on rhel7 it looks like broker starting very slowly (~1 or 2 minutes)
logs in attachment, threaddump in attachment
here is what I discovered:

When I tried start broker on rhel7 ./bin/amq then progress is stuck on 50% or 64% (almost every time). Broker started after ~1 or 2 minutes!

I tried it too on Rhel6 and Fedora and here it works good (Broker started after ~10 seconds). On rhel7 with 3.10.0-123.el7.x86_64 kernel it worked fine too.

I tried change logger to DEBUG but In logs I saw only following :
Can't find MBean Instance when destroy context
javax.management.InstanceNotFoundException: hawtio:type=plugin,name=hawtio-redhat-fuse-branding

java.io.FileNotFoundException: /opt/jboss-a-mq-6.2.1.redhat-169/etc/overrides.properties (No such file or directory)

Environment: Rhel7.x86_64
CPU: 2
Mem: 2G
Avail disk space: 8.3G

3.10.0-123.el7.x86_64 - without this issue
3.10.0-327.36.1.el7.x86_64 - with this issue
two different machines with this kernel 3.10.0-514.el7.x86_64 - with this issue

on a lot of machines in our CI this issue was occurred