Cheapest way to to determine if a MySQL connection is still alive

Question

I have a pool of MySQL connections for a web-based data service. When it starts to service a request, it takes a connection from the pool to use. The problem is that if ther

Answer 1

"Connection" in this case has multiple meanings. MySQL listens on a socket- that's the network-level "connection." MySQL maintains "database connections," which include a context for query execution and other overhead.

If you just want to know if the service is listening, you should be able to execute a network-level call to see if the port (don't know what the default is) is listening on the target IP. If you want to get the MySQL engine to respond, I think your SELECT 1 idea is good- it doesn't actually fetch any data from the database but does confirm that the engine is spun up and responding.