Re: RPGLE Stored Procedures and Thread Safety

Hi Dan,

I recommended to synchronize on the Connection, not on the stored Procedure. 
every thread could use it's own Connection. That would be no problem for high 
traffic.
The issue with the ResultSets is in my opinion no issue of the stroed 
procedure, ResultSet itself isn't thread safe.

Dieter

On Monday 07 July 2003 20:05, you wrote:
> Dieter,
>         That makes sense. Thanks for your input. I am using the JTOpen
> JDBC driver, and according to their web site there should not be any
> problems, so I should be safe. The main reason I asked is, as I said
> before, stored procedures on the iSeries that return open cursors are not
> thread safe according to the JTOpen web site (see
> http://www-1.ibm.com/servers/eserver/iseries/toolbox/faqjdbc.htm#faqB4),
> and I did experience problems because of that on an earlier project.
>         Unfortunately I don't think synchronizing access to the stored
> procedure will work well in this situation. This stored procedure will be
> used by at least two web applications which will support at least 3
> million hits per month. With that kind of traffic I assume synchronizing
> access to the stored procedure would create a really bad bottle-neck. So,
> I am a little gun shy and couldn't find anything specifically mentioning
> thread-safety of RPGLE stored procedures and didn't want to assume it
> would work until I checked with some people that were more experienced in
> this area than I am. Again, thank you for your response.
>
>
> Dan Feather
>
>
>
>
>
> Dieter.Bender@xxxxxxxxxxx (Dieter Bender)
> Sent by: java400-l-bounces@xxxxxxxxxxxx
> 07/07/2003 12:20 PM
> Please respond to Java Programming on and around the iSeries / AS400
>
>
>         To:     Java Programming on and around the iSeries / AS400
> <java400-l@xxxxxxxxxxxx>
>         cc:
>         Subject:        Re: RPGLE Stored Procedures and Thread Safety
>
>
> Hi,
>
> the source of information should be the documentation of the JDBC
> interfaces.
> AFAIK the driver has to manage the thread safety. But if you synchronize
> your
> application on the Connection, thread safety should not be a problem
> anyway.
>
> Dieter
>
> On Monday 07 July 2003 17:33, you wrote:
> > Hello,
> >         I have written an RPGLE program that utilizes a service program
> > for calculating the price of a given item. I have written this program
>
> so
>
> > that I can use it as a stored procedure, which I plan on calling from
> > several multi-threaded applications. In the past I ran into problems
>
> with
>
> > stored procedures that returned result sets, and I eventually found out
> > via links provided by several nice people on this list that the cursors
> > opened in those stored procedures are not thread safe. So, when I
>
> started
>
> > developing this new stored procedure I went looking for information on
>
> the
>
> > thread-safety of RPGLE stored procedures, and I have not successfully
> > found information leading to a conclusion. I checked the usual resources
> > (google, ibm.com, Redbooks, mid-range archives, etc.), and ran some
>
> tests
>
> > of my own, but I want to be more certain than I am that RPGLE stored
> > procedures are thread safe. So, I was wondering if anyone here knew of a
> > source of information on this specific subject that I may have missed,
>
> or
>
> > knew off-hand if they were thread safe. Thanks in advance!
> >
> > Dan Feather
> > _______________________________________________
> > This is the Java Programming on and around the iSeries / AS400
>
> (JAVA400-L)
>
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-- 
mfG

Dieter Bender


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