2309fd63bf
Summary: A bug occasionally shows up in crash test, and https://github.com/facebook/rocksdb/issues/5851 reproduces it. The bug can surface in the following way. 1. Database has multiple column families. 2. Between one DB restart, the last log file is corrupted in the middle (not the tail) 3. During restart, DB crashes between flushing between two column families. Then DB will fail to be opened again with error "SST file is ahead of WALs". Solution is to update the log number associated with each column family altogether after flushing all column families' memtables. The version edits should be written to a new MANIFEST. Only after writing to all these version edits succeed does RocksDB (atomically) points the CURRENT file to the new MANIFEST. Test plan (on devserver): ``` $make all && make check ``` Specifically ``` $make db_test2 $./db_test2 --gtest_filter=DBTest2.CrashInRecoveryMultipleCF ``` Also checked for compatibility as follows. Use this branch, run DBTest2.CrashInRecoveryMultipleCF and preserve the db directory. Then checkout 5.4, build ldb, and dump the MANIFEST. Pull Request resolved: https://github.com/facebook/rocksdb/pull/5856 Differential Revision: D17620818 Pulled By: riversand963 fbshipit-source-id: b52ce5969c9a8052cacec2bd805fcfb373589039
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/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/
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.