58b12dfe37
Summary: Relating to #1903: In MaybeFlushColumnFamilies() we want to modify the 'getting_flushed' flag before releasing the db mutex when SwitchMemtable() is called. The following 2 actions need to be atomic in MaybeFlushColumnFamilies() - getting_flushed is false on oldest log - we determine that all CFs can be flushed to successfully release oldest log - we set getting_flushed = true on the oldest log. ------- - getting_flushed is false on oldest log - we determine that all CFs can NOT be flushed to successfully release oldest log - we set unable_to_flush_oldest_log_ = true on the oldest log. #### In the 2pc case: T1 enters function but is unable to flush all CFs to release log T1 sets unable_to_flush_oldest_log_ = true T1 begins flushing all CFs possible T2 enters function but is unable to flush all CFs to release log T2 sees unable_to_flush_oldes_log_ has been set so exits T3 enters function and will be able to flush all CFs to release oldest log T3 sets getting_flushed = true on oldes Closes https://github.com/facebook/rocksdb/pull/1909 Differential Revision: D4646235 Pulled By: reidHoruff fbshipit-source-id: c8d0447
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/