3:44 p.m.
Ok, well, i hate to leave it like this but - this is so friggin' odd that I can only
say "it is not my fault" :)
First - note someone changed jmx exporter code because they saw the same thing as we are -
that's what this comment is about:
https://github.com/prometheus/jmx_exporter/blob/master/collector/src/main...
See: https://github.com/prometheus/jmx_exporter/issues/89
But the fix is not 100%.
If you grab these three files - you can see it yourself:
https://github.com/jmazzitelli/test/tree/master/javaagent
(get Makefile and the two .java files and then run "make download-wildfly
unzip-wildfly compile run")
You see i use the same API as the jmx exporter here:
https://github.com/jmazzitelli/test/blob/master/javaagent/TestJavaAgent.j...
and that is what you will see:
16:31:05,290 INFO [stdout] (Test Java Agent Thread)
=============================================================
16:31:05,291 INFO [stdout] (Test Java Agent Thread) FIND INFORMATION ABOUT MBEAN:
jboss.as:management-root=server
16:31:05,291 INFO [stdout] (Test Java Agent Thread)
=============================================================
16:31:05,291 INFO [stdout] (Test Java Agent Thread) isRegistered:
16:31:05,291 INFO [stdout] (Test Java Agent Thread) true
16:31:05,291 INFO [stdout] (Test Java Agent Thread) getMBeanInfo:
16:31:05,291 INFO [stdout] (Test Java Agent Thread) description: The root node of the
server-level management model.
16:31:05,291 INFO [stdout] (Test Java Agent Thread) #attributes: 19
16:31:05,291 INFO [stdout] (Test Java Agent Thread) getAttribute:
16:31:05,291 INFO [stdout] (Test Java Agent Thread) serverState=reload-required
16:31:05,291 INFO [stdout] (Test Java Agent Thread) queryNames:
16:31:05,291 INFO [stdout] (Test Java Agent Thread) []
16:31:05,291 INFO [stdout] (Test Java Agent Thread) queryMBeans:
16:31:05,291 INFO [stdout] (Test Java Agent Thread) []
16:31:05,291 INFO [stdout] (Test Java Agent Thread) queryNames(null, null):
16:31:05,291 INFO [stdout] (Test Java Agent Thread) FOUND IT:
jboss.as:management-root=server
16:31:05,291 INFO [stdout] (Test Java Agent Thread)
=============================================================
You will see SOME JMX APIs can see the MBean, queryMBeans and queryNames canNOT (note the
empty arrays []).
But notice getMBeanInfo CAN see it - I can even get the attribute value from that! (you
can see it is in reload-required state)
But again, queryMBeans returns nothing.
Oddly, queryNames(null, null) DOES return it in the list (see the "FOUND IT"
line). It is only if I specifically ask for it does it fail in the query API.
The end result - JMX Exporter (at least sometimes) is not able to get "Server
Availability" because it can't get this MBean.
For some odd reason it can get it sometimes - but it seems when it can't, it will
never get it.