When “Max connections” limit reached, you might see “Resume All Listeners” errors

You may experience an intermittent issue that http and https requests stop being served correctly however this doesn't seem to affect all sites initially and gradually affects all sites on the server. Litespeed shows as running however when checking the error log we are seeing a continuous loop of “Resume All Listeners” until we manually restart Litespeed which clears the issue.

2019-04-09 12:43:20.252694 [NOTICE] Resume All Listeners
2019-04-09 12:43:20.322407 [NOTICE] Resume All Listeners
2019-04-09 12:43:20.359544 [NOTICE] Resume All Listeners
2019-04-09 12:43:20.435074 [NOTICE] Resume All Listeners
2019-04-09 12:43:20.469055 [NOTICE] Resume All Listeners

What does “Resume All Listeners” mean?

It happens when the server hits the server level Max connections limit. The default value of this limit has been increased from “2000” to “10000” in new installation at the time of this writing. However, for older installation, it may need a manual update. The default for Max SSL connections limit is “5000” now.