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20041022: timeouts in the ldm connection



Christian,

> To: address@hidden
> From: "Christian =?ISO-8859-1?Q?Pag=E9?=" <address@hidden>
> Subject: General Support - Network congestion
> Organization: UCAR/Unidata
> Keywords: 200410191329.i9JDT0Ad013666

The above message contained the following:

> Institution: UQAM
> Package Version: LDM 6.1.0
> Operating System: IRIX64
> Hardware Information: SGI
> Inquiry: Hi,
> 
> We are experiencing network congestion at UQAM, because of the network
> people that installed a packet filter at the gateway to Internet2 which
> slows down to a crawl all our connections. We are in the process of
> urging them to fix that, but this could take days... :-(
>
> In the meantime, my ldm connections are dropping with repetitive
> messages like:
> Oct 19 13:19:45 3Q:io atm[83566951]: ERROR: requester6.c:205: Connection to 
> upstream LDM closed 
> Oct 19 13:19:45 5Q:io atm[83566951]: Desired product class: 
> 20041019130445.726 TS_ENDT {{NIMAGE,  "(VIS|IR|WV).*CONUS"}} 
> Oct 19 13:19:45 5Q:io atm[83566951]: Connected to upstream LDM-6 
> Oct 19 13:19:45 5Q:io atm[83566951]: Upstream LDM is willing to feed 
> 
> I have limited the latency to 900 secs, in the hope to see part of
> our products to be generated partially (better that than nothing at
> all since by default latency is 1 hour I think, so much too late for
> automated prods generation).  Also, I have put as much as 3 ALTERNATE
> servers to WMO feed type to hope that when one disconnects, at least
> another one is receiving data.
>
> Is there anything else I can do in the meantime in ldm
> configuration? Is it possible to increase the tolerance to timeouts in
> the ldm connection?

The problem isn't the timeouts, the problem is that the packet filter
is throwing packets away.  We've seen this problem before at certain
institutions and the solution is to not restrict any traffic on port
388.

You need to scream loudly to your IT people and/or increase the
importance of this problem within your institution as quickly as
possible.

> Thanks,
> 
> Christian

Regards,
Steve Emmerson

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