f72fd58565
Summary: In atomic flush, concurrent background flush threads will commit to the MANIFEST one by one, in the order of the IDs of their picked memtables for all included column families. Each time, a background flush thread decides whether to wait based on two criteria: - Is db stopped? If so, don't wait. - Am I the one to commit the currently earliest memtable? If so, don't wait and ready to go. When atomic flush was implemented, error writing to or syncing the MANIFEST would cause the db to be stopped. Therefore, this background thread does not have to check for the background error while waiting. If there has been such an error, `DBStopped()` would have been true, and this thread will **not** wait forever. After we improved error handling, RocksDB may map an IOError while writing to MANIFEST to a soft error, if there is no WAL. This requires the background threads to check for background error while waiting. Otherwise, a background flush thread may wait forever. Pull Request resolved: https://github.com/facebook/rocksdb/pull/9034 Test Plan: make check Reviewed By: zhichao-cao Differential Revision: D31639225 Pulled By: riversand963 fbshipit-source-id: e9ab07c4d8f2eade238adeefe3e42dd9a5a3ebbd
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 especially suitable for storing multiple terabytes of data in a single database.
Start with example usage here: https://github.com/facebook/rocksdb/tree/main/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/ and https://rocksdb.slack.com/
License
RocksDB is dual-licensed under both the GPLv2 (found in the COPYING file in the root directory) and Apache 2.0 License (found in the LICENSE.Apache file in the root directory). You may select, at your option, one of the above-listed licenses.