431e8afba7
Summary: In the original stacked BlobDB implementation, which writes blobs to blob files immediately and treats blob files as logs, it makes sense to flush the file after writing each blob to protect against process crashes; however, in the integrated implementation, which builds blob files in the background jobs, this unnecessarily reduces performance. This patch fixes this by simply adding a `do_flush` flag to `BlobLogWriter`, which is set to `true` by the stacked implementation and to `false` by the new code. Note: the change itself is trivial but the tests needed some work; since in the new implementation, blobs are now buffered, adding a blob to `BlobFileBuilder` is no longer guaranteed to result in an actual I/O. Therefore, we can no longer rely on `FaultInjectionTestEnv` when testing failure cases; instead, we manipulate the return values of I/O methods directly using `SyncPoint`s. Pull Request resolved: https://github.com/facebook/rocksdb/pull/7892 Test Plan: `make check` Reviewed By: jay-zhuang Differential Revision: D26022814 Pulled By: ltamasi fbshipit-source-id: b3dce419f312137fa70d84cdd9b908fd5d60d8cd
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/ 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.