Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!cornell!rcbc
From: rcbc@honir.cs.cornell.edu (Robert Cooper)
Newsgroups: comp.sys.isis
Subject: Re: Recommended values for restart timeout parameters?
Message-ID: <34157@cornell.UUCP>
Date: 12 Nov 89 23:26:53 GMT
Sender: nobody@cornell.UUCP
Organization: Cornell Univ. CS Dept. Ithaca NY
Lines: 25

This concerns two parameters that you can change when setting up ISIS.
The first is the "auto restart interval" specified by the -A option to
the "isis" command. This specifies how long ISIS must remain down
at a site before restarting. This must be long enough that other
ISIS sites have time to notice the failure before the site restarts.

Which brings us to the second parameter, the "failure detector timeout",
which is settable by the -f option to the "protos" utility. This 
controls how long a site must be inoperative before another site
will consider it to have failed.

Clearly these two parameters must have mutually consistent values, and
also take into account how "slow" and "lossy" normal message traffic
is in your environment.

We "recommend" the default values supplied with ISIS, namely an 
auto restart interval of 5 minutes, and a failure timeout of 60 seconds.
We don't recommend changing these unless you have very specific requirements.
Here at Cornell we often set the failure timeout to much less than
60 seconds to speed up testing of failure modes, but we leave the
restart interval at five minutes normally. Basically restarts shouldn't
happen at all really (it means that ISIS has crashed even though the 
machine hasn't). If it does crash often you should get back to us.

                                -- Robert Cooper