Re: Glassfish

Joe Sam Shirah skrev den 30-10-2007 07:21:

We develop against 1.4

If you're not stuck with a particular Java release ( like WebSphere
imposes, ) IMO you should at least go to 1.5 to pick up the performance and
GC benefits without changing any code. And that's for any system, not just an AS/400.

We are not stuck with a particular Java release, but we develop against 1.4 to be able to run on whatever JVM the client has installed.
I have not found much performance difference between the various JVM's after the JIT has settled. This includes the new 32-bit JVM. I have found that the documentation is correct - the JIT is noticeably faster than DE - but it requires quite some cpucycles to get there (for instance a graphics heavy program I wrote requires over 60 seconds to process the first image due to JIT'ting - the whole batch is processed faster in the end though).

The whole system is slower than a PC.

I have understood it is enough to "just" stow the Java stuff away in a
subsystem with 1Gb RAM for itself.

No offense, but that makes no sense to me except for the particular case
where a particular app happens to fit. Otherwise, you're either throwing
away memory that could be used in other areas or not giving Java enough.

Sure, but we are still learning how the various parts of OS/400 interact and Java apps are different because they have a very large memory footprint. To avoid swapping it in we have found that it helps reserving a large chunk of memory AFTER performance degradation has been found.

I notice you toppost while copying in the original text

I just prefer not to have to search through a lot of intermingled pieces
somewhere throughout the original message, which I leave intact, and try to
do the same favor for others.

Habits are individual. It was just a suggestion.