Re: AS/400 and Java

["Bruce Jin" <brucej@xxxxxxxxxxxxxxxxxxxx>]

<zqRNUXuvxA0b1SvskN2V4Q@public.gmane.org> wrote

> 1. read the recent manuals (Performance Capabilities Reference
> recommends the JIT environment since V4R5!)
> 2. don't use CRTJVAPGM on boxes > V4R5

I stopped using CRTJVAPGM long ago. Everything seems to be OK.

> 3. don't use the native driver, its buggy, use the latest Toolbox  driver

I use the native driver all the time. Everything seems to be OK.

> 4. don't use record level access (more IO Operations compared to SQL)

 I have not used record level access. Everything seems OK. I primarily code
interactive applications and SQL seems to be good enough.

> 5. run your application server on inexpensive boxes (Wintel, or Linux  on
Intel), if possible (scalability)

Linux may offer some hope. My new Intel/win2000 crashes at least once a
month and they can't fix it.
In 9 years I did see AS400 crash, once.

> 6. Don't mix Java with RPG and/or COBOL, the context change is very
expensive

The context change cost probably is often more than compensated. I have a
Java application that calls a big RPG program which calls other CL and RPG
programs and they all do file read/update/delete. The timer shows that all
these take 100 ms (0.1 second). I time it from getting a connection to
returning a connection. Other applications with fewer file operations but
exclusive JDBC SQL calls would always take more than 100 ms.

> 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.

 Labor is more expensive than hardware.

 Bruce