote storage. MANIFEST does not need the same precreation treatment as WAL because most MANIFEST writes come from background flush and compaction work, but user-facing metadata operations can still pay MANIFEST rotation file creation latency inline. File ingestion performance is a particular concern to some Meta users.

Relax the effective MANIFEST rotation limit by 25% for MANIFEST write batches containing any foreground VersionEdit, while keeping background-only flush/compaction batches on the configured or auto-tuned limit. This covers column family manipulation, external file ingestion and import, and DeleteFilesInRange(s). SetOptions remains expected to avoid MANIFEST writes; the test keeps a regression guard for that behavior.

The relaxation is intentionally bounded. It reduces the chance that foreground metadata operations create a new MANIFEST inline, while still allowing foreground operations to rotate once the current MANIFEST is beyond the relaxed threshold. Heavier blocking operations like manual Flush or CompactRange already trigger additional file creation and do not get this treatment here, though that could be reconsidered later.

This should reduce a potential latency hazard of manifest file size auto-tuning: more frequent MANIFEST rotations. With this change, rotation latency is shifted toward background-only MANIFEST batches when possible.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/14797

Test Plan:
Expanded DBEtc3Test.AutoTuneManifestSize to cover the foreground threshold behavior and the original auto-tuning behavior in separate phases:
- verifies foreground-only CreateColumnFamily writes get only bounded 25% headroom by asserting the first four large-CF additions do not rotate and the fifth does;
- verifies auto-tuned background thresholds still prevent excessive rotation;
- verifies foreground operations stay below the relaxed threshold for CreateColumnFamily, IngestExternalFile, CreateColumnFamilyWithImport, and DeleteFilesInRanges;
- verifies SetOptions still does not write to MANIFEST;
- verifies a following background flush still rotates at the normal threshold;
- preserves the persisted compacted manifest size close/reopen coverage.

Reviewed By: xingbowang

Differential Revision: D106578771

Pulled By: pdillinger

fbshipit-source-id: f8e274032cd9e7f50e95b685c949242f95351498
2026-06-01 18:13:29 -07:00
Peter Dillinger
87c554b492 Persist compacted manifest size for auto-tuning across DB::Open (#14725)
Summary:
last_compacted_manifest_file_size_ drives TuneMaxManifestFileSize() to compute the manifest rotation threshold, but it started at 0 on every DB::Open and was only populated after the first manifest rotation. This is really only a problem with reuse_manifest_on_open, because no fresh manifest is created on open.

Add a new forward-compatible (safe-to-ignore) MANIFEST tag kLastCompactedManifestFileSize that records the approximate compacted manifest size at the end of WriteCurrentStateToManifest. During recovery, the value is loaded and used to immediately tune the rotation threshold.

The record includes a rough estimate of its own overhead (~15 bytes) and must be the last record written by WriteCurrentStateToManifest for accurate estimation.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/14725

Test Plan:
Extended AutoTuneManifestSize in db_etc3_test to close and reopen with reuse_manifest_on_open after establishing a known auto-tuning state. Verifies that the manifest file number is preserved (no spurious rotation) and that subsequent CF additions don't trigger rotation -- proving the persisted compacted size keeps the tuned threshold correct. Verified the test fails when the recovery loading is disabled.

Relax a fragile Java test that was dependent on the exact size of the manifest file.

SHORT_TEST=1 ./tools/check_format_compatible.sh

Reviewed By: anand1976

Differential Revision: D104464522

Pulled By: pdillinger

fbshipit-source-id: 4f5d22d2e149bd40a523ee11780e5e3344803c19
2026-05-13 18:31:49 -07:00
Anand Ananthabhotla
02a2b3501d Add optimize_manifest_for_recovery DBOption (#14702)
Summary:
Pull Request resolved: https://github.com/facebook/rocksdb/pull/14702

Add a mutable DBOption `optimize_manifest_for_recovery` (default false) as a temporary rollout / kill switch for warm-reopen MANIFEST optimizations.

In this diff, enabling the option lets recovery skip MANIFEST updates during `DB::Open` when the recovered state is already reflected on disk, which reduces metadata appends after a clean shutdown and can lower warm-reopen latency on storage where MANIFEST appends are expensive.

If the option is disabled, RocksDB follows the existing recovery path unchanged. The optimization is disabled under `best_efforts_recovery`, where recovery intentionally rewrites metadata as part of salvage, and the option is mutable so later diffs in this stack can share the same rollout knob.

Reviewed By: pdillinger, hx235

Differential Revision: D103568448

fbshipit-source-id: 9ec930343e434f1bee6130bcdbd7738dddd92b6d
2026-05-07 11:44:37 -07:00
Anand Ananthabhotla
1cc216a45b Fast file open: retrieve, persist, and pass file open metadata (#14596)
Summary:
Pull Request resolved: https://github.com/facebook/rocksdb/pull/14596

When DBOptions::fast_sst_open is enabled, RocksDB retrieves opaque file system
metadata for SST files after flush, compaction, and external file ingestion via
FSRandomAccessFile::GetFileOpenMetadata(). This metadata is persisted in the
MANIFEST using a new forward-compatible NewFileCustomTag (kFileOpenMetadata = 17),
and passed back to the file system via FileOptions::file_metadata on subsequent
file opens. This accelerates DB open time on remote storage systems by allowing
the file system to skip expensive metadata RPCs.

The feature is gated by DBOptions::fast_sst_open (default false). Everything
works seamlessly regardless of the option setting, file metadata support, or
presence/absence of the metadata in the MANIFEST. The MANIFEST change is backward
compatible - older RocksDB versions safely ignore the new tag.

Reviewed By: xingbowang

Differential Revision: D100220973

fbshipit-source-id: f52de9dd853a50653b3297ab4a37a868fe41cc04
2026-04-14 19:07:29 -07:00
Josh Kang
42eff8b632 Add new heauristic 'num_collapsible_entry_reads_sampled' (#14434)
Summary:
Add per-file sampling of "collapsible" entry reads (single deletions, merges, and kNotFound results) that may later be used to help inform read-triggered compactions. This is a better metric than `num_reads_sampled` as it is more targeted towards reads that could be avoided via compaction.

The existing behavior of `num_reads_sampled` is that reads only gets sampled on iterator creation for a file. It is problematic because next/prev() calls are not sampled, nor are additional seeks().

This PR moves sampling to per-seek/next granularity within `LevelIterator` and adds a new `num_collapsible_entry_reads_sampled` counter that tracks how often a file serves entries that could be eliminated by compaction.

 Note only L1+ files have iterator seeks/nexts/prevs sampled. Introducing this at L0 would require wrapping table reader iterators, introducing a performance cost.

## Key changes

- **New counter `num_collapsible_entry_reads_sampled`** in `FileSampledStats` tracks sampled reads that encounter deletions, single deletions, merges, or kNotFound results in both Get and Iterator paths.
- **Moved sampling from file-open to per-operation** in `LevelIterator`: sampling now happens in `SampleRead()` called from `Seek()`, `SeekForPrev()`, `SeekToFirst()`, `SeekToLast()`, `Next()`, `NextAndGetResult()`, and `Prev()`. The `should_sample` parameter was removed from `LevelIterator`'s constructor.
- **Differentiated sampling rate for Next() vs Seek()**: `should_sample_file_read_next()` uses a 64x lower sampling rate (`kFileReadSampleRate * 64`) since Next() is cheaper than Seek() and called more frequently.
- **Collapsible tracking in Get path**: `Version::Get()` now increments the collapsible counter when `GetContext::State()` is `kNotFound`, `kMerge`, or `kDeleted`.
- **Collapsible tracking in MultiGet path**: `MultiGetFromSST` also increments the collapsible counter for the same states.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/14434

Test Plan:
- Added new DB tests for both num_reads_sampled and num_collapsible_entry_reads_sampled

### Benchmark results (readrandom, readseq)

Setup: 1M keys, 16-byte keys, 100-byte values, no compression, fillrandom+compact

| Benchmark  | Params             | ops/s (main) | ops/s (feature) | % change |
|------------|--------------------|-------------|--------------------------|----------|
| readrandom | seed=1, threads=1  | 387,194     | 389,449                  | +0.6%    |
| readseq    | seed=1, threads=1  | 5,598,371   | 5,572,975                | -0.5%    |

No meaningful performance regression observed — differences are within run-to-run noise.

Reviewed By: xingbowang

Differential Revision: D95613793

Pulled By: joshkang97

fbshipit-source-id: 9dd09c9b7527b148424bde5686f4157c7a9e1214
2026-03-09 16:42:41 -07:00
Josh Kang
f25fb41da6 Add option to validate sst files in the background on DB open (#14322)
Summary:
Add `open_files_async` option for faster DB startup. When enabled, SST file opening and validation is deferred to a background thread after `DB::Open` returns, reducing startup latency for databases with many SST files. WAL recovery remains synchronous.

To support this, `FindTable` is extended with a pinning mechanism that stores the cache handle directly on `FileMetaData` via a new `PinnedTableReader` class, and sets the table reader atomically so subsequent reads skip cache lookups. `FileDescriptor::table_reader` is replaced with `PinnedTableReader pinned_reader` which wraps a `std::atomic<TableReader*>` with acquire/release ordering to safely handle concurrent access between the background opener and read threads.

Should validations fail, the background opener sets a `kAsyncFileOpen` background error. Future read requests will look up the table reader again via the cache, and if any validations fail there it will get propagated to the user (existing behavior when `max_open_files > 0`).

This feature is most useful when `max_open_files=-1`, because otherwise file opening is already capped at 16 files and DB open should be fast.

## Restrictions
- This feature also is incompatible with fifo compaction because fifo compaction requires reading table properties under DB mutex. When table reader is unpinned, this may cause a DB hang.
- This feature is also incompatible with `skip_stats_update_on_db_open=false` because it will result in even longer DB open

## Key changes

- New `open_files_async` DB option with C, Java, and `db_bench` bindings
- `BGWorkAsyncFileOpen` background worker that opens all SST files post-`DB::Open`, with shutdown awareness via `shutting_down_` flag
- New `PinnedTableReader` class in `version_edit.h` — thread-safe wrapper holding `std::atomic<TableReader*>` and `Cache::Handle*` with proper acquire/release ordering. Replaces the old `FileDescriptor::table_reader` raw pointer and `FileMetaData::table_reader_handle`
- Extract `LoadTableHandlersHelper` into `db/version_util.cc` — shared between `VersionBuilder::LoadTableHandlers` (for version edits during recovery) and `BGWorkAsyncFileOpen` (for base storage post-open)
- `FindTable` extended with `pin_table_handle` and `out_table_reader` params — when pinning is enabled, the table reader is stored on `FileMetaData` so Get/MultiGet/Iterator skip redundant cache lookups. `FindTable` now performs the pinned-reader fast-path check internally instead of requiring callers to check `fd.table_reader` beforehand
  - Note: pinning is explicit (not default) because some callers create temporary `FileMetaData`s that would need to properly clean up table handles
- `CompactedDBImpl` updated to use `FindTable` + pinning instead of raw `fd.table_reader` access for Get/MultiGet
- New `kAsyncFileOpen` background error reason in `listener.h` and `error_handler.cc`
- Add a check in ~DBImpl to ensure async file open task has not been forgotten to be scheduled in (future) subclasses of DBImpl. Certain subclasses that never use it will need to explicitly mark it.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/14322

Test Plan:
- `OpenFilesAsyncTest` parameterized over `num_flushes` (1, 20), `ReadType` (Get, MultiGet, Iterator), `max_open_files` (-1, 10), and `read_only` (true, false)
  - **ConcurrentFileAccess**: concurrent reads and compactions race with async opener
  - **AfterRead**: reads happen before async opener, verifying lazy open and that the opener sees already-pinned readers
  - **BeforeRead**: async opener completes first, verifying reads use pre-loaded table readers
  - **Shutdown**: DB closes before async opener starts, verifying clean cancellation with 0 file opens
  - **Error**: corrupted SST files, verifying `kAsyncFileOpen` background error is set and reads return corruption
  - **DropColumnFamily**: CF dropped before async opener runs, verifying the opener gracefully skips dropped CFs
- Added to crash test

### Benchmark

To simulate a high-latency remote filesystem, I set up a virtual filesystem with dm-delay using 10ms reads, 0 ms writes.

```
# Generate a DB with many L0 files

TEST_TMPDIR=/data/users/jkangs/dm-delay-test/mnt ./db_bench -benchmarks=fillseq -disable_auto_compactions=true -write_buffer_size=1000 -num=1000000
```

```
./db_bench -use_existing_db=true -db=/data/users/jkangs/dm-delay-test/mnt/dbbench -benchmarks=readrandom -reads=1 -report_open_timing=true -open_files_async=true -use_direct_reads -file_opening_threads=1 -skip_stats_update_on_db_open

OpenDb:     25.1419 milliseconds
```

```
./db_bench -use_existing_db=true -db=/data/users/jkangs/dm-delay-test/mnt/dbbench -benchmarks=readrandom -reads=1 -report_open_timing=true -open_files_async=false -use_direct_reads -file_opening_threads=1 -skip_stats_update_on_db_open

OpenDb:     23109.4 milliseconds
```

### No read regressions

On main branch
```
./db_bench -use_existing_db=true -db=/dev/shm/dbbench -benchmarks=readrandom -seed=1 -threads=8 -duration=30

readrandom   :       4.827 micros/op 1657100 ops/sec 30.005 seconds 49720992 operations;  183.3 MB/s (6198999 of 6198999 found)
```

On this branch
```
./db_bench -use_existing_db=true -db=/dev/shm/dbbench -benchmarks=readrandom -seed=1 -threads=8 -duration=30

readrandom   :       4.863 micros/op 1644808 ops/sec 30.007 seconds 49354992 operations;  182.0 MB/s (6099999 of 6099999 found)

./db_bench -use_existing_db=true -db=/dev/shm/dbbench -benchmarks=readrandom -seed=1 -threads=8 -duration=30 -open_files_async=true

readrandom   :       4.803 micros/op 1665392 ops/sec 30.004 seconds 49968992 operations;  184.2 MB/s (6222999 of 6222999 found)
```

Reviewed By: pdillinger, xingbowang

Differential Revision: D93538033

Pulled By: joshkang97

fbshipit-source-id: 32ac70c112cd733b7c1e1c1e2e7ce6422318a5ae
2026-03-02 16:18:14 -08:00
Peter Dillinger
672389fd8c Remove obsolete compression code and some .h->.cc movement (#14325)
Summary:
In follow-up to https://github.com/facebook/rocksdb/issues/14315

Remove obsolete code replaced by new Compressor/Decompressor interface:
* OLD_CompressData and OLD_UncompressData
* Individual compression/decompression functions (Snappy_*, Zlib_*, BZip2_*, LZ4_*, LZ4HC_*, XPRESS_*, ZSTD_Compress, ZSTD_Uncompress)
* CompressionInfo and UncompressionInfo classes
* UncompressionDict class
* compression::PutDecompressedSizeInfo and GetDecompressedSizeInfo

The only small refactoring in this change that is not pure code removal or movement is in blob_file_builder_test.cc.

Move some function implementations etc. from compression.h to compression.cc:
* CompressionTypeToString, CompressionTypeFromString, CompressionOptionsToString
* ZSTD_TrainDictionary (both overloads), ZSTD_FinalizeDictionary
* DecompressorDict::Populate
* Most compression library includes

Also cleaned up other includes of compression.h, which caused some other files to need new includes.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/14325

Test Plan: existing tests

Reviewed By: hx235

Differential Revision: D93120580

Pulled By: pdillinger

fbshipit-source-id: ab5c50db7379c0387a8c0e379642c9ea2799eae5
2026-02-13 11:18:05 -08:00
Xingbo Wang
ea5e649225 Fix an infinite compaction loop bug with udt (#14228)
Summary:
Problem

The TEST_WaitForCompact in
TimestampCompatibleCompactionTest.UdtTombstoneCollapsingTest would sometimes
run forever, indicating an infinite compaction loop.
Issue https://github.com/facebook/rocksdb/issues/14223

Root Cause

In ComputeBottommostFilesMarkedForCompaction(), files were marked for
bottommost compaction based only on the condition largest_seqno <
oldest_snapshot_seqnum. However, for User-Defined Timestamps (UDT) columns,
compaction can only zero sequence numbers when the file's maximum timestamp is
below full_history_ts_low.

When timestamps were above this threshold:
1. File gets marked for compaction (seqno condition met)
2. Compaction runs but cannot zero seqno (timestamp condition not met)
3. Output file immediately gets re-marked for compaction
4. Infinite loop

Solution

Added timestamp range tracking to FileMetaData and updated the marking logic to
check timestamps before marking files.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/14228

Test Plan: Unit test

Reviewed By: pdillinger

Differential Revision: D90586045

Pulled By: xingbowang

fbshipit-source-id: addfa4f988db8c87fb513a1bf58ee54623a6c210
2026-01-20 14:10:41 -08:00
Hui Xiao
a1d8318563 Fix resumable compaction to prevent resumption at truncated range deletion boundaries (#14184)
Summary:
**Context/Summary:**

Truncated range deletion in input files can be output by CompactionIterator with type kMaxValid instead of kTypeRangeDeletion, to satisfy ordering requirement between the truncated range deletion start key and a file's point keys. There was a plan to skip such key in https://github.com/facebook/rocksdb/pull/14122 but blockers remain to fulfill the plan.

Resumable compaction is not able to handle resumption from range deletion well at this point and should consider kMaxValid type same as kTypeRangeDeletion for resumption. Previously, it didn't and mistakenly allow resumption from a delete range. That led to an assertion failure, complaining about lacking information to update file boundaries in the presence of range deletion needed during cutting an output file, after the compaction resumes from that delete range and happens to cut the output file shortly after without any point keys in between.

```
frame https://github.com/facebook/rocksdb/issues/9: 0x00007f4f4743bc93 libc.so.6`__GI___assert_fail(assertion="meta.smallest.size() > 0", file="db/compaction/compaction_outputs.cc", line=530, function="rocksdb::Status rocksdb::CompactionOutputs::AddRangeDels(rocksdb::CompactionRangeDelAggregator&, const rocksdb::Slice*, const rocksdb::Slice*, rocksdb::CompactionIterationStats&, bool, const rocksdb::InternalKeyComparator&, rocksdb::SequenceNumber, std::pair<long unsigned int, long unsigned int>, const rocksdb::Slice&, const string&)") at assert.c:101:3
frame https://github.com/facebook/rocksdb/issues/10: 0x00007f4f4808c68c librocksdb.so.10.9`rocksdb::CompactionOutputs::AddRangeDels(this=0x00007f4f0c27e1a0, range_del_agg=0x00007f4f0c21ecc0, comp_start_user_key=0x0000000000000000, comp_end_user_key=0x0000000000000000, range_del_out_stats=0x00007f4f0dffa140, bottommost_level=false, icmp=0x00007f4ef4c93040, earliest_snapshot=13108729, keep_seqno_range=<unavailable>, next_table_min_key=0x00007f4ef4c8f540, full_history_ts_low="") at compaction_outputs.cc:530:7
frame https://github.com/facebook/rocksdb/issues/11: 0x00007f4f480480dd librocksdb.so.10.9`rocksdb::CompactionJob::FinishCompactionOutputFile(this=0x00007f4f0dffb890, input_status=<unavailable>, prev_table_last_internal_key=0x00007f4f0dffa650, next_table_min_key=0x00007f4ef4c8f540, comp_start_user_key=0x0000000000000000, comp_end_user_key=0x0000000000000000, c_iter=0x00007f4ef4c8f400, sub_compact=0x00007f4f0c27e000, outputs=0x00007f4f0c27e1a0) at compaction_job.cc:1917:31
```

This PR simply prevents  MaxValid from being a resumption point like regular range deletion - see commit 842d66eb18ea67e965d6acb1fce12c18eeb778d2

Besides that, the PR also improves the testing, variable naming, logging in resumable compaction codes that were needed to debug this assertion failure - see commit aecd4e7f97. These improvements are covered by existing tests.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/14184

Test Plan:
- The stress initially surfaced the error. Using the exact same LSM shapes and files that were used in stress test but in a unit test, I'm able to get a deterministic repro and confirmed the fix resolves the error.  This is the repro test 1075936e69
```
./compaction_service_test --gtest_filter=ResumableCompactionServiceTest.CompactSpecificFilesFromExistingDBWithCancelAndResume
# Before fix
[==========] Running 1 test from 1 test case.
[----------] Global test environment set-up.
[----------] 1 test from ResumableCompactionServiceTest
[ RUN      ] ResumableCompactionServiceTest.CompactSpecificFilesFromExistingDBWithCancelAndResume
compaction_service_test: db/compaction/compaction_outputs.cc:530: rocksdb::Status rocksdb::CompactionOutputs::AddRangeDels(rocksdb::CompactionRangeDelAggregator&, const rocksdb::Slice*, const rocksdb::Slice*, rocksdb::CompactionIterationStats&, bool, const rocksdb::InternalKeyComparator&, rocksdb::SequenceNumber, std::pair<long unsigned int, long unsigned int>, const rocksdb::Slice&, const string&): Assertion `meta.smallest.size() > 0' failed.
Received signal 6 (Aborted)
Invoking GDB for stack trace...
[New LWP 2621610]
[New LWP 2621611]
[New LWP 2621612]
[New LWP 2621613]
[New LWP 2621614]
[New LWP 2621630]
[New LWP 2621631]

# After fix
Note: Google Test filter = ResumableCompactionServiceTest.CompactSpecificFilesFromExistingDBWithCancelAndResume
[==========] Running 1 test from 1 test case.
[----------] Global test environment set-up.
[----------] 1 test from ResumableCompactionServiceTest
[ RUN      ] ResumableCompactionServiceTest.CompactSpecificFilesFromExistingDBWithCancelAndResume
[       OK ] ResumableCompactionServiceTest.CompactSpecificFilesFromExistingDBWithCancelAndResume (4722 ms)
[----------] 1 test from ResumableCompactionServiceTest (4722 ms total)

[----------] Global test environment tear-down
[==========] 1 test from 1 test case ran. (4722 ms total)
[  PASSED  ] 1 test.

```
- Follow-up: I tried a couple time to coerce the truncated range delete from scratch in the unit test but failed doing so. Considering kMaxValid may not be outputted by compaction iterator anymore after https://github.com/facebook/rocksdb/pull/14122/files gets landed again (and obsolete the bug) ADN the simple nature of this fix 842d66eb18ea67e965d6acb1fce12c18eeb778d2 AND the worst case of such fix going wrong is just less resumption, I decided to leave writing a unit test to coerce truncated ranged deletion from scratch a follow-up. Maybe I will draw inspiration from https://github.com/facebook/rocksdb/pull/14122/files.

Reviewed By: jaykorean

Differential Revision: D88912663

Pulled By: hx235

fbshipit-source-id: 80a01135684c8fea659650faaa00c2dc452c482a
2025-12-11 16:50:42 -08:00
Xingbo Wang
707e405492 Revert #14122 "Fix a bug where compaction ..." (#14170)
Summary:
Revert "Fix a bug where compaction with range deletion can persist kTypeMaxValid in file metadata (https://github.com/facebook/rocksdb/issues/14122)"

Add a new unit test to capture the situation found by stress test

This reverts commit 8c7c8b8dab.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/14170

Test Plan: Unit Test

Reviewed By: anand1976

Differential Revision: D88395956

Pulled By: xingbowang

fbshipit-source-id: 226649dc79a86010ad326ffb2eae35109dc96bc4
2025-12-04 12:28:01 -08:00
Changyu Bi
8c7c8b8dab Fix a bug where compaction with range deletion can persist kTypeMaxValid in file metadata (#14122)
Summary:
Range deletion start keys are considered during compaction for cutting output files. Due to some ordering requirement (see comment above InsertNextValidRangeTombstoneAtLevel()) between truncated range deletion start key and a file's point keys, there was logic in f6c9c3bf1c/db/range_del_aggregator.cc (L39) that changes the value type to be kTypeMaxValid. However, kTypeMaxValid is not supposed to be persisted per f6c9c3bf1c/db/dbformat.h (L75-L76). This can cause forward compatibility issues reported in https://github.com/facebook/rocksdb/issues/14101. This PR fixes this issue by removing the logic that sets kTypeMaxValid and always skip truncated range deletion start key in CompactionMergingIterator.

For existing SST files, we want to avoid using this kTypeMaxValid, so this PR also introduces a new placeholder value type. This allows us to re-strengthen the relevant value type checks (IsExtendedValueType()) that was loosen for kTypeMaxValid.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/14122

Test Plan:
- a unit test that persists kTypeMaxValid before this fix
- crash test with frequent range deletion: `python3 ./tools/db_crashtest.py blackbox --delrangepercent=11 --readpercent=35`
- Generate SST files with 0x1A as value type (kTypeMaxValid before this change) in file metadata. Run ldb with the strengthened check in IsExtendedValueType() to dump the MANIFEST. It failed to parse MANIFEST as expected before this PR and succeeds after this PR.
```
Error in processing file /tmp/rocksdbtest-543376/db_range_del_test_2549357_6547198162080866792/MANIFEST-000005 Corruption: VersionEdit: new-file4 entry  The file /tmp/rocksdbtest-543376/db_range_del_test_2549357_6547198162080866792/MANIFEST-000005 may be corrupted.
```

Reviewed By: pdillinger

Differential Revision: D87016541

Pulled By: cbi42

fbshipit-source-id: 9957a095db2cd9947463b403f352bd9a1fd70a76
2025-11-21 14:18:38 -08:00
Hui Xiao
ad83352c39 Support dumping compaction progress file in ldb (#14058)
Summary:
**Context/Summary:**

This PR adds support to dump compaction progress file in ldb for debugging resumable compaction issue

Pull Request resolved: https://github.com/facebook/rocksdb/pull/14058

Test Plan:
```
/data/users/huixiao/rocksdb$ ./ldb compaction_progress_dump --path=/home/huixiao/COMPACTION_PROGRESS-123
Compaction Progress File: /home/huixiao/COMPACTION_PROGRESS-123
============================================
Progress Record 0:
SubcompactionProgress{ next_internal_key_to_compact=user_key="b" (hex:62), seq=kMaxSequenceNumber, type=24, num_processed_input_records=1, output_level_progress=SubcompactionProgressPerLevel{ num_processed_output_records=1, output_files_count=1, last_persisted_output_files_count=0 }, proximal_output_level_progress=SubcompactionProgressPerLevel{ num_processed_output_records=0, output_files_count=0, last_persisted_output_files_count=0 } }
Progress Record 1:
SubcompactionProgress{ next_internal_key_to_compact=user_key="bb" (hex:6262), seq=kMaxSequenceNumber, type=24, num_processed_input_records=2, output_level_progress=SubcompactionProgressPerLevel{ num_processed_output_records=2, output_files_count=1, last_persisted_output_files_count=0 }, proximal_output_level_progress=SubcompactionProgressPerLevel{ num_processed_output_records=0, output_files_count=0, last_persisted_output_files_count=0 } }
Progress Record 2:
SubcompactionProgress{ next_internal_key_to_compact=user_key="cancel_before_this_key" (hex:63616E63656C5F6265666F72655F746869735F6B6579), seq=kMaxSequenceNumber, type=24, num_processed_input_records=3, output_level_progress=SubcompactionProgressPerLevel{ num_processed_output_records=3, output_files_count=1, last_persisted_output_files_count=0 }, proximal_output_level_progress=SubcompactionProgressPerLevel{ num_processed_output_records=0, output_files_count=0, last_persisted_output_files_count=0 } }

Total records: 3
```

Reviewed By: jaykorean

Differential Revision: D84840680

Pulled By: hx235

fbshipit-source-id: 8e448c50348eb1dba92c4ffdbd2d1bb6306288d6
2025-10-17 10:54:25 -07:00
Hui Xiao
f7e4009de1 Integrate compaction resumption with DB::OpenAndCompact() (#13984)
Summary:
### Context/Summary:
This is stacked on top of https://github.com/facebook/rocksdb/pull/13983 and integrate compaction resumption with OpenAndCompact().

Flow of resuming: DB::OpenAndCompact() -> Compaction progress file  -> SubcompactionProgress -> CompactionJob
Flow of persistence: CompactionJob -> SubcompactionProgress -> Compaction progress file  -> DB that is called with OpenAndCompact()

This PR focuses on DB::OpenAndCompact() -> Compaction progress file  -> SubcompactionProgress  and Compaction progress file -> DB that is called with OpenAndCompact()

**Resume Flow**
1. Check configuration. Right now paranoid_file_check=true (by default false) is not yet compatible with allow_resumption=true. Also only single subcompaction is supported as OpenAndCompact() does not partition compaction anyway
2. Scan compaction output files for latest, old and temporary compaction progress file and output files. If latest compaction progress file exists, we should resume.
3. Clean up older or temporary progress files if any. They can exist if the last OpenAndCompact() crashed during resume flow
4. If any, parse the latest progress file into CompactionProgress and clean up extra compaction output files that are not yet tracked. These compaction output files can exist as tracking every output file is just best-effort and interrupted output files in the middle is not tracked as progress yet.
5. If allow_resumption=false or no valid compaction progress is found or parsed, clean up the latest progress file and existing compaction output files to start fresh compaction. If the clean up itself fails, fail the OpenAndCompact() call to prevent resuming with inconsistency between output files and progress file.

 **Progress File Creation**
1. Create temporary progress file
2. Persist the progress from latest compaction progress file to the temporary progress file. This is to simplify resuming from an interrupted compaction that was just resumed. Similar to how manifest recovery works.
3. Rename the temporary progress file to the newer compaction progress so it atomically becomes the "new" latest progress file
4. Delete the "old" latest progress file since it's useless now.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/13984

Test Plan:
- Integrated unit tests to simulate OpenAndCompact gets canceled and optionally resumed for remote compaction
- Existing UTs and stress/crash test
- Manual stress test with https://github.com/facebook/rocksdb/pull/14041

### Performance testing:
**1. Latency**
Using
```
./db_bench --benchmarks=OpenAndCompact[X5] --openandcompact_test_cancel_on_odd=false --openandcompact_cancel_after_seconds=0 --openandcompact_allow_resumption=$openandcompact_allow_resumption  --use_existing_db=true --db=$db --disable_auto_compactions=true --compression_type=none --secondary_path=$secondary_path  --target_file_size_base=268435456
```
**allow_resumption = false**
Input files: 101 files, 10000 keys
OpenAndCompact() API call : 26766256.000 micros/op 0 ops/sec 26.766 seconds 1 operations;
OpenAndCompact status: OK
Output: 92 files, average size: 271747380 bytes (259.16 MB)
OpenAndCompact : 27837249.000 micros/op 0 ops/sec 27.837 seconds 1 operations;

Input files: 101 files, 10000 keys
OpenAndCompact() API call : 26546234.000 micros/op 0 ops/sec 26.546 seconds 1 operations;
OpenAndCompact status: OK
Output: 92 files, average size: 271747380 bytes (259.16 MB)
OpenAndCompact : 27918621.000 micros/op 0 ops/sec 27.919 seconds 1 operations;
OpenAndCompact [AVG 2 runs] : 0 (± 0) ops/sec

Input files: 101 files, 10000 keys
OpenAndCompact() API call : 42243571.000 micros/op 0 ops/sec 42.244 seconds 1 operations;
OpenAndCompact status: OK
Output: 92 files, average size: 271747380 bytes (259.16 MB)
OpenAndCompact : 43497581.000 micros/op 0 ops/sec 43.498 seconds 1 operations;
OpenAndCompact [AVG 3 runs] : 0 (± 0) ops/sec

Input files: 101 files, 10000 keys
OpenAndCompact() API call : 34241357.000 micros/op 0 ops/sec 34.241 seconds 1 operations;
OpenAndCompact status: OK
Output: 92 files, average size: 271747380 bytes (259.16 MB)
OpenAndCompact : 35655346.000 micros/op 0 ops/sec 35.655 seconds 1 operations;
OpenAndCompact [AVG 4 runs] : 0 (± 0) ops/sec

Input files: 101 files, 10000 keys
OpenAndCompact() API call : 27083361.000 micros/op 0 ops/sec 27.083 seconds 1 operations;
OpenAndCompact status: OK
Output: 92 files, average size: 271747380 bytes (259.16 MB)
OpenAndCompact : 28487999.000 micros/op 0 ops/sec 28.488 seconds 1 operations;
OpenAndCompact [AVG 5 runs] : 0 (± 0) ops/sec

OpenAndCompact [AVG    5 runs] : 0 (± 0) ops/sec; 31669.681 ms/op
OpenAndCompact [MEDIAN 5 runs] : 0 ops/sec

**allow_resumption= true**
Input files: 101 files, 10000 keys
OpenAndCompact() API call : 25446470.000 micros/op 0 ops/sec 25.446 seconds 1 operations;
OpenAndCompact status: OK
Output: 92 files, average size: 271747380 bytes (259.16 MB)
OpenAndCompact : 26833415.000 micros/op 0 ops/sec 26.833 seconds 1 operations;

Input files: 101 files, 10000 keys
OpenAndCompact() API call : 240745.000 micros/op 0 ops/sec 0.241 seconds 1 operations;
OpenAndCompact status: OK
Output: 92 files, average size: 271747380 bytes (259.16 MB)
OpenAndCompact :  244934.000 micros/op 4 ops/sec 0.245 seconds 1 operations;
OpenAndCompact [AVG 2 runs] : 2 (± 3) ops/sec

Input files: 101 files, 10000 keys
OpenAndCompact() API call : 24843383.000 micros/op 0 ops/sec 24.843 seconds 1 operations;
OpenAndCompact status: OK
Output: 92 files, average size: 271747380 bytes (259.16 MB)
OpenAndCompact : 26192235.000 micros/op 0 ops/sec 26.192 seconds 1 operations;
OpenAndCompact [AVG 3 runs] : 1 (± 2) ops/sec

Input files: 101 files, 10000 keys
OpenAndCompact() API call : 270819.000 micros/op 0 ops/sec 0.271 seconds 1 operations;
OpenAndCompact status: OK
Output: 92 files, average size: 271747380 bytes (259.16 MB)
OpenAndCompact :  275140.000 micros/op 3 ops/sec 0.275 seconds 1 operations;
OpenAndCompact [AVG 4 runs] : 1 (± 2) ops/sec

Input files: 101 files, 10000 keys
OpenAndCompact() API call : 23038311.000 micros/op 0 ops/sec 23.038 seconds 1 operations;
OpenAndCompact status: OK
Output: 92 files, average size: 271747380 bytes (259.16 MB)
OpenAndCompact : 24439097.000 micros/op 0 ops/sec 24.439 seconds 1 operations;
OpenAndCompact [AVG 5 runs] : 1 (± 1) ops/sec

OpenAndCompact [AVG    5 runs] : 1 (± 1) ops/sec; 638.417 ms/op
OpenAndCompact [MEDIAN 5 runs] : 0 ops/sec

**Persistence cost:** If we compare the odd number of OpenAndCompact() API, it's actually faster.
**Resumption saving:** (0.2 - 26.766 ) / 26.766 * 100 = 99.25% improvement when all the compaction progress is redone without the allow_resumption feature

**2.  Memory usage** (in case SubcompactionProgress storing its own memory copies of output filemetadata in https://github.com/facebook/rocksdb/pull/13983/files is a trouble)
 ```
// ~= 90 output files
/usr/bin/time -f "
Resource Summary:
  Wall time: %e seconds
  CPU time: %U user + %S system (%P total)
  Peak memory: %M KB
  Page faults: %F major + %R minor
" ./db_bench --benchmarks=OpenAndCompact[X1] --openandcompact_test_cancel_on_odd=false --openandcompact_cancel_after_seconds=0 --openandcompact_allow_resumption=$openandcompact_allow_resumption  --use_existing_db=true --db=$db --disable_auto_compactions=true --compression_type=none --secondary_path=$secondary_path  --target_file_size_base=268435456
```
**allow_resumption = false**
Peak memory: 275828 KB
**allow_resumption = true**
Peak memory: 277204 KB (regress 0.49% memory usage, most likely due to storing own copies of output files' file metadata in subcompaction progress)

### Near-term follow up:
- Add statistics to record the successfully resumed compaction output files bytes
- Add stress/crash test support to cover error paths (including progress file sync error), crash/cancel OpenAndCompact() at random compaction progress point and surface feature incompatibility
   - See https://github.com/facebook/rocksdb/pull/14041
- Resolve the TODO https://github.com/facebook/rocksdb/pull/13984/files#diff-17fbdec07244b1f07d1a4e5aed0a6feecf4474d20b3129818c10fc0ff9f3d547R1303-R1314
   - See https://github.com/facebook/rocksdb/pull/14042

Reviewed By: jaykorean

Differential Revision: D84299662

Pulled By: hx235

fbshipit-source-id: 69bbf395401604172a1a5c557ca834011a3d51d7
2025-10-15 13:43:53 -07:00
Hui Xiao
1e5fa69c99 Resuming and persisting subcompaction progress in CompactionJob (#13983)
Summary:
### Context/Summary:
Flow of resuming: DB::OpenAndCompact() -> Compaction progress file  -> SubcompactionProgress -> CompactionJob
Flow of persistence: CompactionJob -> SubcompactionProgress -> Compaction progress file  -> DB that is called with OpenAndCompact()

This PR focuses on SubcompactionProgress -> CompactionJob and  CompactionJob -> SubcompactionProgress -> Compaction progress file. For now only single subcompaction is supported as OpenAndCompact() does not partition compaction anyway.

The actual triggering of progress persistence and resuming (i.e, integration) is through DB::OpenAndCompact() in the upcoming PR.

**Resume Flow**
1. input_iter->Seek(next_internal_key_to_compact)  // Position iterator
2. ReadTableProperties()                           // Validate existing outputs
3. RestoreCompactionOutputs() in CompactionOutputs                     // Rebuild output file metadata
4. Restore critical statistics about processed input and output records count for verification later
5. AdvanceFileNumbers()                            // Prevent file number conflicts
6. Continue normal compaction from positioned iterator or fallback to not resuming compaction in limited case or fail the compaction entirely

**Persistence Strategy**
1. When: At each SST file completion (FinishCompactionOutputFile()). This is the simplest but most expensive frequency. See below for benchmarking and potential follow-up items
2. What: Serialize, write and sync the in-memory SubcompactionProgress to a dedicated manifest-like file
3. For simplicity: Only persist at "clean" boundaries (no overlapping user keys, no range deletions, no timestamp for now)

Pull Request resolved: https://github.com/facebook/rocksdb/pull/13983

Test Plan:
- New unit test in CompactionJob level to cover basic compaction progress resumption
- Existing UTs and stress/crash test to test no correctness regression to existing compaction code
- Run benchmark to ensure no performance regression to existing compaction code
```
./db_bench --benchmarks=fillseq[-X10] --db=$db --disable_auto_compactions=true --num=100000 --value_size=25000 --compression_type=none --target_file_size_base=268435456 --write_buffer_size=268435456
```
Pre-PR:
fillseq [AVG    10 runs] : 45127 (± 799) ops/sec; 1076.6 (± 19.1) MB/sec
fillseq [MEDIAN 10 runs] : 45375 ops/sec; 1082.5 MB/sec
Post-PR (regressed 0.057%, ignorable)
fillseq [AVG    10 runs] : 45101 (± 920) ops/sec; 1076.0 (± 22.0) MB/sec
fillseq [MEDIAN 10 runs] : 45385 ops/sec; 1082.8 MB/sec

Reviewed By: jaykorean

Differential Revision: D82889188

Pulled By: hx235

fbshipit-source-id: 8553fd478f134969d331af2c5a125b94bd747268
2025-10-01 14:21:55 -07:00
Hui Xiao
ab10ea0aac Add in-memory data structures and (de)serialization support for subcompaction progress (#13928)
Summary:
**Context**
Resuming compaction is designed to periodically record the progress of an ongoing compaction and can resume from that saved progress after interruptions such as cancellation, database shutdown, or crashes.

This PR introduces the data structures needed to store  subcompaction progress in memory, along with serialization and deserialization support to persist and parse this progress to/from "a manifest-like compaction progress file" (the actual creation of such file is in upcoming PRs).

Flow of resuming: DB::OpenAndCompact() -> Compaction progress file  -> SubcompactionProgress -> CompactionJob
Flow of persistence: CompactionJob -> SubcompactionProgress -> Compaction progress file  -> DB that is called with OpenAndCompact()

**Summary**
Progress represented by `SubcompactionProgress` will be tracked at the scope of a subcompaction, which is the smallest independent unit of compaction work.

The frequency of recording this progress is once every N compaction output files (to be detailed in future PRs).

When recording, all fields, except for the output files metadata in `SubcompactionProgress`, will directly overwrite the corresponding fields from the last saved progress (See `SubcompactionProgress` and `SubcompactionProgressBuilder` for more).

As a bonus, this PR refactors the file metadata encoding and decoding utilities into two static helper functions, EncodeToNewFile4() and DecodeNewFile4From(), to support subcompaction progress usage.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/13928

Test Plan:
- Added various `SubcompactionProgressTest` unit tests in version_edit_test.cc to verify basic serialization/deserialization and forward compatibility handling
- Existing UTs and stress/crash test

**Follow up:**
- Move output entry number and file verification to after each file creation so we can remove kNumProcessedOutputRecords persistence support and make resuming compaction work with `paranoid_file_checks=true` (by default false). Output verification will be done before persistence of progress. As long as this follow-up is done before the landing of the integration PR to create the progress file, we can change the manifest-like compaction progress file format freely.

Reviewed By: jaykorean

Differential Revision: D81986583

Pulled By: hx235

fbshipit-source-id: b42766da7d9c2e2f596c892d050c753238d1039f
2025-09-22 15:03:46 -07:00
Changyu Bi
3bd7d968e1 Introduce column family option cf_allow_ingest_behind (#13810)
Summary:
this option has the same functionality as DBOptions::allow_ingest_behind but allows the feature at per CF level. `DBOptions::allow_ingest_behind` is deprecated after this PR and users should use `cf_allow_ingest_behind` instead.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/13810

Test Plan: updated some existing tests to use the new option.

Reviewed By: xingbowang

Differential Revision: D79191969

Pulled By: cbi42

fbshipit-source-id: 0da45f6be472ace6754ad15df93d45ac86313837
2025-08-05 23:19:09 -07:00
Hui Xiao
07b09c7548 Persist tail size of remote compaction output file to manifest (#13522)
Summary:
**Context/Summary:**

This is to fix a bug that tail size of remote compaction output SST file is not persisted to manifest in primary instance. This prevent us from using direct tail prefetch optimization each time opening this SST file.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/13522

Test Plan: Modify existing UT that failed before the fix

Reviewed By: anand1976

Differential Revision: D72479612

Pulled By: hx235

fbshipit-source-id: 1ba8aa66fac71b9196589f60076229c29a103706
2025-04-07 09:39:54 -07:00
Peter Dillinger
c9ce4a3d6b Improve atomicity of SetOptions, skip manifest write (#13384)
Summary:
Motivated by code review issue in https://github.com/facebook/rocksdb/issues/13316, we don't want to release the DB mutex in SetOptions between updating the cfd latest options and installing the new Version and SuperVersion. SetOptions uses LogAndApply to install a new Version but this currently incurs an unnecessary manifest write. (This is not a big performance concern because SetOptions dumps a new OPTIONS file, which is much larger than the redundant manifest update.) Since we don't want IO while holding the DB mutex, we need to get rid of the manifest write, and that's what this change does. We introduce a kind of dummy VersionEdit that allows the existing code paths of LogAndApply to install a new Version (with the updated mutable options), recompute resulting compaction scores etc., but without the manifest write.

Part of the validation for this is new assertions in SetOptions verifying the consistency of the various copies of MutableCFOptions. (I'm not convinced we need it in SuperVersion in addition to Version, but that's not for here and now.) These checks depend on defaulted `operator==` so depend on C++20.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/13384

Test Plan:
New unit test in addition to new assertions. SetOptions already tested heavily in crash test. Used
`ROCKSDB_CXX_STANDARD=c++20 make -j100 check` to ensure the new assertions are verified

Reviewed By: cbi42

Differential Revision: D69408829

Pulled By: pdillinger

fbshipit-source-id: 4cf026010c6bb381e0ea27567cce2708d4678e7d
2025-02-10 16:46:13 -08:00
Andrew Ryan Chang
af2a36d2c7 Record newest_key_time as a table property (#13083)
Summary:
This PR does two things:
1. Adds a new table property `newest_key_time`
2. Uses this property to improve TTL and temperature change compaction.

### Context

The current `creation_time` table property should really be named `oldest_ancestor_time`. For flush output files, this is the oldest key time in the file. For compaction output files, this is the minimum among all oldest key times in the input files.

The problem with using the oldest ancestor time for TTL compaction is that we may end up dropping files earlier than we should. What we really want is the newest (i.e. "youngest") key time. Right now we take a roundabout way to estimate this value -- we take the value of the _oldest_ key time for the _next_ (newer) SST file. This is also why the current code has checks for `index >= 1`.

Our new property `newest_key_time` is set to the file creation time during flushes, and the max over all input files for compactions.

There were some additional smaller changes that I had to make for testing purposes:
- Refactoring the mock table reader to support specifying my own table properties
- Refactoring out a test utility method `GetLevelFileMetadatas`  that would otherwise be copy/pasted in 3 places

Credit to cbi42 for the problem explanation and proposed solution

### Testing

- Added a dedicated unit test to my `newest_key_time` logic in isolation (i.e. are we populating the property on flush and compaction)
- Updated the existing unit tests (for TTL/temperate change compaction), which were comprehensive enough to break when I first made my code changes. I removed the test setup code which set the file metadata `oldest_ancestor_time`, so we know we are actually only using the new table property instead.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/13083

Reviewed By: cbi42

Differential Revision: D65298604

Pulled By: archang19

fbshipit-source-id: 898ef91b692ab33f5129a2a16b64ecadd4c32432
2024-11-01 10:08:35 -07:00
Yu Zhang
9c94559de7 Optimize compaction for standalone range deletion files (#13078)
Summary:
This PR adds some optimization for compacting standalone range deletion files. A standalone range deletion file is one with just a single range deletion. Currently, such a file is used in bulk loading to achieve something like atomically delete old version of all data with one big range deletion and adding new version of data. These are the changes included in the PR:

1) When a standalone range deletion file is ingested via bulk loading, it's marked for compaction.
2) When picking input files during compaction picking, we attempt to only pick a standalone range deletion file when oldest snapshot is at or above the file's seqno. To do this, `PickCompaction` API is updated to take existing snapshots as an input. This is only done for the universal compaction + UDT disabled combination, we save querying for existing snapshots and not pass it for all other cases.
3) At `Compaction` construction time, the input files will be filtered to examine if any of them can be skipped for compaction iterator. For example, if all the data of the file is deleted by a standalone range tombstone, and the oldest snapshot is at or above such range tombstone, this file will be filtered out.
4) Every time a snapshot is released, we examine if any column family has standalone range deletion files that becomes eligible to be scheduled for compaction. And schedule one for it.

Potential future improvements:
- Add some dedicated statistics for the filtered files.
- Extend this input filtering to L0 files' compactions cases when a newer L0 file could shadow an older L0 file

Pull Request resolved: https://github.com/facebook/rocksdb/pull/13078

Test Plan: Added unit tests and stress tested a few rounds

Reviewed By: cbi42

Differential Revision: D64879415

Pulled By: jowlyzhang

fbshipit-source-id: 02b8683fddbe11f093bcaa0a38406deb39f44d9e
2024-10-25 09:32:14 -07:00
Peter Dillinger
4e60663b31 Remove unnecessary, confusing 'extern' (#12300)
Summary:
In C++, `extern` is redundant in a number of cases:
* "Global" function declarations and definitions
* "Global" variable definitions when already declared `extern`

For consistency and simplicity, I've removed these in code that *we own*. In a couple of cases, I removed obsolete declarations, and for MagicNumber constants, I have consolidated the declarations into a header file (format.h)
as standard best practice would prescribe.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/12300

Test Plan: no functional changes, CI

Reviewed By: ajkr

Differential Revision: D53148629

Pulled By: pdillinger

fbshipit-source-id: fb8d927959892e03af09b0c0d542b0a3b38fd886
2024-01-29 10:38:08 -08:00
Yu Zhang
509947ce2c Quarantine files in a limbo state after a manifest error (#12030)
Summary:
Part of the procedures to handle manifest IO error is to disable file deletion in case some files in limbo state get deleted prematurely. This is not ideal because: 1) not all the VersionEdits whose commit encounter such an error contain updates for files, disabling file deletion sometimes are not necessary. 2) `EnableFileDeletion` has a force mode that could make other threads accidentally disrupt this procedure in recovery.  3) Disabling file deletion as a whole is also not as efficient as more precisely tracking impacted files from being prematurely deleted.  This PR replaces this mechanism with tracking such files and quarantine them from being deleted in `ErrorHandler`.

These are the types of files being actively tracked in quarantine in this PR:
1) new table files and blob files from a background job
2) old manifest file whose immediately following new manifest file's CURRENT file creation gets into unclear state. Current handling is not sufficient to make sure the old manifest file is kept in case it's needed.

Note that WAL logs are not part of the quarantine because `min_log_number_to_keep` is a safe mechanism and it's only updated after successful manifest commits so it can prevent this premature deletion issue from happening.

We track these files' file numbers because they share the same file number space.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/12030

Test Plan: Modified existing unit tests

Reviewed By: ajkr

Differential Revision: D51036774

Pulled By: jowlyzhang

fbshipit-source-id: 84ef26271fbbc888ef70da5c40fe843bd7038716
2023-11-11 08:11:11 -08:00
Yu Zhang
4b013dcbed Remove VersionEdit's friends pattern (#12024)
Summary:
Almost each of VersionEdit private member has its own getter and setter. Current code access them with a combination of directly accessing private members and via getter and setters. There is no obvious benefits to have this pattern except potential performance gains. I tried this simple benchmark for removing the friends pattern completely, and there is no obvious regression. So I think it would good to remove VersionEdit's friends completely.

```TEST_TMPDIR=/dev/shm/rocksdb1 ./db_bench -benchmarks=fillseq -memtablerep=vector -allow_concurrent_memtable_write=false -num_column_families=10 -num=50000000```

With change:
fillseq      :       2.994 micros/op 333980 ops/sec 149.710 seconds 50000000 operations;   36.9 MB/s
fillseq      :       3.033 micros/op 329656 ops/sec 151.673 seconds 50000000 operations;   36.5 MB/s
fillseq      :       2.991 micros/op 334369 ops/sec 149.535 seconds 50000000 operations;   37.0 MB/s
Without change:
fillseq      :       3.015 micros/op 331715 ops/sec 150.732 seconds 50000000 operations;   36.7 MB/s
fillseq      :       3.044 micros/op 328553 ops/sec 152.182 seconds 50000000 operations;   36.3 MB/s
fillseq      :       3.091 micros/op 323520 ops/sec 154.550 seconds 50000000 operations;   35.8 MB/s

Pull Request resolved: https://github.com/facebook/rocksdb/pull/12024

Reviewed By: pdillinger

Differential Revision: D50806066

Pulled By: jowlyzhang

fbshipit-source-id: 35d287ce638a38c30f243f85992e615b4c90eb27
2023-11-01 12:04:11 -07:00
Hui Xiao
8e949116f7 Fix comments about creation_time/oldest_ancester_time/oldest_key_time (#11921)
Summary:
Code reference for the comments change:

40b618f234/table/block_based/block_based_table_builder.cc (L2093)

40b618f234/db/flush_job.cc (L945-L949)

40b618f234/db/compaction/compaction_job.cc (L1882-L1904)

Pull Request resolved: https://github.com/facebook/rocksdb/pull/11921

Reviewed By: cbi42

Differential Revision: D49921304

Pulled By: hx235

fbshipit-source-id: 2ae17e43c0fd52044404d7b63fea254d2d1f3595
2023-10-04 14:42:35 -07:00
Changyu Bi
6a0f637633 Compare the number of input keys and processed keys for compactions (#11571)
Summary:
... to improve data integrity validation during compaction.

A new option `compaction_verify_record_count` is introduced for this verification and is enabled by default. One exception when the verification is not done is when a compaction filter returns kRemoveAndSkipUntil which can cause CompactionIterator to seek until some key and hence not able to keep track of the number of keys processed.

For expected number of input keys, we sum over the number of total keys - number of range tombstones across compaction input files (`CompactionJob::UpdateCompactionStats()`). Table properties are consulted if `FileMetaData` is not initialized for some input file. Since table properties for all input files were also constructed during `DBImpl::NotifyOnCompactionBegin()`, `Compaction::GetTableProperties()` is introduced to reduce duplicated code.

For actual number of keys processed, each subcompaction will record its number of keys processed to `sub_compact->compaction_job_stats.num_input_records` and aggregated when all subcompactions finish (`CompactionJob::AggregateCompactionStats()`). In the case when some subcompaction encountered kRemoveAndSkipUntil from compaction filter and does not have accurate count, it propagates this information through `sub_compact->compaction_job_stats.has_num_input_records`.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/11571

Test Plan:
* Add a new unit test `DBCompactionTest.VerifyRecordCount` for the corruption case.
* All other unit tests for non-corrupted case.
* Ran crash test for a few hours: `python3 ./tools/db_crashtest.py whitebox --simple`

Reviewed By: ajkr

Differential Revision: D47131965

Pulled By: cbi42

fbshipit-source-id: cc8e94565dd526c4347e9d3843ecf32f6727af92
2023-07-28 09:47:31 -07:00
Yu Zhang
c24ef26ca7 Support switching on / off UDT together with in-Memtable-only feature (#11623)
Summary:
Add support to allow enabling / disabling user-defined timestamps feature for an existing column family in combination with the in-Memtable only feature.

To do this, this PR includes:
1) Log the `persist_user_defined_timestamps` option per column family in Manifest to facilitate detecting an attempt to enable / disable UDT. This entry is enforced to be logged in the same VersionEdit as the user comparator name entry.

2) User-defined timestamps related options are validated when re-opening a column family, including user comparator name and the `persist_user_defined_timestamps` flag. These type of settings and settings change are considered valid:
     a) no user comparator change and no effective `persist_user_defined_timestamp` flag change.
     b) switch user comparator to enable UDT provided the immediately effective `persist_user_defined_timestamps` flag
         is false.
     c) switch user comparator to disable UDT provided that the before-change `persist_user_defined_timestamps` is
         already false.
3) when an attempt to enable UDT is detected, we mark all its existing SST files as "having no UDT" by marking its `FileMetaData.user_defined_timestamps_persisted` flag to false and handle their file boundaries `FileMetaData.smallest`, `FileMetaData.largest` by padding a min timestamp.

4) while enabling / disabling UDT feature, timestamp size inconsistency in existing WAL logs are handled to make it compatible with the running user comparator.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/11623

Test Plan:
```
make all check
./db_with_timestamp_basic_test --gtest-filter="*EnableDisableUDT*"
./db_wal_test --gtest_filter="*EnableDisableUDT*"
```

Reviewed By: ltamasi

Differential Revision: D47636862

Pulled By: jowlyzhang

fbshipit-source-id: dcd19f67292da3c3cc9584c09ad00331c9ab9322
2023-07-26 20:16:32 -07:00
Yu Zhang
f74526341d Handle file boundaries when timestamps should not be persisted (#11578)
Summary:
Handle file boundaries `FileMetaData.smallest`, `FileMetaData.largest` for when `persist_user_defined_timestamps` is false:
    1) on the manifest write path, the original user-defined timestamps in file boundaries are stripped. This stripping is done during `VersionEdit::Encode` to limit the effect of the stripping to only the persisted version of the file boundaries.
    2) on the manifest read path during DB open, a a min timestamp is padded to the file boundaries. Ideally, this padding should happen during `VersionEdit::Decode` so that all in memory file boundaries have a compatible user key format as the running user comparator. However, because the user-defined timestamp size information is not available at that time. This change is added to `VersionEditHandler::OnNonCfOperation`.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/11578

Test Plan:
```
make all check
./version_edit_test --gtest_filter="*EncodeDecodeNewFile4HandleFileBoundary*".
./db_with_timestamp_basic_test --gtest_filter="*HandleFileBoundariesTest*"
```

Reviewed By: pdillinger

Differential Revision: D47309399

Pulled By: jowlyzhang

fbshipit-source-id: 21b4d54d2089a62826b31d779094a39cb2bbbd51
2023-07-10 11:03:25 -07:00
Yu Zhang
7521478b43 Record the persist_user_defined_timestamps flag in manifest (#11515)
Summary:
Start to record the value of the flag `AdvancedColumnFamilyOptions.persist_user_defined_timestamps` in the Manifest and table properties for a SST file when it is created. And use the recorded flag when creating a table reader for the SST file. This flag's default value is true, it is only explicitly recorded if it's false.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/11515

Test Plan:
```
make all check
./version_edit_test
```

Reviewed By: ltamasi

Differential Revision: D46920386

Pulled By: jowlyzhang

fbshipit-source-id: 075c20363d3d2cc1368422ecc805617ed135cc26
2023-06-21 21:49:01 -07:00
Hui Xiao
8f763bdeab Record and use the tail size to prefetch table tail (#11406)
Summary:
**Context:**
We prefetch the tail part of a SST file (i.e, the blocks after data blocks till the end of the file) during each SST file open in hope to prefetch all the stuff at once ahead of time for later read e.g, footer, meta index, filter/index etc. The existing approach to estimate the tail size to prefetch is through `TailPrefetchStats` heuristics introduced in https://github.com/facebook/rocksdb/pull/4156, which has caused small reads in unlucky case (e.g,  small read into the tail buffer during table open in thread 1 under the same BlockBasedTableFactory object can make thread 2's tail prefetching use a small size that it shouldn't) and is hard to debug.  Therefore we decide to record the exact tail size and use it directly  to prefetch tail of the SST instead of relying heuristics.

**Summary:**
- Obtain and record in manifest the tail size in `BlockBasedTableBuilder::Finish()`
   - For backward compatibility, we fall back to TailPrefetchStats and last to simple heuristics that the tail size is a linear portion of the file size - see PR conversation for more.
- Make`tail_start_offset` part of the table properties and deduct tail size to record in manifest for external files (e.g, file ingestion, import CF) and db repair (with no access to manifest).

Pull Request resolved: https://github.com/facebook/rocksdb/pull/11406

Test Plan:
1. New UT
2. db bench
Note: db bench on /tmp/ where direct read is supported is too slow to finish and the default pinning setting in db bench is not helpful to profile # sst read of Get. Therefore I hacked the following to obtain the following comparison.
```
 diff --git a/table/block_based/block_based_table_reader.cc b/table/block_based/block_based_table_reader.cc
index bd5669f0f..791484c1f 100644
 --- a/table/block_based/block_based_table_reader.cc
+++ b/table/block_based/block_based_table_reader.cc
@@ -838,7 +838,7 @@ Status BlockBasedTable::PrefetchTail(
                            &tail_prefetch_size);

   // Try file system prefetch
-  if (!file->use_direct_io() && !force_direct_prefetch) {
+  if (false && !file->use_direct_io() && !force_direct_prefetch) {
     if (!file->Prefetch(prefetch_off, prefetch_len, ro.rate_limiter_priority)
              .IsNotSupported()) {
       prefetch_buffer->reset(new FilePrefetchBuffer(
 diff --git a/tools/db_bench_tool.cc b/tools/db_bench_tool.cc
index ea40f5fa0..39a0ac385 100644
 --- a/tools/db_bench_tool.cc
+++ b/tools/db_bench_tool.cc
@@ -4191,6 +4191,8 @@ class Benchmark {
           std::shared_ptr<TableFactory>(NewCuckooTableFactory(table_options));
     } else {
       BlockBasedTableOptions block_based_options;
+      block_based_options.metadata_cache_options.partition_pinning =
+      PinningTier::kAll;
       block_based_options.checksum =
           static_cast<ChecksumType>(FLAGS_checksum_type);
       if (FLAGS_use_hash_search) {
```
Create DB
```
./db_bench --bloom_bits=3 --use_existing_db=1 --seed=1682546046158958 --partition_index_and_filters=1 --statistics=1 -db=/dev/shm/testdb/ -benchmarks=readrandom -key_size=3200 -value_size=512 -num=1000000 -write_buffer_size=6550000 -disable_auto_compactions=false -target_file_size_base=6550000 -compression_type=none
```
ReadRandom
```
./db_bench --bloom_bits=3 --use_existing_db=1 --seed=1682546046158958 --partition_index_and_filters=1 --statistics=1 -db=/dev/shm/testdb/ -benchmarks=readrandom -key_size=3200 -value_size=512 -num=1000000 -write_buffer_size=6550000 -disable_auto_compactions=false -target_file_size_base=6550000 -compression_type=none
```
(a) Existing (Use TailPrefetchStats for tail size + use seperate prefetch buffer in PartitionedFilter/IndexReader::CacheDependencies())
```
rocksdb.table.open.prefetch.tail.hit COUNT : 3395
rocksdb.sst.read.micros P50 : 5.655570 P95 : 9.931396 P99 : 14.845454 P100 : 585.000000 COUNT : 999905 SUM : 6590614
```

(b) This PR (Record tail size + use the same tail buffer in PartitionedFilter/IndexReader::CacheDependencies())
```
rocksdb.table.open.prefetch.tail.hit COUNT : 14257
rocksdb.sst.read.micros P50 : 5.173347 P95 : 9.015017 P99 : 12.912610 P100 : 228.000000 COUNT : 998547 SUM : 5976540
```

As we can see, we increase the prefetch tail hit count and decrease SST read count with this PR

3. Test backward compatibility by stepping through reading with post-PR code on a db generated pre-PR.

Reviewed By: pdillinger

Differential Revision: D45413346

Pulled By: hx235

fbshipit-source-id: 7d5e36a60a72477218f79905168d688452a4c064
2023-05-08 13:14:28 -07:00
Peter Dillinger
3cacd4b4ec Put Cache and CacheWrapper in new public header (#11192)
Summary:
The definition of the Cache class should not be needed by the vast majority of RocksDB users, so I think it is just distracting to include it in cache.h, which is primarily needed for configuring and creating caches. This change moves the class to a new header advanced_cache.h. It is just cut-and-paste except for modifying the class API comment.

In general, operations on shared_ptr<Cache> should continue to work when only a forward declaration of Cache is available, as long as all the Cache instances provided are already shared_ptr. See https://stackoverflow.com/a/17650101/454544

Also, the most common way to customize a Cache is by wrapping an existing implementation, so it makes sense to provide CacheWrapper in the public API. This was a cut-and-paste job except removing the implementation of Name() so that derived classes must provide it.

Intended follow-up: consolidate Release() into one function to reduce customization bugs / confusion

Pull Request resolved: https://github.com/facebook/rocksdb/pull/11192

Test Plan: `make check`

Reviewed By: anand1976

Differential Revision: D43055487

Pulled By: pdillinger

fbshipit-source-id: 7b05492df35e0f30b581b4c24c579bc275b6d110
2023-02-09 12:12:02 -08:00
Changyu Bi
6a82b68788 Avoid counting extra range tombstone compensated size in AddRangeDels() (#11091)
Summary:
in `CompactionOutputs::AddRangeDels()`, range tombstones with the same start and end key but different sequence numbers all contribute to compensated range tombstone size. This PR removes this redundancy. This PR also includes a fix from https://github.com/facebook/rocksdb/issues/11067 where a range tombstone that is not within a file's range was being added to the file. This fixes an assertion failure for `icmp.Compare(start, end) <= 0` in VersionSet::ApproximateSize() when calculating compensated range tombstone size. Assertions and a comment/essay was added to reason that no such range tombstone will be added after this fix.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/11091

Test Plan:
- Added unit tests
- Stress test with small key range: `python3 tools/db_crashtest.py blackbox --simple --max_key=100 --interval=600 --write_buffer_size=262144 --target_file_size_base=256 --max_bytes_for_level_base=262144 --block_size=128 --value_size_mult=33 --subcompactions=10`

Reviewed By: ajkr

Differential Revision: D42521588

Pulled By: cbi42

fbshipit-source-id: 5bda3fe38997995314e1f7592319af12b69bc4f8
2023-01-17 12:47:44 -08:00
Changyu Bi
cc6f323705 Include estimated bytes deleted by range tombstones in compensated file size (#10734)
Summary:
compensate file sizes in compaction picking so files with range tombstones are preferred, such that they get compacted down earlier as they tend to delete a lot of data. This PR adds a `compensated_range_deletion_size` field in FileMeta that is computed during Flush/Compaction and persisted in MANIFEST. This value is added to `compensated_file_size` which will be used for compaction picking. Currently, for a file in level L, `compensated_range_deletion_size` is set to the estimated bytes deleted by range tombstone of this file in all levels > L. This helps to reduce space amp when data in older levels are covered by range tombstones in level L.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/10734

Test Plan:
- Added unit tests.
- benchmark to check if the above definition `compensated_range_deletion_size` is reducing space amp as intended, without affecting write amp too much. The experiment set up favorable for this optimization: large range tombstone issued infrequently. Command used:
```
./db_bench -benchmarks=fillrandom,waitforcompaction,stats,levelstats -use_existing_db=false -avoid_flush_during_recovery=true -write_buffer_size=33554432 -level_compaction_dynamic_level_bytes=true -max_background_jobs=8 -max_bytes_for_level_base=134217728 -target_file_size_base=33554432 -writes_per_range_tombstone=500000 -range_tombstone_width=5000000 -num=50000000 -benchmark_write_rate_limit=8388608 -threads=16 -duration=1800 --max_num_range_tombstones=1000000000
```

In this experiment, each thread wrote 16 range tombstones over the duration of 30 minutes, each range tombstone has width 5M that is the 10% of the key space width. Results shows this PR generates a smaller DB size.

Compaction stats from this PR:
```
Level    Files   Size     Score Read(GB)  Rn(GB) Rnp1(GB) Write(GB) Wnew(GB) Moved(GB) W-Amp Rd(MB/s) Wr(MB/s) Comp(sec) CompMergeCPU(sec) Comp(cnt) Avg(sec) KeyIn KeyDrop Rblob(GB) Wblob(GB)
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
  L0      2/0   31.54 MB   0.5      0.0     0.0      0.0       8.4      8.4       0.0   1.0      0.0     63.4    135.56            110.94       544    0.249       0      0       0.0       0.0
  L4      3/0   96.55 MB   0.8     18.5     6.7     11.8      18.4      6.6       0.0   2.7     65.3     64.9    290.08            284.03       108    2.686    284M  1957K       0.0       0.0
  L5     15/0   404.41 MB   1.0     19.1     7.7     11.4      18.8      7.4       0.3   2.5     66.6     65.7    292.93            285.34       220    1.332    293M  3808K       0.0       0.0
  L6    143/0    4.12 GB   0.0     45.0     7.5     37.5      41.6      4.1       0.0   5.5     71.2     65.9    647.00            632.66       251    2.578    739M    47M       0.0       0.0
 Sum    163/0    4.64 GB   0.0     82.6    21.9     60.7      87.2     26.5       0.3  10.4     61.9     65.4   1365.58           1312.97      1123    1.216   1318M    52M       0.0       0.0
```

Compaction stats from main:
```
Level    Files   Size     Score Read(GB)  Rn(GB) Rnp1(GB) Write(GB) Wnew(GB) Moved(GB) W-Amp Rd(MB/s) Wr(MB/s) Comp(sec) CompMergeCPU(sec) Comp(cnt) Avg(sec) KeyIn KeyDrop Rblob(GB) Wblob(GB)
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
  L0      0/0    0.00 KB   0.0      0.0     0.0      0.0       8.4      8.4       0.0   1.0      0.0     60.5    142.12            115.89       569    0.250       0      0       0.0       0.0
  L4      3/0   85.68 MB   1.0     17.7     6.8     10.9      17.6      6.7       0.0   2.6     62.7     62.3    289.05            281.79       112    2.581    272M  2309K       0.0       0.0
  L5     11/0   293.73 MB   1.0     18.8     7.5     11.2      18.5      7.2       0.5   2.5     64.9     63.9    296.07            288.50       220    1.346    288M  4365K       0.0       0.0
  L6    130/0    3.94 GB   0.0     51.5     7.6     43.9      47.9      3.9       0.0   6.3     67.2     62.4    784.95            765.92       258    3.042    848M    51M       0.0       0.0
 Sum    144/0    4.31 GB   0.0     88.0    21.9     66.0      92.3     26.3       0.5  11.0     59.6     62.5   1512.19           1452.09      1159    1.305   1409M    58M       0.0       0.0```

Reviewed By: ajkr

Differential Revision: D39834713

Pulled By: cbi42

fbshipit-source-id: fe9341040b8704a8fbb10cad5cf5c43e962c7e6b
2022-12-29 13:28:24 -08:00
Hui Xiao
98d5db5c2e Sort L0 files by newly introduced epoch_num (#10922)
Summary:
**Context:**
Sorting L0 files by `largest_seqno` has at least two inconvenience:
-  File ingestion and compaction involving ingested files can create files of overlapping seqno range with the existing files. `force_consistency_check=true` will catch such overlap seqno range even those harmless overlap.
    - For example, consider the following sequence of events ("key@n" indicates key at seqno "n")
       - insert k1@1 to memtable m1
       - ingest file s1 with k2@2, ingest file s2 with k3@3
        - insert k4@4 to m1
       - compact files s1, s2 and  result in new file s3 of seqno range [2, 3]
       - flush m1 and result in new file s4 of seqno range [1, 4]. And `force_consistency_check=true` will think s4 and s3 has file reordering corruption that might cause retuning an old value of k1
    - However such caught corruption is a false positive since s1, s2 will not have overlapped keys with k1 or whatever inserted into m1 before ingest file s1 by the requirement of file ingestion (otherwise the m1 will be flushed first before any of the file ingestion completes). Therefore there in fact isn't any file reordering corruption.
- Single delete can decrease a file's largest seqno and ordering by `largest_seqno` can introduce a wrong ordering hence file reordering corruption
    - For example, consider the following sequence of events ("key@n" indicates key at seqno "n", Credit to ajkr  for this example)
        - an existing SST s1 contains only k1@1
        - insert k1@2 to memtable m1
        - ingest file s2 with k3@3, ingest file s3 with k4@4
        - insert single delete k5@5 in m1
        - flush m1 and result in new file s4 of seqno range [2, 5]
        - compact s1, s2, s3 and result in new file s5 of seqno range [1, 4]
        - compact s4 and result in new file s6 of seqno range [2] due to single delete
    - By the last step, we have file ordering by largest seqno (">" means "newer") : s5 > s6 while s6 contains a newer version of the k1's value (i.e, k1@2) than s5, which is a real reordering corruption. While this can be caught by `force_consistency_check=true`, there isn't a good way to prevent this from happening if ordering by `largest_seqno`

Therefore, we are redesigning the sorting criteria of L0 files and avoid above inconvenience. Credit to ajkr , we now introduce `epoch_num` which describes the order of a file being flushed or ingested/imported (compaction output file will has the minimum `epoch_num` among input files'). This will avoid the above inconvenience in the following ways:
- In the first case above, there will no longer be overlap seqno range check in `force_consistency_check=true` but `epoch_number`  ordering check. This will result in file ordering s1 <  s2 <  s4 (pre-compaction) and s3 < s4 (post-compaction) which won't trigger false positive corruption. See test class `DBCompactionTestL0FilesMisorderCorruption*` for more.
- In the second case above, this will result in file ordering s1 < s2 < s3 < s4 (pre-compacting s1, s2, s3), s5 < s4 (post-compacting s1, s2, s3), s5 < s6 (post-compacting s4), which are correct file ordering without causing any corruption.

**Summary:**
- Introduce `epoch_number` stored per `ColumnFamilyData` and sort CF's L0 files by their assigned `epoch_number` instead of `largest_seqno`.
  - `epoch_number` is increased and assigned upon `VersionEdit::AddFile()` for flush (or similarly for WriteLevel0TableForRecovery) and file ingestion (except for allow_behind_true, which will always get assigned as the `kReservedEpochNumberForFileIngestedBehind`)
  - Compaction output file  is assigned with the minimum `epoch_number` among input files'
      - Refit level: reuse refitted file's epoch_number
  -  Other paths needing `epoch_number` treatment:
     - Import column families: reuse file's epoch_number if exists. If not, assign one based on `NewestFirstBySeqNo`
     - Repair: reuse file's epoch_number if exists. If not, assign one based on `NewestFirstBySeqNo`.
  -  Assigning new epoch_number to a file and adding this file to LSM tree should be atomic. This is guaranteed by us assigning epoch_number right upon `VersionEdit::AddFile()` where this version edit will be apply to LSM tree shape right after by holding the db mutex (e.g, flush, file ingestion, import column family) or  by there is only 1 ongoing edit per CF (e.g, WriteLevel0TableForRecovery, Repair).
  - Assigning the minimum input epoch number to compaction output file won't misorder L0 files (even through later `Refit(target_level=0)`). It's due to for every key "k" in the input range, a legit compaction will cover a continuous epoch number range of that key. As long as we assign the key "k" the minimum input epoch number, it won't become newer or older than the versions of this key that aren't included in this compaction hence no misorder.
- Persist `epoch_number` of each file in manifest and recover `epoch_number` on db recovery
   - Backward compatibility with old db without `epoch_number` support is guaranteed by assigning `epoch_number` to recovered files by `NewestFirstBySeqno` order. See `VersionStorageInfo::RecoverEpochNumbers()` for more
   - Forward compatibility with manifest is guaranteed by flexibility of `NewFileCustomTag`
- Replace `force_consistent_check` on L0 with `epoch_number` and remove false positive check like case 1 with `largest_seqno` above
   - Due to backward compatibility issue, we might encounter files with missing epoch number at the beginning of db recovery. We will still use old L0 sorting mechanism (`NewestFirstBySeqno`) to check/sort them till we infer their epoch number. See usages of `EpochNumberRequirement`.
- Remove fix https://github.com/facebook/rocksdb/pull/5958#issue-511150930 and their outdated tests to file reordering corruption because such fix can be replaced by this PR.
- Misc:
   - update existing tests with `epoch_number` so make check will pass
   - update https://github.com/facebook/rocksdb/pull/5958#issue-511150930 tests to verify corruption is fixed using `epoch_number` and cover universal/fifo compaction/CompactRange/CompactFile cases
   - assert db_mutex is held for a few places before calling ColumnFamilyData::NewEpochNumber()

Pull Request resolved: https://github.com/facebook/rocksdb/pull/10922

Test Plan:
- `make check`
- New unit tests under `db/db_compaction_test.cc`, `db/db_test2.cc`, `db/version_builder_test.cc`, `db/repair_test.cc`
- Updated tests (i.e, `DBCompactionTestL0FilesMisorderCorruption*`) under https://github.com/facebook/rocksdb/pull/5958#issue-511150930
- [Ongoing] Compatibility test: manually run 36a5686ec0 (with file ingestion off for running the `.orig` binary to prevent this bug affecting upgrade/downgrade formality checking) for 1 hour on `simple black/white box`, `cf_consistency/txn/enable_ts with whitebox + test_best_efforts_recovery with blackbox`
- [Ongoing] normal db stress test
- [Ongoing] db stress test with aggressive value https://github.com/facebook/rocksdb/pull/10761

Reviewed By: ajkr

Differential Revision: D41063187

Pulled By: hx235

fbshipit-source-id: 826cb23455de7beaabe2d16c57682a82733a32a9
2022-12-13 13:29:37 -08:00
Andrew Kryczka
5cf6ab6f31 Ran clang-format on db/ directory (#10910)
Summary:
Ran `find ./db/ -type f | xargs clang-format -i`. Excluded minor changes it tried to make on db/db_impl/. Everything else it changed was directly under db/ directory. Included minor manual touchups mentioned in PR commit history.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/10910

Reviewed By: riversand963

Differential Revision: D40880683

Pulled By: ajkr

fbshipit-source-id: cfe26cda05b3fb9a72e3cb82c286e21d8c5c4174
2022-11-02 14:34:24 -07:00
Peter Dillinger
6de7081cf3 Always verify SST unique IDs on SST file open (#10532)
Summary:
Although we've been tracking SST unique IDs in the DB manifest
unconditionally, checking has been opt-in and with an extra pass at DB::Open
time. This changes the behavior of `verify_sst_unique_id_in_manifest` to
check unique ID against manifest every time an SST file is opened through
table cache (normal DB operations), replacing the explicit pass over files
at DB::Open time. This change also enables the option by default and
removes the "EXPERIMENTAL" designation.

One possible criticism is that the option no longer ensures the integrity
of a DB at Open time. This is far from an all-or-nothing issue. Verifying
the IDs of all SST files hardly ensures all the data in the DB is readable.
(VerifyChecksum is supposed to do that.) Also, with
max_open_files=-1 (default, extremely common), all SST files are
opened at DB::Open time anyway.

Implementation details:
* `VerifySstUniqueIdInManifest()` functions are the extra/explicit pass
that is now removed.
* Unit tests that manipulate/corrupt table properties have to opt out of
this check, because that corrupts the "actual" unique id. (And even for
testing we don't currently have a mechanism to set "no unique id"
in the in-memory file metadata for new files.)
* A lot of other unit test churn relates to (a) default checking on, and
(b) checking on SST open even without DB::Open (e.g. on flush)
* Use `FileMetaData` for more `TableCache` operations (in place of
`FileDescriptor`) so that we have access to the unique_id whenever
we might need to open an SST file. **There is the possibility of
performance impact because we can no longer use the more
localized `fd` part of an `FdWithKeyRange` but instead follow the
`file_metadata` pointer. However, this change (possible regression)
is only done for `GetMemoryUsageByTableReaders`.**
* Removed a completely unnecessary constructor overload of
`TableReaderOptions`

Possible follow-up:
* Verification only happens when opening through table cache. Are there
more places where this should happen?
* Improve error message when there is a file size mismatch vs. manifest
(FIXME added in the appropriate place).
* I'm not sure there's a justification for `FileDescriptor` to be distinct from
`FileMetaData`.
* I'm skeptical that `FdWithKeyRange` really still makes sense for
optimizing some data locality by duplicating some data in memory, but I
could be wrong.
* An unnecessary overload of NewTableReader was recently added, in
the public API nonetheless (though unusable there). It should be cleaned
up to put most things under `TableReaderOptions`.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/10532

Test Plan:
updated unit tests

Performance test showing no significant difference (just noise I think):
`./db_bench -benchmarks=readwhilewriting[-X10] -num=3000000 -disable_wal=1 -bloom_bits=8 -write_buffer_size=1000000 -target_file_size_base=1000000`
Before: readwhilewriting [AVG 10 runs] : 68702 (± 6932) ops/sec
After: readwhilewriting [AVG 10 runs] : 68239 (± 7198) ops/sec

Reviewed By: jay-zhuang

Differential Revision: D38765551

Pulled By: pdillinger

fbshipit-source-id: a827a708155f12344ab2a5c16e7701c7636da4c2
2022-09-07 22:52:42 -07:00
Yanqin Jin
fbfcf5cbcd Remove unused fields from FileMetaData (temporarily) (#10443)
Summary:
FileMetaData::[min|max]_timestamp are not currently being used or
tracked by RocksDB, even when user-defined timestamp is enabled. Each of
them is a std::string which can occupy 32 bytes. Remove them for now.
They may be added back when we have a pressing need for them. When we do
add them back, consider store them in a more compact way, e.g. one
boolean flag and a byte array of size 16.

Per file min/max timestamp bounds are available as table properties.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/10443

Test Plan: make check

Reviewed By: pdillinger

Differential Revision: D38292275

Pulled By: riversand963

fbshipit-source-id: 841dc4e855ad8f8481c80cb020603de9607c9c94
2022-08-01 17:56:13 -07:00
Bo Wang
c073ed7601 Fix typo in comments and code (#10233)
Summary:
Fix typo in comments and code.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/10233

Test Plan: Existing unit tests should pass.

Reviewed By: jay-zhuang, anand1976

Differential Revision: D37356702

Pulled By: gitbw95

fbshipit-source-id: 32c019adcc6dcc95a9882b38147a310091368e51
2022-06-22 15:45:21 -07:00
zczhu
30141461f9 Add basic kRoundRobin compaction policy (#10107)
Summary:
Add `kRoundRobin` as a compaction priority. The implementation is as follows.

- Define a cursor as the smallest Internal key in the successor of the selected file. Add `vector<InternalKey> compact_cursor_` into `VersionStorageInfo` where each element (`InternalKey`) in `compact_cursor_` represents a cursor. In round-robin compaction policy, we just need to select the first file (assuming files are sorted) and also has the smallest InternalKey larger than/equal to the cursor. After a file is chosen, we create a new `Fsize` vector which puts the selected file is placed at the first position in `temp`, the next cursor is then updated as the smallest InternalKey in successor of the selected file (the above logic is implemented in `SortFileByRoundRobin`).
- After a compaction succeeds, typically `InstallCompactionResults()`, we choose the next cursor for the input level and save it to `edit`. When calling `LogAndApply`, we save the next cursor with its level into some local variable and finally apply the change to `vstorage` in `SaveTo` function.
- Cursors are persist pair by pair (<level, InternalKey>) in `EncodeTo` so that they can be reconstructed when reopening. An empty cursor will not be encoded to MANIFEST

Pull Request resolved: https://github.com/facebook/rocksdb/pull/10107

Test Plan: add unit test (`CompactionPriRoundRobin`) in `compaction_picker_test`, add `kRoundRobin` priority in `CompactionPriTest` from `db_compaction_test`, and add `PersistRoundRobinCompactCursor` in `db_compaction_test`

Reviewed By: ajkr

Differential Revision: D37316037

Pulled By: littlepig2013

fbshipit-source-id: 9f481748190ace416079139044e00df2968fb1ee
2022-06-21 11:56:53 -07:00
Hui Xiao
d665afdbf3 Account memory of FileMetaData in global memory limit (#9924)
Summary:
**Context/Summary:**
As revealed by heap profiling, allocation of `FileMetaData` for [newly created file added to a Version](https://github.com/facebook/rocksdb/pull/9924/files#diff-a6aa385940793f95a2c5b39cc670bd440c4547fa54fd44622f756382d5e47e43R774) can consume significant heap memory. This PR is to account that toward our global memory limit based on block cache capacity.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/9924

Test Plan:
- Previous `make check` verified there are only 2 places where the memory of  the allocated `FileMetaData` can be released
- New unit test `TEST_P(ChargeFileMetadataTestWithParam, Basic)`
- db bench (CPU cost of `charge_file_metadata` in write and compact)
   - **write micros/op: -0.24%** : `TEST_TMPDIR=/dev/shm/testdb ./db_bench -benchmarks=fillseq -db=$TEST_TMPDIR -charge_file_metadata=1 (remove this option for pre-PR) -disable_auto_compactions=1 -write_buffer_size=100000 -num=4000000 | egrep 'fillseq'`
   - **compact micros/op -0.87%** : `TEST_TMPDIR=/dev/shm/testdb ./db_bench -benchmarks=fillseq -db=$TEST_TMPDIR -charge_file_metadata=1 -disable_auto_compactions=1 -write_buffer_size=100000 -num=4000000 -numdistinct=1000 && ./db_bench -benchmarks=compact -db=$TEST_TMPDIR -use_existing_db=1 -charge_file_metadata=1 -disable_auto_compactions=1 | egrep 'compact'`

table 1 - write

#-run | (pre-PR) avg micros/op | std micros/op | (post-PR)  micros/op | std micros/op | change (%)
-- | -- | -- | -- | -- | --
10 | 3.9711 | 0.264408 | 3.9914 | 0.254563 | 0.5111933721
20 | 3.83905 | 0.0664488 | 3.8251 | 0.0695456 | -0.3633711465
40 | 3.86625 | 0.136669 | 3.8867 | 0.143765 | 0.5289363078
80 | 3.87828 | 0.119007 | 3.86791 | 0.115674 | **-0.2673865734**
160 | 3.87677 | 0.162231 | 3.86739 | 0.16663 | **-0.2419539978**

table 2 - compact

#-run | (pre-PR) avg micros/op | std micros/op | (post-PR)  micros/op | std micros/op | change (%)
-- | -- | -- | -- | -- | --
10 | 2,399,650.00 | 96,375.80 | 2,359,537.00 | 53,243.60 | -1.67
20 | 2,410,480.00 | 89,988.00 | 2,433,580.00 | 91,121.20 | 0.96
40 | 2.41E+06 | 121811 | 2.39E+06 | 131525 | **-0.96**
80 | 2.40E+06 | 134503 | 2.39E+06 | 108799 | **-0.78**

- stress test: `python3 tools/db_crashtest.py blackbox --charge_file_metadata=1  --cache_size=1` killed as normal

Reviewed By: ajkr

Differential Revision: D36055583

Pulled By: hx235

fbshipit-source-id: b60eab94707103cb1322cf815f05810ef0232625
2022-06-14 13:06:40 -07:00
Jay Zhuang
c6d326d3d7 Track SST unique id in MANIFEST and verify (#9990)
Summary:
Start tracking SST unique id in MANIFEST, which is used to verify with
SST properties to make sure the SST file is not overwritten or
misplaced. A DB option `try_verify_sst_unique_id` is introduced to
enable/disable the verification, if enabled, it opens all SST files
during DB-open to read the unique_id from table properties (default is
false), so it's recommended to use it with `max_open_files = -1` to
pre-open the files.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/9990

Test Plan: unittests, format-compatible test, mini-crash

Reviewed By: anand1976

Differential Revision: D36381863

Pulled By: jay-zhuang

fbshipit-source-id: 89ea2eb6b35ed3e80ead9c724eb096083eaba63f
2022-05-19 11:04:21 -07:00
Levi Tamasi
db536ee045 Propagate errors from UpdateBoundaries (#9851)
Summary:
In `FileMetaData`, we keep track of the lowest-numbered blob file
referenced by the SST file in question for the purposes of BlobDB's
garbage collection in the `oldest_blob_file_number` field, which is
updated in `UpdateBoundaries`. However, with the current code,
`BlobIndex` decoding errors (or invalid blob file numbers) are swallowed
in this method. The patch changes this by propagating these errors
and failing the corresponding flush/compaction. (Note that since blob
references are generated by the BlobDB code and also parsed by
`CompactionIterator`, in reality this can only happen in the case of
memory corruption.)

This change necessitated updating some unit tests that involved
fake/corrupt `BlobIndex` objects. Some of these just used a dummy string like
`"blob_index"` as a placeholder; these were replaced with real `BlobIndex`es.
Some were relying on the earlier behavior to simulate corruption; these
were replaced with `SyncPoint`-based test code that corrupts a valid
blob reference at read time.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/9851

Test Plan: `make check`

Reviewed By: riversand963

Differential Revision: D35683671

Pulled By: ltamasi

fbshipit-source-id: f7387af9945c48e4d5c4cd864f1ba425c7ad51f6
2022-04-15 20:25:48 -07:00
Levi Tamasi
42e0751b3a Clean up VersionStorageInfo a bit (#9494)
Summary:
The patch does some cleanup in and around `VersionStorageInfo`:
* Renames the method `PrepareApply` to `PrepareAppend` in `Version`
to make it clear that it is to be called before appending the `Version` to
`VersionSet` (via `AppendVersion`), not before applying any `VersionEdit`s.
* Introduces a helper method `VersionStorageInfo::PrepareForVersionAppend`
(called by `Version::PrepareAppend`) that encapsulates the population of the
various derived data structures in `VersionStorageInfo`, and turns the
methods computing the derived structures (`UpdateNumNonEmptyLevels`,
`CalculateBaseBytes` etc.) into private helpers.
* Changes `Version::PrepareAppend` so it only calls `UpdateAccumulatedStats`
if the `update_stats` flag is set. (Earlier, this was checked by the callee.)
Related to this, it also moves the call to `ComputeCompensatedSizes` to
`VersionStorageInfo::PrepareForVersionAppend`.
* Updates and cleans up `version_builder_test`, `version_set_test`, and
`compaction_picker_test` so `PrepareForVersionAppend` is called anytime
a new `VersionStorageInfo` is set up or saved. This cleanup also involves
splitting `VersionStorageInfoTest.MaxBytesForLevelDynamic`
into multiple smaller test cases.
* Fixes up a bunch of comments that were outdated or just plain incorrect.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/9494

Test Plan: Ran `make check` and the crash test script for a while.

Reviewed By: riversand963

Differential Revision: D33971666

Pulled By: ltamasi

fbshipit-source-id: fda52faac7783041126e4f8dec0fe01bdcadf65a
2022-02-04 08:19:20 -08:00
Andrew Kryczka
b860a42158 Recover to exact latest seqno of data committed to MANIFEST (#9305)
Summary:
The LastSequence field in the MANIFEST file is the baseline seqno for a recovered DB. Recovering WAL entries might cause the recovered DB's seqno to advance above this baseline, but the recovered DB will never use a smaller seqno.

Before this PR, we were writing the DB's seqno at the time of LogAndApply() as the LastSequence value. This works in the sense that it is a large enough baseline for the recovered DB that it'll never overwrite any records in existing SST files. At the same time, it's arbitrarily larger than what's needed. This behavior comes from LevelDB, where there was no tracking of largest seqno in an SST file.

Now we know the largest seqno of newly written SST files, so we can write an exact value in LastSequence that actually reflects the largest seqno in any file referred to by the MANIFEST. This is primarily useful for correctness testing with unsynced data loss, where the recovered DB's seqno needs to indicate what records were recovered.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/9305

Test Plan:
- https://github.com/facebook/rocksdb/issues/9338 adds crash-recovery correctness testing coverage for WAL disabled use cases
- https://github.com/facebook/rocksdb/issues/9357 will extend that testing to cover file ingestion
- Added assertion at end of LogAndApply() for `VersionSet::descriptor_last_sequence_` consistency with files
- Manually tested upgrade/downgrade compatibility with a custom crash test that randomly picks between a `db_stress` built with and without this PR (for old code it must run with `-disable_wal=0`)

Reviewed By: riversand963

Differential Revision: D33182770

Pulled By: ajkr

fbshipit-source-id: 0bfafaf685f347cc8cb0e1d62e0186340a738f7d
2022-01-05 16:02:21 -08:00
sdong
88875df821 File temperature information should be preserved when restart the DB (#9242)
Summary:
Fix a bug that causes file temperature not preserved after DB is restarted, or options.max_manifest_file_size is hit.
Also, pass temperature information to NewRandomAccessFile() to allow users to hack a solution where they don't preserve tiering information.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/9242

Test Plan: Add a unit test that would fail without the fix.

Reviewed By: jay-zhuang

Differential Revision: D32818150

fbshipit-source-id: 36aa3f148c60107f7b8e9d65b63b039f9e1a1eec
2021-12-03 14:43:14 -08:00