Re: Best practices for restarting MySQL

[Rick James]

Make your application more robust. You have given one example of how MySQL could "go away"; there are many others. Solve them all, at the same time:

* Check for errors after every operation.

* Use InnoDB, not MyISAM.

* Don't turn on auto-reconnect; instead follow the same code as you have for recovering from Deadlocks and other transaction 'errors'. (That is restart the transaction, after reconnecting if necessary.)

* Have some kind of "timeout" in your application -- in the case where it cannot recover or gets in a loop.

* For graceful shutdowns, use SET readonly=1 (and do _not_ connect as 'root'). This prevents writes -- by providing an error to the INSERT/UPDATE/etc statement.

* For graceful shutdowns, use SET max_connections=1. This will give errors for new connections and "reconnect" attempts by the application.

* etc.