77eef9fa2e
Summary: Pull Request resolved: https://github.com/facebook/rocksdb/pull/15376 RocksDB `DBIter` polled `ROCKSDB_THREAD_YIELD_CHECK_ABORT()` while scanning ordinary forward entries, but reverse `Prev()` / `SeekForPrev()` traversal and `MergeValuesNewToOld()` could scan many internal keys without polling. Long tombstone, version, or merge-operand runs could therefore keep a MyRocks query running after `KILL QUERY` until the scan finished. Poll the existing hook before each potentially expensive internal iterator movement in the forward scan, forward merge-operand scan, and four reverse traversal loops. Mark the abort branch `UNLIKELY`; on abort, invalidate the iterator and return `Status::Aborted("Query abort.")`. MyRocks already defines the hook and maps `Status::Aborted` for a killed THD to `HA_ERR_QUERY_INTERRUPTED`, so no MyRocks change is required. There are no API, ABI, or persisted-format changes. The hook remains Linux-only, and cancellation remains cooperative: this cannot preempt an individual underlying iterator operation that never returns. The change is rebased onto current master, including D124377137's fix for the unrelated `WriteBufferManagerTest.FlushPolicyRetiresAndRestartsHandoffWorkers` failures seen on V1. Reviewed By: pdillinger Differential Revision: D124441004 fbshipit-source-id: 53bf83a00121b42566dbd93de232e973cbe78688
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.