Is it safe to delete replication relay-bin files?

Question

I've got a small database, around 50mb. It's a master replicating to a remote server. I noticed that the relay-bin files total to over 5GB. Is it safe to delete them?

Hoary

Answer 1

No, do not delete the relay-bin files manually. What you can do is to purge the binary files using MySQL commands. See the MySQL 5.0 Manual for more on the PURGE BINARY LOGS command.

Crumpet

Thanks, that's what i needed? Will purge ensure that replication is not affected? – Hoary

Yes, replication will not be affected at any time. – Crumpet

Can these files be deleted if replication has been turned off and won't be used again? – Epanorthosis

"PURGE BINARY LOGS" only related to binary logs, not relay logs – Exuberate

This does something different as it wask asked, that might harm your mariadb setup. The proper answer is Rodo's. – Trigg

Answer 2

I think a better answer is 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.

Territorialize

This should be the accepted answer IMO. We just found a server that had apparently had relay_log_purge turned off manually several months ago and had been steadily filling up its disk with relay logs. Running these commands worked perfectly. – Araujo

Answer 3

Maybe try to resync your master and slave.

If possible, cleanup the slave by running a

reset slave

it will purge all relay binary logs.

Then set the replication again with change master to ... You may have too much lag between your master and slave.

Luting

Worked where the other suggestions didn't – Dozen

Answer 4

From the MySQL manual:

The SQL thread automatically deletes each relay log file after it has executed all events in the file and no longer needs it. There is no explicit mechanism for deleting relay logs because the SQL thread takes care of doing so. However, FLUSH LOGS rotates relay logs, which influences when the SQL thread deletes them.

Hermaphroditus