https://github.com/smallrye/smallrye-metrics/blob/master/implementation/src/main/java/io/smallrye/metrics/setup/JmxRegistrar.java#L58

I think InputStream propertiesResource needs to be explicitly closed.

https://docs.oracle.com/javase/8/docs/api/java/util/Properties.html#load-java.io.InputStream- says: The specified stream remains open after this method returns.