Summary:
We forgot to recompute compaction scores after picking a universal compaction like we do in level compaction (a34b2e388e/db/compaction_picker.cc (L691-L695)
). This leads to a fairness issue where we waste compactions on CFs/DB instances that don't need it while others can starve.
Previously, ccecf3f4fb8e6eeaa06504b9d477b6db4137831a fixed the issue for the read-amp-based compaction case; this PR avoids the issue earlier and also for size-ratio-based compactions.
Closes https://github.com/facebook/rocksdb/pull/2688
Differential Revision: D5566191
Pulled By: ajkr
fbshipit-source-id: 010bccb2a107f6a76f3d3022b90aadce5cc48feb
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 specially suitable for storing multiple terabytes of data in a single database.
Start with example usage here: https://github.com/facebook/rocksdb/tree/master/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.
Design discussions are conducted in https://www.facebook.com/groups/rocksdb.dev/