Summary: See https://gist.github.com/mdcallag/89ebb2b8cbd331854865 for the IO stats. I added "Cumulative compaction:" and "Interval compaction:" lines. The IO rates can be confusing. Rates fro per-level stats lines, Wr(MB/s) & Rd(MB/s), are computed using the duration of the compaction job. If the job reads 10MB, writes 9MB and the job (IO & merging) takes 1 second then the rates are 10MB/s for read and 9MB/s for writes. The IO rates in the Cumulative compaction line uses the total uptime. The IO rates in the Interval compaction line uses the interval uptime. So these Cumalative & Interval compaction IO rates cannot be compared to the per-level IO rates. But both forms of the rates are useful for debugging perf. Task ID: # Blame Rev: Test Plan: run db_bench Revert Plan: Database Impact: Memcache Impact: Other Notes: EImportant: - begin *PUBLIC* platform impact section - Bugzilla: # - end platform impact - Reviewers: igor Reviewed By: igor Subscribers: dhruba Differential Revision: https://reviews.facebook.net/D38667
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/