29877ec7b4
Summary: On initial call to BlobDBImpl::WaStats() `all_periods_write_` would be empty, so it will crash when we call pop_front() at line 1627. Apparently it is mean to pop only when `all_periods_write_.size() > kWriteAmplificationStatsPeriods`. The whole write amp calculation doesn't seems to be correct and it is not being exposed. Will work on it later. Test Plan Change kWriteAmplificationStatsPeriodMillisecs to 1000 (1 second) and run db_bench --use_blob_db for 5 minutes. Closes https://github.com/facebook/rocksdb/pull/2751 Differential Revision: D5648269 Pulled By: yiwu-arbug fbshipit-source-id: b843d9a09bb5f9e1b713d101ec7b87e54b5115a4
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/