MySQL Bugs: #66733: Need to be able to set binary_log_space

Bug #66733	Need to be able to set binary_log_space_limit
Submitted:	7 Sep 2012 13:45	Modified:	4 Jun 2013 1:59
Reporter:	Morgan Tocker	Email Updates:
Status:	Verified	Impact on me:	None
Category:	MySQL Server: Replication	Severity:	S3 (Non-critical)
Version:	5.6	OS:	Any
Assigned to:		CPU Architecture:	Any

Description:
It's possible to set a maximum amount of bytes for the relay log: relay_log_space_limit.  The binary log however, can only be set in days (expire_logs_days).  This is not always useful to me, since storage is provision in bytes - and depending on what I am doing, I might accidentally create far more binary logs than I expected (suddenly chose to reload a mysqldump file etc).

How to repeat:
N/A with a feature request, but:

- Use row based replication and a bulk insert of data
- Import a MySQLdump or otherwise modify a lot of data at once.
- Watch what happens when you run out of space.

Suggested fix:
Keep expire_logs_days, but add configuration variable: binary_log_space_limit.  Both limits should apply at once.

Thank you for the reasonable feature request.

An alternative fix is this one in Percona Server: http://www.percona.com/doc/percona-server/5.6/flexibility/max_binlog_files.html#maximum-bi...

A large import from one system to another makes the management of the log file space which I have in a separate filesystem (which is smaller than the filesystem holding $datadir) a nuisance.

A *dynamic* binary_log_space_limit setting would make that a non-issue.

This is still an issue in 5.7.

relay_log_space_limit is still not useful because it can not be set dynamically. So having the value is fine but I may resize the partition where the logs are written or I my want to control how many relay logs are written and not having this configuration setting being a dynamic value severely limits its usefulness. 

Planning on sizes is great but some servers I run have a MySQL uptime of over a year, and the disks have been extended "under the server" without shutting it down. So having a static setting here is really useless (I've never used it because of this.)

Given 5.7 has many new dynamic replication configuration settings making this variable a dynamic configuration setting would be a very useful change.

Morgan, the max_binlog_files in Percona Server was obviously still not an ideal solution. 
It was recently replaced with a better and consistent with relay_log_space_limit one - the binlog_space_limit https://www.percona.com/doc/percona-server/5.7/flexibility/max_binlog_files.html#binlog_sp...

I hope it will be implemented in upstream as well.