Re: problem multi-threading a stored procedure

[Dieter.Bender@xxxxxxxxxxx (Dieter Bender)]

Hi,

you have two possibilities:
1. synchronize on the connection object 
2. use a seperate connection for every transaction

second would be state of the art, using a connection pool.

Dieter

On Friday 07 March 2003 20:24, you wrote:
> I am having a problem with a stored procedure.  Hopefully, someone has
> experience with this.  Here is my environment.
>
> - Jakarta Tomcat 4.0.4 running on iSeries.
> - Servlet calls a stored procedure to get list of results.
> - Stored Procedure is written in RPG, running on same iSeries.
>
> Everything works great when there are not simultanious requests to the
> same Stored Procedure.  If two users request the results at
> approximately the same time, one of them doesn't get any results.  From
> what I can tell, the second person to request the results get the
> results, and the first person gets none.
>
> I have verified that the Servlet (as expected) is being executed in two
> seperate threads.  The Connection and the CallableStatement are declared
> as fields (class level variables).  The ResultSet is a local variable
> that immediately gets turned into an ArrayList which is passed to a JSP
> page for display.  So, I am using the same Connection for every user,
> and calling the "executeQuery()" method on the same CallableStatement.
>
> Can anyone see what is wrong?  My guess is that this connection is being
> serviced by the same QZDASOINIT prestart job, therefore it is
> technically the same job that is calling the Stored Procedure each time,
> and that is why it can't handle multi-threading.  Does anyone know how
> to get around this?  Should I create a seperate Connection object for
> each user?  That seems ineffecient.
>
> _______________________________________________
> This is the Java Programming on and around the iSeries / AS400 (JAVA400-L)
> mailing list To post a message email: JAVA400-L@xxxxxxxxxxxx
> To subscribe, unsubscribe, or change list options,
> visit: http://lists.midrange.com/mailman/listinfo/java400-l
> or email: JAVA400-L-request@xxxxxxxxxxxx
> Before posting, please take a moment to review the archives
> at http://archive.midrange.com/java400-l.

-- 
mfG

Dieter Bender


DV-Beratung Dieter Bender
Wetzlarerstr. 25
35435 Wettenberg
Tel. +49 641 9805855
Fax +49 641 9805856
www.bender-dv.de