7824444bfc
Summary: Under a tailing workload, there were increased block cache misses when a memtable was flushed because we were rebuilding iterators in that case since the version set changed. This was exacerbated in the case of iterate_upper_bound, since file iterators which were over the iterate_upper_bound would have been deleted and are now brought back as part of the Rebuild, only to be deleted again. We now renew the iterators and only build iterators for files which are added and delete file iterators for files which are deleted. Refer to https://reviews.facebook.net/D50463 for previous version Test Plan: DBTestTailingIterator.TailingIteratorTrimSeekToNext Reviewers: anthony, IslamAbdelRahman, igor, tnovak, yhchiang, sdong Reviewed By: sdong Subscribers: yhchiang, march, dhruba, leveldb, lovro Differential Revision: https://reviews.facebook.net/D50679
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/