Package io.atomix.copycat.server.storage.compaction

Classes and interfaces that facilitate compaction of the Copycat log.

See: Description

Interface Summary

Interface	Description
CompactionManager	Manages a single compaction process.
CompactionTask	Performs compaction on a set of log Segments.

Class Summary

Class	Description
Compactor	Manages compaction of log Segments in a pool of background threads.
MajorCompactionManager	Builds tasks for the Compaction.MAJOR compaction process.
MajorCompactionTask	Removes tombstones from the log and combines Segments to reclaim disk space.
MinorCompactionManager	Builds tasks for the Compaction.MINOR compaction process.
MinorCompactionTask	Removes released entries from an individual log Segment to reclaim disk space.

Enum Summary

Enum	Description
Compaction	Log compaction type identifier.
Compaction.Mode	Constants for specifying entry compaction modes.

Package io.atomix.copycat.server.storage.compaction Description

Classes and interfaces that facilitate compaction of the Copycat log.

The log compaction package implements compaction for Copycat logs using a custom log cleaning algorithm. As entries are written to the log and applied to the server's state machine, the state machine can arbitrarily mark entries for removal from the log. Periodically, a set of log compaction threads will compact segments of the log in the background. Log compaction is performed in two phases: minor and major. The minor compaction process efficiently rewrites individual segments to remove standard entries that have been marked for cleaning. The major compaction process periodically rewrites the entire log to combine segments that have previously been compacted.

Author:

Jordan Halterman