I have been running a rest distributed microservice rest benchmark and have seen that on every request in our use case org.jboss.resteasy.plugins.providers.jsonp.AbstractJsonpProvider.findWriter() makes a call to Json.createWriterFactory(null). This is a very expensive call being passed through to the Classloader.

In our test case we observe this call stack consuming 18.65% of cpu time.

As the WriterFactory (and ReadFactory) are created with a null configuration, they are targets for caching and should reduce the cpu utilization in our test case by 18.65%.