I posted a java performance issue on java400-l and one reply from Tim Rowe
at IBM mentions a great tool that among many options, will help  find
network issues within your configuration. 
See Tim's response below about the ARE tool, which should already be on your
systems (V7R1 and later). There is also a link to an IBM page in Tim's
response about the ARE tool. 
I thought this should be shared on midrange-l
Btw - running the areVerify.sh without any parm will display a list of
possible parameters..
Maybe everyone knows about it except me, but I thought it pretty cool.
Enjoy
Jim Franz
 
 
   Greetings,
   The DNS issues is a potential issue.  Java does a ton of access using
   TCP/IP.  If its on the same box, that request may never leave the TCP
   stack, so when things are working well, you many never be aware.  The
   issue with a BAD DNS, is you end up with a pile of time outs.  The TCP
   request has to wait for that bad DNS to respond. One time out would
likely
   never be noticed, but if you have 40 requests (or more) yea you can see a
   major slow down for NO apparent reason.  I have hit this many times at
the
   COMMON conference.  Years ago, we shipped a tool to help you identify
that
   you have a problem.  Its part of ARE.  The tool is shipped with the
   operating system, so its available to anyone to use.
 
   Go into qshell  - Type QSH from the IBM i command line, then enter the
   areVerify command with the network option.
 
   /QIBM/ProdData/OS/OSGi/templates/bin/areVerify.sh  -network
   Review the results to see if you have someone poorly configured with your
   Network settings.
 
   Tim
 
   Tim Rowe, timmr@xxxxxxxxxx <mailto:timmr@xxxxxxxxxx> 
   Business Architect Application Development & Systems Management for IBM i
   IBM i Development Lab, Rochester, MN
   (507) 253-6191 (Tie) 553-6191
 
   
http://www-03.ibm.com/systems/power/software/i/are/index.html
 
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