Re: [wildfly-dev] Gathering diagnostic data

On 02/25/2014 09:26 PM, James Livingston wrote: > Hi, > > I do support for JBoss at RH, especially lower level components like the > JVM and core server, and I've come to realise that we don't have > particularly good mechanisms for gathering diagnostic data. Obviously > there is logging, but for a number of problems it isn't enough. There is > also the JDR subsystem, but that has the serious limitation that the > server instance(s) have to be working correctly to use it. > > > One piece of data that I think can be useful for a common set of > problems are thread dumps. For standalone instances Oracle/OpenJDK's > 'jstack' tool is useful, but for domain mode you need to manually go to > each machine and find the correct process ID to use it. Something that > could potentially be useful is to be able to tell Host Controllers to > take a thread dump from the servers it manages (or all of them), using > the same Attach/SA APIs as jstack. > > A feature to allow HC-based extensions as mentioned in the thread about > the RHQ agent could be useful for implementing this too. Right now, I > believe it would need to be added to the HC code directly. > > > Is this something that might be possible or a good idea to do? I have > some ideas about other things that may be useful, like per-thread CPU > usage which RH support currently uses a pile of shell scripts for, but > starting with one thing may be simpler. I believe that the management model that is already defined for host controllers' views of their servers could easily accommodate this kind of thing. I don't think it'd have to be an extension - in fact, it probably should not be in this case.