Change Data Capture (CDC) logging

Change Data Capture (CDC) logging captures changes to data.

cassandra.yaml

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

CDC directory location

The location of the CDC directory depends on the type of installation:
Package installations /var/lib/cassandra/cdc_raw
Tarball installations /var/lib/cassandra/cdc_raw

Change Data Capture (CDC) logging captures and tracks data that has changed. CDC logging is configured per table, with limits on the amount of disk space to consume for storing the CDC logs. CDC logs use the same binary format as the commit log. Database tables can be created or altered with a table property to use CDC logging.

CDC logging must be enabled in the cassandra.yaml file to begin logging. A plan should be in place for moving and consuming the CDC log information before enabling. Upon flushing the memtable to disk, CommitLogSegments containing data for CDC-enabled tables are moved to the configured cdc_raw directory. Once the disk space limit is reached, writes to CDC enabled tables will be rejected until space is freed. Four CDC settings are configured in the cassandra.yaml file.