Re: AS/400 and Java -- JAVA400-L

Dieter,

I completely disagree with your statements.  The fastest method of
communications in Java is TCP/IP.  The CRTJVAPGM command will compile a Java
program to a bytecode used by the AS/400, not the JIT compiler.  CRTJVAPGM
will make the execution of Java programs on the AS/400 faster...

Mike

----- Original Message -----
From: <Dieter.Bender@t-online.de>
To: <java400-l@midrange.com>
Sent: Monday, November 04, 2002 9:59 AM
Subject: Re: AS/400 and Java


> Mike,
>
> Mike Silvers schrieb:
> > Dieter,
> >
> > Do not use CRTJVAPGM???  When a Java program is run, the
> > system
> > automatically does the CRTJVAPGM if one has not been done
> > before.  I think
> > that you should look at the command defaults and adjust
> > them accordingly to
> > get the best performance in the CRTJVAPGM command...
>
> this has changed with V4R5, by default the system uses the new JIT
> environment!!!
> >
> > Do not mix Java with RPG or COBOL????  Performance
> > depends on the method of
> > interaction.  I think such a blanket statement is
> > overstated.  I agree that
> > direct program calls are expensive, but other methods
> > (such as Socket/XML
> > processing) do not significantly degrade the performance.
> >  I have found that
> > it is faster to use a socket to communicate with an RPG
> > program and do
> > database access than using JDBC with Java.
>
> Why do you use jave, when you do such work arounds to get it fast. BTW,
> if ibm won't succeed to get jdbc faster than this socket things, the
> as400 will disappear and your applications too. The afford to do this
> programming stuff by your own is not in any relation to the performance
> benefits. Buying more hardware to get the engine flying would be
> cheaper.
>
> Dieter
> >
> > Mike
> >
> >
> > ----- Original Message -----
> > From: "Scott Johnson" <sjohnson@highsmith.com>
> > To: <java400-l@midrange.com>
> > Sent: Monday, November 04, 2002 9:39 AM
> > Subject: Re: AS/400 and Java
> >
> >
> > >
> > > Dieter,
> > >
> > > In reference to number 2, are you saying to NOT use
> > CRTJVAPGM on a V5R1 or
> > > V5R2 box? Can you please tell me why?
> > >
> > > Thanks,
> > >    Scott P. Johnson
> > >
> > > > To: java400-l@midrange.com
> > > > Subject: Re: AS/400 and Java
> > > > From: Dieter.Bender@t-online.de
> > > > Date: Mon, 04 Nov 2002 11:49:38 +0100 (CET)
> > > > Reply-To: java400-l@midrange.com
> > > >
> > > > Hi,
> > > >
> > > > and here my performance tips:
> > > >
> > > > 1. read the recent manuals (Performance Capabilities
> > Reference
> > > > recommends the JIT environment since V4R5!)
> > > > 2. don't use CRTJVAPGM on boxes > V4R5
> > > > 3. don't use the native driver, its buggy, use the
> > latest Toolbox
> > > > driver
> > > > 4. don't use record level access (more IO Operations
> > compared to SQL)
> > > > 5. run your application server on inexpensive boxes
> > (Wintel, or Linux
> > > > on Intel), if possible (scalability)
> > > > 6. Don't mix Java with RPG and/or COBOL, the context
> > change is very
> > > > expensive
> > > > 7. use all features of the as400 as database server,
> > you've paid for
> > > > it
> > > > 8. for maximal speed with minimal hardware
> > requirements use assembler
> > > > and shift your bytes bit by bit
> > > >
> > > > Dieter
> > >
> > > _______________________________________________
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> >
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