RocksDB 7.5.3

7.5.2 (2022-08-02)

Bug Fixes

• Fix a bug starting in 7.4.0 in which some fsync operations might be skipped in a DB after any DropColumnFamily on that DB, until it is re-opened. This can lead to data loss on power loss. (For custom FileSystem implementations, this could lead to FSDirectory::Fsync or FSDirectory::Close after the first FSDirectory::Close; Also, valgrind could report call to close() with fd=-1.)

7.5.1 (2022-08-01)

Bug Fixes

• Fix a bug where rate_limiter_parameter is not passed into PartitionedFilterBlockReader::GetFilterPartitionBlock.

7.5.0 (2022-07-15)

New Features

• Mempurge option flag experimental_mempurge_threshold is now a ColumnFamilyOptions and can now be dynamically configured using SetOptions().
• Support backward iteration when ReadOptions::iter_start_ts is set.
• Provide support for ReadOptions.async_io with direct_io to improve Seek latency by using async IO to parallelize child iterator seek and doing asynchronous prefetching on sequential scans.
• Added support for blob caching in order to cache frequently used blobs for BlobDB.
  • User can configure the new ColumnFamilyOptions blob_cache to enable/disable blob caching.
  • Either sharing the backend cache with the block cache or using a completely separate cache is supported.
  • A new abstraction interface called BlobSource for blob read logic gives all users access to blobs, whether they are in the blob cache, secondary cache, or (remote) storage. Blobs can be potentially read both while handling user reads (Get, MultiGet, or iterator) and during compaction (while dealing with compaction filters, Merges, or garbage collection) but eventually all blob reads go through Version::GetBlob or, for MultiGet, Version::MultiGetBlob (and then get dispatched to the interface -- BlobSource).
• Add experimental tiered compaction feature AdvancedColumnFamilyOptions::preclude_last_level_data_seconds, which makes sure the new data inserted within preclude_last_level_data_seconds won't be placed on cold tier (the feature is not complete).

Public API changes

• Add metadata related structs and functions in C API, including
  • rocksdb_get_column_family_metadata() and rocksdb_get_column_family_metadata_cf() to obtain rocksdb_column_family_metadata_t.
  • rocksdb_column_family_metadata_t and its get functions & destroy function.
  • rocksdb_level_metadata_t and its and its get functions & destroy function.
  • rocksdb_file_metadata_t and its and get functions & destroy functions.
• Add suggest_compact_range() and suggest_compact_range_cf() to C API.
• When using block cache strict capacity limit (LRUCache with strict_capacity_limit=true), DB operations now fail with Status code kAborted subcode kMemoryLimit (IsMemoryLimit()) instead of kIncomplete (IsIncomplete()) when the capacity limit is reached, because Incomplete can mean other specific things for some operations. In more detail, Cache::Insert() now returns the updated Status code and this usually propagates through RocksDB to the user on failure.
• NewClockCache calls temporarily return an LRUCache (with similar characteristics as the desired ClockCache). This is because ClockCache is being replaced by a new version (the old one had unknown bugs) but this is still under development.
• Add two functions int ReserveThreads(int threads_to_be_reserved) and int ReleaseThreads(threads_to_be_released) into Env class. In the default implementation, both return 0. Newly added xxxEnv class that inherits Env should implement these two functions for thread reservation/releasing features.
• Removed Customizable support for RateLimiter and removed its CreateFromString() and Type() functions.

Bug Fixes

• Fix a bug in which backup/checkpoint can include a WAL deleted by RocksDB.
• Fix a bug where concurrent compactions might cause unnecessary further write stalling. In some cases, this might cause write rate to drop to minimum.
• Fix a bug in Logger where if dbname and db_log_dir are on different filesystems, dbname creation would fail wrt to db_log_dir path returning an error and fails to open the DB.
• Fix a CPU and memory efficiency issue introduce by #8336 which made InternalKeyComparator configurable as an unintended side effect
• Fix a bug where GenericRateLimiter could revert the bandwidth set dynamically using SetBytesPerSecond() when a user configures a structure enclosing it, e.g., using GetOptionsFromString() to configure an Options that references an existing RateLimiter object.

Behavior Change

• In leveled compaction with dynamic levelling, level multiplier is not anymore adjusted due to oversized L0. Instead, compaction score is adjusted by increasing size level target by adding incoming bytes from upper levels. This would deprioritize compactions from upper levels if more data from L0 is coming. This is to fix some unnecessary full stalling due to drastic change of level targets, while not wasting write bandwidth for compaction while writes are overloaded.
• For track_and_verify_wals_in_manifest, revert to the original behavior before #10087: syncing of live WAL file is not tracked, and we track only the synced sizes of closed WALs. (PR #10330).
• WAL compression now computes/verifies checksum during compression/decompression.

Performance Improvements

• Rather than doing total sort against all files in a level, SortFileByOverlappingRatio() to only find the top 50 files based on score. This can improve write throughput for the use cases where data is loaded in increasing key order and there are a lot of files in one LSM-tree, where applying compaction results is the bottleneck.
• In leveled compaction, L0->L1 trivial move will allow more than one file to be moved in one compaction. This would allow L0 files to be moved down faster when data is loaded in sequential order, making slowdown or stop condition harder to hit. Also seek L0->L1 trivial move when only some files qualify.
• In leveled compaction, try to trivial move more than one files if possible, up to 4 files or max_compaction_bytes. This is to allow higher write throughput for some use cases where data is loaded in sequential order, where appying compaction results is the bottleneck.

RocksDB 7.4.5

7.4.5 (2022-09-02)

Bug Fixes

• Fix a bug starting in 7.4.0 in which some fsync operations might be skipped in a DB after any DropColumnFamily on that DB, until it is re-opened. This can lead to data loss on power loss. (For custom FileSystem implementations, this could lead to FSDirectory::Fsync or FSDirectory::Close after the first FSDirectory::Close; Also, valgrind could report call to close() with fd=-1.)

RocksDB 7.4.4

7.4.4 (2022-07-19)

Public API changes

• Removed Customizable support for RateLimiter and removed its CreateFromString() and Type() functions.

Bug Fixes

• Fix a bug where GenericRateLimiter could revert the bandwidth set dynamically using SetBytesPerSecond() when a user configures a structure enclosing it, e.g., using GetOptionsFromString() to configure an Options that references an existing RateLimiter object.

7.4.3 (2022-07-13)

Behavior Changes

• For track_and_verify_wals_in_manifest, revert to the original behavior before #10087: syncing of live WAL file is not tracked, and we track only the synced sizes of closed WALs. (PR #10330).

7.4.2 (2022-06-30)

Bug Fixes

• Fix a bug in Logger where if dbname and db_log_dir are on different filesystems, dbname creation would fail wrt to db_log_dir path returning an error and fails to open the DB.

7.4.1 (2022-06-28)

Bug Fixes

• Pass rate_limiter_priority through filter block reader functions to FileSystem.

7.4.0 (2022-06-19)

Bug Fixes

• Fixed a bug in calculating key-value integrity protection for users of in-place memtable updates. In particular, the affected users would be those who configure protection_bytes_per_key > 0 on WriteBatch or WriteOptions, and configure inplace_callback != nullptr.
• Fixed a bug where a snapshot taken during SST file ingestion would be unstable.
• Fixed a bug for non-TransactionDB with avoid_flush_during_recovery = true and TransactionDB where in case of crash, min_log_number_to_keep may not change on recovery and persisting a new MANIFEST with advanced log_numbers for some column families, results in "column family inconsistency" error on second recovery. As a solution, RocksDB will persist the new MANIFEST after successfully syncing the new WAL. If a future recovery starts from the new MANIFEST, then it means the new WAL is successfully synced. Due to the sentinel empty write batch at the beginning, kPointInTimeRecovery of WAL is guaranteed to go after this point. If future recovery starts from the old MANIFEST, it means the writing the new MANIFEST failed. We won't have the "SST ahead of WAL" error.
• Fixed a bug where RocksDB DB::Open() may creates and writes to two new MANIFEST files even before recovery succeeds. Now writes to MANIFEST are persisted only after recovery is successful.
• Fix a race condition in WAL size tracking which is caused by an unsafe iterator access after container is changed.
• Fix unprotected concurrent accesses to WritableFileWriter::filesize_ by DB::SyncWAL() and DB::Put() in two write queue mode.
• Fix a bug in WAL tracking. Before this PR (#10087), calling SyncWAL() on the only WAL file of the db will not log the event in MANIFEST, thus allowing a subsequent DB::Open even if the WAL file is missing or corrupted.
• Fix a bug that could return wrong results with index_type=kHashSearch and using SetOptions to change the prefix_extractor.
• Fixed a bug in WAL tracking with wal_compression. WAL compression writes a kSetCompressionType record which is not associated with any sequence number. As result, WalManager::GetSortedWalsOfType() will skip these WALs and not return them to caller, e.g. Checkpoint, Backup, causing the operations to fail.
• Avoid a crash if the IDENTITY file is accidentally truncated to empty. A new DB ID will be written and generated on Open.
• Fixed a possible corruption for users of manual_wal_flush and/or FlushWAL(true /* sync */), together with track_and_verify_wals_in_manifest == true. For those users, losing unsynced data (e.g., due to power loss) could make future DB opens fail with a Status::Corruption complaining about missing WAL data.
• Fixed a bug in WriteBatchInternal::Append() where WAL termination point in write batch was not considered and the function appends an incorrect number of checksums.
• Fixed a crash bug introduced in 7.3.0 affecting users of MultiGet with kDataBlockBinaryAndHash.
• Add some fixes in async_io which was doing extra prefetching in shorter scans.

Public API changes

• Add new API GetUnixTime in Snapshot class which returns the unix time at which Snapshot is taken.
• Add transaction get_pinned and multi_get to C API.
• Add two-phase commit support to C API.
• Add rocksdb_transaction_get_writebatch_wi and rocksdb_transaction_rebuild_from_writebatch to C API.
• Add rocksdb_options_get_blob_file_starting_level and rocksdb_options_set_blob_file_starting_level to C API.
• Add blobFileStartingLevel and setBlobFileStartingLevel to Java API.
• Add SingleDelete for DB in C API
• Add User Defined Timestamp in C API.
  • rocksdb_comparator_with_ts_create to create timestamp aware comparator
  • Put, Get, Delete, SingleDelete, MultiGet APIs has corresponding timestamp aware APIs with suffix with_ts
  • And Add C API's for Transaction, SstFileWriter, Compaction as mentioned here
• The contract for implementations of Comparator::IsSameLengthImmediateSuccessor has been updated to work around a design bug in auto_prefix_mode.
• The API documentation for auto_prefix_mode now notes some corner cases in which it returns different results than total_order_seek, due to design bugs that are not easily fixed. Users using built-in comparators and keys at least the size of a fixed prefix length are not affected.
• Obsoleted the NUM_DATA_BLOCKS_READ_PER_LEVEL stat and introduced the NUM_LEVEL_READ_PER_MULTIGET and MULTIGET_COROUTINE_COUNT stats
• Introduced WriteOptions::protection_bytes_per_key, which can be used to enable key-value integrity protection for live updates.

New Features

• Add FileSystem::ReadAsync API in io_tracing
• Add blob garbage collection parameters blob_garbage_collection_policy and blob_garbage_collection_age_cutoff to both force-enable and force-disable GC, as well as selectively override age cutoff when using CompactRange.
• Add an extra sanity check in GetSortedWalFiles() (also used by GetLiveFilesStorageInfo(), BackupEngine, and Checkpoint) to reduce risk of successfully created backup or checkpoint failing to open because of missing WAL file.
• Add a new column family option blob_file_starting_level to enable writing blob files during flushes and compactions starting from the specified LSM tree level.
• Add support for timestamped snapshots (#9879)
• Provide support for AbortIO in posix to cancel submitted asynchronous requests using io_uring.
• Add support for rate-limiting batched MultiGet() APIs

Behavior changes

• DB::Open(), DB::OpenAsSecondary() will fail if a Logger cannot be created (#9984)
• Removed support for reading Bloom filters using obsolete block-based filter format. (Support for writing such filters was dropped in 7.0.) For good read performance on old DBs using these filters, a full compaction is required.
• Per KV checksum in write batch is verified before a write batch is written to WAL to detect any corruption to the write batch (#10114).

Performance Improvements

• When compiled with folly (Meta-internal integration; experimental in open source build), improve the locking performance (CPU efficiency) of LRUCache by using folly DistributedMutex in place of standard mutex.

RocksDB 7.4.3

7.4.3 (2022-07-13)

Behavior Changes

• For track_and_verify_wals_in_manifest, revert to the original behavior before #10087: syncing of live WAL file is not tracked, and we track only the synced sizes of closed WALs. (PR #10330).

7.4.2 (2022-06-30)

Bug Fixes

• Fix a bug in Logger where if dbname and db_log_dir are on different filesystems, dbname creation would fail wrt to db_log_dir path returning an error and fails to open the DB.

7.4.1 (2022-06-28)

Bug Fixes

• Pass rate_limiter_priority through filter block reader functions to FileSystem.

7.4.0 (2022-06-19)

Bug Fixes

• Fixed a bug in calculating key-value integrity protection for users of in-place memtable updates. In particular, the affected users would be those who configure protection_bytes_per_key > 0 on WriteBatch or WriteOptions, and configure inplace_callback != nullptr.
• Fixed a bug where a snapshot taken during SST file ingestion would be unstable.
• Fixed a bug for non-TransactionDB with avoid_flush_during_recovery = true and TransactionDB where in case of crash, min_log_number_to_keep may not change on recovery and persisting a new MANIFEST with advanced log_numbers for some column families, results in "column family inconsistency" error on second recovery. As a solution, RocksDB will persist the new MANIFEST after successfully syncing the new WAL. If a future recovery starts from the new MANIFEST, then it means the new WAL is successfully synced. Due to the sentinel empty write batch at the beginning, kPointInTimeRecovery of WAL is guaranteed to go after this point. If future recovery starts from the old MANIFEST, it means the writing the new MANIFEST failed. We won't have the "SST ahead of WAL" error.
• Fixed a bug where RocksDB DB::Open() may creates and writes to two new MANIFEST files even before recovery succeeds. Now writes to MANIFEST are persisted only after recovery is successful.
• Fix a race condition in WAL size tracking which is caused by an unsafe iterator access after container is changed.
• Fix unprotected concurrent accesses to WritableFileWriter::filesize_ by DB::SyncWAL() and DB::Put() in two write queue mode.
• Fix a bug in WAL tracking. Before this PR (#10087), calling SyncWAL() on the only WAL file of the db will not log the event in MANIFEST, thus allowing a subsequent DB::Open even if the WAL file is missing or corrupted.
• Fix a bug that could return wrong results with index_type=kHashSearch and using SetOptions to change the prefix_extractor.
• Fixed a bug in WAL tracking with wal_compression. WAL compression writes a kSetCompressionType record which is not associated with any sequence number. As result, WalManager::GetSortedWalsOfType() will skip these WALs and not return them to caller, e.g. Checkpoint, Backup, causing the operations to fail.
• Avoid a crash if the IDENTITY file is accidentally truncated to empty. A new DB ID will be written and generated on Open.
• Fixed a possible corruption for users of manual_wal_flush and/or FlushWAL(true /* sync */), together with track_and_verify_wals_in_manifest == true. For those users, losing unsynced data (e.g., due to power loss) could make future DB opens fail with a Status::Corruption complaining about missing WAL data.
• Fixed a bug in WriteBatchInternal::Append() where WAL termination point in write batch was not considered and the function appends an incorrect number of checksums.
• Fixed a crash bug introduced in 7.3.0 affecting users of MultiGet with kDataBlockBinaryAndHash.
• Add some fixes in async_io which was doing extra prefetching in shorter scans.

Public API changes

• Add new API GetUnixTime in Snapshot class which returns the unix time at which Snapshot is taken.
• Add transaction get_pinned and multi_get to C API.
• Add two-phase commit support to C API.
• Add rocksdb_transaction_get_writebatch_wi and rocksdb_transaction_rebuild_from_writebatch to C API.
• Add rocksdb_options_get_blob_file_starting_level and rocksdb_options_set_blob_file_starting_level to C API.
• Add blobFileStartingLevel and setBlobFileStartingLevel to Java API.
• Add SingleDelete for DB in C API
• Add User Defined Timestamp in C API.
  • rocksdb_comparator_with_ts_create to create timestamp aware comparator
  • Put, Get, Delete, SingleDelete, MultiGet APIs has corresponding timestamp aware APIs with suffix with_ts
  • And Add C API's for Transaction, SstFileWriter, Compaction as mentioned here
• The contract for implementations of Comparator::IsSameLengthImmediateSuccessor has been updated to work around a design bug in auto_prefix_mode.
• The API documentation for auto_prefix_mode now notes some corner cases in which it returns different results than total_order_seek, due to design bugs that are not easily fixed. Users using built-in comparators and keys at least the size of a fixed prefix length are not affected.
• Obsoleted the NUM_DATA_BLOCKS_READ_PER_LEVEL stat and introduced the NUM_LEVEL_READ_PER_MULTIGET and MULTIGET_COROUTINE_COUNT stats
• Introduced WriteOptions::protection_bytes_per_key, which can be used to enable key-value integrity protection for live updates.

New Features

• Add FileSystem::ReadAsync API in io_tracing
• Add blob garbage collection parameters blob_garbage_collection_policy and blob_garbage_collection_age_cutoff to both force-enable and force-disable GC, as well as selectively override age cutoff when using CompactRange.
• Add an extra sanity check in GetSortedWalFiles() (also used by GetLiveFilesStorageInfo(), BackupEngine, and Checkpoint) to reduce risk of successfully created backup or checkpoint failing to open because of missing WAL file.
• Add a new column family option blob_file_starting_level to enable writing blob files during flushes and compactions starting from the specified LSM tree level.
• Add support for timestamped snapshots (#9879)
• Provide support for AbortIO in posix to cancel submitted asynchronous requests using io_uring.
• Add support for rate-limiting batched MultiGet() APIs

Behavior changes

• DB::Open(), DB::OpenAsSecondary() will fail if a Logger cannot be created (#9984)
• Removed support for reading Bloom filters using obsolete block-based filter format. (Support for writing such filters was dropped in 7.0.) For good read performance on old DBs using these filters, a full compaction is required.
• Per KV checksum in write batch is verified before a write batch is written to WAL to detect any corruption to the write batch (#10114).

Performance Improvements

• When compiled with folly (Meta-internal integration; experimental in open source build), improve the locking performance (CPU efficiency) of LRUCache by using folly DistributedMutex in place of standard mutex.

RocksDB 7.3.1

7.3.1 (2022-06-08)

Bug Fixes

• Fix a bug in WAL tracking. Before this PR (#10087), calling SyncWAL() on the only WAL file of the db will not log the event in MANIFEST, thus allowing a subsequent DB::Open even if the WAL file is missing or corrupted.
• Fixed a bug for non-TransactionDB with avoid_flush_during_recovery = true and TransactionDB where in case of crash, min_log_number_to_keep may not change on recovery and persisting a new MANIFEST with advanced log_numbers for some column families, results in "column family inconsistency" error on second recovery. As a solution, RocksDB will persist the new MANIFEST after successfully syncing the new WAL. If a future recovery starts from the new MANIFEST, then it means the new WAL is successfully synced. Due to the sentinel empty write batch at the beginning, kPointInTimeRecovery of WAL is guaranteed to go after this point. If future recovery starts from the old MANIFEST, it means the writing the new MANIFEST failed. We won't have the "SST ahead of WAL" error.
• Fixed a bug where RocksDB DB::Open() may creates and writes to two new MANIFEST files even before recovery succeeds. Now writes to MANIFEST are persisted only after recovery is successful.

7.3.0 (2022-05-20)

Bug Fixes

• Fixed a bug where manual flush would block forever even though flush options had wait=false.
• Fixed a bug where RocksDB could corrupt DBs with avoid_flush_during_recovery == true by removing valid WALs, leading to Status::Corruption with message like "SST file is ahead of WALs" when attempting to reopen.
• Fixed a bug in async_io path where incorrect length of data is read by FilePrefetchBuffer if data is consumed from two populated buffers and request for more data is sent.
• Fixed a CompactionFilter bug. Compaction filter used to use Delete to remove keys, even if the keys should be removed with SingleDelete. Mixing Delete and SingleDelete may cause undefined behavior.
• Fixed a bug in WritableFileWriter::WriteDirect and WritableFileWriter::WriteDirectWithChecksum. The rate_limiter_priority specified in ReadOptions was not passed to the RateLimiter when requesting a token.
• Fixed a bug which might cause process crash when I/O error happens when reading an index block in MultiGet().

New Features

• DB::GetLiveFilesStorageInfo is ready for production use.
• Add new stats PREFETCHED_BYTES_DISCARDED which records number of prefetched bytes discarded by RocksDB FilePrefetchBuffer on destruction and POLL_WAIT_MICROS records wait time for FS::Poll API completion.
• RemoteCompaction supports table_properties_collector_factories override on compaction worker.
• Start tracking SST unique id in MANIFEST, which will be used to verify with SST properties during DB open to make sure the SST file is not overwritten or misplaced. A db option verify_sst_unique_id_in_manifest is introduced to enable/disable the verification, if enabled all SST files will be opened during DB-open to verify the unique id (default is false), so it's recommended to use it with max_open_files = -1 to pre-open the files.
• Added the ability to concurrently read data blocks from multiple files in a level in batched MultiGet. This can be enabled by setting the async_io option in ReadOptions. Using this feature requires a FileSystem that supports ReadAsync (PosixFileSystem is not supported yet for this), and for RocksDB to be compiled with folly and c++20.
• Add FileSystem::ReadAsync API in io_tracing.

Public API changes

• Add rollback_deletion_type_callback to TransactionDBOptions so that write-prepared transactions know whether to issue a Delete or SingleDelete to cancel a previous key written during prior prepare phase. The PR aims to prevent mixing SingleDeletes and Deletes for the same key that can lead to undefined behaviors for write-prepared transactions.
• EXPERIMENTAL: Add new API AbortIO in file_system to abort the read requests submitted asynchronously.
• CompactionFilter::Decision has a new value: kRemoveWithSingleDelete. If CompactionFilter returns this decision, then CompactionIterator will use SingleDelete to mark a key as removed.
• Renamed CompactionFilter::Decision::kRemoveWithSingleDelete to kPurge since the latter sounds more general and hides the implementation details of how compaction iterator handles keys.
• Added ability to specify functions for Prepare and Validate to OptionsTypeInfo. Added methods to OptionTypeInfo to set the functions via an API. These methods are intended for RocksDB plugin developers for configuration management.
• Added a new immutable db options, enforce_single_del_contracts. If set to false (default is true), compaction will NOT fail due to a single delete followed by a delete for the same key. The purpose of this temporay option is to help existing use cases migrate.
• Introduce BlockBasedTableOptions::cache_usage_options and use that to replace BlockBasedTableOptions::reserve_table_builder_memory and BlockBasedTableOptions::reserve_table_reader_memory.
• Changed GetUniqueIdFromTableProperties to return a 128-bit unique identifier, which will be the standard size now. The old functionality (192-bit) is available from GetExtendedUniqueIdFromTableProperties. Both functions are no longer "experimental" and are ready for production use.
• In IOOptions, mark prio as deprecated for future removal.
• In file_system.h, mark IOPriority as deprecated for future removal.
• Add an option, CompressionOptions::use_zstd_dict_trainer, to indicate whether zstd dictionary trainer should be used for generating zstd compression dictionaries. The default value of this option is true for backward compatibility. When this option is set to false, zstd API ZDICT_finalizeDictionary is used to generate compression dictionaries.
• Seek API which positions itself every LevelIterator on the correct data block in the correct SST file which can be parallelized if ReadOptions.async_io option is enabled.
• Add new stat number_async_seek in PerfContext that indicates number of async calls made by seek to prefetch data.

Bug Fixes

• RocksDB calls FileSystem::Poll API during FilePrefetchBuffer destruction which impacts performance as it waits for read requets completion which is not needed anymore. Calling FileSystem::AbortIO to abort those requests instead fixes that performance issue.
• Fixed unnecessary block cache contention when queries within a MultiGet batch and across parallel batches access the same data block, which previously could cause severely degraded performance in this unusual case. (In more typical MultiGet cases, this fix is expected to yield a small or negligible performance improvement.)

Behavior changes

• Enforce the existing contract of SingleDelete so that SingleDelete cannot be mixed with Delete because it leads to undefined behavior. Fix a number of unit tests that violate the contract but happen to pass.
• ldb --try_load_options default to true if --db is specified and not creating a new DB, the user can still explicitly disable that by --try_load_options=false (or explicitly enable that by --try_load_options).
• During Flush write or Compaction write/read, the WriteController is used to determine whether DB writes are stalled or slowed down. The priority (Env::IOPriority) can then be determined accordingly and be passed in IOOptions to the file system.

RocksDB 7.2.2

7.2.2 (2022-04-28)

Bug Fixes

• Fixed a bug in async_io path where incorrect length of data is read by FilePrefetchBuffer if data is consumed from two populated buffers and request for more data is sent.

7.2.1 (2022-04-26)

Bug Fixes

• Fixed a bug where RocksDB could corrupt DBs with avoid_flush_during_recovery == true by removing valid WALs, leading to Status::Corruption with message like "SST file is ahead of WALs" when attempting to reopen.
• RocksDB calls FileSystem::Poll API during FilePrefetchBuffer destruction which impacts performance as it waits for read requets completion which is not needed anymore. Calling FileSystem::AbortIO to abort those requests instead fixes that performance issue.

7.2.0 (2022-04-15)

Bug Fixes

• Fixed bug which caused rocksdb failure in the situation when rocksdb was accessible using UNC path
• Fixed a race condition when 2PC is disabled and WAL tracking in the MANIFEST is enabled. The race condition is between two background flush threads trying to install flush results, causing a WAL deletion not tracked in the MANIFEST. A future DB open may fail.
• Fixed a heap use-after-free race with DropColumnFamily.
• Fixed a bug that rocksdb.read.block.compaction.micros cannot track compaction stats (#9722).
• Fixed file_type, relative_filename and directory fields returned by GetLiveFilesMetaData(), which were added in inheriting from FileStorageInfo.
• Fixed a bug affecting track_and_verify_wals_in_manifest. Without the fix, application may see "open error: Corruption: Missing WAL with log number" while trying to open the db. The corruption is a false alarm but prevents DB open (#9766).
• Fix segfault in FilePrefetchBuffer with async_io as it doesn't wait for pending jobs to complete on destruction.
• Fix ERROR_HANDLER_AUTORESUME_RETRY_COUNT stat whose value was set wrong in portal.h
• Fixed a bug for non-TransactionDB with avoid_flush_during_recovery = true and TransactionDB where in case of crash, min_log_number_to_keep may not change on recovery and persisting a new MANIFEST with advanced log_numbers for some column families, results in "column family inconsistency" error on second recovery. As a solution the corrupted WALs whose numbers are larger than the corrupted wal and smaller than the new WAL will be moved to archive folder.
• Fixed a bug in RocksDB DB::Open() which may creates and writes to two new MANIFEST files even before recovery succeeds. Now writes to MANIFEST are persisted only after recovery is successful.

New Features

• For db_bench when --seed=0 or --seed is not set then it uses the current time as the seed value. Previously it used the value 1000.
• For db_bench when --benchmark lists multiple tests and each test uses a seed for a RNG then the seeds across tests will no longer be repeated.
• Added an option to dynamically charge an updating estimated memory usage of block-based table reader to block cache if block cache available. To enable this feature, set BlockBasedTableOptions::reserve_table_reader_memory = true.
• Add new stat ASYNC_READ_BYTES that calculates number of bytes read during async read call and users can check if async code path is being called by RocksDB internal automatic prefetching for sequential reads.
• Enable async prefetching if ReadOptions.readahead_size is set along with ReadOptions.async_io in FilePrefetchBuffer.
• Add event listener support on remote compaction compactor side.
• Added a dedicated integer DB property rocksdb.live-blob-file-garbage-size that exposes the total amount of garbage in the blob files in the current version.
• RocksDB does internal auto prefetching if it notices sequential reads. It starts with readahead size initial_auto_readahead_size which now can be configured through BlockBasedTableOptions.
• Add a merge operator that allows users to register specific aggregation function so that they can does aggregation using different aggregation types for different keys. See comments in include/rocksdb/utilities/agg_merge.h for actual usage. The feature is experimental and the format is subject to change and we won't provide a migration tool.
• Meta-internal / Experimental: Improve CPU performance by replacing many uses of std::unordered_map with folly::F14FastMap when RocksDB is compiled together with Folly.
• Experimental: Add CompressedSecondaryCache, a concrete implementation of rocksdb::SecondaryCache, that integrates with compression libraries (e.g. LZ4) to hold compressed blocks.

Behavior changes

• Disallow usage of commit-time-write-batch for write-prepared/write-unprepared transactions if TransactionOptions::use_only_the_last_commit_time_batch_for_recovery is false to prevent two (or more) uncommitted versions of the same key in the database. Otherwise, bottommost compaction may violate the internal key uniqueness invariant of SSTs if the sequence numbers of both internal keys are zeroed out (#9794).
• Make DB::GetUpdatesSince() return NotSupported early for write-prepared/write-unprepared transactions, as the API contract indicates.

Public API changes

• Exposed APIs to examine results of block cache stats collections in a structured way. In particular, users of GetMapProperty() with property kBlockCacheEntryStats can now use the functions in BlockCacheEntryStatsMapKeys to find stats in the map.
• Add fail_if_not_bottommost_level to IngestExternalFileOptions so that ingestion will fail if the file(s) cannot be ingested to the bottommost level.
• Add output parameter is_in_sec_cache to SecondaryCache::Lookup(). It is to indicate whether the handle is possibly erased from the secondary cache after the Lookup.

RocksDB 7.1.2

7.1.2 (2022-04-19)

Bug Fixes

• Fixed bug which caused rocksdb failure in the situation when rocksdb was accessible using UNC path
• Fixed a race condition when 2PC is disabled and WAL tracking in the MANIFEST is enabled. The race condition is between two background flush threads trying to install flush results, causing a WAL deletion not tracked in the MANIFEST. A future DB open may fail.
• Fixed a heap use-after-free race with DropColumnFamily.
• Fixed a bug that rocksdb.read.block.compaction.micros cannot track compaction stats (#9722).
• Fixed file_type, relative_filename and directory fields returned by GetLiveFilesMetaData(), which were added in inheriting from FileStorageInfo.
• Fixed a bug affecting track_and_verify_wals_in_manifest. Without the fix, application may see "open error: Corruption: Missing WAL with log number" while trying to open the db. The corruption is a false alarm but prevents DB open (#9766).

RocksDB 7.1.1

7.1.1 (2022-04-07)

Bug Fixes

• Fix segfault in FilePrefetchBuffer with async_io as it doesn't wait for pending jobs to complete on destruction.

7.1.0 (2022-03-23)

New Features

• Allow WriteBatchWithIndex to index a WriteBatch that includes keys with user-defined timestamps. The index itself does not have timestamp.
• Add support for user-defined timestamps to write-committed transaction without API change. The TransactionDB layer APIs do not allow timestamps because we require that all user-defined-timestamps-aware operations go through the Transaction APIs.
• Added BlobDB options to ldb
• BlockBasedTableOptions::detect_filter_construct_corruption can now be dynamically configured using DB::SetOptions.
• Automatically recover from retryable read IO errors during backgorund flush/compaction.
• Experimental support for preserving file Temperatures through backup and restore, and for updating DB metadata for outside changes to file Temperature (UpdateManifestForFilesState or ldb update_manifest --update_temperatures).
• Experimental support for async_io in ReadOptions which is used by FilePrefetchBuffer to prefetch some of the data asynchronously, if reads are sequential and auto readahead is enabled by rocksdb internally.

Bug Fixes

• Fixed a major performance bug in which Bloom filters generated by pre-7.0 releases are not read by early 7.0.x releases (and vice-versa) due to changes to FilterPolicy::Name() in #9590. This can severely impact read performance and read I/O on upgrade or downgrade with existing DB, but not data correctness.
• Fixed a data race on versions_ between DBImpl::ResumeImpl() and threads waiting for recovery to complete (#9496)
• Fixed a bug caused by race among flush, incoming writes and taking snapshots. Queries to snapshots created with these race condition can return incorrect result, e.g. resurfacing deleted data.
• Fixed a bug that DB flush uses options.compression even options.compression_per_level is set.
• Fixed a bug that DisableManualCompaction may assert when disable an unscheduled manual compaction.
• Fix a race condition when cancel manual compaction with DisableManualCompaction. Also DB close can cancel the manual compaction thread.
• Fixed a potential timer crash when open close DB concurrently.
• Fixed a race condition for alive_log_files_ in non-two-write-queues mode. The race is between the write_thread_ in WriteToWAL() and another thread executing FindObsoleteFiles(). The race condition will be caught if __glibcxx_requires_nonempty is enabled.
• Fixed a bug that Iterator::Refresh() reads stale keys after DeleteRange() performed.
• Fixed a race condition when disable and re-enable manual compaction.
• Fixed automatic error recovery failure in atomic flush.
• Fixed a race condition when mmaping a WritableFile on POSIX.

Public API changes

• Added pure virtual FilterPolicy::CompatibilityName(), which is needed for fixing major performance bug involving FilterPolicy naming in SST metadata without affecting Customizable aspect of FilterPolicy. This change only affects those with their own custom or wrapper FilterPolicy classes.
• options.compression_per_level is dynamically changeable with SetOptions().
• Added WriteOptions::rate_limiter_priority. When set to something other than Env::IO_TOTAL, the internal rate limiter (DBOptions::rate_limiter) will be charged at the specified priority for writes associated with the API to which the WriteOptions was provided. Currently the support covers automatic WAL flushes, which happen during live updates (Put(), Write(), Delete(), etc.) when WriteOptions::disableWAL == false and DBOptions::manual_wal_flush == false.
• Add DB::OpenAndTrimHistory API. This API will open DB and trim data to the timestamp specified by trim_ts (The data with timestamp larger than specified trim bound will be removed). This API should only be used at a timestamp-enabled column families recovery. If the column family doesn't have timestamp enabled, this API won't trim any data on that column family. This API is not compatible with avoid_flush_during_recovery option.
• Remove BlockBasedTableOptions.hash_index_allow_collision which already takes no effect.

RocksDB 7.0.4

7.0.4 (2022-03-29)

Bug Fixes

• Fixed a race condition when disable and re-enable manual compaction.
• Fixed a race condition for alive_log_files_ in non-two-write-queues mode. The race is between the write_thread_ in WriteToWAL() and another thread executing FindObsoleteFiles(). The race condition will be caught if __glibcxx_requires_nonempty is enabled.
• Fixed a race condition when mmaping a WritableFile on POSIX.
• Fixed a race condition when 2PC is disabled and WAL tracking in the MANIFEST is enabled. The race condition is between two background flush threads trying to install flush results, causing a WAL deletion not tracked in the MANIFEST. A future DB open may fail.
• Fixed a heap use-after-free race with DropColumnFamily.
• Fixed a bug that rocksdb.read.block.compaction.micros cannot track compaction stats (#9722).

RocksDB 6.29.5

6.29.5 (2022-03-29)

Bug Fixes

• Fixed a race condition for alive_log_files_ in non-two-write-queues mode. The race is between the write_thread_ in WriteToWAL() and another thread executing FindObsoleteFiles(). The race condition will be caught if __glibcxx_requires_nonempty is enabled.
• Fixed a race condition when mmaping a WritableFile on POSIX.
• Fixed a race condition when 2PC is disabled and WAL tracking in the MANIFEST is enabled. The race condition is between two background flush threads trying to install flush results, causing a WAL deletion not tracked in the MANIFEST. A future DB open may fail.
• Fixed a heap use-after-free race with DropColumnFamily.
• Fixed a bug that rocksdb.read.block.compaction.micros cannot track compaction stats (#9722).