55f7ded80d
Summary: Originally the 2 options `db_log_dir` and `wal_dir` will be reused in a snapshot db since the options files are just copied. By default, if `wal_dir` was not set when a db was created, it is set to the db's dir. Therefore, the snapshot db will use the same WAL dir. If both the original db and the snapshot db write to or delete from the WAL dir, one may modify or delete files which belong to the other. The same applies to `db_log_dir` as well, but as info log files are not copied or linked, it is simpler for this option. 2 arguments are added to `Checkpoint::CreateCheckpoint()`, allowing to override these 2 options. `wal_dir`: If the function argument `wal_dir` is empty, or set to the original db location, or the checkpoint location, the snapshot's `wal_dir` option will be updated to the checkpoint location. Otherwise, the absolute path specified in the argument will be used. During checkpointing, live WAL files will be copied or linked the new location, instead of the current WAL dir specified in the original db. `db_log_dir`: Same as `wal_dir`, but no files will be copied or linked. A new unit test was added: `CheckpointTest.CheckpointWithOptionsDirsTest`. Pull Request resolved: https://github.com/facebook/rocksdb/pull/8572 Test Plan: New unit test ``` checkpoint_test --gtest_filter="CheckpointTest.CheckpointWithOptionsDirsTest" ``` Output ``` Note: Google Test filter = CheckpointTest.CheckpointWithOptionsDirsTest [==========] Running 1 test from 1 test case. [----------] Global test environment set-up. [----------] 1 test from CheckpointTest [ RUN ] CheckpointTest.CheckpointWithOptionsDirsTest [ OK ] CheckpointTest.CheckpointWithOptionsDirsTest (11712 ms) [----------] 1 test from CheckpointTest (11712 ms total) [----------] Global test environment tear-down [==========] 1 test from 1 test case ran. (11713 ms total) [ PASSED ] 1 test. ``` This test will fail without this patch. Just modify the code to remove the 2 arguments introduced in this patch in `CreateCheckpoint()`. Reviewed By: zhichao-cao Differential Revision: D29832761 Pulled By: autopear fbshipit-source-id: e6a639b4d674380df82998c0839e79cab695fe29
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.