Posted By: barfoon
How can I trace MySQL queries on my Linux server as they happen?
For example I’d love to set up some sort of listener, then request a web page and view all of the queries the engine executed, or just view all of the queries being run on a production server. How can I do this?
You can run the MySQL command
SHOW FULL PROCESSLIST; to see what queries are being processed at any given time, but that probably won’t achieve what you’re hoping for.
The best method to get a history without having to modify every application using the server is probably through triggers. You could set up triggers so that every query run results in the query being inserted into some sort of history table, and then create a separate page to access this information.
Do be aware that this will probably considerably slow down everything on the server though, with adding an extra
INSERT on top of every single query.
Edit: another alternative is the General Query Log, but having it written to a flat file would remove a lot of possibilities for flexibility of displaying, especially in real-time. If you just want a simple, easy-to-implement way to see what’s going on though, enabling the GQL and then using running
tail -f on the logfile would do the trick.