Datadog employee here, you don't need to run your own collector to collect codecache usage. As it's exposed through JMX, the JMX collector can collect it http://docs.datadoghq.com/integrations/java/ . It doesn't by default though, so you'll need to configure it to collect the metrics from the "java.lang:name=Code Cache,type=MemoryPool" bean. We should add that in our default configuration.