what happens if LB_FAILED is not handled

My opinion is that if Reselect Tries is at the default value of 0, then the client connection is reset using a RST. I would also expect the client to attempt to reconnect at that point. However, this is no doubt introducing some delay and you should really be trying to establish why Pool Member selection is failing. Perhaps you could add some further logging to the rule that contains the LB_FAILED event to ascertain the cause, or at least add the LB::reselect command?

 

 

If your servers are perhaps reaching their connection limits OneConnect may also help here.