how to enable database auto-reconnect in PHP?

Question

and the database is MYSQL

Answer 1

You can write a function which will ping the database via connection and in case it down, reconnect it again and then proceed the query or whatever you want, also take a look on mysqli php library, it can be useful for you.

PS. Also could be useful to implement Singleton design pattern in order to maintain the database connection, once created it will connect to database and then you can implement the method called getConnection which each time will proceed with the check I've described above.

PPS. You can use an exception, try you query, whenever it fails catch an exception, reconnect and try again.

Answer 2

You can use the mysql_ping() function to test the status of the connection and reconnect when it returns false. mysql_ping() will even reconnect for you if you're using a MySQL before 5.0.13 as mentioned on that documentation page; "Since MySQL 5.0.13, automatic reconnection feature is disabled.".

Answer 3

You should be checking if the query fails anyway. By checking the error code you can tell if it failed because of no connection and reconnect. Just make sure you keep track of reconnection attempts so you don't get stuck in a loop.

Answer 4

why not use a persistent connection?

Answer 5

Why do you need to "reconnect" in the first place? How/Why are you getting disconnected? In PHP you connect at the beginning of the script and the connection is closed automatically at the end of the script.

There's no need to call mysql_close in your script at all (and it would be silly to "automatically reconnect" if you explicitly closed the connection).

You can try mysql_pconnect is that's what you're looking for. The connection will then stay open permanently, and other scripts that connect can use the connection.