mirror of https://github.com/facebook/rocksdb.git
b860a42158
Summary: The LastSequence field in the MANIFEST file is the baseline seqno for a recovered DB. Recovering WAL entries might cause the recovered DB's seqno to advance above this baseline, but the recovered DB will never use a smaller seqno. Before this PR, we were writing the DB's seqno at the time of LogAndApply() as the LastSequence value. This works in the sense that it is a large enough baseline for the recovered DB that it'll never overwrite any records in existing SST files. At the same time, it's arbitrarily larger than what's needed. This behavior comes from LevelDB, where there was no tracking of largest seqno in an SST file. Now we know the largest seqno of newly written SST files, so we can write an exact value in LastSequence that actually reflects the largest seqno in any file referred to by the MANIFEST. This is primarily useful for correctness testing with unsynced data loss, where the recovered DB's seqno needs to indicate what records were recovered. Pull Request resolved: https://github.com/facebook/rocksdb/pull/9305 Test Plan: - https://github.com/facebook/rocksdb/issues/9338 adds crash-recovery correctness testing coverage for WAL disabled use cases - https://github.com/facebook/rocksdb/issues/9357 will extend that testing to cover file ingestion - Added assertion at end of LogAndApply() for `VersionSet::descriptor_last_sequence_` consistency with files - Manually tested upgrade/downgrade compatibility with a custom crash test that randomly picks between a `db_stress` built with and without this PR (for old code it must run with `-disable_wal=0`) Reviewed By: riversand963 Differential Revision: D33182770 Pulled By: ajkr fbshipit-source-id: 0bfafaf685f347cc8cb0e1d62e0186340a738f7d |
||
|---|---|---|
| .. | ||
| benchmark/src/main/java/org/rocksdb/benchmark | ||
| crossbuild | ||
| jmh | ||
| rocksjni | ||
| samples/src/main/java | ||
| src | ||
| CMakeLists.txt | ||
| HISTORY-JAVA.md | ||
| Makefile | ||
| RELEASE.md | ||
| jdb_bench.sh | ||
| pom.xml.template | ||
| understanding_options.md | ||