There's an use-case in twelve factor apps where GC pauses would be unacceptable but high availability would allow downtime of an individual stateless app instan

There's an use-case in twelve factor apps where GC pauses would be unacceptable but high availability would allow downtime of an individual stateless app instance. So instead of spending any time GCing, just eat memory and throw it all away and start over fresh as necessary. With various tricks, an instance can be swapped quickly (start a new instance just before killing)... probably want some sort of user-space "OOM killer" to handle it. ulimits lower than JVM option limits would work too, but wouldn't have fast restarts without some magic.