facebook/rocksdb v8.4.4

RocksDB 8.4.4

on GitHub

8.4.4 (09/01/2023)

Bug Fixes

• Fix a bug where if there is an error reading from offset 0 of a file from L1+ and that the file is not the first file in the sorted run, data can be lost in compaction and read/scan can return incorrect results.
• Fix a bug where iterator may return incorrect result for DeleteRange() users if there was an error reading from a file.
• Fixed a race condition in GenericRateLimiter that could cause it to stop granting requests

8.4.3 (07/27/2023)

Bug Fixes

• Fix use_after_free bug in async_io MultiReads when underlying FS enabled kFSBuffer. kFSBuffer is when underlying FS pass their own buffer instead of using RocksDB scratch in FSReadRequest.

8.4.0 (06/26/2023)

New Features

• Add FSReadRequest::fs_scratch which is a data buffer allocated and provided by underlying FileSystem to RocksDB during reads, when FS wants to provide its own buffer with data instead of using RocksDB provided FSReadRequest::scratch. This can help in cpu optimization by avoiding copy from file system's buffer to RocksDB buffer. More details on how to use/enable it in file_system.h. Right now its supported only for MultiReads(async + sync) with non direct io.
• Start logging non-zero user-defined timestamp sizes in WAL to signal user key format in subsequent records and use it during recovery. This change will break recovery from WAL files written by early versions that contain user-defined timestamps. The workaround is to ensure there are no WAL files to recover (i.e. by flushing before close) before upgrade.
• Added new property "rocksdb.obsolete-sst-files-size-property" that reports the size of SST files that have become obsolete but have not yet been deleted or scheduled for deletion
• 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 is only explicitly record if it's false.
• Add a new option OptimisticTransactionDBOptions::shared_lock_buckets that enables sharing mutexes for validating transactions between DB instances, for better balancing memory efficiency and validation contention across DB instances. Different column families and DBs also now use different hash seeds in this validation, so that the same set of key names will not contend across DBs or column families.
• Add a new ticker rocksdb.files.marked.trash.deleted to track the number of trash files deleted by background thread from the trash queue.
• Add an API NewTieredVolatileCache() in include/rocksdb/cache.h to allocate an instance of a block cache with a primary block cache tier and a compressed secondary cache tier. A cache of this type distributes memory reservations against the block cache, such as WriteBufferManager, table reader memory etc., proportionally across both the primary and compressed secondary cache.
• Add WaitForCompact() to wait for all flush and compactions jobs to finish. Jobs to wait include the unscheduled (queued, but not scheduled yet).
• Add WriteBatch::Release() that releases the batch's serialized data to the caller.

Public API Changes

• Add C API rocksdb_options_add_compact_on_deletion_collector_factory_del_ratio.
• change the FileSystem::use_async_io() API to SupportedOps API in order to extend it to various operations supported by underlying FileSystem. Right now it contains FSSupportedOps::kAsyncIO and FSSupportedOps::kFSBuffer. More details about FSSupportedOps in filesystem.h
• Add new tickers: rocksdb.error.handler.bg.error.count, rocksdb.error.handler.bg.io.error.count, rocksdb.error.handler.bg.retryable.io.error.count to replace the misspelled ones: rocksdb.error.handler.bg.errro.count, rocksdb.error.handler.bg.io.errro.count, rocksdb.error.handler.bg.retryable.io.errro.count ('error' instead of 'errro'). Users should switch to use the new tickers before 9.0 release as the misspelled old tickers will be completely removed then.
• Overload the API CreateColumnFamilyWithImport() to support creating ColumnFamily by importing multiple ColumnFamilies It requires that CFs should not overlap in user key range.

Behavior Changes

• Change the default value for option level_compaction_dynamic_level_bytes to true. This affects users who use leveled compaction and do not set this option explicitly. These users may see additional background compactions following DB open. These compactions help to shape the LSM according to level_compaction_dynamic_level_bytes such that the size of each level Ln is approximately size of Ln-1 * max_bytes_for_level_multiplier. Turning on this option has other benefits too: see more detail in wiki: https://github.com/facebook/rocksdb/wiki/Leveled-Compaction#option-level_compaction_dynamic_level_bytes-and-levels-target-size and in option comment in advanced_options.h (#11525).
• For Leveled Compaction users, CompactRange() will now always try to compact to the last non-empty level. (#11468)
  For Leveled Compaction users, CompactRange() with bottommost_level_compaction = BottommostLevelCompaction::kIfHaveCompactionFilter will behave similar to kForceOptimized in that it will skip files created during this manual compaction when compacting files in the bottommost level. (#11468)
• RocksDB will try to drop range tombstones during non-bottommost compaction when it is safe to do so. (#11459)
• When a DB is openend with allow_ingest_behind=true (currently only Universal compaction is supported), files in the last level, i.e. the ingested files, will not be included in any compaction. (#11489)
• Statistics rocksdb.sst.read.micros scope is expanded to all SST reads except for file ingestion and column family import (some compaction reads were previously excluded).

Bug Fixes

• Reduced cases of illegally using Env::Default() during static destruction by never destroying the internal PosixEnv itself (except for builds checking for memory leaks). (#11538)
• Fix extra prefetching during seek in async_io when BlockBasedTableOptions.num_file_reads_for_auto_readahead is 1 leading to extra reads than required.
• Fix a bug where compactions that are qualified to be run as 2 subcompactions were only run as one subcompaction.
• Fix a use-after-move bug in block.cc.