James:
For configurations with Apache, Tomcat, WAS, PHP, etc. I always want a 95%
confidence level that a thread will get an activity level when it needs it.
Performance starts to suffer if it's not set that way.
First make sure they are NOT running in *BASE, that's the worst place to run
it. Set up a memory pool just for WEB serving. Next make sure the
QZDASOINIT and QSQSRVR (SQL requests) jobs have their own memory as well.
I watch it for a couple of days and set the activity level for the WEB pool
at about 90% of the total threads. I'll equal the number of threads if the
server is heavily used.
Now the hard part, memory. Make really sure there is sufficient memory
for the server. Memory is really cheap by comparison to an upgrade so if
you need more for a P7, buy it on the open market. (P8 and P9 memory should
be acquired from IBM)
Watch the paging and faulting rates, if they are thrashing then the whole
machine slows down. There's almost no such thing as too much memory in the
SQL and Web serving memory pools.
--
Jim Oberholtzer
Agile Technology Architects
-----Original Message-----
From: MIDRANGE-L [mailto:midrange-l-bounces@xxxxxxxxxxxx] On Behalf Of James
H. H. Lampert
Sent: Friday, June 22, 2018 11:35 AM
To: Midrange Systems Technical Discussion <midrange-l@xxxxxxxxxxxx>
Subject: Setting "Max Active" on a memory pool.
I'm not quite sure I fully understand what "Max Active" on a memory pool
does.
I know that the helptext from WRKSYSSTS says "The maximum number of threads
that can use the processor concurrently." But I don't quite understand how
that could be specific to a memory pool.
Re: the specific situation that brings up this question, we have a rather
heavily loaded Tomcat server running on a customer box. And it's running in
a 64-bit Java 7 JVM, with max heap of 4G, in a subsystem that has a 6G
private pool with Max Active 200.
WRKSYSSTS shows that the JVM job for the Tomcat server has over 700 threads.
Should the Max Active be bumped up? Are there ways, other than
trial-and-error, to optimize Max Active?
--
JHHL
--
This is the Midrange Systems Technical Discussion (MIDRANGE-L) mailing list
To post a message email: MIDRANGE-L@xxxxxxxxxxxx To subscribe, unsubscribe,
or change list options,
visit:
https://lists.midrange.com/mailman/listinfo/midrange-l
or email: MIDRANGE-L-request@xxxxxxxxxxxx Before posting, please take a
moment to review the archives at
https://archive.midrange.com/midrange-l.
Please contact support@xxxxxxxxxxxx for any subscription related questions.
Help support midrange.com by shopping at amazon.com with our affiliate link:
http://amzn.to/2dEadiD
midrange.com
