How to find out which user issue the MQ command?

(1) enable qmgr command event
     alter qmgr cmdev(enabled)

(2) the command event will be put into SYSTEM.ADMIN.COMMAND.EVENT queue

(3) use MH05 SupportPac to parse the command events or

(4) use MS0P SupportPac to format the command events in MQ Explorer

command events
https://www.ibm.com/support/knowledgecenter/SSFKSJ_7.1.0/com.ibm.mq.doc/mo11290_.htm

MH05: WebSphere MQ - Events Display Tool
http://www-01.ibm.com/support/docview.wss?uid=swg24029241

MS0P: WMQ explorer plugin
http://www-01.ibm.com/support/docview.wss?uid=swg24011617

How to find out the high CPU thread for WAS on Windows

follow the CPU high mustgather for Windows platform

http://www-01.ibm.com/support/docview.wss?uid=swg21111364

In the threadsout.txt, the Handle column stands for the thread id. You can use this thread id to find out
the java stack in the javacore files.