dc4006480b
Summary: Pull Request resolved: https://github.com/facebook/rocksdb/pull/15052 When `persist_user_defined_timestamps=false`, `full_history_ts_low` is automatically advanced by flushes to just above the newest timestamp in the flushed memtable. This creates the following race: ``` Reader Concurrent writer / flush ------ ------------------------- T0: Sample read timestamp: 892779959679761 T1: Write with a newer timestamp: 892779963289806 T2: Flush the memtable. T3: Advance full_history_ts_low: 892779963289807 T4: Validate the read: 892779959679761 < 892779963289807 Result: InvalidArgument ``` This is expected RocksDB behavior because history below `full_history_ts_low` is no longer guaranteed to be complete. However, the stress test intends these operations to read the latest value. This change adds ten seconds of headroom to read timestamps when user-defined timestamps are not persisted. This makes it substantially less likely that a concurrent flush overtakes a read timestamp. Unlike tolerating every `InvalidArgument`, this preserves reporting for genuine timestamp errors. Persisted read timestamps and write timestamps remain unchanged. The triggering non-default options are `persist_user_defined_timestamps=false` and `user_timestamp_size=8`. Reviewed By: xingbowang Differential Revision: D114565978 fbshipit-source-id: 6939df9163fd97fefec2fa185bc2ca72231ab04f
RocksDB: A Persistent Key-Value Store for Flash and RAM Storage
RocksDB is developed and maintained by Facebook Database Engineering Team. It is built on earlier work on LevelDB by Sanjay Ghemawat (sanjay@google.com) and Jeff Dean (jeff@google.com)
This code is a library that forms the core building block for a fast key-value server, especially suited for storing data on flash drives. It has a Log-Structured-Merge-Database (LSM) design with flexible tradeoffs between Write-Amplification-Factor (WAF), Read-Amplification-Factor (RAF) and Space-Amplification-Factor (SAF). It has multi-threaded compactions, making it especially suitable for storing multiple terabytes of data in a single database.
Start with example usage here: https://github.com/facebook/rocksdb/tree/main/examples
See the github wiki for more explanation.
The public interface is in include/. Callers should not include or
rely on the details of any other header files in this package. Those
internal APIs may be changed without warning.
Questions and discussions are welcome on the RocksDB Developers Public Facebook group and email list on Google Groups.
License
RocksDB is dual-licensed under both the GPLv2 (found in the COPYING file in the root directory) and Apache 2.0 License (found in the LICENSE.Apache file in the root directory). You may select, at your option, one of the above-listed licenses.