George, I don't have all the information, but a few things to consider:

0) What are your system resources?  Zenoss 4.2 requires significantly more RAM than 3.2.1 - what is your available RAM?  Are you using swap?

1) Have you run mysqltuner.pl to tweak the default MySQL database configuration values?

2) There should be at least one device present in the system (a fresh install adds localhost) - any chance that it is generating an event flow?

As the root user, can you please execute "rabbitmqctl list_queues -p /zenoss".  This will show you the queues that Zenoss is using and their size - if any of these are non-zero, that would be an indicator of what is going on.  If all of these are zero, and mysql has been tuned, I'm not certain where to look next.

You could check your log files for any repeating errors, perhaps (one thing we do in QA is the following:)

If "ack" is not already installed (try running "ack" from the command line") you can download it from

curl http://betterthangrep.com/ack-standalone > /bin/ack && chmod 0755 !#:3

As the "zenoss" user, perform the following:

cd $ZENHOME/log

ack -uil traceback

  If there are any returned results, you need to examine those files and see if these require tickets or are known issues

ack -uil error

  If there are any returned results, you need to examine those files and see if these require tickets or are known issues

Hopefully some of this can help or get you moving in the right direction.

  -- Brian