Enabling incremental backups

Steps to enable incremental backups. When incremental backups are enabled, the DataStax Distribution of Apache Cassandra 3.11 hard-links each memtable flushed to an SSTable to a backups directory under the keyspace data directory.

When incremental backups are enabled (disabled by default), DataStax Distribution of Apache Cassandra (DDAC) hard-links each memtable-flushed SSTable to a backups directory under the keyspace data directory. This allows storing backups offsite without transferring entire snapshots. Also, incremental backups combined with snapshots to provide a dependable, up-to-date backup mechanism. Compacted SSTables do not create hard links in /backups because these SSTables do not contain any data that has not already been linked. A snapshot at a point in time, plus all incremental backups and commit logs since that time form a compete backup.

As with snapshots, Cassandra does not automatically clear incremental backup files. DataStax recommends setting up a process to clear incremental backup hard-links each time a new snapshot is created.

cassandra.yaml

  • The cassandra.yaml file is located in the installation_location/conf directory.

Procedure

Edit the cassandra.yaml configuration file on each node in the cluster and change the value of incremental_backups to true.