Re: Java on 7.1 one system fast other system very slow

Hi John

I suggest you run database monitors from Navigator over the jobs in question, on each system - then do the Visual Explain thing - you'll be able to see what optimization choices were made, and maybe see a difference there.

Good luck, and come on back with the results, then we can speak to this better, I think.

Vern

On 8/17/2015 4:01 PM, John Allen wrote:

We have a CL program that calls a java program to read modify and
write a file in the IFS


Both machines let's call them F and S (Fast and Slow)


They are configured the same (except slight difference in memory and
disk storage see below)

Both running IBM I 7.1

Both at the same PTF levels for both the SS1 and JV1

Both have similar memory

Both have similar System ASP used (10 % vs 23%)

Both have Java Version =

java version "1.6.0"


Java(TM) SE Runtime Environment (build pap3260sr16fp1-20140706_01(SR16
FP1))

IBM J9 VM (build 2.4, JRE 1.6.0 IBM J9 2.4 OS/400 ppc-32
jvmap3260sr16fp1-20140706_01 (JIT enabled, AOT enabled)

J9VM - 20140626_204542


JIT - r9_20130920_46510ifx7


GC - GA24_Java6_SR16_20140626_1848_B204542)


JCL - 20140704_01




Note:

Executing JAVA *VERSION

System F response is instant

System S Response is 20 seconds


We are seeing something similar with our CL program

System F= 5-10 seconds

System S=60-80 seconds


The "JAVA *VERSION" execution is so different I don't think it is
anything in our CL or java program.


I keep comparing the 2 and can't find a difference other than the
performance of Java being so vastly different


What could cause a variance of the simple execution of "JAVA *VERSION"


Any idea or suggestions on where to I can look?


Thanks in advance for any assistance


John