Re: Netview status polling and DNS

2000-11-03 09:50:32
Subject: Re: Netview status polling and DNS
From: Gareth_Holl AT tivoli DOT com
To: nv-l AT lists.tivoli DOT com
Date: Fri, 3 Nov 2000 09:50:32 -0500
You are right in that NetView's performance can be seriously affected by
poor DNS operation. The daemons netmon and snmpCollect are two that come to
mind first which rely heavily on name resolution I believe. Status polling
is probably the most dependent on name resolution and thus the DNS Server
because of its frequency. What I experienced recently was the importance of
correctly configuring the local ARP cache on the box where the NetView
Server is installed as this can affect the status polling of nodes in the
same subnet as NetView, especially if you have aggressive polling
parameters. Demand Polling and the daily Configuration Check would also
need name resolution.

snmpCollect is also very dependent on name resolution and this is an area
where I have seen delays caused by poor name resolution resulting in data
collection taking longer than the scheduled polling period and thus the
next polling cycle gets completely skipped. At least this is what happened
in releases of version 5 but many changes have been made to snmpCollect
since 5.1. snmpCollect on NetView for NT seemed to more affected by poor
name resolution and it also use to be the cause of Dr Watson's when the
Grapher tool was used.

It is probably also important to note that your name resolution must
provide forward and reverse resolution. To reduce the negative affects poor
DNS operation can have on NetView, the following parameters in your
"/etc/environment" file were advised:
to limit the retries to 1 attempt with a timeout of 1 second. I think this
is still advised for version 6 of NetView but you could refer to the
Release Notes or call Support to check.

There is probably other NetView daemons and operations that rely on DNS
operation ???

Gareth Holl
Software Engineer
gholl AT tivoli DOT com

Tivoli Systems / IBM Corporation
Research Triangle Park,  NC  27703.    1-800-TIVOLI-8

"McCarter, Bill" <mccarter_we AT nns DOT com> on 11/03/2000 08:55:02 AM

Please respond to IBM NetView Discussion <nv-l AT tkg DOT com>

To:   "'nv-l AT tkg DOT com'" <nv-l AT tkg DOT com>
cc:    (bcc: Gareth Holl/Tivoli Systems)
Subject:  [NV-L] Netview status polling and DNS

     I'm thinking about installing a DNS server on my Netview box and would
like to know what all the benefits will be.  I know Netview relies on DNS
for performance reasons, but name resolution really doesn't seem to be a
problem right now. I have Netview 6.0.1, a Sun Ultra 60, 1 gig of memory
5000 devices to monitor. Performance is  good.

My question is, exactly when does Netview make calls to the O.S for name
resolution. To be more specific. During status polling does Netview
require name resolution, or only during discovery, demand polling and ??
what else.

Thanks on advance to the list.

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