Revision fb09ef05dcee8fa0ccaebf88ef1992858ea5a083 authored by Yanqin Jin on 21 March 2020, 02:17:54 UTC, committed by Facebook GitHub Bot on 21 March 2020, 02:30:48 UTC
Summary:
There are situations when RocksDB tries to recover, but the db is in an inconsistent state due to SST files referenced in the MANIFEST being missing. In this case, previous RocksDB will just fail the recovery and return a non-ok status.
This PR enables another possibility. During recovery, RocksDB checks possible MANIFEST files, and try to recover to the most recent state without missing table file. `VersionSet::Recover()` applies version edits incrementally and "materializes" a version only when this version does not reference any missing table file. After processing the entire MANIFEST, the version created last will be the latest version.
`DBImpl::Recover()` calls `VersionSet::Recover()`. Afterwards, WAL replay will *not* be performed.
To use this capability, set `options.best_efforts_recovery = true` when opening the db. Best-efforts recovery is currently incompatible with atomic flush.

Test plan (on devserver):
```
$make check
$COMPILE_WITH_ASAN=1 make all && make check
```
Pull Request resolved: https://github.com/facebook/rocksdb/pull/6334

Reviewed By: anand1976

Differential Revision: D19778960

Pulled By: riversand963

fbshipit-source-id: c27ea80f29bc952e7d3311ecf5ee9c54393b40a8
1 parent 4fc2166
Raw File
README.md
## RocksDB: A Persistent Key-Value Store for Flash and RAM Storage

[![Linux/Mac Build Status](https://travis-ci.org/facebook/rocksdb.svg?branch=master)](https://travis-ci.org/facebook/rocksdb)
[![Windows Build status](https://ci.appveyor.com/api/projects/status/fbgfu0so3afcno78/branch/master?svg=true)](https://ci.appveyor.com/project/Facebook/rocksdb/branch/master)
[![PPC64le Build Status](http://140.211.168.68:8080/buildStatus/icon?job=Rocksdb)](http://140.211.168.68:8080/job/Rocksdb)

RocksDB is developed and maintained by Facebook Database Engineering Team.
It is built on earlier work on [LevelDB](https://github.com/google/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](https://github.com/facebook/rocksdb/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.
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