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?