I'm currently maintaining check_yum which is THE Nagios/Icinga check for the YUM package update status.
A rather important feature of check_yum is its "--no-warn-on-lock" option, which makes that invocations of check_yum that fail (due to an already running/blocking YUM) are ignored.
Otherwise one would get many false positives.
Now the thing is that (since some time?) YUM blocks, when another YUM process is already running (which is undesired for check_yum, as it will run into a timeout, which must be considered an error).
Now recent yum versions support a feature (--setopt=exit_on_lock=true) which makes YUM exit, when the lock cannot be gained.
In a thread on yum-devel, James Antill suggested me that it should be very easy to backport that feature for RHEL5 and that I should ask here for it.
Yes, it's simple. I have the backport ready.
This request was evaluated by Red Hat Product Management for
inclusion in the current release of Red Hat Enterprise Linux.
Because the affected component is not scheduled to be updated
in the current release, Red Hat is unable to address this
request at this time.
Red Hat invites you to ask your support representative to
propose this request, if appropriate, in the next release of
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So I'm going to close this out now, as it's really too late in RHEL-5 to add those kinds of UI features. But if you do want them then the first version of yum for RHEL-6 did contain them, and could be rebuilt for RHEL-5.
Also might be better to go straight to yum API instead of using cmd line client.