Rants, Raves, and Rhetoric v4

Last Known Good config.xml

Saw this on Laura Gekeler’s blog:

Tip: Keep a ‘last known good’ config.xml file on your admin node.
Your Bb Vista cluster config.xml file | laura gekeler

Very good tip! We learned this lesson a couple months into hosting Vista 8 in pre-production.

She goes on to explain this file gets overwritten any time a change in Weblogic is made. Sometimes these changes are (un)intentionally made by an administrator using the console. Sometimes Weblogic detects problematic conditions and makes the change itself. When these changes create problematic conditions, then the last known good version saved us from having to go make the changes ourselves and potentially miss something.

In our cases of problems, a single node failing to shutdown after the JMS node was shutdown caused Weblogic to rewrite who should be the JMS node. It also caused a jumbling of the user preferred server stanzas. We now monitor for these problems and page ourselves to warn us about the problem so we can address it immediately rather than let our clients discover the problem a few days later. (I also somewhat mentioned this in the Forcing Weblogic’s Config.xml post.)

The times I’ve done this I didn’t go as far as Laura. I just…

  1. Stop all the nodes in the cluster.
  2. Copy the current version from $WEBLOGIC_DOMAIN/config/config.xml to /home/<user>.
  3. Copy the last known version from /pathto/lastknownversion/config.xml to $WEBLOGIC_DOMAIN/config/.
  4. Use “touch $WEBLOGIC_DOMAIN/REFRESH” on each managed node.

I am now curious about why she wanted new server directories or a new Vista_WLSstore database table?

Ezra S F

One response to “Last Known Good config.xml”

  1. Laura Avatar
    Laura

    In my posted procedure I outlined renaming the ../WebCTDomain/servers directory to prevent the stored configuration there from being read instead of the ‘last known good’ version I copy into ../WebCTDomain/config/config.xml

    I personally do not believe the renaming of the Vista_WLSstore database table is necessary but I included it because Matt Brady of Blackboard has seen occasions (he didn’t elaborate) when it was necessary. I’m guessing it can contain old config information that is somehow passed back to the pristine ‘last known good’ config.xml you’re trying to get the Vista 8 implementation to ‘eat’. I really want to know more about the relationship between that table and the config.xml file. So much research, so little time…

    Reply

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