I need a Java flight recording to diagnose a performance problem on production Weblogic servers. I'd like to also get the Weblogic events. Is there any difference between starting the flight recording from either Java Mission Control (or in my case JCMD) versus initiating a WLDF diagnostic image capture? I understand the WLDF contains zipped files in addition to the .jfr, but right now I'm only interested in the flight recording (.jfr) with both the HotspotJVM and Weblogic events.
The reason I ask is because I notice something in the WLDF docs called Configure WLDF diagnostic volume (off, low, medium, high) where you set what types of Weblogic events you want to record. Will starting a flight recording from JCMD on a weblogic java instance include the Weblogic events at the preconfigured diagnostic volume? Or do you need to start it from the Weblogic Admin Console?
There is no mechanism in WLS that continuously polls to see if a recording has been started, using jcmd or JMC, and if so enable the WLDF events.
You have to enable them separately in the WLDF GUI [1]. When you do that you will also get JVM events roughly corresponding to what you get when you create a default recording. If you want more detailed information (profile), you need to start two seperate recodings.
[1] It can be good to know that the WLDF events are added using bytecode instrumentation, so the events are not even in the code until you enable the diagnostic feature.