Re: java performance in batch of a packaged tool

[Vernon Hamberg <vhamberg@xxxxxxxxxxxxxxx>]

Pete - Are these calls coming from different jobs? Then the JVM warmup 
would be a killer - and I think you know that - if coming from ONE job, 
that startup is only done once per job.

Just a clarification that you probably didn't need!!

Vern

On 12/29/2016 9:13 AM, Pete Helgren wrote:
> Depends upon how the call to JavaMail is implemented (I am assuming 
> that JavaMail is used).  If it is a call to JavaMail EACH time an 
> email is sent, then the JVM warmup is probably killing the 
> performance.   Each invocation would start the JVM, invoke the 
> JavaMail API, tear down the JVM and then repeat.  That is my guess, 
> not knowing how the code is written.
>
> Better approach is to use something like AppServer4RPG that Dieter 
> Bender created that starts a Java "server" and uses a dataqueue (I 
> think) to pass requests to and from RPG without the JVM startup 
> overhead.  Might be worth a look.
>
> Pete Helgren
> www.petesworkshop.com
> GIAC Secure Software Programmer-Java
> Twitter - Sys_i_Geek  IBM_i_Geek
>
> On 12/28/2016 9:28 PM, midrange wrote:
> > Investigating a performance issue.
> >
> > Is there anything (within reason) one can do increase performance in 
> > a java
> > tool (email) which is called from RPGLE.
> >
> > Not a java programmer.
> >
> > All the emails are sent to an Exchange server in the same lan.
> >
> > Batch pool *base has 18-20 gig memory (auto adjust with paging set to
> > *calc).
> >
> > Server not heavily loaded but same pool serving cgi web server, no heavy
> > traffic and no performance issues.
> >
> > CPU usage during batch process is maybe 4%.
> >
> > Power 8 and V7R1
> >
> > Emails taking 30-40 seconds each, for a little text and a 0.5 to 3 meg
> > attachment.
> >
> > Average batch process migh send anywhere from 2 to 200.
> >
> > Two ethernet lines - 1G, Full Duplex, 1496 packet size
> >
> > This started before the Power 8 upgrade., prev Power 7 also 7.1
> >
> > Same code & tool, in past (maybe year ago)could send each email in 3-4
> > seconds - but cannot put a finger on what has changed, other than a 
> > catch up
> > of ptfs - several cumes and all the groups, but with nobody watching, 
> > not
> > positive it started then.
> >
> > Win Exchange server takes in other  bulk email (like scanners) with no
> > problem.
> >
> > Can see the jdk is 6.0 (and I know it's going away).
> >
> > Joblog shows setting environment variables, change directory, and 
> > then 30+
> > seconds later start next one.
> >
> > Have no logs from when this was faster.
> >
> >
> > Already looking at other tools so no need to mention.. but a simple 
> > tweak
> > would be nice.
> >
> >
> > Jim