Relay logs can be 'deleted' but mysql should manage it automatically.

Relay logs can be 'deleted' but mysql should manage it automatically.
One way to do this is to check for the value of relay_log_purge.

It should be set to 1 if you want mysql to manage them:

set global relay_log_purge=1;

You would probably need to flush the logs:

flush logs;

This does not affect the binary logs.