Database sessions, Application Modules and Pools

Question

Hi,
I have an ADF 10.1.3 application (ADF Faces on ADF BC) that uses JAAS to authenticate it's users. After the user has logged in I would like my session_user_info managed bean to query the database and retrieve all the user's details, for access throughout the user's session. Initially I wrote the following code to achieve this:
      ApplicationModule am = Configuration.createRootApplicationModule(applicationModuleName, applicationConfigName);
      ViewObject vo = am.findViewObject("CurrentUserView1") ;
      vo.setNamedWhereClauseParam("v_userName",userName);
      vo.executeQuery();
      if(vo.getRowCount() <= 0)
        user = null ;
      else
        user = (CurrentUserViewRowImpl) vo.first();
      Configuration.releaseRootApplicationModule(am, true); This works fine BUT because it's creating a new root ApplicationModule each time I end up with an excessive number of database connections after a very short space of time (the call to Configuration.releaseRootApplicationModule does not seem to be releasing the database connection, even though the application module is released). I also don't like this as it feels like I'm "breaking" the framework by making a direct call to the model layer.
So the next thing I wanted to try was creating a DataControl (by dragging my CurrentUserView1 on to a jspx page, then deleting it to preserve the bindings) and make a call to that using something like this:
        /**** TODO GET BINDING TO CurrentUserView1 ******/
        OperationBinding operationBinding =
            bindings.getOperationBinding("ExecuteWithParams");
        JUCtrlAttrsBinding vUsername =
            (JUCtrlAttrsBinding)bindings.findNamedObject("v_userName");
        statusCode.setAttribute("v_userName", username);
        Object result = operationBinding.execute();
        if (operationBinding.getErrors().isEmpty()) {
           /***** TODO Cast this result object in to something useful *****/
            setUser(result)
        }But as you can see I still don't completely understand what I have to do here (and yes I have trawled the various guides and documentation - but I can't work out exactly what applies to me as this isn't a backing bean).
If any of you Aces out there can give me some pointers it would be MUCH appreciated as I've beat my head against this for a week now!!
Dave
Edited by: Short Dave on Dec 1, 2008 2:52 PM

Answer 1

John,
It's been 2 months since I asked this question and in that time I have tried innumerable ways of getting my application and database pools to behave in such a way that doesn't end up filling my database with unclosed sessions. The situation I'd ideally like to achieve is this:
Application Modules
A pool of application modules minimum 5 maximum 150 with a "working set" of about 25 (the jbo.recyclethreshold setting)
For application modules to timeout if they are inactive for > 120 seconds (so if somebody has left their browser open in the background I don't want them hogging my AMs)
Database Connections +(I am using a JDBC data source to allow multiple applications to reuse my connection pool settings)+
A pool of database connections minimum 5 maximum 150
If a connection is inactive for > 300 seconds for that connection to be closed (i.e. if an AM has been returned to the pool, but is not re-used within 5 minutes then I'd like the connection closed)
Obviously, for the purposes of testing, I don't want to try and manage 150 browser sessions to see if this setup works, so I have been trying to create a scaled-down version of my requirements:
Application Modules
A pool of application modules minimum 1 maximum 5 with a "working set" of 1 (the jbo.recyclethreshold setting)
For application modules to timeout if they are inactive for > 30 seconds
Database Connections
A pool of database connections minimum 1 maximum 5
If a connection is inactive for > 60 seconds for that connection to be closed
My problem is that, despite all the API's, the ADF for 4GL guide, forum entries and Steve Muench's guide to AM Pooling I still can't get this relatively simple example to work.
My bc4j.xcfg file looks like (assume all other settings are as default):
         <jbo.recyclethreshold>1</jbo.recyclethreshold>
         <jbo.ampool.maxavailablesize>5</jbo.ampool.maxavailablesize>
         <jbo.ampool.maxinactiveage>30000</jbo.ampool.maxinactiveage>
         <jbo.ampool.minavailablesize>1</jbo.ampool.minavailablesize>
         <ApplicationName>gpl.model.PreUserLoginModule</ApplicationName>
         <jbo.ampool.monitorsleepinterval>30000</jbo.ampool.monitorsleepinterval>My data-sources.xml file has the following entries for the connection used by that application module (assume all other settings are as default):
  <connection-pool name="jdev-connection-pool-gslportal_at_ppmsdb"
                   disable-server-connection-pooling="false"
                   validate-connection="false" inactivity-timeout="60"
                   max-connections="5" min-connections="1"
                   property-check-interval="30"
                   used-connection-wait-timeout="30">With this configuration I can open a maximum of 5 browsers and each one connects successfully. On opening the 6th I get an exception because no more connections are available (as expected). My problem is that if I wait for 5 minutes I'd expect that
a) 4 of the inactive application modules should be released (with one left available as per the min setting)
b) The database connections of the 4 inactive application modules should be released as per the "inactivity" and "used-connection-wait" timeouts on the data-source
c) I'd now expect the 6th browser to be able to connect because of the "freed up" resources
From what I can make out none of these things happens. Even if I close the original 5 browsers, the 6th still cannot connect.
I have noticed that if I set the "time-to-live-timeout" for the datasource then this will close the connection after the given period of time, but regardless of whether or not the connection was in use and in doing so renders the application module held in the pool as useless. (So if any of my original 5 sessions attempt to re-use the application module with the closed database connection, a "Closed Connection" SQLException is raised).
I do appreciate this topic has been given LOTS of forum discussion already - but I really have done my research and am still none the wiser. Any help or guidance will be much appreciated.
Kind Regards
Dave