Jay Huh
43d60bfe9e
Summary: Pull Request resolved: https://github.com/facebook/rocksdb/pull/14887 This reverts two changes to the range-lock endpoint comparator and restores the prior, direction-agnostic behavior: - https://github.com/facebook/rocksdb/pull/14831 ("Fix range lock manager crash with reverse comparator"), which made RangeTreeLockManager::CompareDbtEndpoints reverse-aware, and - https://github.com/facebook/rocksdb/pull/14880 (a follow-up that only corrected the equal-length / point-range branch). Why: #14831 taught the endpoint comparator about reverse-ordered column families by flipping the suffix tie-break based on comparator direction. However, callers that use range locking on a reverse-ordered CF already flip the start/end endpoints themselves before calling lock_range() -- for example, MyRocks does this in ha_rocksdb::set_range_lock() (see its "RangeFlagsShouldBeFlippedForRevCF" comment). The two corrections stack and produce left > right again, which: (a) trips paranoid_invariant(compare(left, right) <= 0) in toku::locktree::try_acquire_lock() and aborts on equality/point locks, and (b) for range scans, mis-orders the endpoints and produces an incorrect lock range, leading to silent correctness issues under concurrency. #14880 only addressed (a) (the equal-length / point-range branch), not (b), so it was an incomplete fix at the wrong layer. Decision: keep CompareDbtEndpoints direction-agnostic and make it an explicit caller requirement to pass a flipped (swapped start/end, with negated infimum/supremum flags) range for range locking to work on a reverse-ordered column family. A function-level comment documenting this contract is added so reverse-awareness is not reintroduced here. Removes the RangeLockWithReverseComparator unit test added by #14831 (it asserts the reverted direction-flipped ordering). Keeps a regression test that a point range lock [infimum(K), supremum(K)] works on a reverse-comparator column family. Reviewed By: xingbowang Differential Revision: D109713989 fbshipit-source-id: 4ea0999c92645e1adc9cd1114d924cad142f2001
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.