Summary: WAL records RocksDB writes to all column families. When user flushes a a column family, the old WAL will not accept new writes but cannot be deleted yet because it may still contain live data for other column families. (See https://github.com/facebook/rocksdb/wiki/Write-Ahead-Log#life-cycle-of-a-wal for detailed explanation) Because of this, if there is a column family that receive very infrequent writes and no manual flush is called for it, it could prevent a lot of WALs from being deleted. PR https://github.com/facebook/rocksdb/pull/5046 introduced persistent stats column family which is a good example of such column families. Depending on the config, it may have long intervals between writes, and user is unaware of it which makes it difficult to call manual flush for it. This PR addresses the problem for persistent stats column family by forcing a flush for persistent stats column family when 1) another column family is flushed 2) persistent stats column family's log number is the smallest among all column families, this way persistent stats column family will keep advancing its log number when necessary, allowing RocksDB to delete old WAL files. Pull Request resolved: https://github.com/facebook/rocksdb/pull/5509 Differential Revision: D16045896 Pulled By: miasantreble fbshipit-source-id: 286837b633e988417f0096ff38384742d3b40ef4 |
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db_impl_compaction_flush.cc | ||
db_impl_debug.cc | ||
db_impl_experimental.cc | ||
db_impl_files.cc | ||
db_impl_open.cc | ||
db_impl_readonly.cc | ||
db_impl_readonly.h | ||
db_impl_secondary.cc | ||
db_impl_secondary.h | ||
db_impl_write.cc | ||
db_impl.cc | ||
db_impl.h | ||
db_secondary_test.cc |