Description of problem: Rolling upgrades from RHEL5 to RHEL6 will work better if we add code to RHEL5 groupd that sends out a message advertising its version. Without this, RHEL6 groupd assumes an old version after not receiving a version message after a timeout period. The timeout+assumption works (and needs to for rolling upgrades of 5.1 or 5.2 to RHEL6), but is obviously slower and less reliable than actually getting a message. The sooner we include this in RHEL5, the more likely that RHEL5->6 upgrades can take advantage of this improvement. These version messages will not affect the behavior of a RHEL5-only cluster. Another future problem we can mitage now, is the case where RHEL6 nodes form a new cluster, and select the new incompatible groupd mode because no RHEL5 nodes are found (this "auto-detection" is the behavior we want). Then, an old RHEL5 node joins the cluster (people shouldn't do this, but it may happen). It would be nice to prevent the old RHEL5 groupd from doing anything, because it won't be in sync with the RHEL6 nodes running in the new mode. The simplest way to do this is for the old groupd to look at the version messages from the new RHEL6 nodes, and exit when it sees they are incompatible. Again, this will only affect the groupd behavior once there are mixed RHEL5/RHEL6 nodes. Version-Release number of selected component (if applicable): How reproducible: Steps to Reproduce: 1. 2. 3. Actual results: Expected results: Additional info:
This request was evaluated by Red Hat Product Management for inclusion in a Red Hat Enterprise Linux maintenance release. Product Management has requested further review of this request by Red Hat Engineering, for potential inclusion in a Red Hat Enterprise Linux Update release for currently deployed products. This request is not yet committed for inclusion in an Update release.
Created attachment 314758 [details] groupd patch Patch is attached. Have now tested this on RHEL5 without problems. There's not much to test, really, because the new code never does anything; it just sends a new message that's ignored. Most of the new code is the standard setup for a new message type. The RHEL6 version of groupd will actually use these new messages being sent to "see" the RHEL5 nodes.
pushed to RHEL5 and STABLE2 branches
An advisory has been issued which should help the problem described in this bug report. This report is therefore being closed with a resolution of ERRATA. For more information on therefore solution and/or where to find the updated files, please follow the link below. You may reopen this bug report if the solution does not work for you. http://rhn.redhat.com/errata/RHBA-2009-0189.html