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| author | Yanqin Jin <yanqin@fb.com> | 2019-03-26 16:41:31 -0700 |
|---|---|---|
| committer | Facebook Github Bot <facebook-github-bot@users.noreply.github.com> | 2019-03-26 16:45:31 -0700 |
| commit | 9358178edc584102f644eaf281ef2cc4676dda09 (patch) | |
| tree | 1d10f244c5aedb2d9512f093ebda617abfc70d43 /HISTORY.md | |
| parent | 2a5463ae8497a122ea91f74a8604da17ab60557b (diff) | |
Support for single-primary, multi-secondary instances (#4899)
Summary:
This PR allows RocksDB to run in single-primary, multi-secondary process mode.
The writer is a regular RocksDB (e.g. an `DBImpl`) instance playing the role of a primary.
Multiple `DBImplSecondary` processes (secondaries) share the same set of SST files, MANIFEST, WAL files with the primary. Secondaries tail the MANIFEST of the primary and apply updates to their own in-memory state of the file system, e.g. `VersionStorageInfo`.
This PR has several components:
1. (Originally in #4745). Add a `PathNotFound` subcode to `IOError` to denote the failure when a secondary tries to open a file which has been deleted by the primary.
2. (Similar to #4602). Add `FragmentBufferedReader` to handle partially-read, trailing record at the end of a log from where future read can continue.
3. (Originally in #4710 and #4820). Add implementation of the secondary, i.e. `DBImplSecondary`.
3.1 Tail the primary's MANIFEST during recovery.
3.2 Tail the primary's MANIFEST during normal processing by calling `ReadAndApply`.
3.3 Tailing WAL will be in a future PR.
4. Add an example in 'examples/multi_processes_example.cc' to demonstrate the usage of secondary RocksDB instance in a multi-process setting. Instructions to run the example can be found at the beginning of the source code.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/4899
Differential Revision: D14510945
Pulled By: riversand963
fbshipit-source-id: 4ac1c5693e6012ad23f7b4b42d3c374fecbe8886
Diffstat (limited to 'HISTORY.md')
| -rw-r--r-- | HISTORY.md | 13 |
1 files changed, 3 insertions, 10 deletions
diff --git a/HISTORY.md b/HISTORY.md index 6046bb1e7..f63bfb97b 100644 --- a/HISTORY.md +++ b/HISTORY.md @@ -2,24 +2,17 @@ ## Unreleased ### New Features * Introduce two more stats levels, kExceptHistogramOrTimers and kExceptTimers. +* Added a feature to perform data-block sampling for compressibility, and report stats to user. * Add support for trace filtering. - ### Public API Change * Remove bundled fbson library. * statistics.stats_level_ becomes atomic. It is preferred to use statistics.set_stats_level() and statistics.get_stats_level() to access it. - +* Introduce a new IOError subcode, PathNotFound, to indicate trying to open a nonexistent file or directory for read. +* Add initial support for multiple db instances sharing the same data in single-writer, multi-reader mode. ### Bug Fixes * Fix JEMALLOC_CXX_THROW macro missing from older Jemalloc versions, causing build failures on some platforms. * Fix SstFileReader not able to open file ingested with write_glbal_seqno=true. - -## Unreleased -### New Features -* Added a feature to perform data-block sampling for compressibility, and report stats to user. -### Public API Change -### Bug fixes - - ## 6.0.0 (2/19/2019) ### New Features * Enabled checkpoint on readonly db (DBImplReadOnly). |