Summary:
Leveled compaction combined with preserve_internal_time_seconds or preclude_last_level_data_seconds is a known-broken combination, but it is easy to enable by accident -- for example a fleet-wide config rollout that turns on the preserve time for CFs that happen to be leveled. Rather than degrading gracefully, it triggers an infinite kBottommostFiles compaction loop: a bottommost file gets marked, rewritten with no progress, and immediately re-marked, continuously rewriting the file and growing the MANIFEST so the file set never quiesces. This change makes such a misconfiguration a harmless no-op instead.
Before this change, the marking logic
(ComputeBottommostFilesMarkedForCompaction) marked a bottommost file whenever its largest seqno was below the oldest snapshot, without checking whether a compaction could actually zero that seqno. Recently written seqnos stay within the seqno->time "preserve" window and cannot be zeroed, so the rewrite never made progress. The same futile marking also occurred with user-defined timestamps when full_history_ts_low is unset. The underlying issue is that the "can this bottommost seqno be zeroed?" question was answered independently by the marking logic and by the compaction output path (CompactionIterator::PrepareOutput), and the two had drifted apart.
With this change, both paths answer that question through one shared predicate (BottommostSeqnoCanBeZeroed), and the preserve-window boundary that marking needs is plumbed into VersionStorageInfo from DBImpl, mirroring the existing oldest-snapshot plumbing. Snapshot visibility stays a per-site check. On CFs without preserve/preclude the predicate is a no-op. Confirmed that caller invariants ensure that relocating the `ikey_.sequence <= preserve_seqno_after_` check in CompactionIterator::PrepareOutput() will not trip the ROCKSDB_LOG_FATAL.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/15146
Test Plan:
- compaction_picker_test: new CompactionPickerTest BottommostFileNotMarkedWithinPreserveWindow / BottommostFileMarkedBelowPreserveWindow cover the preserve-window boundary; new CompactionPickerU64TsTest BottommostNotMarkedWithEmptyFullHistoryTsLowAndUnknownMaxTs covers the UDT edge case.
- tiered_compaction_test: new PrecludeBottommostLoopTest LeveledPreserveTimeNoBottommostLoop is an end-to-end regression for the loop and the DBImpl plumbing: a bottommost file with a nonzero largest seqno inside the preserve window, made a marking candidate via a snapshot release, must not be marked. It reproduces the loop (hangs) when the plumbing is neutralized and passes with the fix.
Reviewed By: xingbowang
Differential Revision: D117299979
Pulled By: pdillinger
fbshipit-source-id: 51e8e2d4e2116984d16d3c7ef54a9635d5aded74
Summary:
Follow-up cleanup to the embedded (same-file) blob wide-column work (PR https://github.com/facebook/rocksdb/issues/14990): the "ReadOptions usage cleanup/optimization" item.
Split the Version-backed blob fetcher into two variants sharing a common VersionBlobFetcherBase (which implements FetchBlob via a virtual read_options()):
- VersionBlobFetcher now holds a `const ReadOptions&` for transient/stack fetchers (the common case: point Get/MultiGet, DBIter, version_set), so the growing ReadOptions is no longer copied per fetcher on the hot path. A deleted rvalue-ref constructor rejects binding to a temporary.
- OwningVersionBlobFetcher takes `ReadOptions&&` and owns a copy, for fetchers whose lifetime is independent of the caller (the read-path lazy resolver and compaction), making ownership transfer explicit.
DBIter::BlobReader now holds a single blob fetcher instead of decomposed scalar fields (read_tier/verify_checksums/fill_cache/io_activity). This removes the decompose-then-recompose that the old CreateBlobFetcher and RetrieveAndSetBlobValue performed, and closes the field-loss gap: all ReadOptions fields now flow through to blob reads rather than just those four. CreateBlobFetcher is gone; the merge path uses the reader's owned fetcher directly. A CanResolve() predicate on the fetcher preserves the prior "unexpected blob index" Corruption instead of dereferencing a null Version, and the now-redundant allow_blob_write_path_fallback_ member/ parameter (equal to the fetcher's own flag) was dropped.
ReadPathBlobResolver keeps owning its fetcher (now OwningVersionBlobFetcher) so it stays self-contained for the planned lazy entity read path, where the result outlives the read call. A TODO in db_iter.h records the remaining duplication (BlobReader and ReadPathBlobResolver each own a fetcher with the same {version, read_options, blob_file_cache, allow_write_path_fallback}), deferred to that work.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/15003
Test Plan:
Pure refactoring with no intended behavior change; Version::GetBlob's Slice overload just decodes and calls the BlobIndex overload, so routing whole-value blob reads through the fetcher is equivalent, and the direct-write fallback flag/read options are unchanged. Covered by existing tests:
- db/blob/db_blob_index_test.cc: embedded/entity blob GetEntity/MultiGetEntity zero-copy, plain Get of an embedded default column, merge over an embedded-blob entity, read_tier == kBlockCacheTier Incomplete, corrupt record Corruption.
- db/blob/db_blob_basic_test.cc and db/wide/db_wide_blob_direct_write_test.cc: separate-file and direct-write blob resolution (the fallback branch).
- db/db_iterator_test.cc (blob) and db/compaction/compaction_iterator_test.cc: DBIter blob/merge paths and the compaction (owning) fetcher.
Reviewed By: xingbowang
Differential Revision: D113582247
Pulled By: pdillinger
fbshipit-source-id: 231c9364e266b826d12a8479cbb7f026a0d26bf6
Summary:
This is a follow-up to D112212266 /
https://github.com/facebook/rocksdb/pull/14943 (multi-buffer PinnableWideColumns), which added the zero-copy read path for separate-blob-file references and explicitly left extending it to SST embedded-blob references as a follow-up.
Point GetEntity/MultiGetEntity of a wide-column entity whose columns are stored as embedded (same-file) blob records previously deserialized the entity, copied every column name/value, fetched each embedded blob (copying it), and re-serialized the whole entity before GetContext ever saw it (BlockBasedTable::MaybeResolveEmbeddedValue's wide-column branch). This extends the existing multi-buffer PinnableWideColumns zero-copy machinery (previously only for separate blob files / direct-write) to embedded blob columns.
Changes:
- New SameFileBlobReader interface (db/blob/same_file_blob_reader.h), a narrow seam for resolving a same-file BlobIndex against the current SST. BlockBasedTable implements it (GetSameFileBlob), delegating to the existing blob-cache-backed / pinned embedded reads.
- BlobFetcher is now an abstract interface; the Version-backed implementation moved to VersionBlobFetcher. Added an EmbeddedAwareBlobFetcher decorator that routes same-file references to a SameFileBlobReader and delegates all others to a base fetcher (EffectiveFetcher() selects the decorator only when a same-file reader is present).
- The point-Get and MultiGet loops now hand the raw entity to GetContext with the table as SameFileBlobReader, instead of pre-resolving/re-serializing. This is gated on not building a row-cache replay log, so a row-cache entry still captures a fully resolved entity (a later row-cache hit never reopens the SST to resolve same-file references).
- GetContext composes the decorator and resolves same-file and separate-file blob columns zero-copy across the columns / default-value / merge consumers.
- The iterator (DBIter) path is unchanged (still re-serializes via MaybeResolveEmbeddedValue).
- Also fixes latent method hiding in the test-only MockBlobFetcher.
Intended follow-ups:
- Lazy/deferred embedded resolution: return a LazyWideColumns result whose blob columns stay unresolved and are resolved on demand (whole or by byte range). The SameFileBlobReader seam and the polymorphic BlobFetcher introduced here are the mechanism for embedded support there.
- ReadOptions usage cleanup/optimization: have DBIter/BlobReader hold a single ReadOptions instead of decomposed scalar fields (removing the decompose-then-recompose in CreateBlobFetcher and closing the field-loss gap), and split VersionBlobFetcher into a ReadOptions-referencing variant for transient/stack fetchers plus an owning variant for lifetime-independent ones (the lazy resolver and compaction), to avoid copying the (growing) ReadOptions on the hot path.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/14990
Test Plan:
Added embedded wide-column tests to db/blob/db_blob_index_test.cc:
- GetEntity/MultiGetEntity of an embedded-blob wide-column entity return the correct columns and resolve them zero-copy (blob columns served from the blob cache: identical data() across reads and in separate backing buffers; pointer-stable across a PinnableWideColumns move).
- Plain Get of an entity whose default column is an embedded blob.
- Merge base and GetMergeOperands over an embedded-blob entity.
- read_tier == kBlockCacheTier yields Incomplete for an unresolved same-file reference.
- A corrupt embedded record surfaces Corruption, not a raw BlobIndex.
# Performance validation with db_bench
Measured with db_bench benchmarks added in https://github.com/facebook/rocksdb/issues/14995 / D113455538, temporarily stacked
on this diff for A/B testing.
## Setup
- **Baseline**: this diff's parent + db_bench benchmark commit.
- **Treatment**: this diff, incl. its test/lint fixups + the same
db_bench benchmark commit.
- Both are release builds (`DEBUG_LEVEL=0 make db_bench`). The diff touches only
the read path, so both binaries produce byte-identical SSTs; the db_bench commit
is additive (`tools/db_bench_tool.cc` only) and identical in both.
- Host: AMD EPYC-Genoa, 166 vCPU, 224 GiB RAM. Single reader thread.
## Method
- Datasets are created **once** and read by **both** binaries via
`--use_existing_db`, so the A/B compares identical on-disk data.
- Each read runs twice in-process (warmup + measured); the blob cache (1 GiB) and
block cache (512 MiB) hold the whole ~400 MiB dataset, so the reported (2nd) run
is fully warm — isolating the column-resolution cost the diff changes rather than
I/O.
- 100k keys, `value_size=1024`, `embedded_blob_min_size=256`,
`compression_type=none`, `format_version=7`, `--duration=10` per measured run.
- Datasets:
- **A** — wide-column entity, `num_short_wide_columns=1` + `num_wide_columns=4`
(small inline default column + 4 embedded-blob columns). Read via
`readrandomentity` (GetEntity) and `multireadentity` (MultiGetEntity, batch 32).
- **B** — wide-column entity, `num_short_wide_columns=0` + `num_wide_columns=4`
(the default column itself is an embedded blob). Read via plain `readrandom`
(Get returns the resolved default column).
- **C** — whole-value embedded blobs (`fillembeddedblob`). Read via plain
`readrandom`. This path is **not** changed by the diff — a regression check.
Example commands:
```
# create (once)
db_bench --benchmarks=fillembeddedentity --db=/tmp/perfA --use_existing_db=0 \
--num=100000 --value_size=1024 --embedded_blob_min_size=256 --format_version=7 \
--num_wide_columns=4 --num_short_wide_columns=1 \
--use_blob_cache=true --blob_cache_size=1073741824 --cache_size=536870912 \
--compression_type=none
# read (each binary; warmup + measured)
db_bench --benchmarks=readrandomentity,readrandomentity --db=/tmp/perfA \
--use_existing_db=1 --threads=1 --duration=10 <same options>
```
## Results (warm, 2 runs each)
| Benchmark (read path) | Baseline µs/op | Treatment µs/op | Latency | Baseline Kops/s | Treatment Kops/s | Throughput |
|---|---|---|---|---|---|---|
| `readrandomentity` — GetEntity, inline default + 4 embedded cols | 7.16 | 5.00 | **-30%** | 140 | 200 | **1.43×** |
| `multireadentity` — MultiGetEntity (batch 32) | 6.46 | 4.54 | **-30%** | 155 | 220 | **1.42×** |
| `readrandom` — Get of embedded default column (dataset B) | 6.55 | 2.12 | **-68%** | 153 | 471 | **3.09×** |
| `readrandom` — whole-value embedded blob (dataset C, unchanged path) | 1.92 | 1.91 | ~0% | 521 | 524 | neutral |
Both runs were within ~1–3% of each other (raw numbers below).
## Interpretation
- **GetEntity / MultiGetEntity of embedded-blob wide-column entities improve ~30%
in latency (~1.4× throughput)** — the expected win from resolving embedded blob
columns zero-copy into the `PinnableWideColumns` backing buffers instead of the
old deserialize + per-column copy + re-serialize round trip.
- **Plain `Get` of an entity whose default column is an embedded blob improves
~3×** — the largest win, because the old path re-serialized the entire entity
even when only the default column is returned, whereas the new path resolves just
that column.
- **The whole-value embedded blob `Get` path is unchanged (~0% delta), confirming
no regression** on the pre-existing zero-copy path.
No unexpected regressions observed; all deltas match the diff's intended scope.
## Raw measured numbers (both runs)
```
readrandomentity BASELINE 7.183 / 7.137 µs/op 139225 / 140118 ops/s
readrandomentity TREATMENT 4.992 / 5.008 µs/op 200333 / 199681 ops/s
multireadentity BASELINE 6.458 / 6.458 µs/op 154837 / 154843 ops/s
multireadentity TREATMENT 4.509 / 4.577 µs/op 221798 / 218463 ops/s
readrandom (Bdef) BASELINE 6.497 / 6.609 µs/op 153920 / 151307 ops/s
readrandom (Bdef) TREATMENT 2.126 / 2.120 µs/op 470317 / 471805 ops/s
readrandom (Cblob) BASELINE 1.891 / 1.947 µs/op 528760 / 513554 ops/s
readrandom (Cblob) TREATMENT 1.895 / 1.920 µs/op 527767 / 520807 ops/s
```
Reviewed By: xingbowang
Differential Revision: D113347622
Pulled By: pdillinger
fbshipit-source-id: c51bc187085695d559411d9c0555bb52c8e0a61a
Summary:
Wide-column read paths that materialize blob-referenced columns used to re-serialize the entire entity into a fresh contiguous buffer, copying the (potentially large) resolved column values byte-for-byte. This was forced by PinnableWideColumns holding a single backing buffer with all column Slices pointing into it.
PinnableWideColumns now holds its columns as zero-copy Slices into one or more stable backing buffers, kept in a std::forward_list<PinnableSlice> whose nodes never relocate on move, move-assignment, or splice. Resolved blob columns can be spliced in as additional backing buffers instead of re-serializing the entity.
Using address-stable nodes also cleans up the old Slice-invalidation handling. The previous single-buffer representation had to cope with a self-pinned PinnableSlice whose small (SSO) std::string relocates when the PinnableSlice is moved: on every move it detected the relocated backing pointer and re-derived the column Slices by re-parsing. With forward_list nodes that never move, the column Slices stay valid across move / move-assignment / splice, so that handling is gone and the move operations are now the defaulted member-wise moves.
The multi-buffer plumbing is internal only: a new PinnableWideColumnsHelper (a friend) performs the splice and the little bit of private-member access the read paths need, so there is no new public API surface and the previous `friend class DBImpl` is gone. The public view is unchanged: columns() still returns a single, in-order set.
Read paths converted to resolve without re-serializing:
- GetContext::SaveWideColumnEntityToColumns (eager GetEntity SST reads, separate-blob-file references)
- DBImpl::ResolveDirectWriteWideColumns (direct-write blob references)
- DBImpl::MaybeResolveMemtableBlobValue (blob-backed memtable reads)
Merge output still serializes (the MergeOperator API consumes/produces a serialized entity). Same-file ("embedded") blob columns are resolved -- and still re-serialized -- earlier in the block-based table reader (MaybeResolveEmbeddedValue / ResolveEmbeddedValueForGet) before the entity reaches GetContext, so the GetEntity path above only avoids re-serialization for separate-blob-file references. Compaction's separate entity machinery is unchanged.
API/accounting: deprecated PinnableWideColumns::serialized_size() (comment-only, per repo convention) in favor of the new payload_size() (sum of column name + value sizes; equals the value size for a plain value). Read statistics for entities (BYTES_READ, BYTES_PER_READ, per-key GetEntity/MultiGetEntity byte counts) and the ReadOptions::value_size_soft_limit threshold now measure entities by payload_size() instead of the serialized size. This drops framing bytes (entity measurements are slightly smaller), thus making plain-value and wide-column accounting consistent and reducing unnecessary exposure to implementation details.
Serialization cleanup enabled by the above:
- Consolidated Deserialize/DeserializeV2 into a single Deserialize(const Slice&, WideColumns&, blob_columns*) plus a DeserializeSimple alias for the no-blob-references case; both take const Slice&, require the input to be exactly one serialized entity, and reject any trailing data uniformly (V1 previously ignored trailing bytes). An unexpected blob reference where a fully-resolved entity is required now returns Corruption.
- ResolveEntityBlobColumns (serialized output, used only by merge) is now a thin wrapper over the new multi-buffer resolver plus Serialize, removing the duplicated fetch loop and the SerializeResolvedEntity helper.
- Consistently use `const Slice& input` rather than `Slice& input` for wide column functions expecting an input slice with no trailing data.
Design/polish from human review:
* The initial plan called for more complex handling around a vector<PinnableSlice> backing store (unique_ptr indirection and re-deriving the column Slices on move to cope with reallocation and SSO relocation); switching the backing store to a std::forward_list of address-stable nodes was a human suggestion that removed that complexity and the move-time Slice re-derivation entirely.
* Keep resolve plumbing off the public API via PinnableWideColumnsHelper and removing the DBImpl friend
* Various pieces of cleanup and polish (more left to do)
* The eager-GetEntity optimization
* The memtable inline-copy NOTE/TODO.
Intended follow-up:
* Resolve FIXME about pre-existing swallowed non-OK status in db_impl.cc
* Resolve TODO about value_size_soft_limit in db_impl.cc
* Extend this optimization to SST embedded-blob references
* Error-status/API cleanup: classify an unrecognized wide-column version as Corruption (not NotSupported) at all entry points; replace the NotSupported sentinel from GetValueOfDefaultColumn with an explicit is_blob_reference out-param (removing GetValueOfDefaultColumnResolvingBlobs); and centralize the "blob-backed value without a blob fetcher" Corruption into the resolvers (resolving the ResolveEntityForMerge FIXME) rather than repeating it at each caller
Pull Request resolved: https://github.com/facebook/rocksdb/pull/14943
Test Plan:
Extended db/wide/wide_column_serialization_test.cc with PinnableWideColumns unit tests: set/payload_size for plain, V1, and resolved entities; move and move-assign of a multi-buffer result preserve column data pointers (the node-stability guarantee); Reset; ResolveColumns splices blob buffers in zero-copy (resolved values' data() point into the spliced-in buffers, not a re-serialized entity); serialized_size() == SerializedSizeV1(columns()); and Deserialize rejects trailing data after a serialized entity for both V1 and V2 layouts.
Built and ran (debug): wide_column_serialization_test, db_wide_basic_test, db_wide_blob_direct_write_test, db_blob_basic_test, compaction_iterator_test, db_merge_operator_test, db_iterator_test, udt_util_test, write_batch_with_index_test -- all pass. librocksdb and db_stress build. make format-auto and build_tools/check-sources.sh are clean.
Reviewed By: xingbowang
Differential Revision: D112212266
Pulled By: pdillinger
fbshipit-source-id: 13b89e2bb7d8371f4c1ff18b234a549bea9c9e77
Summary:
Restore the iterator contract for blob-backed wide-column entities by eagerly materializing all blob-backed columns before a `DBIter` entry is exposed as valid. Also capture similar error inside compaction filter V4, so that the error is captured a surfaced up like older compaction filter V3.
## Problem
Lazy wide-column blob resolution let `DBIter` report `Valid() == true` before all columns were actually prepared. Callers could read `value()` successfully, then hit a blob-read failure in `columns()`, which flipped the iterator to invalid after the entry had already been observed as valid.
## Solution
- Restore back to old behavior.
- Resolve and materialize all blob-backed wide columns during iterator positioning.
- Keep `columns()` as a pure accessor once `Valid()` is true.
- Add coverage for eager blob resolution on iterator scans.
- Add coverage for blob resolution failures invalidating the iterator before the entry is exposed.
- Capture the same error in compaction filter and set db to bg error status if the error is not retriable.
## Next step
If we want lazy iterator resolution in the future, we will need an API that can surface lazy resolution failures explicitly instead of hiding I/O and status transitions inside value() or columns().
## Testing
- `make -j14 db_wide_blob_direct_write_test`
- `timeout 60s ./db_wide_blob_direct_write_test --gtest_filter='*DirectWriteIteratorValueScanEagerlyResolvesBlobColumns:*DirectWriteIteratorBlobResolutionErrorInvalidatesEntry'`
## Task
T265294130
# Bonus fix
## Non-compaction blob filtering fixes
### 1. Flush-time wide-entity lazy blob resolution now works correctly
Blob direct-write can leave wide-entity blob references in memtables before flush. Flush already runs through `CompactionIterator`, but outside a real compaction it did not have blob read support. As a result, `FilterV4` lazy resolution on flush could fail immediately with
`NotSupported("Blob fetcher not available")` instead of either:
- resolving the blob successfully, or
- surfacing the real blob read error and failing the flush
This stack fixes that by plumbing blob read support into non-compaction table-file creation. `BuildTable()` now gives `CompactionIterator` enough context to construct a `BlobFetcher` for flush/recovery table building, including write-path fallback for direct-write blob files
that are not yet manifest-visible.
With that in place:
- flush-time `FilterV4` can lazily resolve blob-backed wide columns
- if resolution fails, the failure is latched and flush fails after `FilterV4()` returns
- `bg_error` is set instead of silently preserving the entry
### 2. Plain blob fallback outside compaction now uses the resolved user value
For plain blob-backed values, `FilterBlobByKey()` is allowed to return `kUndetermined`, which is supposed to fall back to the normal value-based filter path. That fallback worked in compaction, but the non-compaction `BuildTable()` path still treated plain blob indexes as
unsupported/corrupt because it could not read the blob.
This stack fixes that behavior for flush/recovery table-file creation:
- when `FilterBlobByKey()` returns `kUndetermined`, RocksDB now eagerly resolves the plain blob value
- `FilterV2`/`FilterV3`/`FilterV4` then see the actual user value as `ValueType::kValue`, not the `BlobIndex` encoding
- legacy filters therefore behave the same way outside compaction as they already do inside compaction
Wide-column entities still use the `FilterV4` lazy resolver path. The plain-blob fix is specifically about restoring the documented fallback behavior for blob-backed `kValue` records outside compaction.
## Why this matters
Without these last two commits, flush-time filtering still had two inconsistent behaviors:
- wide-entity lazy resolution could not actually read blob-backed columns in the direct-write case
- plain blob-backed values could not fall back to normal value-based filtering outside compaction
So even after fixing iterator validity and compaction error propagation, non-compaction table-file creation still had remaining contract holes. These commits make flush/recovery behave consistently with compaction.
## Coverage added
The tests added in these commits cover:
- flush-time plain-blob `FilterV3` fallback using the resolved user value
- flush-time plain-blob `FilterV4` fallback using the resolved user value
- flush-time direct-write wide-entity lazy resolver success
- flush-time direct-write wide-entity lazy resolver failure on missing blob file, including flush failure and `bg_error` latching
Pull Request resolved: https://github.com/facebook/rocksdb/pull/14632
Reviewed By: anand1976
Differential Revision: D101425233
Pulled By: xingbowang
fbshipit-source-id: 695b2df5189033d30309b35849815e31fd965664
Summary:
BlockBuilder was somewhat inconsistent in its treatment of Slices whose size exceeds 4GB, which in a random corruption case could lead to (for example) serializing only the bottom 32 bits of a value size (uncorrupted) but appending the full multi-GB (corrupted) size. Because this is inner loop code, we don't want to pay CPU for extra conversions, data movements, or Status plumbing (already ruled out by Xingbo).
In this change we make BlockBuilder more internally consistent and lift the 32-bit size requirement to callers (of a few functions specifically, for now). To ensure that's satisfied, I've added additional checks near the perimeter of RocksDB to ensure keys and values do not exceed 4GB, plus an extra random corruption or backstop check in BlockBasedTableBuilder. In detail,
BlockBuilder (block_builder.cc/h):
* Add API comments documenting the < 4GB assumption on Add/AddWithLastKey
* Add debug assertions verifying input slice sizes < 4GB
* Simplify AddWithLastKeyImpl to use uint32_t locals, reducing static_cast
* Use only bottom 32 bits when appending derivative slices for consistency
* Update MaybeStripTimestampFromKey to also truncate to 32-bit size
* Add FIXME comments where buffer_/values_buffer_ sizes are truncated
BlockBasedTableBuilder (block_based_table_builder.cc):
* Add value size check (> uint32_t max) as a safety net against random corruption, since we have seen such corruptions in production
WriteBatch (write_batch.cc):
* Tighten existing key size checks to account for kNumInternalBytes (8-byte internal key suffix), using new kMaxWriteBatchKeySize constant
* Add missing size checks to Delete, SingleDelete, and DeleteRange (both Slice and SliceParts variants)
SstFileWriter (sst_file_writer.cc):
* Add key and value size checks in AddImpl and DeleteRangeImpl, which bypass WriteBatch and go directly to the table builder
MergeHelper (merge_helper.cc):
* Add merge result size check (> uint32_t max) in both overloads of TimedFullMergeImpl, returning Corruption if exceeded
* Add PartialMergeMulti result size check in MergeUntil
CompactionIterator (compaction_iterator.cc):
* Add size check on compaction filter output values (kChangeValue and kChangeWideColumnEntity), returning Corruption if > 4GB
meta_blocks.cc:
* Use Slice with uint32_t-truncated sizes in PropertyBlockBuilder::Finish to handle potentially oversized user property collector output
Needed follow-up:
* Check for blocks that are mis-encoded due to overflowing 32 bits for restart point offsets (and similar). See FIXME comments in block_builder.cc for why this is tricky.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/14461
Test Plan:
New extreme-size unit tests, along with some testing infrastructure improvements:
Added test::HasBigMem() (in test_util/testharness.h) which returns true when the system has ≥128GB RAM (via sysconf(_SC_PHYS_PAGES) on Linux/macOS) or when ROCKSDB_BIGMEM_TESTS is set. All extreme-size tests use HasBigMem() to skip gracefully on smaller machines rather than being permanently disabled.
Where possible, tests use MemMapping::AllocateLazyZeroed() to supply large keys/values as Slices backed by anonymous mmap (cleaner with new MemMapping::AsSlice()). On Linux, read-only access to these pages maps to the shared kernel zero page, so the source data consumes no physical RAM — only the destination copy (e.g., WriteBatch::rep_) materializes, cutting peak memory roughly in half vs. std::string.
Tests (all enabled, skip via HasBigMem()):
./write_batch_test --gtest_filter='*LargeKeyValueSizeLimit*'
./external_sst_file_basic_test --gtest_filter='*LargeSizeSstFileWriter*'
./merge_test --gtest_filter='*LargeMergeResultRejected*'
./merge_helper_test --gtest_filter='*LargePartialMergeResultRejected*'
./db_compaction_test --gtest_filter='*CompactionFilterLargeValueRejected*'
All 5 pass (verified on a 128GB+ machine). On smaller machines, all 5 bypass cleanly with "insufficient memory for reliable continuous testing".
Reviewed By: xingbowang
Differential Revision: D96521899
Pulled By: pdillinger
fbshipit-source-id: 70f4b5e6a23ab074d60e653fbb7ddc5edbe162ab
Summary:
Wide-column blob separation: lazy resolution through read, compaction, and write paths
Extend blob direct write to support wide-column entities (PutEntity), and add
lazy blob resolution for wide-column values across all read and compaction paths.
**Write path -- PutEntity blob separation:**
- BlobWriteBatchTransformer::PutEntityCF now extracts large column values
(>= min_blob_size) to blob files and serializes V2 entities with BlobIndex
references, matching the existing Put behavior.
- Add MaybePreprocessWideColumns() static helper to share blob extraction
logic between the WriteBatch transformer and the new PutEntity fast path.
- Add PutEntityFastPath() in DBImpl that preprocesses columns (sort, blob
extract, serialize) before calling WriteImpl, skipping the redundant
WriteBatch transformation pass. Trace batch preserves the original columns.
**Read path -- blob resolution for Get/MultiGet/Iterator:**
- GetContext::SaveValue resolves V2 entity blob columns eagerly: for
value (Get), resolves the default column's blob reference; for columns
(GetEntity), resolves all blob columns and re-serializes as V1.
- DBIter::SetValueAndColumnsFromEntity detects V2 entities, deserializes
with DeserializeV2, and eagerly resolves all blob columns via a new
ReadPathBlobResolver. Resolved values are cached in the resolver and
wide_columns_ Slices point into the cache, avoiding copies.
- Add ReadPathBlobResolver (new file) -- on-demand blob fetcher for the
read path with per-column caching, used by both DBIter and GetContext.
- BlobFetcher gains allow_write_path_fallback to read from in-flight
direct-write blob files not yet visible through Version (pre-flush reads).
- Memtable lookups for Get(key) on V2 entities with a blob default column
now return the blob index with is_blob_index=true, triggering the
existing BDW resolution in MaybeResolveWritePathValue.
- MaybeResolveWritePathValue (renamed from MaybeResolveDirectWriteBlobIndex)
now also resolves V2 entity blob columns for GetEntity/MultiGetEntity,
re-serializing as V1 after resolution.
**Compaction path -- filter, GC, and extraction:**
- CompactionIterator::InvokeFilterIfNeeded handles V2 entities: FilterV3
gets eagerly-resolved column values for backward compatibility; FilterV4
gets a CompactionBlobResolver for lazy on-demand resolution.
- Add CompactionFilter::FilterV4 with WideColumnBlobResolver* parameter
and SupportsFilterV4() opt-in. Default delegates to FilterV3.
- CompactionBlobResolver (new class) implements WideColumnBlobResolver
for the compaction path with stats tracking.
- ExtractLargeColumnValuesIfNeeded extracts inline columns to blob files
during compaction (entities without existing blob columns only).
- GarbageCollectEntityBlobsIfNeeded relocates blob values from old blob
files to new ones during compaction GC, with helpers FetchBlobsNeedingGC,
RelocateBlobValues, and SerializeEntityAfterGC.
- PrepareOutput unified entity deserialization: single DeserializeV2 call
reused by both filter and GC/extraction paths via entity_deserialized_
flag, avoiding redundant parsing.
**Merge path -- V2 entity base value resolution:**
- MergeHelper::MergeUntil, GetContext::MergeWithWideColumnBaseValue, and
DBIter::MergeWithWideColumnBaseValue resolve V2 blob columns before
calling TimedFullMerge, using ResolveEntityForMerge.
**Blob garbage accounting:**
- BlobGarbageMeter tracks blob file in/out flow for V2 entity blob
columns via ForEachBlobFileNumber, used for accurate GC decisions.
- FileMetaData::UpdateBoundaries tracks oldest_blob_file_number for
V2 entities, ensuring blob files referenced by entities are not
prematurely deleted.
**Serialization improvements:**
- WideColumnSerialization::SerializeV2Impl allocates serialized_blob_indices
only for actual blob columns (not all columns) and uses autovector for
name/value sizes.
- Add ForEachBlobFileNumber for lightweight blob file number extraction
without full deserialization.
- Add ResolveEntityForMerge helper for merge-path resolution.
- Add section-size validation in DeserializeV2Impl.
- Add empty blob index and column type validation.
- blob_column_resolver_util.h -- shared helpers (FindBlobColumn, FindInCache,
CacheInlinedBlob) used by both ReadPathBlobResolver and CompactionBlobResolver.
**Testing:**
- db_blob_direct_write_test: end-to-end PutEntity with BDW before/after flush,
verifying Get, GetEntity, MultiGetEntity, and Iterator.
- db_blob_index_test: ~1550 lines covering V2 entity blob resolution through
Get, GetEntity, MultiGet, Iterator, compaction filter (V3 compat and V4 lazy),
merge with blob base, and compaction GC/extraction.
- compaction_iterator_test: ~950 lines testing entity blob GC, extraction,
filter interaction, and combined GC+filter scenarios.
- db_wide_basic_test: ~1200 lines for wide-column lazy blob resolution through
all read paths plus compaction round-trips.
- db_open_with_config_test: ~450 lines for BDW entity config validation.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/14386
Reviewed By: anand1976
Differential Revision: D99739701
Pulled By: xingbowang
fbshipit-source-id: 6badd89b577f3054802eaaa654738468efb9dbdb
Summary:
This bug caused seqno to be incorrectly zeroed when UDT is enabled. This is one of the contributing factor that caused tombstones to be accumulated at bottommost level, causing high space amp.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/14207
Test Plan: Unit test
Reviewed By: pdillinger
Differential Revision: D89826564
Pulled By: xingbowang
fbshipit-source-id: 62ab1e37c36ae1ed95f26213c97a591a17e962a6
Summary:
**Context/Summary:**
A small change as titled.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/13891
Test Plan: - Existing UT and rehearsal stress test
Reviewed By: jaykorean
Differential Revision: D80588011
Pulled By: hx235
fbshipit-source-id: 6987e08a4855782305ad742eef6c0196da0d67ca
Summary:
Pull Request resolved: https://github.com/facebook/rocksdb/pull/13882
The `expect_valid_internal_key` parameter was always passed as true, with false only used in one unit test. This change removes the parameter and always fail compaction when encountering corrupted internal keys, which is the expected production behavior.
Reviewed By: mszeszko-meta
Differential Revision: D80287672
fbshipit-source-id: e30a282ac30d7fded677504cec11173de8d15167
Summary:
Preserve tombstone when allow_ingest_behind` is enabled so that they can be applied to ingested files. This can be useful when users use ingest_behind to buffer updates where Deletion needs to be preserved. This fixes https://github.com/facebook/rocksdb/issues/13571.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/13807
Test Plan: updated a unit test to verify that tombstones are not dropped during compaction.
Reviewed By: hx235
Differential Revision: D79016109
Pulled By: cbi42
fbshipit-source-id: c4d31ef32c88468ababcc1ea5af5db6de42a3b0d
Summary:
The primary goal of this change was to support full dynamic mutability of options `preclude_last_level_data_seconds` and `preserve_internal_time_seconds`, which was challenging because of subtle design holes referenced from https://github.com/facebook/rocksdb/issues/13124.
The fix is, in a sense, "doubling down" on the idea of write-time-based tiering, by simplifying the output level decision with a single sequence number threshold. This approach has some advantages:
* Allows option mutability in presence of long snapshots (or UDT)
* Simpler to believe correct because there's no special treatment for range tombstones, and output level assignment does not affect sequence number assignment to the entries (which takes some care to avoid circular dependency; see CompactionIterator stuff below).
* Avoids extra key comparisons, in `WithinPenultimateLevelOutputRange()`, in relevant compactions (more CPU efficient, though untested).
There are two big pieces/changes to enable this simplification to a single `penultimate_after_seqno_` threshold:
* Allow range tombstones to be sent to either output level, based on sequence number.
* Use sequence numbers instead of range checks to avoid data in the last level from moving to penultimate level outside of the permissable range on that level (due to compaction selecting wider range in the later input level, which is the normal output level). With this change, data can only move "back up the LSM" when entire sorted runs are selected for comapction.
Possible disadvantages:
* Extra CPU to iterate over range tombstones in relevant compactions *twice* instead of once. However, work loads with lots of range tombstones relative to other entries should be rare.
* Data might not migrate back up the LSM tree on option changes as aggressively or consistently. This should a a rare concern, however, especially for universal compaction where selecting full sorted runs is normal compaction.
* This approach is arguably "further away from" a design that allows for other kinds of output level placement decisions, such as range-based input data hotness. However, properly handling range tombstones with such policies will likely require flexible placement into outputs, as this change introduces.
Additional details:
* For good code abstraction, separate CompactionIterator from the concern of where to place compaction outputs. CompactionIterator is supposed to provide a stream of entries, including the "best" sequence number we can assign to those entries. If it's safe and proper to zero out a sequence number, the placement of entries to outputs should deal with that safely rather than having complex inter-dependency between sequence number assignment and placement. To achieve this, we migrate all the compaction output placement logic that was in CompactionIterator to CompactionJob and similar. This unfortunately renders some unit tests (PerKeyPlacementCompIteratorTest) depending on the bad abstraction as obsolete, but tiered_compaction_test has pretty good coverage overall, catching many issues during this development.
Intended follow-up:
* See FIXME items in tiered_compaction_test
* More testing / validation / support for tiering + UDT
* Consider generalizing this work to split results at other levels as appropriate based on stats (auto-tuning essentially). Allowing only the last level to be cold is limiting.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/13256
Test Plan: tests were added in previous changes (https://github.com/facebook/rocksdb/issues/13244#13124), and updated here to reflect correct operation (with some known problems for leveled compaction)
Reviewed By: cbi42
Differential Revision: D67683210
Pulled By: pdillinger
fbshipit-source-id: ca3f2bbc2fcc6891516a2a4220f1b0da09af5ade
Summary:
* Simplify some testing callbacks for tiered_compaction_test ahead of some significant functional updates.
* Refactor CompactionJob::Prepare() for sharing with CompactionServiceCompactionJob. This is a minor functional change in computing preserve/preclude sequence numbers for remote compaction, but it is a start toward support for tiered storage with remote compaction. A test is added that is only partly working but does check that outputs are being split (just not to the correct levels).
Pull Request resolved: https://github.com/facebook/rocksdb/pull/13230
Test Plan: mostly test changes and additions. Arguably makes tiered storage + remote compaction MORE broken as a step toward supporting it.
Reviewed By: jaykorean
Differential Revision: D67493682
Pulled By: pdillinger
fbshipit-source-id: fd6db74e08ef0e4fc7fdd599ff8555aab0c8ddc4
Summary:
The compaction will incorrectly drop a key under the following conditions:
1. Open an empty database.
2. Use the `IngestExternalFile` API to ingest an SST file (the global sequence number will be 0).
3. Create a snapshot (the snapshot sequence number will be 0).
4. Trigger compaction; the key in the above SST file will be dropped.
The drop condition is found here: f20d12adc8/db/compaction/compaction_iterator.cc (L875-L878)
The condition does not explicitly check if a previous key exists.
Fix: Add a check of `last_sequence != kMaxSequenceNumber` to verify if there is a previous key
Pull Request resolved: https://github.com/facebook/rocksdb/pull/13155
Reviewed By: jowlyzhang
Differential Revision: D66473015
Pulled By: cbi42
fbshipit-source-id: 93a3ec5c103f95e9bb97e3944ba6e752a5394421
Summary:
This PR adds user property collector factory `CompactForTieringCollectorFactory` to support observe SST file and mark it as need compaction for fast tracking data to the proper tier.
A triggering ratio `compaction_trigger_ratio_` can be configured to achieve the following:
1) Setting the ratio to be equal to or smaller than 0 disables this collector
2) Setting the ratio to be within (0, 1] will write the number of observed eligible entries into a user property and marks a file as need-compaction when aforementioned condition is met.
3) Setting the ratio to be higher than 1 can be used to just writes the user table property, and not mark any file as need compaction.
For a column family that does not enable tiering feature, even if an effective configuration is provided, this collector is still disabled. For a file that is already on the last level, this collector is also disabled.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/12760
Test Plan: Added unit tests
Reviewed By: pdillinger
Differential Revision: D58734976
Pulled By: jowlyzhang
fbshipit-source-id: 6daab2c4f62b5c6689c3c03e3b3907bbbe6b7a81
Summary:
The state of `saved_seq_for_penul_check_` is not correctly maintained with the current flow. It's supposed to store the original sequence number for a `kTypeValuePreferredSeqno` entry for use in the `DecideOutputLevel` function. However, it's not always properly cleared.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/12626
Test Plan:
Added unit test that would fail before the fix
./tiered_compaction_test --gtest_filter="*InterleavedTimedPutAndPut*"
Reviewed By: pdillinger
Differential Revision: D57123469
Pulled By: jowlyzhang
fbshipit-source-id: 8d73214b3b6dc152daf19b6bd6ee9063581dc277
Summary:
To make sure `TimedPut` are placed on proper tier before and when it becomes eligible for cold tier
1) flush and compaction need to keep relevant seqno to time mapping for not just the sequence number contained in internal keys, but also preferred sequence number for `TimedPut` entries.
This PR also fix some bugs in for handling `TimedPut` during compaction:
1) dealing with an edge case when a `TimedPut` entry's internal key is the right bound for penultimate level, the internal key after swapping in its preferred sequence number will fall outside of the penultimate range because preferred sequence number is smaller than its original sequence number. The entry however is still safe to be placed on penultimate level, so we keep track of `TimedPut` entry's original sequence number for this check. The idea behind this is that as long as it's safe for the original key to be placed on penultimate level, it's safe for the entry with swapped preferred sequence number to be placed on penultimate level too. Because we only swap in preferred sequence number when that entry is visible to the earliest snapshot and there is no other data points with the same user key in lower levels. On the other hand, as long as it's not safe for the original key to be placed on penultimate level, we will not place the entry after swapping the preferred seqno on penultimate level either.
2) the assertion that preferred seqno is always bigger than original sequence number may fail if this logic is only exercised after sequence number is zeroed out. We adjust the assertion to handle that case too. In this case, we don't swap in the preferred seqno but will adjust the its type to `kTypeValue`.
3) there was a special case handling for when range deletion may end up incorrectly covering an entry if preferred seqno is swapped in. But it missed the case that if the original entry is already covered by range deletion. The original handling will mistakenly output the entry instead of omitting it.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/12543
Test Plan:
./tiered_compaction_test --gtest_filter="PrecludeLastLevelTest.PreserveTimedPutOnPenultimateLevel"
./compaction_iterator_test --gtest_filter="*TimedPut*"
Reviewed By: pdillinger
Differential Revision: D56195096
Pulled By: jowlyzhang
fbshipit-source-id: 37ebb09d2513abbd9e90cda0217e26874584b8f3
Summary:
This PR adds support for `TimedPut` API. We introduced a new type `kTypeValuePreferredSeqno` for entries added to the DB via the `TimedPut` API.
The life cycle of such an entry on the write/flush/compaction paths are:
1) It is initially added to memtable as:
`<user_key, seq, kTypeValuePreferredSeqno>: {value, write_unix_time}`
2) When it's flushed to L0 sst files, it's converted to:
`<user_key, seq, kTypeValuePreferredSeqno>: {value, preferred_seqno}`
when we have easy access to the seqno to time mapping.
3) During compaction, if certain conditions are met, we swap in the `preferred_seqno` and the entry will become:
`<user_key, preferred_seqno, kTypeValue>: value`. This step helps fast track these entries to the cold tier if they are eligible after the sequence number swap.
On the read path:
A `kTypeValuePreferredSeqno` entry acts the same as a `kTypeValue` entry, the unix_write_time/preferred seqno part packed in value is completely ignored.
Needed follow ups:
1) The seqno to time mapping accessible in flush needs to be extended to cover the `write_unix_time` for possible `kTypeValuePreferredSeqno` entries. This also means we need to track these `write_unix_time` in memtable.
2) Compaction filter support for the new `kTypeValuePreferredSeqno` type for feature parity with other `kTypeValue` and equivalent types.
3) Stress test coverage for the feature
Pull Request resolved: https://github.com/facebook/rocksdb/pull/12419
Test Plan: Added unit tests
Reviewed By: pdillinger
Differential Revision: D54920296
Pulled By: jowlyzhang
fbshipit-source-id: c8b43f7a7c465e569141770e93c748371ff1da9e
Summary:
The test failure in https://github.com/facebook/rocksdb/issues/11909 shows that we may compact keys outside of internal key range of penultimate level input files from last level to penultimate level, which can potentially cause overlapping files in the penultimate level. This PR updates the `Compaction::WithinPenultimateLevelOutputRange()` to check internal key range instead of user key.
Other fixes:
* skip range del sentinels when deciding output level for tiered compaction
Pull Request resolved: https://github.com/facebook/rocksdb/pull/12063
Test Plan:
- existing unit tests
- apply the fix to https://github.com/facebook/rocksdb/issues/11905 and run `./tiered_compaction_test --gtest_filter="*RangeDelsCauseFileEndpointsToOverlap*"`
Reviewed By: ajkr
Differential Revision: D51288985
Pulled By: cbi42
fbshipit-source-id: 70085db5f5c3b15300bcbc39057d57b83fd9902a
Summary:
Pull Request resolved: https://github.com/facebook/rocksdb/pull/11823
Similarly to https://github.com/facebook/rocksdb/pull/11813, the patch is a small refactoring that eliminates some copy-paste around sorting the columns of entities by column name.
Reviewed By: jaykorean
Differential Revision: D49195504
fbshipit-source-id: d48c9f290e3203f838cc5949856c469ecf730008
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
Summary:
**Context:**
The existing stat rocksdb.sst.read.micros does not reflect each of compaction and flush cases but aggregate them, which is not so helpful for us to understand IO read behavior of each of them.
**Summary**
- Update `StopWatch` and `RandomAccessFileReader` to record `rocksdb.sst.read.micros` and `rocksdb.file.{flush/compaction}.read.micros`
- Fixed the default histogram in `RandomAccessFileReader`
- New field `ReadOptions/IOOptions::io_activity`; Pass `ReadOptions` through paths under db open, flush and compaction to where we can prepare `IOOptions` and pass it to `RandomAccessFileReader`
- Use `thread_status_util` for assertion in `DbStressFSWrapper` for continuous testing on we are passing correct `io_activity` under db open, flush and compaction
Pull Request resolved: https://github.com/facebook/rocksdb/pull/11288
Test Plan:
- **Stress test**
- **Db bench 1: rocksdb.sst.read.micros COUNT ≈ sum of rocksdb.file.read.flush.micros's and rocksdb.file.read.compaction.micros's.** (without blob)
- May not be exactly the same due to `HistogramStat::Add` only guarantees atomic not accuracy across threads.
```
./db_bench -db=/dev/shm/testdb/ -statistics=true -benchmarks="fillseq" -key_size=32 -value_size=512 -num=50000 -write_buffer_size=655 -target_file_size_base=655 -disable_auto_compactions=false -compression_type=none -bloom_bits=3 (-use_plain_table=1 -prefix_size=10)
```
```
// BlockBasedTable
rocksdb.sst.read.micros P50 : 2.009374 P95 : 4.968548 P99 : 8.110362 P100 : 43.000000 COUNT : 40456 SUM : 114805
rocksdb.file.read.flush.micros P50 : 1.871841 P95 : 3.872407 P99 : 5.540541 P100 : 43.000000 COUNT : 2250 SUM : 6116
rocksdb.file.read.compaction.micros P50 : 2.023109 P95 : 5.029149 P99 : 8.196910 P100 : 26.000000 COUNT : 38206 SUM : 108689
// PlainTable
Does not apply
```
- **Db bench 2: performance**
**Read**
SETUP: db with 900 files
```
./db_bench -db=/dev/shm/testdb/ -benchmarks="fillseq" -key_size=32 -value_size=512 -num=50000 -write_buffer_size=655 -disable_auto_compactions=true -target_file_size_base=655 -compression_type=none
```run till convergence
```
./db_bench -seed=1678564177044286 -use_existing_db=true -db=/dev/shm/testdb -benchmarks=readrandom[-X60] -statistics=true -num=1000000 -disable_auto_compactions=true -compression_type=none -bloom_bits=3
```
Pre-change
`readrandom [AVG 60 runs] : 21568 (± 248) ops/sec`
Post-change (no regression, -0.3%)
`readrandom [AVG 60 runs] : 21486 (± 236) ops/sec`
**Compaction/Flush**run till convergence
```
./db_bench -db=/dev/shm/testdb2/ -seed=1678564177044286 -benchmarks="fillseq[-X60]" -key_size=32 -value_size=512 -num=50000 -write_buffer_size=655 -disable_auto_compactions=false -target_file_size_base=655 -compression_type=none
rocksdb.sst.read.micros COUNT : 33820
rocksdb.sst.read.flush.micros COUNT : 1800
rocksdb.sst.read.compaction.micros COUNT : 32020
```
Pre-change
`fillseq [AVG 46 runs] : 1391 (± 214) ops/sec; 0.7 (± 0.1) MB/sec`
Post-change (no regression, ~-0.4%)
`fillseq [AVG 46 runs] : 1385 (± 216) ops/sec; 0.7 (± 0.1) MB/sec`
Reviewed By: ajkr
Differential Revision: D44007011
Pulled By: hx235
fbshipit-source-id: a54c89e4846dfc9a135389edf3f3eedfea257132
Summary:
When a user migrates to level compaction + `level_compaction_dynamic_level_bytes=true`, or when a DB shrinks, there can be unnecessary levels in the DB. Before this PR, this is no way to remove these levels except a manual compaction. These extra unnecessary levels make it harder to guarantee max_bytes_for_level_multiplier and can cause extra space amp. This PR boosts compaction score for these levels to allow RocksDB to automatically drain these levels. Together with https://github.com/facebook/rocksdb/issues/11321, this makes migration to `level_compaction_dynamic_level_bytes=true` automatic without needing user to do a one time full manual compaction. Credit: this PR is modified from https://github.com/facebook/rocksdb/issues/3921.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/11340
Test Plan:
- New unit tests
- `python3 tools/db_crashtest.py whitebox --simple` which randomly sets level_compaction_dynamic_level_bytes in each run.
Reviewed By: ajkr
Differential Revision: D44563884
Pulled By: cbi42
fbshipit-source-id: e20d3620bd73dff22be18c5a91a07f340740bcc8
Summary:
A second attempt after https://github.com/facebook/rocksdb/issues/10802, with bug fixes and refactoring. This PR updates compaction logic to take range tombstones into account when determining whether to cut the current compaction output file (https://github.com/facebook/rocksdb/issues/4811). Before this change, only point keys were considered, and range tombstones could cause large compactions. For example, if the current compaction outputs is a range tombstone [a, b) and 2 point keys y, z, they would be added to the same file, and may overlap with too many files in the next level and cause a large compaction in the future. This PR also includes ajkr's effort to simplify the logic to add range tombstones to compaction output files in `AddRangeDels()` ([https://github.com/facebook/rocksdb/issues/11078](https://github.com/facebook/rocksdb/pull/11078#issuecomment-1386078861)).
The main change is for `CompactionIterator` to emit range tombstone start keys to be processed by `CompactionOutputs`. A new class `CompactionMergingIterator` is introduced to replace `MergingIterator` under `CompactionIterator` to enable emitting of range tombstone start keys. Further improvement after this PR include cutting compaction output at some grandparent boundary key (instead of the next output key) when cutting within a range tombstone to reduce overlap with grandparents.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/11113
Test Plan:
* added unit test in db_range_del_test
* crash test with a 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 --use_multiget=1 --delpercent=3 --delrangepercent=2 --verify_iterator_with_expected_state_one_in=2 --num_iterations=10`
Reviewed By: ajkr
Differential Revision: D42655709
Pulled By: cbi42
fbshipit-source-id: 8367e36ef5640e8f21c14a3855d4a8d6e360a34c
Summary:
The patch adds compaction filter support for wide-column entities by introducing
a new `CompactionFilter` API called `FilterV3`. This API is called for regular
key-values, merge operands, and wide-column entities as well. It is passed the
existing value/operand or wide-column structure and it can update the value or
columns or keep/delete/etc. the key-value as usual. For compatibility, the default
implementation of `FilterV3` keeps all wide-column entities and falls back to calling
`FilterV2` for plain old key-values and merge operands.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/11196
Test Plan: `make check`
Reviewed By: akankshamahajan15
Differential Revision: D43094147
Pulled By: ltamasi
fbshipit-source-id: 75acabe9a35254f7f404ba6173ee9c2774382ebd
Summary:
The patch makes some code quality enhancements in `CompactionIterator::InvokeFilterIfNeeded`
including the renaming of `filter` (which is most likely a remnant of the days before the `FilterV2`
API when the compaction filter used to return a boolean) to `decision`, the removal of some
outdated comments, the elimination of an `error` flag which was only used in one failure case
out of many, as well as some small stylistic improvements. (Some the above will also come in
handy when adding compaction filter support for wide-column entities.)
Pull Request resolved: https://github.com/facebook/rocksdb/pull/11174
Test Plan: `make check`
Reviewed By: akankshamahajan15
Differential Revision: D42901408
Pulled By: ltamasi
fbshipit-source-id: ab382d59a4990c5dfe1cee219d49e1d80902b666
Summary:
Prior to this PR, `FullMergeV2()` can only return `false` to indicate failure, which causes any operation invoking it to fail. During a compaction, such a failure causes the compaction to fail and causes the DB to irreversibly enter read-only mode. Some users asked for a way to allow the merge operator to fail without such widespread damage.
To limit the blast radius of merge operator failures, this PR introduces the `MergeOperationOutput::op_failure_scope` API. When unpopulated (`kDefault`) or set to `kTryMerge`, the merge operator failure handling is the same as before. When set to `kMustMerge`, merge operator failure still causes failure to operations that must merge (`Get()`, iterator, `MultiGet()`, etc.). However, under `kMustMerge`, flushes/compactions can survive merge operator failures by outputting the unmerged input operands.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/11092
Reviewed By: siying
Differential Revision: D42525673
Pulled By: ajkr
fbshipit-source-id: 951dc3bf190f86347dccf3381be967565cda52ee
Summary:
This reverts commit f02c708aa3 since it introduced several bugs (see https://github.com/facebook/rocksdb/issues/11078 and https://github.com/facebook/rocksdb/issues/11067 for attempts to fix them) and that I do not have a high confidence to fix all of them and ensure no further ones before the next release branch cut. There are also come existing issue found during bug fixing. We will work on it and try to merge it to the release after.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/11089
Test Plan: existing CI.
Reviewed By: ajkr
Differential Revision: D42505972
Pulled By: cbi42
fbshipit-source-id: 2f66dcde6b85dc94977b317c2ce513872cfbc153
Summary:
This PR is the first step for Issue https://github.com/facebook/rocksdb/issues/4811. Currently compaction output files are cut at point keys, and the decision is made mainly in `CompactionOutputs::ShouldStopBefore()`. This makes it possible for range tombstones to cause large compactions that does not respect `max_compaction_bytes`. For example, we can have a large range tombstone that overlaps with too many files from the next level. Another example is when there is a gap between a range tombstone and another key. The first issue may be more acceptable, as a lot of data is deleted. This PR address the second issue by calling `ShouldStopBefore()` for range tombstone start keys. The main change is for `CompactionIterator` to emit range tombstone start keys to be processed by `CompactionOutputs`. A new `CompactionMergingIterator` is introduced and only used under `CompactionIterator` for this purpose. Further improvement after this PR include 1) cut compaction output at some grandparent boundary key instead of at the next point key or range tombstone start key and 2) cut compaction output file within a large range tombstone (it may be easier and reasonable to only do it for range tombstones at the end of a compaction output).
Pull Request resolved: https://github.com/facebook/rocksdb/pull/10802
Test Plan:
- added unit tests in db_range_del_test.
- stress test: `python3 tools/db_crashtest.py whitebox --[simple|enable_ts] --verify_iterator_with_expected_state_one_in=5 --delrangepercent=5 --prefixpercent=2 --writepercent=58 --readpercen=21 --duration=36000 --range_deletion_width=1000000`
Reviewed By: ajkr, jay-zhuang
Differential Revision: D40308827
Pulled By: cbi42
fbshipit-source-id: a8fd6f70a3f09d0ef7a40e006f6c964bba8c00df
Summary:
We were not resetting it in non-debug mode so it could be true once and then stay true for future keys where it should be false. This PR adds the reset logic.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/10967
Test Plan:
- built `db_bench` with DEBUG_LEVEL=0
- ran benchmark: `TEST_TMPDIR=/dev/shm/prefix ./db_bench -benchmarks=fillrandom -compaction_style=1 -preserve_internal_time_seconds=100 -preclude_last_level_data_seconds=10 -write_buffer_size=1048576 -target_file_size_base=1048576 -subcompactions=8 -duration=120`
- compared "output_to_penultimate_level: X bytes + last: Y bytes" lines in LOG output
- Before this fix, Y was always zero
- After this fix, Y gradually increased throughout the benchmark
Reviewed By: riversand963
Differential Revision: D41417726
Pulled By: ajkr
fbshipit-source-id: ace1e9a289e751a5b0c2fbaa8addd4eda5525329
Summary:
This PR implements the originally disabled `Merge()` APIs when user-defined timestamp is enabled.
Simplest usage:
```cpp
// assume string append merge op is used with '.' as delimiter.
// ts1 < ts2
db->Put(WriteOptions(), "key", ts1, "v0");
db->Merge(WriteOptions(), "key", ts2, "1");
ReadOptions ro;
ro.timestamp = &ts2;
db->Get(ro, "key", &value);
ASSERT_EQ("v0.1", value);
```
Some code comments are added for clarity.
Note: support for timestamp in `DB::GetMergeOperands()` will be done in a follow-up PR.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/10819
Test Plan: make check
Reviewed By: ltamasi
Differential Revision: D40603195
Pulled By: riversand963
fbshipit-source-id: f96d6f183258f3392d80377025529f7660503013
Summary:
When the `preclude_last_level_data_seconds` or
`preserve_internal_time_seconds` is smaller than 100 (seconds), no seqno->time information was recorded.
Also make sure all data will be compacted to the last level even if there's no write to record the time information.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/10829
Test Plan: added unittest
Reviewed By: siying
Differential Revision: D40443934
Pulled By: jay-zhuang
fbshipit-source-id: 2ecf1361daf9f3e5c3385aee6dc924fa59e2813a
Summary:
Add option `preserve_internal_time_seconds` to preserve the internal
time information.
It's mostly for the migration of the existing data to tiered storage (
`preclude_last_level_data_seconds`). When the tiering feature is just
enabled, the existing data won't have the time information to decide if
it's hot or cold. Enabling this feature will start collect and preserve
the time information for the new data.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/10747
Reviewed By: siying
Differential Revision: D39910141
Pulled By: siying
fbshipit-source-id: 25c21638e37b1a7c44006f636b7d714fe7242138
Summary:
Add user-defined timestamp support for range deletion. The new API is `DeleteRange(opt, cf, begin_key, end_key, ts)`. Most of the change is to update the comparator to compare without timestamp. Other than that, major changes are
- internal range tombstone data structures (`FragmentedRangeTombstoneList`, `RangeTombstone`, etc.) to store timestamps.
- Garbage collection of range tombstones and range tombstone covered keys during compaction.
- Get()/MultiGet() to return the timestamp of a range tombstone when needed.
- Get/Iterator with range tombstones bounded by readoptions.timestamp.
- timestamp crash test now issues DeleteRange by default.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/10661
Test Plan:
- Added unit test: `make check`
- Stress test: `python3 tools/db_crashtest.py --enable_ts whitebox --readpercent=57 --prefixpercent=4 --writepercent=25 -delpercent=5 --iterpercent=5 --delrangepercent=4`
- Ran `db_bench` to measure regression when timestamp is not enabled. The tests are for write (with some range deletion) and iterate with DB fitting in memory: `./db_bench--benchmarks=fillrandom,seekrandom --writes_per_range_tombstone=200 --max_write_buffer_number=100 --min_write_buffer_number_to_merge=100 --writes=500000 --reads=500000 --seek_nexts=10 --disable_auto_compactions -disable_wal=true --max_num_range_tombstones=1000`. Did not see consistent regression in no timestamp case.
| micros/op | fillrandom | seekrandom |
| --- | --- | --- |
|main| 2.58 |10.96|
|PR 10661| 2.68 |10.63|
Reviewed By: riversand963
Differential Revision: D39441192
Pulled By: cbi42
fbshipit-source-id: f05aca3c41605caf110daf0ff405919f300ddec2
Summary:
New blobdb has a bug in compaction filter, where `blob_value_` is not reset for next iterated key. This will cause blob_value_ not empty and previous value read from blob is passed into the filter function for next key, even if its value is not in blob. Fixed by reseting regardless of key type.
Test Case:
Add `FilterByValueLength` test case in `DBBlobCompactionTest`
Pull Request resolved: https://github.com/facebook/rocksdb/pull/10391
Reviewed By: riversand963
Differential Revision: D38629900
Pulled By: ltamasi
fbshipit-source-id: 47d23ff2e5ec697958a210db9e6ceeb8b2fc49fa
Summary:
The main purpose is to make debugging easier without sacrificing performance.
Instead of using a boolean variable for `CompactionIterator::valid_`, we can extend it to an `uint8_t`,
using the LSB to denote if the compaction iterator is valid and 4 additional bits to denote where
the iterator is set valid inside `NextFromInput()`. Therefore, when the control flow reaches
`PrepareOutput()` and hits assertion there, we can have a better idea of what has gone wrong.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/10505
Test Plan:
make check
```
TEST_TMPDIR=/dev/shm/rocksdb time ./db_bench -compression_type=none -write_buffer_size=1073741824 -benchmarks=fillseq,flush
```
The above command has a 'flush' benchmark which uses `CompactionIterator`. I haven't observed any CPU regression or drop in throughput or latency increase.
Reviewed By: ltamasi
Differential Revision: D38551615
Pulled By: riversand963
fbshipit-source-id: 1250848fc118bb753d71fa9ff8ba840df999f5e0
Summary:
Change tiered compaction feature from `bottommost_temperture` to
`last_level_temperture`. The old option is kept for migration purpose only,
which is behaving the same as `last_level_temperture` and it will be removed in
the next release.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/10471
Test Plan: CI
Reviewed By: siying
Differential Revision: D38450621
Pulled By: jay-zhuang
fbshipit-source-id: cc1cdf8bad409376fec0152abc0a64fb72a91527
Summary:
During compaction, blobs are currently read using the default
`ReadOptions`, which has the `fill_cache` flag set to true. Earlier,
this didn't make any difference since we didn't have a blob cache;
however, now we have to explicitly set this flag to false to avoid
polluting the cache during compaction.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/10457
Test Plan: `make check`
Reviewed By: riversand963
Differential Revision: D38333528
Pulled By: ltamasi
fbshipit-source-id: 5b4d49a1e39543bee73c7df2aa9194fb101875e2
Summary:
Using the Sequence number to time mapping to decide if a key is hot or not in
compaction and place it in the corresponding level.
Note: the feature is not complete, level compaction will run indefinitely until
all penultimate level data is cold and small enough to not trigger compaction.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/10370
Test Plan:
CI
* Run basic db_bench for universal compaction manually
Reviewed By: siying
Differential Revision: D37892338
Pulled By: jay-zhuang
fbshipit-source-id: 792bbd91b1ccc2f62b5d14c53118434bcaac4bbe
Summary:
Which will be used for tiered storage to preclude hot data from
compacting to the cold tier (the last level).
Internally, adding seqno to time mapping. A periodic_task is scheduled
to record the current_seqno -> current_time in certain cadence. When
memtable flush, the mapping informaiton is stored in sstable property.
During compaction, the mapping information are merged and get the
approximate time of sequence number, which is used to determine if a key
is recently inserted or not and preclude it from the last level if it's
recently inserted (within the `preclude_last_level_data_seconds`).
Pull Request resolved: https://github.com/facebook/rocksdb/pull/10338
Test Plan: CI
Reviewed By: siying
Differential Revision: D37810187
Pulled By: jay-zhuang
fbshipit-source-id: 6953be7a18a99de8b1cb3b162d712f79c2b4899f
Summary:
Support per_key_placement for last level compaction, which will
be used for tiered compaction.
* compaction iterator reports which level a key should output to;
* compaction get the output level information and check if it's safe to
output the data to penultimate level;
* all compaction output files will be installed.
* extra internal compaction stats added for penultimate level.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/9964
Test Plan:
* Unittest
* db_bench, no significate difference: https://gist.github.com/jay-zhuang/3645f8fb97ec0ab47c10704bb39fd6e4
* microbench manual compaction no significate difference: https://gist.github.com/jay-zhuang/ba679b3e89e24992615ee9eef310e6dd
* run the db_stress multiple times (not covering the new feature) looks good (internal: https://fburl.com/sandcastle/9w84pp2m)
Reviewed By: ajkr
Differential Revision: D36249494
Pulled By: jay-zhuang
fbshipit-source-id: a96da57c8031c1df83e4a7a8567b657a112b80a3
Summary:
The patch builds on https://github.com/facebook/rocksdb/pull/9915 and adds
a new API called `PutEntity` that can be used to write a wide-column entity
to the database. The new API is added to both `DB` and `WriteBatch`. Note
that currently there is no way to retrieve these entities; more precisely, all
read APIs (`Get`, `MultiGet`, and iterator) return `NotSupported` when they
encounter a wide-column entity that is required to answer a query. Read-side
support (as well as other missing functionality like `Merge`, compaction filter,
and timestamp support) will be added in later PRs.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/10242
Test Plan: `make check`
Reviewed By: riversand963
Differential Revision: D37369748
Pulled By: ltamasi
fbshipit-source-id: 7f5e412359ed7a400fd80b897dae5599dbcd685d
Summary:
In CompactionIterator code, there are multiple places where the process
will abort in dbg mode before logging the error message describing the
cause. This PR changes only the logging behavior for compaction iterator so
that error message is written to LOG before the process aborts in debug
mode.
Also updated the triggering condition for an assertion for single delete with
user-defined timestamp.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/10183
Test Plan: make check
Reviewed By: akankshamahajan15
Differential Revision: D37190218
Pulled By: riversand963
fbshipit-source-id: 741bb007067be7cfbe94ac9e530ad4b2b339c009
Summary:
As pointed out by [https://github.com/facebook/rocksdb/pull/8351#discussion_r645765422](https://github.com/facebook/rocksdb/pull/8351#discussion_r645765422), check `manual_compaction_paused` and `manual_compaction_canceled` can be reduced by setting `*canceled` to be true in `DisableManualCompaction()` and `*canceled` to be false in the last time calling `EnableManualCompaction()`.
Changed Tests: The origin `DBTest2.PausingManualCompaction1` uses a callback function to increase `manual_compaction_paused` and the origin CompactionJob/CompactionIterator with `manual_compaction_paused` can detect this. I changed the callback function so that it sets `*canceled` as true if `canceled` is not `nullptr` (to notify CompactionJob/CompactionIterator the compaction has been canceled).
Pull Request resolved: https://github.com/facebook/rocksdb/pull/10070
Test Plan: This change does not introduce new features, but some slight difference in compaction implementation. Run the same manual compaction unit tests as before (e.g., PausingManualCompaction[1-4], CancelManualCompaction[1-2], CancelManualCompactionWithListener in db_test2, and db_compaction_test).
Reviewed By: ajkr
Differential Revision: D36949133
Pulled By: littlepig2013
fbshipit-source-id: c5dc4c956fbf8f624003a0f5ad2690240063a821
Summary:
PR https://github.com/facebook/rocksdb/issues/9888 started to enforce the contract of single delete described in https://github.com/facebook/rocksdb/wiki/Single-Delete.
For some of existing use cases, it is desirable to have a transition during which compaction will not fail
if the contract is violated. Therefore, we add a temporary option `enforce_single_del_contracts` to allow
application to opt out from this new strict behavior. Once transition completes, the flag can be set to `true` again.
In a future release, the option will be removed.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/9983
Test Plan: make check
Reviewed By: ajkr
Differential Revision: D36333672
Pulled By: riversand963
fbshipit-source-id: dcb703ea0ed08076a1422f1bfb9914afe3c2caa2
Summary:
PR 9929 adds a new CompactionFilter::Decision, i.e.
kRemoveWithSingleDelete so that CompactionFilter can indicate to
CompactionIterator that a PUT can only be removed with SD. However, how
CompactionIterator handles such a key is implementation detail which
should not be implied in the public API. In fact,
such a PUT can just be dropped. This is an optimization which we will apply in the near future.
Discussion thread: https://github.com/facebook/rocksdb/pull/9929#discussion_r863198964
Pull Request resolved: https://github.com/facebook/rocksdb/pull/9951
Test Plan: make check
Reviewed By: ajkr
Differential Revision: D36156590
Pulled By: riversand963
fbshipit-source-id: 7b7d01f47bba4cad7d9cca6ca52984f27f88b372
Summary:
When compaction filter determines that a key should be removed, it updates the internal key's type
to `Delete`. If this internal key is preserved in current compaction but seen by a later compaction
together with `SingleDelete`, it will cause compaction iterator to return Corruption.
To fix the issue, compaction filter should return more information in addition to the intention of removing
a key. Therefore, we add a new `kRemoveWithSingleDelete` to `CompactionFilter::Decision`. Seeing
`kRemoveWithSingleDelete`, compaction iterator will update the op type of the internal key to `kTypeSingleDelete`.
In addition, I updated db_stress_shared_state.[cc|h] so that `no_overwrite_ids_` becomes `const`. It is easier to
reason about thread-safety if accessed from multiple threads. This information is passed to `PrepareTxnDBOptions()`
when calling from `Open()` so that we can set up the rollback deletion type callback for transactions.
Finally, disable compaction filter for multiops_txn because the key removal logic of `DbStressCompactionFilter` does
not quite work with `MultiOpsTxnsStressTest`.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/9929
Test Plan:
make check
make crash_test
make crash_test_with_txn
Reviewed By: anand1976
Differential Revision: D36069678
Pulled By: riversand963
fbshipit-source-id: cedd2f1ba958af59ad3916f1ba6f424307955f92
Summary:
Enforce the contract of SingleDelete so that they are not mixed with
Delete for the same key. Otherwise, it will lead to undefined behavior.
See https://github.com/facebook/rocksdb/wiki/Single-Delete#notes.
Also fix unit tests and write-unprepared.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/9888
Test Plan: make check
Reviewed By: ajkr
Differential Revision: D35837817
Pulled By: riversand963
fbshipit-source-id: acd06e4dcba8cb18df92b44ed18c57e10e5a7635
