Commit Log Archiving

Commit log archiving extends backups with point-in-time recovery. When enabled, axon-agent collects commit log segments and uploads them to the configured remote storage. This allows you to restore to a specific moment between two backup snapshots.

How it works

AxonOps enables and manages commit log archiving dynamically through the Cassandra JVM agent and axon-agent binary.

AxonOps enables archiving dynamically The AxonOps Java agent (running inside the Cassandra JVM) receives a command from axon-agent and applies commit log archiving configuration at runtime.

Standard Cassandra behavior (for reference)

Without AxonOps, operators must edit $CASSANDRA_HOME/conf/commitlog_archiving.properties and restart the node for changes to take effect.

Commit log segment completion triggers archiving When a commit log segment is completed and fsynced, Cassandra invokes axon-cassandra-commit-log-archiver.
Hardlink staging The archiver creates a hardlink in commitlog_directory/.axon_commit_log/. Cassandra may delete the original segment, but AxonOps keeps the hardlinked copy alive and manages its lifecycle.
Remote upload and cleanup axon-agent uploads the hardlinked segment to the configured remote storage. After a successful upload, the hardlink is removed.

When to use it

Use commit log archiving if you need:

Point-in-time recovery (PITR)
Protection against operator error between backups
A smaller recovery window than snapshot frequency

Requirements

Remote backup storage configured and reachable
Sufficient remote storage space for commit logs
Network bandwidth to upload new segments continuously

Enable commit log archiving

Commit log archiving is configured as part of Point-in-Time Restore (PITR).

Follow:

Operational notes

Archiving is remote-only. Local-only backups do not support PITR.
Commit log upload failures surface as backup warnings and should be investigated promptly.
Keep retention aligned with your recovery objectives (RPO/RTO).