[RFE] binlog_expire_logs_seconds option

[pedrofragola]

[Feature request]

The mysql-k8s charm currently uses the default parameter for binary log retention (binlog_expire_logs_seconds), which is set to rotate the logs after 30 days as per the documentation[0]. In some scenarios, such as when using Kubeflow, this binary log can fill up very quickly. It would be beneficial to have the ability to modify this configuration directly through Juju, allowing users to set this parameter permanently on the charm to accommodate their specific usage patterns.

[0] https://dev.mysql.com/doc/refman/8.0/en/replication-options-binary-log.html#sysvar_binlog_expire_logs_seconds

[github-actions[bot]]

https://warthogs.atlassian.net/browse/DPE-4247

[paulomach]

Hi @pedrofragola , we are discussing this and will fup here

[paulomach]

@pedrofragola we are going to change it to 7 days, which is inline with retention period for other logs

[pedrofragola]

@paulomach thanks for the heads-up :) ... Do you think for the next releases it will be possible to have an option to update this config using the charm option?

[paulomach]

@pedrofragola, an option is out of the cards for now

[slapcat]

Hi @paulomach - We are seeing multiple customers affected by full disks from binlogs in Kubeflow environments. The current workaround is to adjust this value during runtime from the mysql-k8s pod, for example:

kubectl exec -it -n kubeflow kfp-db-0 -c mysql --  mysql -userverconfig -p$(juju run kfp-db/0 get-password username=serverconfig | awk -F': ' '/password/ {print $2}') -e 'SET GLOBAL MAX_BINLOG_SIZE=4096;'
kubectl exec -it -n kubeflow kfp-db-0 -c mysql --  mysql -userverconfig -p$(juju run kfp-db/0 get-password username=serverconfig | awk -F': ' '/password/ {print $2}') -e 'SET GLOBAL BINLOG_EXPIRE_LOGS_SECONDS=86400;'

However, this needs to be manually reset every time the pod restarts, so it is very inconvenient. Is it possible to have this prioritized or at least have a clearer picture of when this feature might be added?

[paulomach]

@slapcat PR will be up today or tomorrow.

[paulomach]

@slapcat @pedrofragola I'll need to refactor the PR, for your benefit though. Our PM approved having a dedicated configuration parameter as per comment

[paulomach]

@slapcat @pedrofragola Feature now published to channel 8.0/edge One can set charm configuration binlog_retention_days at a minimum of 1 day (default being 7 days). Appreciate if you can test it.

[pedrofragola]

Hi @paulomach thanks for checking it ... I did the test using the edge channel:

mysql-k8s 8.0.37-0ubuntu0.22.04.3 active 1 mysql-k8s 8.0/edge 178 10.152.183.190 no

juju config mysql-k8s binlog_retention_days=2

mysql> SHOW VARIABLES LIKE '%expire_logs%'; +-------------------------------+--------+ | Variable_name | Value | +-------------------------------+--------+ | binlog_expire_logs_auto_purge | ON | | binlog_expire_logs_seconds | 172800 | | expire_logs_days | 0 | +-------------------------------+--------+ 3 rows in set (0.01 sec)

It worked... do you happen to know when this charm will be promoted to stable channel?

[paulomach]

Hi @paulomach thanks for checking it ... I did the test using the edge channel:

mysql-k8s 8.0.37-0ubuntu0.22.04.3 active 1 mysql-k8s 8.0/edge 178 10.152.183.190 no

juju config mysql-k8s binlog_retention_days=2

mysql> SHOW VARIABLES LIKE '%expire_logs%'; +-------------------------------+--------+ | Variable_name | Value | +-------------------------------+--------+ | binlog_expire_logs_auto_purge | ON | | binlog_expire_logs_seconds | 172800 | | expire_logs_days | 0 | +-------------------------------+--------+ 3 rows in set (0.01 sec)

It worked... do you happen to know when this charm will be promoted to stable channel?

We will be releasing a candidate next week and ask test from sunbeam/kubeflow. We can promote as soon they validate it