Major Description
the pattern of jmx.acl.....cfg comes from the jmx ObjectName, basically it's the domain name + property value(the order matters here). Some property value is dynamically created so that the ObjectName could change due to different MBean instance.
For example, an ObjectName looks like
org.apache.activemq:type=Broker,brokerName=amq-broker,service=Health
here the brokerName would change for different amq brokers, so it's better we can provide a way so that one jmx.acl configuration file can match all brokers with service "Health", so the file name could be like
jmx.acl.org.apache.activemq.Broker._.Health.cfg
here the "_" is just a placeholder and can match all brokers