Topic
5 replies Latest Post - ‏2013-10-02T20:54:40Z by swlinn
KumSub
KumSub
14 Posts
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Pinned topic DataPower LBG

‏2013-08-16T15:18:45Z |

Hello,

I am running into problem during service migration process between environments. Especially with LBG. My end point LBG number of members change depending up on environments. DataPower functions doesn't allow me to add LBG members dynamically using XML management interface when I migrate my service to upper environments. I am trying to eliminate manual updates through WebGUI. What is the best approach to address this situation ? We use Websphere end points and LBG has members of the JVMs node name and container port. Webserver is not an option here. Based on number of JVMs in each environments, LBG members will need to updated accordingly during migration process using script that use XML management interface.

Thanks.

  • swlinn
    swlinn
    1344 Posts
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    Re: DataPower LBG

    ‏2013-08-16T15:35:33Z  in response to KumSub

    Since your backends are WebSphere, with the Application Optimization add on feature, you have dynamically created LBGs.  You point your LBG to your WebSphere cell, and as backend members are enabled or disabled, the LBG will automatically be reconfigured.  With this configuration you would thereby leave your member configuration empty initially.  This feature in Verson 5 or earlier requires the deployment of a servlet to your WAS environment (ODCInfo) which will be polled periodically and the response will result in the configuration of the LBG.  Under the covers, it uses an extension function to update the LBG members (dp:load-balancer-group-update).  I have not had a chance to play with V6 of the firmware, but I believe some changes have been made there and with the later versions of WAS were the servlet is built in an not something you would need to deploy.  Now AO is not free, so if you wanted to go to a more static configuration as you may be accustomed to, you could maintain an XML file with a list of your backend servers, and have a scheduled rule read that XML and update your LBG based on the data from the XML file by using the extension function.

    Regards,

    Steve

    • checkmin
      checkmin
      2 Posts
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      Re: DataPower LBG

      ‏2013-10-02T16:11:06Z  in response to swlinn

      Hi Steve,

      Is there a way to log the LBG member picked in every transaction. I tried looking at service variables in the request through probe but all are empty. I would like to log the member/server endpoint that was picked by the LBG for each transaction coming in.

      Thanks!

      • swlinn
        swlinn
        1344 Posts
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        Re: DataPower LBG

        ‏2013-10-02T16:37:39Z  in response to checkmin

        For back end urls only I believe, in your response rule you should have var://service/lb/group and var://service/lb/member populated.  You can then construct your own log record.  I don't believe these variables are not populated for a url-open done in your stylesheets.

        Regards,

        Steve

        • checkmin
          checkmin
          2 Posts
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          Re: DataPower LBG

          ‏2013-10-02T17:54:18Z  in response to swlinn

          Great, thanks Steve for quick response. I was looking only at the request rule and these variables were empty there. But yes, I see them in response rule.

          Do you think, irrespective of the LBG members being static or dynamic added through(WLM) this variables will always be populated?

          Thanks, again!

          • swlinn
            swlinn
            1344 Posts
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            Re: DataPower LBG

            ‏2013-10-02T20:54:40Z  in response to checkmin

            I would think they would be populated regardless of how the LBG itself is populated.

            Regards,

            Steve