Xingbo Wang
de7b8e8f7d
Summary:
This PR adds flush observability for debugging write stalls and flush bottlenecks.
Changes include:
- Add flush reason tickers for physical flush jobs:
- rocksdb.flush.reason.write_buffer_full
- rocksdb.flush.reason.write_buffer_manager
- rocksdb.flush.reason.memtable_max_range_deletions
- Add flush memtable size histograms:
- rocksdb.flush.memtable.memory.bytes
- rocksdb.flush.memtable.total.data.size.bytes
- rocksdb.flush.write_buffer_full.memtable.memory.bytes
- rocksdb.flush.write_buffer_manager.memtable.memory.bytes
- Add FlushReason::kMemtableMaxRangeDeletions and propagate it from memtables when memtable_max_range_deletions triggers a flush.
- Preserve atomic flush as a single request-level reason. For atomic flush, the reason is derived only from CFs that scheduled the flush, not every CF selected into the atomic flush cut.
- Add atomic flush request-level counters:
- rocksdb.atomic_flush.request.reason.write_buffer_full
- rocksdb.atomic_flush.request.reason.write_buffer_manager
- rocksdb.atomic_flush.request.reason.memtable_max_range_deletions
- rocksdb.atomic_flush.request.reason.other
- Keep existing per-CF flush job reason counters unchanged. Under atomic flush, rocksdb.flush.reason.* still counts physical CF flush jobs, while rocksdb.atomic_flush.request.reason.* counts one logical atomic flush request.
- Wire the new flush reason, ticker, and histogram types through Java and JNI bindings.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/14898
Test Plan: CI
Reviewed By: anand1976
Differential Revision: D110214337
Pulled By: xingbowang
fbshipit-source-id: 4a445c4175d2e09ff5edbe66fde81fa00bb9e8da
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.