08721293ea
Summary: `db_stress` is a user of `FaultInjectionTestFS`. After injecting a write error, `db_stress` probabilistically determins data drop (https://github.com/facebook/rocksdb/blob/6.27.fb/db_stress_tool/db_stress_test_base.cc#L2615:L2619). In some of our recent runs of `db_stress`, we found duplicate trailing entries corresponding to file trivial move in the MANIFEST, causing the recovery to fail, because the file move operation is not idempotent: you cannot delete a file from a given level twice. Investigation suggests that data buffering in both `WritableFileWriter` and `FaultInjectionTestFS` may be the root cause. WritableFileWriter buffers data to write in a memory buffer, `WritableFileWriter::buf_`. After each `WriteBuffered()`/`WriteBufferedWithChecksum()` succeeds, the `buf_` is cleared. If the underlying file `WritableFileWriter::writable_file_` is opened in buffered IO mode, then `FaultInjectionTestFS` buffers data written for each file until next file sync. After an injected error, user of `FaultInjectionFS` can choose to drop some or none of previously buffered data. If `db_stress` does not drop any unsynced data, then such data will still exist in the `FaultInjectionTestFS`'s buffer. Existing implementation of `WritableileWriter::WriteBuffered()` does not clear `buf_` if there is an error. This may lead to the data being buffered two copies: one in `WritableFileWriter`, and another in `FaultInjectionTestFS`. We also know that the `WritableFileWriter` of MANIFEST file will close upon an error. During `Close()`, it will flush the content in `buf_`. If no write error is injected to `FaultInjectionTestFS` this time, then we end up with two copies of the data appended to the file. To fix, we clear the `WritableFileWriter::buf_` upon failure as well. We focus this PR on files opened in non-direct mode. This PR includes a unit test to reproduce a case when write error injection to `WritableFile` can cause duplicate trailing entries. Pull Request resolved: https://github.com/facebook/rocksdb/pull/9236 Test Plan: make check Reviewed By: zhichao-cao Differential Revision: D33033984 Pulled By: riversand963 fbshipit-source-id: ebfa5a0db8cbf1ed73100528b34fcba543c5db31 |
||
|---|---|---|
| .circleci | ||
| .github/workflows | ||
| buckifier | ||
| build_tools | ||
| cache | ||
| cmake | ||
| coverage | ||
| db | ||
| db_stress_tool | ||
| docs | ||
| env | ||
| examples | ||
| file | ||
| fuzz | ||
| hdfs | ||
| include/rocksdb | ||
| java | ||
| logging | ||
| memory | ||
| memtable | ||
| microbench | ||
| monitoring | ||
| options | ||
| plugin | ||
| port | ||
| table | ||
| test_util | ||
| third-party | ||
| tools | ||
| trace_replay | ||
| util | ||
| utilities | ||
| .clang-format | ||
| .gitignore | ||
| .lgtm.yml | ||
| .travis.yml | ||
| .watchmanconfig | ||
| appveyor.yml | ||
| AUTHORS | ||
| CMakeLists.txt | ||
| CODE_OF_CONDUCT.md | ||
| CONTRIBUTING.md | ||
| COPYING | ||
| DEFAULT_OPTIONS_HISTORY.md | ||
| defs.bzl | ||
| DUMP_FORMAT.md | ||
| HISTORY.md | ||
| INSTALL.md | ||
| issue_template.md | ||
| LANGUAGE-BINDINGS.md | ||
| LICENSE.Apache | ||
| LICENSE.leveldb | ||
| Makefile | ||
| PLUGINS.md | ||
| README.md | ||
| ROCKSDB_LITE.md | ||
| src.mk | ||
| TARGETS | ||
| thirdparty.inc | ||
| USERS.md | ||
| Vagrantfile | ||
| WINDOWS_PORT.md | ||
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.