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226 Commits
| Author | SHA1 | Message | Date | |
|---|---|---|---|---|
Peter Dillinger
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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 |
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Josh Kang
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dbc2db5228 |
Make external table APIs more consistent with native tables (#15241)
Summary: Pull Request resolved: https://github.com/facebook/rocksdb/pull/15241 Native `TableFactory` implementations receive the RocksDB `WritableFileWriter` in `NewTableBuilder()` and `RandomAccessFileReader` in `NewTableReader()`. These wrappers provide buffering, checksums, rate limiting, statistics, listeners, tracing, and direct-I/O handling. External table implementations previously received a limited writable-file adapter and reopened readers from a path, bypassing parts of this wrapper logic. This change makes `WritableFileWriter` and `RandomAccessFileReader` implement `FSWritableFile` and `FSRandomAccessFile`, respectively, so the same RocksDB wrappers can be passed to external tables. `ExternalTableFactory::NewTableReader()` now receives the already-opened reader and file size. The filesystem interfaces expose standard append, flush, sync, fsync, file metadata, synchronous reads, asynchronous reads, and batched reads. `RandomAccessFileReader::SubmitReadAsync()` schedules its wrapped coroutine read on the configured filesystem read executor, and the DB table-cache and `SstFileReader` construction paths pass that filesystem through. `SstFileReader` also supplies its configured statistics, listeners, rate limiter, and file temperature, removing the need for a separate external-table metrics filesystem wrapper. For direct I/O, `MultiRead()` checks whether requests are already sorted. When alignment and merging are needed, it constructs a sorted index only for unsorted input, preserving caller request order and result mapping. Fully aligned requests using aligned caller buffers bypass this path and may be supplied in any order. Reviewed By: xingbowang Differential Revision: D121035539 fbshipit-source-id: 27cb897726c31cb1a4dc811c65c8d79e690d82b1 |
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Anand Ananthabhotla
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0df7ed563b |
Pass SST block CRC32C checksums to file writer (#15155)
Summary: Pull Request resolved: https://github.com/facebook/rocksdb/pull/15155 SST block writing now hands checksum coverage across the table-builder to file-writer boundary when the block checksum algorithm is CRC32C. The block builder passes the raw CRC32C of the block contents to `WritableFileWriter::Append()`, which validates the copied destination-buffer contents and accumulates that checksum into the filesystem handoff checksum instead of recomputing it after the copy. The trailer is still appended separately; table building computes and passes the trailer handoff checksum independently, while preserving the existing persisted block-checksum encoding. Non-CRC32C block checksum algorithms continue to use the existing file-writer checksum path. Destination-buffer validation failures return a stage-specific corruption `Status` that includes the file path. Flush and compaction propagate that status through their existing background error handling, so the same message is logged without adding local duplicate log sites. The SST tests record the builder append stream through sync-point callbacks while writing to a null sink, then replay those exact append calls into a file-backed writer to cover successful handoff, block-content corruption, compression-type corruption, trailer-checksum corruption, non-CRC32C fallback behavior, and a small randomized boundary-injection loop. Reviewed By: xingbowang Differential Revision: D116969191 fbshipit-source-id: f75dcb37936106b7f6f14cf1ed999c81a0879d7b |
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Xingbo Wang
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2d68f30425 |
Support remote file system for blob direct write file (#14585)
Summary: Pull Request resolved: https://github.com/facebook/rocksdb/pull/14585 Adds typed file-open contracts and open-file size handling needed for blob direct-write files on remote or SHM-backed file systems. This diff: - Adds typed `FileOpenContract` semantics to RocksDB `FileOptions`, including `kNoReopenForWrite`, `kNoReadersWhileOpenForWrite`, bitwise helpers, and constructor propagation from `EnvOptions` to `FileOptions`. - Marks SST/table output creation paths with both `kNoReopenForWrite` and `kNoReadersWhileOpenForWrite`, including builder output, compaction output, and external `SstFileWriter` output. - Marks blob write paths with the appropriate contracts: regular blob file builders use both `kNoReopenForWrite` and `kNoReadersWhileOpenForWrite`, while blob direct-write partition output uses `kNoReopenForWrite` so active readers can still observe SHM-backed data through the read path. - Adds `GetFileSizeFromOpenFileOrPath` so readers can prefer an already-open `FSRandomAccessFile::GetFileSize` result and fall back to path-level `FileSystem::GetFileSize` according to the caller's fallback policy. - Updates blob file reader and table footer reader size checks to use the new open-file-or-path size helper, preserving malformed-file validation while supporting file systems where path-level size is not the only valid source. - Extends `FaultInjectionTestFS` to track file-open contracts, reject readers while a no-readers writer is open, reject reopened data writes for `kNoReopenForWrite`, allow `SyncFile` to use a reopened handle, and preserve contract state across create, reopen, reuse, rename, link, reset, and delete paths. - Keeps `IOStatus` return paths simple by returning status locals directly in the file-size helper and fault-injection contract validation paths. - Adds clang-format-compliant tests covering file-open contract enforcement, `SyncFile` being allowed while reopened data writes are rejected, blob direct-write behavior, blob reader behavior, and the new file-size fallback helper behavior. - Leaves WAL and MANIFEST contract assignment for follow-up work because live WAL/MANIFEST readers and `reuse_manifest_on_open` need separate handling before RocksDB can safely claim stronger file-open contracts for those file classes. Reviewed By: anand1976, pdillinger Differential Revision: D100002686 fbshipit-source-id: 26b4021bc13333ede1077f0ff8cbd71335c5f294 |
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Xingbo Wang
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6ff96384dd |
db_iter: eagerly resolve blob-backed iterator columns (#14632)
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
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xingbowang
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7b06a9ae7e |
Track blob garbage during flush of direct-write blob references (#14623)
Summary: - meter blob garbage during `BuildTable()` when flush input can contain direct-write blob references, so overwrite elision and flush-time compaction filters register garbage in the manifest - plumb `BlobFileGarbage` through flush and recovery manifest edits even when the flush produces no SST output - add wide-column direct-write tests covering TTL-filtered flushes with both mixed live/expired records and all-expired input Pull Request resolved: https://github.com/facebook/rocksdb/pull/14623 Reviewed By: anand1976 Differential Revision: D101212841 Pulled By: xingbowang fbshipit-source-id: e5803ddaf17b5dfd92312e42191b76e311257f3b |
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Anand Ananthabhotla
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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 |
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Xingbo Wang
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2dc6d6f765 |
Propagate builder error when flush produces empty output (#14418)
Summary:
Propagate builder error when flush produces empty output
When write fault injection causes the table builder to enter an error
state during flush, all subsequent Add() calls return early (ok() is
false), leaving the builder empty (IsEmpty() == true). Previously,
BuildTable() would call builder->Abandon() but not propagate the
builder's error status to 's', leaving it OK. This caused the downstream
key count validation in flush_job.cc to fire a misleading Corruption
error ('Number of keys in flush output SST files does not match...'),
which the stress test harness couldn't identify as a retryable injected
fault error, leading to SafeTerminate().
This started failing recently because ('Separate keys and
values in data blocks', ) introduced a new SST
block format (separate_key_value_in_data_block) that stores keys and
values in separate sections within data blocks. This format requires
additional write operations during Flush() inside the table builder,
increasing the probability that write fault injection
(--write_fault_one_in=128) hits a data block write and puts the builder
into an error state before any entries are committed. The bug in
BuildTable() existed before, but was rarely triggered because the old
interleaved block format had fewer write points susceptible to fault
injection during the critical Add() path.
Fix: After builder->Abandon(), propagate the builder's error status to
's' when the builder is empty due to an internal error. This ensures the
actual IOError from write fault injection is reported, which the stress
test can properly handle via IsErrorInjectedAndRetryable().
The analysis was based on stack trace. However, it would be great
if we could get direct evidence from fault injection.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/14418
Test Plan: Unit test
Reviewed By: hx235
Differential Revision: D95121070
Pulled By: xingbowang
fbshipit-source-id: cfb513bd744ac34ac90cda11c1cbe49a9d0a7c6c
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Xingbo Wang
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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 |
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Peter Dillinger
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3c85aa8a69 |
Some follow-up to parallel compression revamp (#13959)
Summary: * Fix compaction/flush CPU usage stats to include CPU usage by parallel compression workers. (Validated with manual db_bench testing.) * Disable the parallel compression framework when compression is disabled. See new code comment for details, because in theory it could be useful to hide SST write latency, but manual testing with db_bench and -rate_limiter_bytes_per_sec or -simulate_hdd options shows no useful increase in throughput, just more CPU usage. * Fix some minor clean-up items in the implementation Pull Request resolved: https://github.com/facebook/rocksdb/pull/13959 Test Plan: Also ran some tests like in https://github.com/facebook/rocksdb/issues/13910 to ensure the new CPU usage tracking did not regress performance, all good. Reviewed By: xingbowang Differential Revision: D82556686 Pulled By: pdillinger fbshipit-source-id: 77c522159a7e6ab0ab6f7fb1d662070a46661557 |
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Changyu Bi
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972fd9adf1 |
Remove expect_valid_internal_key parameter from CompactionIterator (#13882)
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 |
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Peter Dillinger
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9d490593d0 |
Preliminary support for custom compression algorithms (#13659)
Summary: This change builds on https://github.com/facebook/rocksdb/issues/13540 and https://github.com/facebook/rocksdb/issues/13626 in allowing a CompressionManager / Compressor / Decompressor to use a custom compression algorithm, with a distinct CompressionType. For background, review the API comments on CompressionManager and its CompatibilityName() function. Highlights: * Reserve and name 127 new CompressionTypes that can be used for custom compression algorithms / schemas. In many or most cases I expect the enumerators such as `kCustomCompression8F` to be used in user code rather than casting between integers and CompressionTypes, as I expect the supported custom compression algorithms to be identifiable / enumerable at compile time. * When using these custom compression types, a CompressionManager must use a CompatibilityName() other than the built-in one AND new format_version=7 (see below). * When building new SST files, track the full set of CompressionTypes actually used (usually just one aside from kNoCompression), using our efficient bitset SmallEnumSet, which supports fast iteration over the bits set to 1. Ideally, to support mixed or non-mixed compression algorithms in a file as efficiently as possible, we would know the set of CompressionTypes as SST file open time. * New schema for `TableProperties::compression_name` in format_version=7 to represent the CompressionManager's CompatibilityName(), the set of CompressionTypes used, and potentially more in the future, while keeping the data relatively human-readable. * It would be possible to do this without a new format_version, but then the only way to ensure incompatible versions fail is with an unsupported CompressionType tag, not with a compression_name property. Therefore, (a) I prefer not to put something misleading in the `compression_name` property (a built-in compression name) when there is nuance because of a CompressionManager, and (b) I prefer better, more consistent error messages that refer to either format_version or the CompressionManager's CompatibilityName(), rather than an unrecognized custom CompressionType value (which could have come from various CompressionManagers). * The current configured CompressionManager is passed in to TableReaders so that it (or one it knows about) can be used if it matches the CompatibilityName() used for compression in the SST file. Until the connection with ObjectRegistry is implemented, the only way to read files generated with a particular CompressionManager using custom compression algorithms is to configure it (or a known relative; see FindCompatibleCompressionManager()) in the ColumnFamilyOptions. * Optimized snappy compression with BuiltinDecompressorV2SnappyOnly, to offset some small added overheads with the new tracking. This is essentially an early part of the planned refactoring that will get rid of the old internal compression APIs. * Another small optimization in eliminating an unnecessary key copy in flush (builder.cc). * Fix some handling of named CompressionManagers in CompressionManager::CreateFromString() (problem seen in https://github.com/facebook/rocksdb/issues/13647) Smaller things: * Adds Name() and GetId() functions to Compressor for debugging/logging purposes. (Compressor and Decompressor are not expected to be Customizable because they are only instantiated by a CompressionManager.) * When using an explicit compression_manager, the GetId() of the CompressionManager and the Compressor used to build the file are stored as bonus entries in the compression_options table property. This table property is not parsed anywhere, so it is currently for human reading, but still could be parsed with the new underscore-prefixed bonus entries. IMHO, this is preferable to additional table properties, which would increase memory fragmentation in the TableProperties objects and likely take slightly more CPU on SST open and slightly more storage. * ReleaseWorkingArea() function from protected to public to make wrappers work, because of a quirk in C++ (vs. Java) in which you cannot access protected members of another instance of the same class (sigh) * Added `CompressionManager:: SupportsCompressionType()` for early options sanity checking. Follow-up before release: * Make format_version=7 official / supported * Stress test coverage Sooner than later: * Update tests for RoundRobinManager and SimpleMixedCompressionManager to take advantage of e.g. set of compression types in compression_name property * ObjectRegistry stuff * Refactor away old internal compression APIs Pull Request resolved: https://github.com/facebook/rocksdb/pull/13659 Test Plan: Basic unit test added. ## Performance ### SST write performance ``` SUFFIX=`tty | sed 's|/|_|g'`; for ARGS in "-compression_type=none" "-compression_type=snappy" "-compression_type=zstd" "-compression_type=snappy -verify_compression=1" "-compression_type=zstd -verify_compression=1" "-compression_type=zstd -compression_max_dict_bytes=8180"; do echo $ARGS; (for I in `seq 1 20`; do BIN=/dev/shm/dbbench${SUFFIX}.bin; rm -f $BIN; cp db_bench $BIN; $BIN -db=/dev/shm/dbbench$SUFFIX --benchmarks=fillseq -num=10000000 -compaction_style=2 -fifo_compaction_max_table_files_size_mb=1000 -fifo_compaction_allow_compaction=0 -disable_wal -write_buffer_size=12000000 -format_version=7 $ARGS 2>&1 | grep micros/op; done) | awk '{n++; sum += $5;} END { print int(sum / n); }'; done ``` Ops/sec, Before -> After, both fv=6: -compression_type=none 1894386 -> 1858403 (-2.0%) -compression_type=snappy 1859131 -> 1807469 (-2.8%) -compression_type=zstd 1191428 -> 1214374 (+1.9%) -compression_type=snappy -verify_compression=1 1861819 -> 1858342 (+0.2%) -compression_type=zstd -verify_compression=1 979435 -> 995870 (+1.6%) -compression_type=zstd -compression_max_dict_bytes=8180 905349 -> 940563 (+3.9%) Ops/sec, Before fv=6 -> After fv=7: -compression_type=none 1879365 -> 1836159 (-2.3%) -compression_type=snappy 1865460 -> 1830916 (-1.9%) -compression_type=zstd 1191428 -> 1210260 (+1.6%) -compression_type=snappy -verify_compression=1 1866756 -> 1818989 (-2.6%) -compression_type=zstd -verify_compression=1 982640 -> 997129 (+1.5%) -compression_type=zstd -compression_max_dict_bytes=8180 912608 -> 937248 (+2.7%) ### SST read performance Create DBs ``` for COMP in none snappy zstd; do echo $ARGS; ./db_bench -db=/dev/shm/dbbench-7-$COMP --benchmarks=fillseq,flush -num=10000000 -compaction_style=2 -fifo_compaction_max_table_files_size_mb=1000 -fifo_compaction_allow_compaction=0 -disable_wal -write_buffer_size=12000000 -compression_type=$COMP -format_version=7; done ``` And test ``` for COMP in none snappy zstd none; do echo $COMP; (for I in `seq 1 8`; do ./db_bench -readonly -db=/dev/shm/dbbench -7-$COMP --benchmarks=readrandom -num=10000000 -duration=20 -threads=8 2>&1 | grep micros/op; done ) | awk '{n++; sum += $5;} END { print int(sum / n); }'; done ``` Ops/sec, Before -> After (both fv=6) none 1491732 -> 1500209 (+0.6%) snappy 1157216 -> 1169202 (+1.0%) zstd 695414 -> 703719 (+1.2%) none (again) 1491787 -> 1528789 (+2.4%) Ops/sec, Before fv=6 -> After fv=7: none 1492278 -> 1508668 (+1.1%) snappy 1140769 -> 1152613 (+1.0%) zstd 696437 -> 696511 (+0.0%) none (again) 1500585 -> 1512037 (+0.7%) Overall, I think we can take the read CPU improvement in exchange for the hit (in some cases) on background write CPU Reviewed By: hx235 Differential Revision: D76520739 Pulled By: pdillinger fbshipit-source-id: e73bd72502ff85c8779cba313f26f7d1fd50be3a |
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Changyu Bi
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0102b1769b |
Log pre-compression size written per level in compaction stats (#13596)
Summary: Add a new field to Compaction Stats to track the pre-compression size written to each level. This logged in LOG files as column WPreComp(GB). Also improved logging of compaction_started event to include cf name. Pull Request resolved: https://github.com/facebook/rocksdb/pull/13596 Test Plan: * Manually check LOG of db_bench runs: With no compression ``` ** Compaction Stats [default] ** Level Files Size Score Read(GB) Rn(GB) Rnp1(GB) Write(GB) WPreComp(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 21/9 96.06 MB 3.0 0.0 0.0 0.0 0.4 0.4 0.4 0.0 1.0 0.0 202.0 2.22 1.27 98 0.023 3829K 0 0.0 0.0 L1 6/6 344.89 MB 0.0 1.5 0.3 1.2 1.5 1.5 0.3 0.0 4.4 280.4 279.1 5.52 5.15 10 0.552 13M 44K 0.0 0.0 Sum 27/15 440.95 MB 0.0 1.5 0.3 1.2 1.9 1.9 0.8 0.0 4.4 200.0 257.0 7.74 6.42 108 0.072 17M 44K 0.0 0.0 Int 0/0 0.00 KB 0.0 0.3 0.1 0.3 0.4 0.4 0.1 0.0 6.8 219.2 255.7 1.58 1.36 14 0.113 3484K 12K 0.0 0.0 ** Compaction Stats [default] ** Priority Files Size Score Read(GB) Rn(GB) Rnp1(GB) Write(GB) WPreComp(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) ---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- Low 0/0 0.00 KB 0.0 1.5 0.3 1.2 1.5 1.5 0.3 0.0 0.0 280.4 279.1 5.52 5.15 10 0.552 13M 44K 0.0 0.0 High 0/0 0.00 KB 0.0 0.0 0.0 0.0 0.4 0.4 0.4 0.0 0.0 0.0 202.0 2.22 1.27 98 0.023 3829K 0 0.0 0.0 ``` With expected compression ratio = 0.5 ``` ** Compaction Stats [default] ** Level Files Size Score Read(GB) Rn(GB) Rnp1(GB) Write(GB) WPreComp(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 21/10 54.23 MB 2.8 0.0 0.0 0.0 0.2 0.4 0.2 0.0 1.0 0.0 105.2 1.96 1.29 80 0.025 3126K 0 0.0 0.0 L1 3/3 140.18 MB 0.0 0.5 0.1 0.4 0.5 0.9 0.1 0.0 3.4 131.1 128.1 3.99 3.89 8 0.499 8324K 26K 0.0 0.0 Sum 24/13 194.41 MB 0.0 0.5 0.1 0.4 0.7 1.3 0.3 0.0 3.5 87.9 120.5 5.96 5.17 88 0.068 11M 26K 0.0 0.0 Int 0/0 0.00 KB 0.0 0.3 0.1 0.2 0.3 0.6 0.1 0.0 5.7 105.7 125.9 2.45 2.23 23 0.107 4973K 15K 0.0 0.0 ** Compaction Stats [default] ** Priority Files Size Score Read(GB) Rn(GB) Rnp1(GB) Write(GB) WPreComp(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) ---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- Low 0/0 0.00 KB 0.0 0.5 0.1 0.4 0.5 0.9 0.1 0.0 0.0 131.1 128.1 3.99 3.89 8 0.499 8324K 26K 0.0 0.0 High 0/0 0.00 KB 0.0 0.0 0.0 0.0 0.2 0.4 0.2 0.0 0.0 0.0 105.2 1.96 1.29 80 0.025 3126K 0 0.0 0.0 ``` Reviewed By: hx235 Differential Revision: D74588464 Pulled By: cbi42 fbshipit-source-id: a998c0433230db4f3d7808636215b886b9ca5220 |
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Hui Xiao
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613e1a9a38 |
Verify flush output file record count + minor clean up (#13556)
Summary: **Context/Summary:** Similar to |
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Maciej Szeszko
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6ac13a5f0a |
Expose WriteLifeTimeHint at the FileOptions level (#13461)
Summary: The original implementation of NVMe write lifetime hints (https://github.com/facebook/rocksdb/pull/3095) assumed a flexible interface which decouples file creation from the explicit act of setting write lifetime hint (see `PosixWritableFile` for more context). However, there are existing file systems implementations (ex. Warm Storage) that require all the options (including file write lifetime hints) to be specified once at the time of the actual `FSWritableFile` object instantiation. We're extending the `FileOptions` with `Env::WriteLifeTimeHint` and patch existing callsites accordingly to enable one-shot metadata setup for those more constraint implementations. NOTE: Today `CalculateSSTWriteHint` only sets write lifetime hint for Level compactions. We'll fill that gap in following PRs and add calculation for Universal Compactions which would unblock Zippy's use case. Pull Request resolved: https://github.com/facebook/rocksdb/pull/13461 Reviewed By: anand1976 Differential Revision: D71144645 Pulled By: mszeszko-meta fbshipit-source-id: 6c09b62a360d48bd6e4fb08a1265bce2a49f3f4a |
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Peter Dillinger
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485ee4f45c |
Fix and test for leaks of open SST files (#13117)
Summary: Follow-up to https://github.com/facebook/rocksdb/issues/13106 which revealed that some SST file readers (in addition to blob files) were being essentially leaked in TableCache (until DB::Close() time). Patched sources of leaks: * Flush that is not committed (builder.cc) * Various obsolete SST files picked up by directory scan but not caught by SubcompactionState::Cleanup() cleaning up from some failed compactions. Dozens of unit tests fail without the "backstop" TableCache::Evict() call in PurgeObsoleteFiles(). We also needed to adjust the check for leaks as follows: * Ok if DB::Open never finished (see comment) * Ok if deletions are disabled (see comment) * Allow "quarantined" files to be in table_cache because (presumably) they might become live again. * Get live files from all live Versions. Suggested follow-up: * Potentially delete more obsolete files sooner with a FIXME in db_impl_files.cc. This could potentially be high value because it seems to gate deletion of any/all newer obsolete files on all older compactions finishing. * Try to catch obsolete files in more places using the VersionSet::obsolete_files_ pipeline rather than relying on them being picked up with directory scan, or deleting them outside of normal mechanisms. Pull Request resolved: https://github.com/facebook/rocksdb/pull/13117 Test Plan: updated check used in most all unit tests in ASAN build Reviewed By: hx235 Differential Revision: D65502988 Pulled By: pdillinger fbshipit-source-id: aa0795a8a09d9ec578d25183fe43e2a35849209c |
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Peter Dillinger
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ac24f152a1 |
Refactor table_factory into MutableCFOptions (#13077)
Summary: This is setting up for a fix to a data race in SetOptions on BlockBasedTableOptions (BBTO), https://github.com/facebook/rocksdb/issues/10079 The race will be fixed by replacing `table_factory` with a modified copy whenever we want to modify a BBTO field. An argument could be made that this change creates more entaglement between features (e.g. BlobSource <-> MutableCFOptions), rather than (conceptually) minimizing the dependencies of each feature, but * Most of these things already depended on ImmutableOptions * Historically there has been a lot of plumbing (and possible small CPU overhead) involved in adding features that need to reach a lot of places, like `block_protection_bytes_per_key`. Keeping those wrapped up in options simplifies that. * SuperVersion management generally takes care of lifetime management of MutableCFOptions, so is not that difficult. (Crash test agrees so far.) There are some FIXME places where it is known to be unsafe to replace `block_cache` unless/until we handle shared_ptr tracking properly. HOWEVER, replacing `block_cache` is generally dubious, at least while existing users of the old block cache (e.g. table readers) can continue indefinitely. The change to cf_options.cc is essentially just moving code (not changing). I'm not concerned about the performance of copying another shared_ptr with MutableCFOptions, but I left a note about considering an improvement if more shared_ptr are added to it. Pull Request resolved: https://github.com/facebook/rocksdb/pull/13077 Test Plan: existing tests, crash test. Unit test DBOptionsTest.GetLatestCFOptions updated with some temporary logic. MemoryTest required some refactoring (simplification) for the change. Reviewed By: cbi42 Differential Revision: D64546903 Pulled By: pdillinger fbshipit-source-id: 69ae97ce5cf4c01b58edc4c5d4687eb1e5bf5855 |
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Yu Zhang
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8592517c89 |
Remove stale entries from L0 files when UDT is not persisted (#13035)
Summary: When user-defined timestamps are not persisted, currently we replace the actual timestamp with min timestamp after an entry is output from compaction iterator. Compaction iterator won't be able to help with removing stale entries this way. This PR adds a wrapper iterator `TimestampStrippingIterator` for `MemTableIterator` that does the min timestamp replacement at the memtable iteration step. It is used by flush and can help remove stale entries from landing in L0 files. Pull Request resolved: https://github.com/facebook/rocksdb/pull/13035 Test Plan: Added unit test Reviewed By: pdillinger, cbi42 Differential Revision: D63423682 Pulled By: jowlyzhang fbshipit-source-id: 087dcc9cee97b9ea51b8d2b88dc91c2984d54e55 |
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Yu Zhang
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c73cf7a878 |
Add CompactForTieringCollector to support automatically trigger compaction for tiering use case (#12760)
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 |
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Yu Zhang
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2c02a9b76f |
Preserve TimedPut on penultimate level until it actually expires (#12543)
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 |
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Yu Zhang
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13e1c32a18 |
Follow ups for TimedPut and write time property (#12455)
Summary: This PR contains a few follow ups from https://github.com/facebook/rocksdb/issues/12419 and https://github.com/facebook/rocksdb/issues/12428 including: 1) Handle a special case for `WriteBatch::TimedPut`. When the user specified write time is `std::numeric_limits<uint64_t>::max()`, it's not treated as an error, but it instead creates and writes a regular `Put` entry. 2) Update the `InternalIterator::write_unix_time` APIs to handle `kTypeValuePreferredSeqno` entries. 3) FlushJob is updated to use the seqno to time mapping copy in `SuperVersion`. FlushJob currently copy the DB's seqno to time mapping while holding db mutex and only copies the part of interest, a.k.a, the part that only goes back to the earliest sequence number of the to-be-flushed memtables. While updating FlushJob to use the mapping copy in `SuperVersion`, it's given access to the full mapping to help cover the need to convert `kTypeValuePreferredSeqno`'s write time to preferred seqno as much as possible. Test plans: Added unit tests Pull Request resolved: https://github.com/facebook/rocksdb/pull/12455 Reviewed By: pdillinger Differential Revision: D55165422 Pulled By: jowlyzhang fbshipit-source-id: dc022653077f678c24661de5743146a74cce4b47 |
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Yu Zhang
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1104eaa35e |
Add initial support for TimedPut API (#12419)
Summary:
This PR adds support for `TimedPut` API. We introduced a new type `kTypeValuePreferredSeqno` for entries added to the DB via the `TimedPut` API.
The life cycle of such an entry on the write/flush/compaction paths are:
1) It is initially added to memtable as:
`<user_key, seq, kTypeValuePreferredSeqno>: {value, write_unix_time}`
2) When it's flushed to L0 sst files, it's converted to:
`<user_key, seq, kTypeValuePreferredSeqno>: {value, preferred_seqno}`
when we have easy access to the seqno to time mapping.
3) During compaction, if certain conditions are met, we swap in the `preferred_seqno` and the entry will become:
`<user_key, preferred_seqno, kTypeValue>: value`. This step helps fast track these entries to the cold tier if they are eligible after the sequence number swap.
On the read path:
A `kTypeValuePreferredSeqno` entry acts the same as a `kTypeValue` entry, the unix_write_time/preferred seqno part packed in value is completely ignored.
Needed follow ups:
1) The seqno to time mapping accessible in flush needs to be extended to cover the `write_unix_time` for possible `kTypeValuePreferredSeqno` entries. This also means we need to track these `write_unix_time` in memtable.
2) Compaction filter support for the new `kTypeValuePreferredSeqno` type for feature parity with other `kTypeValue` and equivalent types.
3) Stress test coverage for the feature
Pull Request resolved: https://github.com/facebook/rocksdb/pull/12419
Test Plan: Added unit tests
Reviewed By: pdillinger
Differential Revision: D54920296
Pulled By: jowlyzhang
fbshipit-source-id: c8b43f7a7c465e569141770e93c748371ff1da9e
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Andrew Kryczka
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f9d45358ca |
Removed check_flush_compaction_key_order (#12311)
Summary: `check_flush_compaction_key_order` option was introduced for the key order checking online validation. It gave users the ability to disable the validation without downgrade in case the validation caused inefficiencies or false positives. Over time this validation has shown to be cheap and correct, so the option to disable it can now be removed. Pull Request resolved: https://github.com/facebook/rocksdb/pull/12311 Reviewed By: cbi42 Differential Revision: D53233379 Pulled By: ajkr fbshipit-source-id: 1384361104021d6e3e580dce2ec123f9f99ce637 |
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Yu Zhang
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071a146fa0 |
Add support for range deletion when user timestamps are not persisted (#12254)
Summary:
For the user defined timestamps in memtable only feature, some special handling for range deletion blocks are needed since both the key (start_key) and the value (end_key) of a range tombstone can contain user-defined timestamps. Handling for the key is taken care of in the same way as the other data blocks in the block based table. This PR adds the special handling needed for the value (end_key) part. This includes:
1) On the write path, when L0 SST files are first created from flush, user-defined timestamps are removed from an end key of a range tombstone. There are places where it's logically removed (replaced with a min timestamp) because there is still logic with the running comparator that expects a user key that contains timestamp. And in the block based builder, it is eventually physically removed before persisted in a block.
2) On the read path, when range deletion block is being read, we artificially pad a min timestamp to the end key of a range tombstone in `BlockBasedTableReader`.
3) For file boundary `FileMetaData.largest`, we artificially pad a max timestamp to it if it contains a range deletion sentinel. Anytime when range deletion end_key is used to update file boundaries, it's using max timestamp instead of the range tombstone's actual timestamp to mark it as an exclusive end.
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Peter Dillinger
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cb08a682d4 |
Fix/cleanup SeqnoToTimeMapping (#12253)
Summary: The SeqnoToTimeMapping class (RocksDB internal) used by the preserve_internal_time_seconds / preclude_last_level_data_seconds options was essentially in a prototype state with some significant flaws that would risk biting us some day. This is a big, complicated change because both the implementation and the behavioral requirements of the class needed to be upgraded together. In short, this makes SeqnoToTimeMapping more internally responsible for maintaining good invariants, so that callers don't easily encounter dangerous scenarios. * Some API functions were confusingly named and structured, so I fully refactored the APIs to use clear naming (e.g. `DecodeFrom` and `CopyFromSeqnoRange`), object states, function preconditions, etc. * Previously the object could informally be sorted / compacted or not, and there was limited checking or enforcement on these states. Now there's a well-defined "enforced" state that is consistently checked in debug mode for applicable operations. (I attempted to create a separate "builder" class for unenforced states, but IIRC found that more cumbersome for existing uses than it was worth.) * Previously operations would coalesce data in a way that was better for `GetProximalTimeBeforeSeqno` than for `GetProximalSeqnoBeforeTime` which is odd because the latter is the only one used by DB code currently (what is the seqno cut-off for data definitely older than this given time?). This is now reversed to consistently favor `GetProximalSeqnoBeforeTime`, with that logic concentrated in one place: `SeqnoToTimeMapping::SeqnoTimePair::Merge()`. Unfortunately, a lot of unit test logic was specifically testing the old, suboptimal behavior. * Previously, the natural behavior of SeqnoToTimeMapping was to THROW AWAY data needed to get reasonable answers to the important `GetProximalSeqnoBeforeTime` queries. This is because SeqnoToTimeMapping only had a FIFO policy for staying within the entry capacity (except in aggregate+sort+serialize mode). If the DB wasn't extremely careful to avoid gathering too many time mappings, it could lose track of where the seqno cutoff was for cold data (`GetProximalSeqnoBeforeTime()` returning 0) and preventing all further data migration to the cold tier--until time passes etc. for mappings to catch up with FIFO purging of them. (The problem is not so acute because SST files contain relevant snapshots of the mappings, but the problem would apply to long-lived memtables.) * Now the SeqnoToTimeMapping class has fully-integrated smarts for keeping a sufficiently complete history, within capacity limits, to give good answers to `GetProximalSeqnoBeforeTime` queries. * Fixes old `// FIXME: be smarter about how we erase to avoid data falling off the front prematurely.` * Fix an apparent bug in how entries are selected for storing into SST files. Previously, it only selected entries within the seqno range of the file, but that would easily leave a gap at the beginning of the timeline for data in the file for the purposes of answering GetProximalXXX queries with reasonable accuracy. This could probably lead to the same problem discussed above in naively throwing away entries in FIFO order in the old SeqnoToTimeMapping. The updated testing of GetProximalSeqnoBeforeTime in BasicSeqnoToTimeMapping relies on the fixed behavior. * Fix a potential compaction CPU efficiency/scaling issue in which each compaction output file would iterate over and sort all seqno-to-time mappings from all compaction input files. Now we distill the input file entries to a constant size before processing each compaction output file. Intended follow-up (me or others): * Expand some direct testing of SeqnoToTimeMapping APIs. Here I've focused on updating existing tests to make sense. * There are likely more gaps in availability of needed SeqnoToTimeMapping data when the DB shuts down and is restarted, at least with WAL. * The data tracked in the DB could be kept more accurate and limited if it used the oldest seqno of unflushed data. This might require some more API refactoring. Pull Request resolved: https://github.com/facebook/rocksdb/pull/12253 Test Plan: unit tests updated Reviewed By: jowlyzhang Differential Revision: D52913733 Pulled By: pdillinger fbshipit-source-id: 020737fcbbe6212f6701191a6ab86565054c9593 |
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Hui Xiao
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06e593376c |
Group SST write in flush, compaction and db open with new stats (#11910)
Summary: ## Context/Summary Similar to https://github.com/facebook/rocksdb/pull/11288, https://github.com/facebook/rocksdb/pull/11444, categorizing SST/blob file write according to different io activities allows more insight into the activity. For that, this PR does the following: - Tag different write IOs by passing down and converting WriteOptions to IOOptions - Add new SST_WRITE_MICROS histogram in WritableFileWriter::Append() and breakdown FILE_WRITE_{FLUSH|COMPACTION|DB_OPEN}_MICROS Some related code refactory to make implementation cleaner: - Blob stats - Replace high-level write measurement with low-level WritableFileWriter::Append() measurement for BLOB_DB_BLOB_FILE_WRITE_MICROS. This is to make FILE_WRITE_{FLUSH|COMPACTION|DB_OPEN}_MICROS include blob file. As a consequence, this introduces some behavioral changes on it, see HISTORY and db bench test plan below for more info. - Fix bugs where BLOB_DB_BLOB_FILE_SYNCED/BLOB_DB_BLOB_FILE_BYTES_WRITTEN include file failed to sync and bytes failed to write. - Refactor WriteOptions constructor for easier construction with io_activity and rate_limiter_priority - Refactor DBImpl::~DBImpl()/BlobDBImpl::Close() to bypass thread op verification - Build table - TableBuilderOptions now includes Read/WriteOpitons so BuildTable() do not need to take these two variables - Replace the io_priority passed into BuildTable() with TableBuilderOptions::WriteOpitons::rate_limiter_priority. Similar for BlobFileBuilder. This parameter is used for dynamically changing file io priority for flush, see https://github.com/facebook/rocksdb/pull/9988?fbclid=IwAR1DtKel6c-bRJAdesGo0jsbztRtciByNlvokbxkV6h_L-AE9MACzqRTT5s for more - Update ThreadStatus::FLUSH_BYTES_WRITTEN to use io_activity to track flush IO in flush job and db open instead of io_priority ## Test ### db bench Flush ``` ./db_bench --statistics=1 --benchmarks=fillseq --num=100000 --write_buffer_size=100 rocksdb.sst.write.micros P50 : 1.830863 P95 : 4.094720 P99 : 6.578947 P100 : 26.000000 COUNT : 7875 SUM : 20377 rocksdb.file.write.flush.micros P50 : 1.830863 P95 : 4.094720 P99 : 6.578947 P100 : 26.000000 COUNT : 7875 SUM : 20377 rocksdb.file.write.compaction.micros P50 : 0.000000 P95 : 0.000000 P99 : 0.000000 P100 : 0.000000 COUNT : 0 SUM : 0 rocksdb.file.write.db.open.micros P50 : 0.000000 P95 : 0.000000 P99 : 0.000000 P100 : 0.000000 COUNT : 0 SUM : 0 ``` compaction, db oopen ``` Setup: ./db_bench --statistics=1 --benchmarks=fillseq --num=10000 --disable_auto_compactions=1 -write_buffer_size=100 --db=../db_bench Run:./db_bench --statistics=1 --benchmarks=compact --db=../db_bench --use_existing_db=1 rocksdb.sst.write.micros P50 : 2.675325 P95 : 9.578788 P99 : 18.780000 P100 : 314.000000 COUNT : 638 SUM : 3279 rocksdb.file.write.flush.micros P50 : 0.000000 P95 : 0.000000 P99 : 0.000000 P100 : 0.000000 COUNT : 0 SUM : 0 rocksdb.file.write.compaction.micros P50 : 2.757353 P95 : 9.610687 P99 : 19.316667 P100 : 314.000000 COUNT : 615 SUM : 3213 rocksdb.file.write.db.open.micros P50 : 2.055556 P95 : 3.925000 P99 : 9.000000 P100 : 9.000000 COUNT : 23 SUM : 66 ``` blob stats - just to make sure they aren't broken by this PR ``` Integrated Blob DB Setup: ./db_bench --enable_blob_files=1 --statistics=1 --benchmarks=fillseq --num=10000 --disable_auto_compactions=1 -write_buffer_size=100 --db=../db_bench Run:./db_bench --enable_blob_files=1 --statistics=1 --benchmarks=compact --db=../db_bench --use_existing_db=1 pre-PR: rocksdb.blobdb.blob.file.write.micros P50 : 7.298246 P95 : 9.771930 P99 : 9.991813 P100 : 16.000000 COUNT : 235 SUM : 1600 rocksdb.blobdb.blob.file.synced COUNT : 1 rocksdb.blobdb.blob.file.bytes.written COUNT : 34842 post-PR: rocksdb.blobdb.blob.file.write.micros P50 : 2.000000 P95 : 2.829360 P99 : 2.993779 P100 : 9.000000 COUNT : 707 SUM : 1614 - COUNT is higher and values are smaller as it includes header and footer write - COUNT is 3X higher due to each Append() count as one post-PR, while in pre-PR, 3 Append()s counts as one. See https://github.com/facebook/rocksdb/pull/11910/files#diff-32b811c0a1c000768cfb2532052b44dc0b3bf82253f3eab078e15ff201a0dabfL157-L164 rocksdb.blobdb.blob.file.synced COUNT : 1 (stay the same) rocksdb.blobdb.blob.file.bytes.written COUNT : 34842 (stay the same) ``` ``` Stacked Blob DB Run: ./db_bench --use_blob_db=1 --statistics=1 --benchmarks=fillseq --num=10000 --disable_auto_compactions=1 -write_buffer_size=100 --db=../db_bench pre-PR: rocksdb.blobdb.blob.file.write.micros P50 : 12.808042 P95 : 19.674497 P99 : 28.539683 P100 : 51.000000 COUNT : 10000 SUM : 140876 rocksdb.blobdb.blob.file.synced COUNT : 8 rocksdb.blobdb.blob.file.bytes.written COUNT : 1043445 post-PR: rocksdb.blobdb.blob.file.write.micros P50 : 1.657370 P95 : 2.952175 P99 : 3.877519 P100 : 24.000000 COUNT : 30001 SUM : 67924 - COUNT is higher and values are smaller as it includes header and footer write - COUNT is 3X higher due to each Append() count as one post-PR, while in pre-PR, 3 Append()s counts as one. See https://github.com/facebook/rocksdb/pull/11910/files#diff-32b811c0a1c000768cfb2532052b44dc0b3bf82253f3eab078e15ff201a0dabfL157-L164 rocksdb.blobdb.blob.file.synced COUNT : 8 (stay the same) rocksdb.blobdb.blob.file.bytes.written COUNT : 1043445 (stay the same) ``` ### Rehearsal CI stress test Trigger 3 full runs of all our CI stress tests ### Performance Flush ``` TEST_TMPDIR=/dev/shm ./db_basic_bench_pre_pr --benchmark_filter=ManualFlush/key_num:524288/per_key_size:256 --benchmark_repetitions=1000 -- default: 1 thread is used to run benchmark; enable_statistics = true Pre-pr: avg 507515519.3 ns 497686074,499444327,500862543,501389862,502994471,503744435,504142123,504224056,505724198,506610393,506837742,506955122,507695561,507929036,508307733,508312691,508999120,509963561,510142147,510698091,510743096,510769317,510957074,511053311,511371367,511409911,511432960,511642385,511691964,511730908, Post-pr: avg 511971266.5 ns, regressed 0.88% 502744835,506502498,507735420,507929724,508313335,509548582,509994942,510107257,510715603,511046955,511352639,511458478,512117521,512317380,512766303,512972652,513059586,513804934,513808980,514059409,514187369,514389494,514447762,514616464,514622882,514641763,514666265,514716377,514990179,515502408, ``` Compaction ``` TEST_TMPDIR=/dev/shm ./db_basic_bench_{pre|post}_pr --benchmark_filter=ManualCompaction/comp_style:0/max_data:134217728/per_key_size:256/enable_statistics:1 --benchmark_repetitions=1000 -- default: 1 thread is used to run benchmark Pre-pr: avg 495346098.30 ns 492118301,493203526,494201411,494336607,495269217,495404950,496402598,497012157,497358370,498153846 Post-pr: avg 504528077.20, regressed 1.85%. "ManualCompaction" include flush so the isolated regression for compaction should be around 1.85-0.88 = 0.97% 502465338,502485945,502541789,502909283,503438601,504143885,506113087,506629423,507160414,507393007 ``` Put with WAL (in case passing WriteOptions slows down this path even without collecting SST write stats) ``` TEST_TMPDIR=/dev/shm ./db_basic_bench_pre_pr --benchmark_filter=DBPut/comp_style:0/max_data:107374182400/per_key_size:256/enable_statistics:1/wal:1 --benchmark_repetitions=1000 -- default: 1 thread is used to run benchmark Pre-pr: avg 3848.10 ns 3814,3838,3839,3848,3854,3854,3854,3860,3860,3860 Post-pr: avg 3874.20 ns, regressed 0.68% 3863,3867,3871,3874,3875,3877,3877,3877,3880,3881 ``` Pull Request resolved: https://github.com/facebook/rocksdb/pull/11910 Reviewed By: ajkr Differential Revision: D49788060 Pulled By: hx235 fbshipit-source-id: 79e73699cda5be3b66461687e5147c2484fc5eff |
||
|
Peter Dillinger
|
02443dd93f |
Refactor, clean up, fixes, and more testing for SeqnoToTimeMapping (#11905)
Summary: This change is before a planned DBImpl change to ensure all sufficiently recent sequence numbers since Open are covered by SeqnoToTimeMapping (bug fix with existing test work-arounds). **Intended follow-up** However, I found enough issues with SeqnoToTimeMapping to warrant this PR first, including very small fixes in DB implementation related to API contract of SeqnoToTimeMapping. Functional fixes / changes: * This fixes some mishandling of boundary cases. For example, if the user decides to stop writing to DB, the last written sequence number would perpetually have its write time updated to "now" and would always be ineligible for migration to cold tier. Part of the problem is that the SeqnoToTimeMapping would return a seqno known to have been written before (immediately or otherwise) the requested time, but compaction_job.cc would include that seqno in the preserve/exclude set. That is fixed (in part) by adding one in compaction_job.cc * That problem was worse because a whole range of seqnos could be updated perpetually with new times in SeqnoToTimeMapping::Append (if no writes to DB). That logic was apparently optimized for GetOldestApproximateTime (now GetProximalTimeBeforeSeqno), which is not used in production, to the detriment of GetOldestSequenceNum (now GetProximalSeqnoBeforeTime), which is used in production. (Perhaps plans changed during development?) This is fixed in Append to optimize for accuracy of GetProximalSeqnoBeforeTime. (Unit tests added and updated.) * Related: SeqnoToTimeMapping did not have a clear contract about the relationships between seqnos and times, just the idea of a rough correspondence. Now the class description makes it clear that the write time of each recorded seqno comes before or at the associated time, to support getting best results for GetProximalSeqnoBeforeTime. And this makes it easier to make clear the contract of each API function. * Update `DBImpl::RecordSeqnoToTimeMapping()` to follow this ordering in gathering samples. Some part of these changes has required an expanded test work-around for the problem (see intended follow-up above) that the DB does not immediately ensure recent seqnos are covered by its mapping. These work-arounds will be removed with that planned work. An apparent compaction bug is revealed in PrecludeLastLevelTest::RangeDelsCauseFileEndpointsToOverlap, so that test is disabled. Filed GitHub issue #11909 Cosmetic / code safety things (not exhaustive): * Fix some confusing names. * `seqno_time_mapping` was used inconsistently in places. Now just `seqno_to_time_mapping` to correspond to class name. * Rename confusing `GetOldestSequenceNum` -> `GetProximalSeqnoBeforeTime` and `GetOldestApproximateTime` -> `GetProximalTimeBeforeSeqno`. Part of the motivation is that our times and seqnos here have the same underlying type, so we want to be clear about which is expected where to avoid mixing. * Rename `kUnknownSeqnoTime` to `kUnknownTimeBeforeAll` because the value is a bad choice for unknown if we ever add ProximalAfterBlah functions. * Arithmetic on SeqnoTimePair doesn't make sense except for delta encoding, so use better names / APIs with that in mind. * (OMG) Don't allow direct comparison between SeqnoTimePair and SequenceNumber. (There is no checking that it isn't compared against time by accident.) * A field name essentially matching the containing class name is a confusing pattern (`seqno_time_mapping_`). * Wrap calls to confusing (but useful) upper_bound and lower_bound functions to have clearer names and more code reuse. Pull Request resolved: https://github.com/facebook/rocksdb/pull/11905 Test Plan: GetOldestSequenceNum (now GetProximalSeqnoBeforeTime) and TruncateOldEntries were lacking unit tests, despite both being used in production (experimental feature). Added those and expanded others. Reviewed By: jowlyzhang Differential Revision: D49755592 Pulled By: pdillinger fbshipit-source-id: f72a3baac74d24b963c77e538bba89a7fc8dce51 |
||
|
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 |
||
|
Yu Zhang
|
15053f3ab4 |
Logically strip timestamp during flush (#11557)
Summary:
Logically strip the user-defined timestamp when L0 files are created during flush when `AdvancedColumnFamilyOptions.persist_user_defined_timestamps` is false. Logically stripping timestamp here means replacing the original user-defined timestamp with a mininum timestamp, which for now is hard coded to be all zeros bytes.
While working on this, I caught a missing piece on the `BlockBuilder` level for this feature. The current quick path `std::min(buffer_size, last_key_size)` needs a bit tweaking to work for this feature. When user-defined timestamp is stripped during block building, on writing first entry or right after resetting, `buffer` is empty and `buffer_size` is zero as usual. However, in follow-up writes, depending on the size of the stripped user-defined timestamp, and the size of the value, what's in `buffer` can sometimes be smaller than `last_key_size`, leading `std::min(buffer_size, last_key_size)` to truncate the `last_key`. Previous test doesn't caught the bug because in those tests, the size of the stripped user-defined timestamps bytes is smaller than the length of the value. In order to avoid the conditional operation, this PR changed the original trivial `std::min` operation into an arithmetic operation. Since this is a change in a hot and performance critical path, I did the following benchmark to check no observable regression is introduced.
```TEST_TMPDIR=/dev/shm/rocksdb1 ./db_bench -benchmarks=fillseq -memtablerep=vector -allow_concurrent_memtable_write=false -num=50000000```
Compiled with DEBUG_LEVEL=0
Test vs. control runs simulaneous for better accuracy, units = ops/sec
PR vs base:
Round 1: 350652 vs 349055
Round 2: 365733 vs 364308
Round 3: 355681 vs 354475
Pull Request resolved: https://github.com/facebook/rocksdb/pull/11557
Test Plan:
New timestamp specific test added or existing tests augmented, both are parameterized with `UserDefinedTimestampTestMode`:
`UserDefinedTimestampTestMode::kNormal` -> UDT feature enabled, write / read with min timestamp
`UserDefinedTimestampTestMode::kStripUserDefinedTimestamps` -> UDT feature enabled, write / read with min timestamp, set Options.persist_user_defined_timestamps to false.
```
make all check
./db_wal_test --gtest_filter="*WithTimestamp*"
./flush_job_test --gtest_filter="*WithTimestamp*"
./repair_test --gtest_filter="*WithTimestamp*"
./block_based_table_reader_test
```
Reviewed By: pdillinger
Differential Revision: D47027664
Pulled By: jowlyzhang
fbshipit-source-id: e729193b6334dfc63aaa736d684d907a022571f5
|
||
|
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 |
||
|
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 |
||
|
Changyu Bi
|
62fc15f009 |
Block per key-value checksum (#11287)
Summary: add option `block_protection_bytes_per_key` and implementation for block per key-value checksum. The main changes are 1. checksum construction and verification in block.cc/h 2. pass the option `block_protection_bytes_per_key` around (mainly for methods defined in table_cache.h) 3. unit tests/crash test updates Tests: * Added unit tests * Crash test: `python3 tools/db_crashtest.py blackbox --simple --block_protection_bytes_per_key=1 --write_buffer_size=1048576` Follow up (maybe as a separate PR): make sure corruption status returned from BlockIters are correctly handled. Performance: Turning on block per KV protection has a non-trivial negative impact on read performance and costs additional memory. For memory, each block includes additional 24 bytes for checksum-related states beside checksum itself. For CPU, I set up a DB of size ~1.2GB with 5M keys (32 bytes key and 200 bytes value) which compacts to ~5 SST files (target file size 256 MB) in L6 without compression. I tested readrandom performance with various block cache size (to mimic various cache hit rates): ``` SETUP make OPTIMIZE_LEVEL="-O3" USE_LTO=1 DEBUG_LEVEL=0 -j32 db_bench ./db_bench -benchmarks=fillseq,compact0,waitforcompaction,compact,waitforcompaction -write_buffer_size=33554432 -level_compaction_dynamic_level_bytes=true -max_background_jobs=8 -target_file_size_base=268435456 --num=5000000 --key_size=32 --value_size=200 --compression_type=none BENCHMARK ./db_bench --use_existing_db -benchmarks=readtocache,readrandom[-X10] --num=5000000 --key_size=32 --disable_auto_compactions --reads=1000000 --block_protection_bytes_per_key=[0|1] --cache_size=$CACHESIZE The readrandom ops/sec looks like the following: Block cache size: 2GB 1.2GB * 0.9 1.2GB * 0.8 1.2GB * 0.5 8MB Main 240805 223604 198176 161653 139040 PR prot_bytes=0 238691 226693 200127 161082 141153 PR prot_bytes=1 214983 193199 178532 137013 108211 prot_bytes=1 vs -10% -15% -10.8% -15% -23% prot_bytes=0 ``` The benchmark has a lot of variance, but there was a 5% to 25% regression in this benchmark with different cache hit rates. Pull Request resolved: https://github.com/facebook/rocksdb/pull/11287 Reviewed By: ajkr Differential Revision: D43970708 Pulled By: cbi42 fbshipit-source-id: ef98d898b71779846fa74212b9ec9e08b7183940 |
||
|
Hui Xiao
|
151242ce46 |
Group rocksdb.sst.read.micros stat by IOActivity flush and compaction (#11288)
Summary:
**Context:**
The existing stat rocksdb.sst.read.micros does not reflect each of compaction and flush cases but aggregate them, which is not so helpful for us to understand IO read behavior of each of them.
**Summary**
- Update `StopWatch` and `RandomAccessFileReader` to record `rocksdb.sst.read.micros` and `rocksdb.file.{flush/compaction}.read.micros`
- Fixed the default histogram in `RandomAccessFileReader`
- New field `ReadOptions/IOOptions::io_activity`; Pass `ReadOptions` through paths under db open, flush and compaction to where we can prepare `IOOptions` and pass it to `RandomAccessFileReader`
- Use `thread_status_util` for assertion in `DbStressFSWrapper` for continuous testing on we are passing correct `io_activity` under db open, flush and compaction
Pull Request resolved: https://github.com/facebook/rocksdb/pull/11288
Test Plan:
- **Stress test**
- **Db bench 1: rocksdb.sst.read.micros COUNT ≈ sum of rocksdb.file.read.flush.micros's and rocksdb.file.read.compaction.micros's.** (without blob)
- May not be exactly the same due to `HistogramStat::Add` only guarantees atomic not accuracy across threads.
```
./db_bench -db=/dev/shm/testdb/ -statistics=true -benchmarks="fillseq" -key_size=32 -value_size=512 -num=50000 -write_buffer_size=655 -target_file_size_base=655 -disable_auto_compactions=false -compression_type=none -bloom_bits=3 (-use_plain_table=1 -prefix_size=10)
```
```
// BlockBasedTable
rocksdb.sst.read.micros P50 : 2.009374 P95 : 4.968548 P99 : 8.110362 P100 : 43.000000 COUNT : 40456 SUM : 114805
rocksdb.file.read.flush.micros P50 : 1.871841 P95 : 3.872407 P99 : 5.540541 P100 : 43.000000 COUNT : 2250 SUM : 6116
rocksdb.file.read.compaction.micros P50 : 2.023109 P95 : 5.029149 P99 : 8.196910 P100 : 26.000000 COUNT : 38206 SUM : 108689
// PlainTable
Does not apply
```
- **Db bench 2: performance**
**Read**
SETUP: db with 900 files
```
./db_bench -db=/dev/shm/testdb/ -benchmarks="fillseq" -key_size=32 -value_size=512 -num=50000 -write_buffer_size=655 -disable_auto_compactions=true -target_file_size_base=655 -compression_type=none
```run till convergence
```
./db_bench -seed=1678564177044286 -use_existing_db=true -db=/dev/shm/testdb -benchmarks=readrandom[-X60] -statistics=true -num=1000000 -disable_auto_compactions=true -compression_type=none -bloom_bits=3
```
Pre-change
`readrandom [AVG 60 runs] : 21568 (± 248) ops/sec`
Post-change (no regression, -0.3%)
`readrandom [AVG 60 runs] : 21486 (± 236) ops/sec`
**Compaction/Flush**run till convergence
```
./db_bench -db=/dev/shm/testdb2/ -seed=1678564177044286 -benchmarks="fillseq[-X60]" -key_size=32 -value_size=512 -num=50000 -write_buffer_size=655 -disable_auto_compactions=false -target_file_size_base=655 -compression_type=none
rocksdb.sst.read.micros COUNT : 33820
rocksdb.sst.read.flush.micros COUNT : 1800
rocksdb.sst.read.compaction.micros COUNT : 32020
```
Pre-change
`fillseq [AVG 46 runs] : 1391 (± 214) ops/sec; 0.7 (± 0.1) MB/sec`
Post-change (no regression, ~-0.4%)
`fillseq [AVG 46 runs] : 1385 (± 216) ops/sec; 0.7 (± 0.1) MB/sec`
Reviewed By: ajkr
Differential Revision: D44007011
Pulled By: hx235
fbshipit-source-id: a54c89e4846dfc9a135389edf3f3eedfea257132
|
||
sdong
|
4720ba4391 |
Remove RocksDB LITE (#11147)
Summary: We haven't been actively mantaining RocksDB LITE recently and the size must have been gone up significantly. We are removing the support. Most of changes were done through following comments: unifdef -m -UROCKSDB_LITE `git grep -l ROCKSDB_LITE | egrep '[.](cc|h)'` by Peter Dillinger. Others changes were manually applied to build scripts, CircleCI manifests, ROCKSDB_LITE is used in an expression and file db_stress_test_base.cc. Pull Request resolved: https://github.com/facebook/rocksdb/pull/11147 Test Plan: See CI Reviewed By: pdillinger Differential Revision: D42796341 fbshipit-source-id: 4920e15fc2060c2cd2221330a6d0e5e65d4b7fe2 |
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Changyu Bi
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e9d6a0d7ce |
Fix asan failure caused by range tombstone start key use-after-free (#11106)
Summary: the `last_tombstone_start_user_key` variable in `BuildTable()` and in `CompactionOutputs::AddRangeDels()` may point to a start key that is freed if user-defined timestamp is enabled. This was causing ASAN failure and this PR fixes this issue. Pull Request resolved: https://github.com/facebook/rocksdb/pull/11106 Test Plan: Added UT for repro. Reviewed By: ajkr Differential Revision: D42590862 Pulled By: cbi42 fbshipit-source-id: c493265ececdf89636d801d55ae929806c4d4b2c |
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Changyu Bi
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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 |
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Changyu Bi
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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 |
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Andrew Kryczka
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5cf6ab6f31 |
Ran clang-format on db/ directory (#10910)
Summary: Ran `find ./db/ -type f | xargs clang-format -i`. Excluded minor changes it tried to make on db/db_impl/. Everything else it changed was directly under db/ directory. Included minor manual touchups mentioned in PR commit history. Pull Request resolved: https://github.com/facebook/rocksdb/pull/10910 Reviewed By: riversand963 Differential Revision: D40880683 Pulled By: ajkr fbshipit-source-id: cfe26cda05b3fb9a72e3cb82c286e21d8c5c4174 |
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Changyu Bi
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9f2363f4c4 |
User-defined timestamp support for DeleteRange() (#10661)
Summary: Add user-defined timestamp support for range deletion. The new API is `DeleteRange(opt, cf, begin_key, end_key, ts)`. Most of the change is to update the comparator to compare without timestamp. Other than that, major changes are - internal range tombstone data structures (`FragmentedRangeTombstoneList`, `RangeTombstone`, etc.) to store timestamps. - Garbage collection of range tombstones and range tombstone covered keys during compaction. - Get()/MultiGet() to return the timestamp of a range tombstone when needed. - Get/Iterator with range tombstones bounded by readoptions.timestamp. - timestamp crash test now issues DeleteRange by default. Pull Request resolved: https://github.com/facebook/rocksdb/pull/10661 Test Plan: - Added unit test: `make check` - Stress test: `python3 tools/db_crashtest.py --enable_ts whitebox --readpercent=57 --prefixpercent=4 --writepercent=25 -delpercent=5 --iterpercent=5 --delrangepercent=4` - Ran `db_bench` to measure regression when timestamp is not enabled. The tests are for write (with some range deletion) and iterate with DB fitting in memory: `./db_bench--benchmarks=fillrandom,seekrandom --writes_per_range_tombstone=200 --max_write_buffer_number=100 --min_write_buffer_number_to_merge=100 --writes=500000 --reads=500000 --seek_nexts=10 --disable_auto_compactions -disable_wal=true --max_num_range_tombstones=1000`. Did not see consistent regression in no timestamp case. | micros/op | fillrandom | seekrandom | | --- | --- | --- | |main| 2.58 |10.96| |PR 10661| 2.68 |10.63| Reviewed By: riversand963 Differential Revision: D39441192 Pulled By: cbi42 fbshipit-source-id: f05aca3c41605caf110daf0ff405919f300ddec2 |
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Gang Liao
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ec4ebeff30 |
Support prepopulating/warming the blob cache (#10298)
Summary: Many workloads have temporal locality, where recently written items are read back in a short period of time. When using remote file systems, this is inefficient since it involves network traffic and higher latencies. Because of this, we would like to support prepopulating the blob cache during flush. This task is a part of https://github.com/facebook/rocksdb/issues/10156 Pull Request resolved: https://github.com/facebook/rocksdb/pull/10298 Reviewed By: ltamasi Differential Revision: D37908743 Pulled By: gangliao fbshipit-source-id: 9feaed234bc719d38f0c02975c1ad19fa4bb37d1 |
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Jay Zhuang
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a3acf2ef87 |
Add seqno to time mapping (#10338)
Summary: Which will be used for tiered storage to preclude hot data from compacting to the cold tier (the last level). Internally, adding seqno to time mapping. A periodic_task is scheduled to record the current_seqno -> current_time in certain cadence. When memtable flush, the mapping informaiton is stored in sstable property. During compaction, the mapping information are merged and get the approximate time of sequence number, which is used to determine if a key is recently inserted or not and preclude it from the last level if it's recently inserted (within the `preclude_last_level_data_seconds`). Pull Request resolved: https://github.com/facebook/rocksdb/pull/10338 Test Plan: CI Reviewed By: siying Differential Revision: D37810187 Pulled By: jay-zhuang fbshipit-source-id: 6953be7a18a99de8b1cb3b162d712f79c2b4899f |
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zczhu
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3ee6c9baec |
Consolidate manual_compaction_paused_ check (#10070)
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 |
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Gang Liao
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e6432dfd4c |
Make it possible to enable blob files starting from a certain LSM tree level (#10077)
Summary: Currently, if blob files are enabled (i.e. `enable_blob_files` is true), large values are extracted both during flush/recovery (when SST files are written into level 0 of the LSM tree) and during compaction into any LSM tree level. For certain use cases that have a mix of short-lived and long-lived values, it might make sense to support extracting large values only during compactions whose output level is greater than or equal to a specified LSM tree level (e.g. compactions into L1/L2/... or above). This could reduce the space amplification caused by large values that are turned into garbage shortly after being written at the price of some write amplification incurred by long-lived values whose extraction to blob files is delayed. In order to achieve this, we would like to do the following: - Add a new configuration option `blob_file_starting_level` (default: 0) to `AdvancedColumnFamilyOptions` (and `MutableCFOptions` and extend the related logic) - Instantiate `BlobFileBuilder` in `BuildTable` (used during flush and recovery, where the LSM tree level is L0) and `CompactionJob` iff `enable_blob_files` is set and the LSM tree level is `>= blob_file_starting_level` - Add unit tests for the new functionality, and add the new option to our stress tests (`db_stress` and `db_crashtest.py` ) - Add the new option to our benchmarking tool `db_bench` and the BlobDB benchmark script `run_blob_bench.sh` - Add the new option to the `ldb` tool (see https://github.com/facebook/rocksdb/wiki/Administration-and-Data-Access-Tool) - Ideally extend the C and Java bindings with the new option - Update the BlobDB wiki to document the new option. Pull Request resolved: https://github.com/facebook/rocksdb/pull/10077 Reviewed By: ltamasi Differential Revision: D36884156 Pulled By: gangliao fbshipit-source-id: 942bab025f04633edca8564ed64791cb5e31627d |
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Bo Wang
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5be1579ead |
Address comments for PR #9988 and #9996 (#10020)
Summary: 1. The latest change of DecideRateLimiterPriority in https://github.com/facebook/rocksdb/pull/9988 is reverted. 2. For https://github.com/facebook/rocksdb/blob/main/db/builder.cc#L345-L349 2.1. Remove `we will regrad this verification as user reads` from the comments. 2.2. `Do not set` the read_options.rate_limiter_priority to Env::IO_USER . Flush should be a background job. 2.3. Update db_rate_limiter_test.cc. 3. In IOOptions, mark `prio` as deprecated for future removal. 4. In `file_system.h`, mark `IOPriority` as deprecated for future removal. Pull Request resolved: https://github.com/facebook/rocksdb/pull/10020 Test Plan: Unit tests. Reviewed By: ajkr Differential Revision: D36525317 Pulled By: gitbw95 fbshipit-source-id: 011ba421822f8a124e6d25a2661c4e242df6ad36 |
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Jay Zhuang
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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 |
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gitbw95
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4da34b97ee |
Set Read rate limiter priority dynamically and pass it to FS (#9996)
Summary: ### Context: Background compactions and flush generate large reads and writes, and can be long running, especially for universal compaction. In some cases, this can impact foreground reads and writes by users. ### Solution User, Flush, and Compaction reads share some code path. For this task, we update the rate_limiter_priority in ReadOptions for code paths (e.g. FindTable (mainly in BlockBasedTable::Open()) and various iterators), and eventually update the rate_limiter_priority in IOOptions for FSRandomAccessFile. **This PR is for the Read path.** The **Read:** dynamic priority for different state are listed as follows: | State | Normal | Delayed | Stalled | | ----- | ------ | ------- | ------- | | Flush (verification read in BuildTable()) | IO_USER | IO_USER | IO_USER | | Compaction | IO_LOW | IO_USER | IO_USER | | User | User provided | User provided | User provided | We will respect the read_options that the user provided and will not set it. The only sst read for Flush is the verification read in BuildTable(). It claims to be "regard as user read". **Details** 1. Set read_options.rate_limiter_priority dynamically: - User: Do not update the read_options. Use the read_options that the user provided. - Compaction: Update read_options in CompactionJob::ProcessKeyValueCompaction(). - Flush: Update read_options in BuildTable(). 2. Pass the rate limiter priority to FSRandomAccessFile functions: - After calling the FindTable(), read_options is passed through GetTableReader(table_cache.cc), BlockBasedTableFactory::NewTableReader(block_based_table_factory.cc), and BlockBasedTable::Open(). The Open() needs some updates for the ReadOptions variable and the updates are also needed for the called functions, including PrefetchTail(), PrepareIOOptions(), ReadFooterFromFile(), ReadMetaIndexblock(), ReadPropertiesBlock(), PrefetchIndexAndFilterBlocks(), and ReadRangeDelBlock(). - In RandomAccessFileReader, the functions to be updated include Read(), MultiRead(), ReadAsync(), and Prefetch(). - Update the downstream functions of NewIndexIterator(), NewDataBlockIterator(), and BlockBasedTableIterator(). ### Test Plans Add unit tests. Pull Request resolved: https://github.com/facebook/rocksdb/pull/9996 Reviewed By: anand1976 Differential Revision: D36452483 Pulled By: gitbw95 fbshipit-source-id: 60978204a4f849bb9261cb78d9bc1cb56d6008cf |
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Yanqin Jin
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3f263ef536 |
Add a temporary option for user to opt-out enforcement of SingleDelete contract (#9983)
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 |
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jsteemann
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95663ff763 |
do not call DeleteFile for not-created sst files (#9920)
Summary: When a memtable is flushed and the flush would lead to a 0 byte .sst file being created, RocksDB does not write out the empty .sst file to disk. However it still calls Env::DeleteFile() on the file as part of some cleanup procedure at the end of BuildTable(). Because the to-be-deleted file does not exist, this requires implementors of the DeleteFile() API to check if the file exists on their own code, or otherwise risk running into PathNotFound errors when DeleteFile is invoked on non-existing files. This PR fixes the situation so that when no .sst file is created, Deletefile will not be called either. TableFileCreationStarted() will still be called as before. Pull Request resolved: https://github.com/facebook/rocksdb/pull/9920 Reviewed By: ajkr Differential Revision: D36107102 Pulled By: riversand963 fbshipit-source-id: 15881ba3fa3192dd448f906280a1cfc7a68a114a |
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Levi Tamasi
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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 |
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Yanqin Jin
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0bd4dcde6b |
CompactionIterator sees consistent view of which keys are committed (#9830)
Summary:
**This PR does not affect the functionality of `DB` and write-committed transactions.**
`CompactionIterator` uses `KeyCommitted(seq)` to determine if a key in the database is committed.
As the name 'write-committed' implies, if write-committed policy is used, a key exists in the database only if
it is committed. In fact, the implementation of `KeyCommitted()` is as follows:
```
inline bool KeyCommitted(SequenceNumber seq) {
// For non-txn-db and write-committed, snapshot_checker_ is always nullptr.
return snapshot_checker_ == nullptr ||
snapshot_checker_->CheckInSnapshot(seq, kMaxSequence) == SnapshotCheckerResult::kInSnapshot;
}
```
With that being said, we focus on write-prepared/write-unprepared transactions.
A few notes:
- A key can exist in the db even if it's uncommitted. Therefore, we rely on `snapshot_checker_` to determine data visibility. We also require that all writes go through transaction API instead of the raw `WriteBatch` + `Write`, thus at most one uncommitted version of one user key can exist in the database.
- `CompactionIterator` outputs a key as long as the key is uncommitted.
Due to the above reasons, it is possible that `CompactionIterator` decides to output an uncommitted key without
doing further checks on the key (`NextFromInput()`). By the time the key is being prepared for output, the key becomes
committed because the `snapshot_checker_(seq, kMaxSequence)` becomes true in the implementation of `KeyCommitted()`.
Then `CompactionIterator` will try to zero its sequence number and hit assertion error if the key is a tombstone.
To fix this issue, we should make the `CompactionIterator` see a consistent view of the input keys. Note that
for write-prepared/write-unprepared, the background flush/compaction jobs already take a "job snapshot" before starting
processing keys. The job snapshot is released only after the entire flush/compaction finishes. We can use this snapshot
to determine whether a key is committed or not with minor change to `KeyCommitted()`.
```
inline bool KeyCommitted(SequenceNumber sequence) {
// For non-txn-db and write-committed, snapshot_checker_ is always nullptr.
return snapshot_checker_ == nullptr ||
snapshot_checker_->CheckInSnapshot(sequence, job_snapshot_) ==
SnapshotCheckerResult::kInSnapshot;
}
```
As a result, whether a key is committed or not will remain a constant throughout compaction, causing no trouble
for `CompactionIterator`s assertions.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/9830
Test Plan: make check
Reviewed By: ltamasi
Differential Revision: D35561162
Pulled By: riversand963
fbshipit-source-id: 0e00d200c195240341cfe6d34cbc86798b315b9f
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