RHEL Engineering is moving the tracking of its product development work on RHEL 6 through RHEL 9 to Red Hat Jira (issues.redhat.com). If you're a Red Hat customer, please continue to file support cases via the Red Hat customer portal. If you're not, please head to the "RHEL project" in Red Hat Jira and file new tickets here. Individual Bugzilla bugs in the statuses "NEW", "ASSIGNED", and "POST" are being migrated throughout September 2023. Bugs of Red Hat partners with an assigned Engineering Partner Manager (EPM) are migrated in late September as per pre-agreed dates. Bugs against components "kernel", "kernel-rt", and "kpatch" are only migrated if still in "NEW" or "ASSIGNED". If you cannot log in to RH Jira, please consult article #7032570. That failing, please send an e-mail to the RH Jira admins at rh-issues@redhat.com to troubleshoot your issue as a user management inquiry. The email creates a ServiceNow ticket with Red Hat. Individual Bugzilla bugs that are migrated will be moved to status "CLOSED", resolution "MIGRATED", and set with "MigratedToJIRA" in "Keywords". The link to the successor Jira issue will be found under "Links", have a little "two-footprint" icon next to it, and direct you to the "RHEL project" in Red Hat Jira (issue links are of type "https://issues.redhat.com/browse/RHEL-XXXX", where "X" is a digit). This same link will be available in a blue banner at the top of the page informing you that that bug has been migrated.

Created attachment 732591 [details]
Proposed patch

Description of problem:
When corosync is running in VM, it can happen, that VM (and thus corosync) is not scheduled for long time (longer then token timeout). Because in such environments, it's very hard to find out, if token was lost because of network overload or because of guest OS didn't scheduled corosync process or because host OS didn't scheduled VM, it would be nice improvement to implement pause detector in corosync. Corosync then displays warning message, when it was not scheduled for long enough time (0.8 * token_timeout). This will give us idea, if problem was network or scheduling and together with guest load monitoring should give as idea if problem was in guest or host.

Version-Release number of selected component (if applicable):
All

How reproducible:
100%

Steps to Reproduce:
1. Pause corosync
2. Unpause corosync
  
Actual results:
Token is lost, but it's not clear why.

Expected results:
Message "Corosync main process was not scheduled for X ms (threshold is Y ms). Consider token timeout increase." should be displayed.

Additional info:

Verified with scheduler-pause-detector.sh 

FAIL on corosync-1.4.1-15.el6.x86_64 (RHEL6.4)
PASS on corosync-1.4.1-17.el6.x86_64 (RHEL6.5)
Sep 11 18:15:31 virt-014 corosync[5927]:   [MAIN  ] Corosync main process was not scheduled for 11066.0088 ms (threshold is 8000.0000 ms). Consider token timeout increase

Since the problem described in this bug report should be
resolved in a recent advisory, it has been closed with a
resolution of ERRATA.

For information on the advisory, and where to find the updated
files, follow the link below.

If the solution does not work for you, open a new bug report.

http://rhn.redhat.com/errata/RHBA-2013-1531.html