Jon, Jim, and Henrik,
Thanks for the replies here. (If you're following the thread on Midrange-L, you may have seen my thanks to you there as well).
I'll be looking into adding a web service call to the start-up stack and see how much I get from that.
-- Michael

-----Original Message-----
From: WEB400 [mailto:web400-bounces@xxxxxxxxxxxx] On Behalf Of Jon Paris
Sent: Monday, March 09, 2015 11:29 AM
To: Web400@Midrange. Web400
Subject: Re: [WEB400] Web Service slow on first call of the day

IWS is a Java App server so the overhead comes from starting up the JVM
itself and then the app server and then your app.

It is not going to be speedy - but yours does seem a little excessive.

Jon Paris

On Mar 9, 2015, at 9:20 AM, Koester, Michael <mkoester@xxxxxxxxxxxxx>

Thanks for that, Charles.
Is it likely that the Web Service is the choke-point, or something else?
My thinking is that it may not be necessary to take down the web server if
that might be a solution. I'd need to check with SysAdmin and others, but
worth pursuing if that is "the beast".
-- Michael
-----Original Message-----
From: WEB400 [mailto:web400-bounces@xxxxxxxxxxxx] On Behalf Of
Charles Wilt
Sent: Monday, March 09, 2015 9:06 AM
To: Web Enabling the IBM i (AS/400 and iSeries)
Subject: Re: [WEB400] Web Service slow on first call of the day

The first call is always going to be slower, that's just the nature
of the beast.

30+45 seems excessive, but I suppose it depends on what's happening
the scenes.

You've got a couple options
1) Stop taking down everything every night
2) In your start up, include a program that makes a priming call to
the web service.


On Mon, Mar 9, 2015 at 8:58 AM, Koester, Michael

(cross-posting to MIDRANGE-L)
I have developed a web service with the Integrated Web Services
(IWS) that is almost production ready, but I'm noticing that the
very first call of the day takes 30-45 seconds to return a response.
A subsequent calls provide sub-second responses, and that continues
throughout the day.
I'm normally pretty patient, but this will be used to provide data
to a customer-facing web site, and if I was the first customer of
the day to the web site, I'd give up if it hung for more than 10
seconds -- by
30 seconds I'd be off doing other things for sure.

My questions are:
1. What are the likely causes for the delay-on-first-call behavior?
2. What might I do to either eliminate the problem, or perhaps
simulate a call on web server start-up, so that the first customer
gets an acceptable response time?

In our environment, we take down most subsystems overnight, for
database back-ups, for about 2 hours. When that completes, a n
orderly CL-driven start-up occurs, and the various subsystems are
restarted and are ready for action by about 4:30 AM. The web
services are automatically active as the web server comes up.

The web service itself calls an ILE-RPG program that calls a number
of service program procedures to gather data elements needed for the
web site presentation and navigation. Most of those procedures use
embedded static SQL. In my testing, I use the SOAPUI utility to
simulate the calls that the web site script would use, and it is
with the SOAPUI calls that I observe the delay in response on that
My guess is that at least one component along the way takes a long
time to set up open data paths or something else that all the
subsequent calls get a free ride on, but I don't know enough about
what goes on behind the IWS curtain to know if there isn't an

All ideas are welcome. Let me know what other details might be

Michael Koester

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