Topic
6 replies Latest Post - ‏2014-08-28T00:11:08Z by george.baker
george.baker
george.baker
312 Posts
ACCEPTED ANSWER

Pinned topic Multiple associated connections

‏2014-08-07T05:40:29Z |

I have a HATS Web service application that connects to a single host IP address.    I am using connection pooling with the option Only allow single connection with each user ID checked.  All this works wonderfully as long as the application is running on a single server.  The problem will come when more than one server in an environment is in the picture such as in one of the following situations.  

  1. Running in a cluster of more than one node
  2. Running in an environment where there are multiple servers in the Development environment, e.g. Development, User Acceptance Test, System Integration Test

The probability that the same user ID will be requested to the host from multiple machines is virtually 100%. This cannot be allowed to happen,  so I am creating a connection pool for each server in the configuration and split up the allocated user IDs across the connections so that it is impossible to attempt a connection with the same ID at the same time.

Now my problem:

I have a single SignOn (connect) macro that I want to use on all the connections.  However, all my efforts to get the connection to accept the same Signon macro have failed.   I can have as many as 12 different connections to manage in this way, so  I really do not want to create and maintain multiple copies of the SignOn macro just for this.  

I cannot find anything in the InfoCenter on how to do this, or if it is even possible.

Anyone done this before, if so how?

 

  • tmparker
    tmparker
    514 Posts
    ACCEPTED ANSWER

    Re: Multiple associated connections

    ‏2014-08-08T13:23:50Z  in response to george.baker

    Hi George,

    The option to allow a single connection per user id applies to the user list feature in HATS connection pooling. I found the section below on the following page in the infocenter, http://pic.dhe.ibm.com/infocenter/hatshelp/v90/topic/com.ibm.hats.doc/doc/ugcon.htm

    Clustering and user lists

    When you create multiple instances of WebSphere application servers running HATS applications and sharing the same application files, you can use user lists on multiple-logon hosts without any special considerations. However, there are special considerations for the use of user lists with single-logon hosts:

    • In vertical clustering, where application-related files are not physically copied to each application server but are merely represented in memory, you cannot use user lists. This restriction exists because every application server running HATS would need a user list for its exclusive use; but in fact there is only one user list.
    • In horizontal clustering, where multiple copies of an application are running in separate application servers, you must modify the user list in each copy of the application to ensure that no two copies have a user ID in common.
    • george.baker
      george.baker
      312 Posts
      ACCEPTED ANSWER

      Re: Multiple associated connections

      ‏2014-08-08T13:38:00Z  in response to tmparker

      Thanks for point that section out to me.  

      I am trying to work around this issue.  I am doing it by creating a unique connection pool per Application server  each containing a unique user ID list.

      As part of this strategy I wish to use and maintain a single Connect and Disconnect macro for all pools.  In HATS v8.5 you could do this by including multiple <connection name="xxx"/> statements in the macros that would allow them to be run on multiple connection pools.  Yesterday I confirmed that this worked in V8.5, but in V9.0 it broke.  The macro editor in v9.0 and v9.0.0.1 both throw an error as soon as you add a second <connection> statement.

      I've opened a PMR on this.

       

      • tmparker
        tmparker
        514 Posts
        ACCEPTED ANSWER

        Re: Multiple associated connections

        ‏2014-08-08T14:19:06Z  in response to george.baker

        My guess is this is a result of the macro schema that was added to HATS 9.0 as a result of an RFE we received.  I think this will be a similar issue as the one you had in this thread, https://www.ibm.com/developerworks/community/forums/html/topic?id=e8ca9d09-f38c-4655-a864-10d54f7a8b15&ps=25

        As a quick test, try disabling this feature and see what happens.

        Thanks
        Tim

        • george.baker
          george.baker
          312 Posts
          ACCEPTED ANSWER

          Re: Multiple associated connections

          ‏2014-08-08T19:14:55Z  in response to tmparker

          I just tested this.  I disabled the feature for the specific macro and saved and for good luck did a Clean.  I then added a new <connection> statement to the macro.  Unfortunately, I still get the same error.

          • tmparker
            tmparker
            514 Posts
            ACCEPTED ANSWER

            Re: Multiple associated connections

            ‏2014-08-08T20:16:45Z  in response to george.baker

            Ok, then I'll let the team look into this through the PMR and see what the deal is.  I'm not aware of any changes other than those in the code that would affect this behavior but there certainly could have been a change I didn't know about.

            Thanks
            Tim

            • george.baker
              george.baker
              312 Posts
              ACCEPTED ANSWER

              Re: Multiple associated connections

              ‏2014-08-28T00:11:08Z  in response to tmparker

              I applied update v9.0.0.1 and still had the problem.  This time I disable the feature and the problem is resolved.

              I recommend in v9.0.0.2 that this be fixed so you do not need to disable the feature.