Re: "Cannot Connect" FTP

Dan,

Some of our customers have reported this symptom in the opposite direction -
AS/400 connecting to mainframe system and getting this message. It appears
that the mainframe "blinks out" for short periods of time, usually just a
few seconds. But we've never encountered this where the AS/400 was the
server. The FTP server will spawn more instances to handle the increased
traffic, so it is not surprising that you find more than the initial number
of jobs running. But I don't think you should see the AS/400 causing this
problem.

Are there multiple FTP jobs starting at the same time on the mainframe side?
Are there any error messages (400 or 500 series errors) coming from the
AS/400? Have you tried running a comms trace on the AS/400 to see if the
connection is being made? Are there routers, gateways, and/or proxy servers
between the AS/400 and MF?

Patrick

---
IBM AS/400 communications, FTP automation, and eCommerce
software and consulting services.

http://www.patownsend.com

----- Original Message -----
From: <D.BALE@handleman.com>
To: <MIDRANGE-L@midrange.com>
Sent: Wednesday, May 09, 2001 8:50 AM
Subject: "Cannot Connect" FTP


> In our environment, we have a mainframe that FTPs hundreds of files daily
to
> our branch AS/400s.
>
> Invariably and unpredictably, a mainframe FTP job will abend with "Cannot
> Connect".  A few minutes later, another mainframe FTP job will run
> successfully.
>
> I've been asked to look at the AS/400 side to see if there's anything we
can
> do to keep this from happening.  This is NOT my area of expertise.  What
I've
> noticed is that our branch boxes have numerous QTFTPnnnnn jobs, for
example,
> our Indianapolis box has 13 of these jobs "active".  When I prompt CHGNETA
on
> this box, the "Number of initial servers" is set to 5.  I presume
(awaiting
> correction from the list) that somewhere along the line since the last IPL
in
> October, we had 13 FTP server jobs actively transferring files from the
> mainframe to the AS/400.
>
> So, I have been asked to consider changing the "Number of initial servers"
to
> the maximum of 20, with the goal of minimizing the "Cannot Connect"
mainframe
> abends.  This doesn't make complete sense to me, but I'd be willing to try
it
> if there's no downside to doing so.  I presume that if a server job is not
in
> use, eventually it gets paged out of memory with no hit on performance.
>
> Or are we slaying the wrong dragon?
>
> - Dan
> Dan Bale says "BAN DALE!"
> IT - AS/400
> Handleman Company
> 248-362-4400  Ext. 4952
> D.Bale@Handleman.com
>   Quiquid latine dictum sit altum viditur.
>   (Whatever is said in Latin seems profound.)
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