Re: starting JVM is slow

["Joe Sam Shirah" <jshirah@xxxxxxxxxxxxx>]

    There are a lot of issues involved in this thread, but to really
oversimplify, I normally use messages.  By building a couple of front ends,
you can start with standard AS/400 message queues and later, if necessary,
go to full blown messaging, JMS and so on.  It eases portability or changing
service providers ( read called programs or decoupling here ), allows one or
your choice of how many VMs to run, a form of logging and even allows for
more graceful RPG, Java or any other language programs that can access
messages ( restart, pause, shutdown, etc ).


                                                         Joe Sam

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----- Original Message -----
From: <meovino@xxxxxxxxxxxxxxxxx>
To: "Java Programming on and around the iSeries / AS400"
<java400-l@xxxxxxxxxxxx>
Sent: Monday, January 12, 2004 3:47 PM
Subject: RE: starting JVM is slow


>
> > Just curious, what are your reasons for not calling RPG from Java?  I
> have a
> > Servlet in production calling an RPG program with PCML as the
> intermediary,
> > and it is very very fast.
>
> Aaron, are you using this in production?  Sounds like you're pretty happy
> with it.  I've only used the RPG Program Call wizard in WSDCi and run it
in
> the test environment, but it seems to execute pretty well.  Have you done
> anything with calling an RPG program that returns an SQL result set?  I'd
> be interested to know if it's possible to call an RPG program that returns
> a result set from a servlet.  I guess if you call the RPG program as a
> stored procedure...
>
> > I agree that calling Java from RPG is pretty much useless unless it is a
> > batch process or if you have a huge machine.
>
> We have an 8-way 830, and the performance on the first call still blows.
> We were using this to use JavaMail, and now that we bought a package that
> sends mail with a CL command, everyone is abandoning the JavaMail/RPG
stuff
> we wrote (at my suggestion).  You have to have some way to create the JVM
> before the initial call.  I think someone once suggested using socket
> servers, data queues would be another way.
>
> > People will tell you to use a
> > data queue or something similar, but that means you most likely need to
> > write your Java interface so it can run off of a completely validated
> data
> > queue record (meaning you don't collaborate with all the different
> methods
> > in a Java class).
>
> Mike E.
>