RocksDB Release v5.17.2

Rocksdb Change Log

5.17.2 (10/24/2018)

Bug Fixes

• Fix the bug that WriteBatchWithIndex's SeekForPrev() doesn't see the entries with the same key.

5.17.1 (10/16/2018)

Bug Fixes

• Fix slow flush/compaction when DB contains many snapshots. The problem became noticeable to us in DBs with 100,000+ snapshots, though it will affect others at different thresholds.
• Properly set the stop key for a truncated manual CompactRange
• Fix corner case where a write group leader blocked due to write stall blocks other writers in queue with WriteOptions::no_slowdown set.

New Features

• Introduced CacheAllocator, which lets the user specify custom allocator for memory in block cache.

5.17.0 (10/05/2018)

Public API Change

• OnTableFileCreated will now be called for empty files generated during compaction. In that case, TableFileCreationInfo::file_path will be "(nil)" and TableFileCreationInfo::file_size will be zero.
• Add FlushOptions::allow_write_stall, which controls whether Flush calls start working immediately, even if it causes user writes to stall, or will wait until flush can be performed without causing write stall (similar to CompactRangeOptions::allow_write_stall). Note that the default value is false, meaning we add delay to Flush calls until stalling can be avoided when possible. This is behavior change compared to previous RocksDB versions, where Flush calls didn't check if they might cause stall or not.
• Application using PessimisticTransactionDB is expected to rollback/commit recovered transactions before starting new ones. This assumption is used to skip concurrency control during recovery.