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From: mycroft@goldman.gnu.ai.mit.edu (Charles Hannum)
Newsgroups: comp.unix.wizards
Subject: Re: Load Avarage graph pattern
Message-ID: <MYCROFT.91May31031208@goldman.gnu.ai.mit.edu>
Date: 31 May 91 07:12:08 GMT
References: <2155@ccsg.tau.ac.il>
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In-reply-to: shani@GENIUS.TAU.AC.IL's message of 30 May 91 12:43:23 GMT

In article <2155@ccsg.tau.ac.il> shani@GENIUS.TAU.AC.IL (Oren Shani) writes:

   Can anyone tell me why the load avarge graph shows definite
   patterns of exponential decay?

   It seems that most (by far most) of the points of the LA graph are
   on lines of the form c*exp(-a*(t-t0))+b, in which 'a' is some cosmic
   constant (I sampled LA in severl computers, for several time periods,
   and got the same 'a' every time). Is this due to some policy of the
   system's time shearing mechanism, or did I discover a new cosmic law?

I noticed this a long time ago, while running xload.  For some reason,
every 30 or 60 seconds, the load will suddenly jump and slowly decay
on an otherwise idle machine.

Note that the load average that xload displays is the average over the
past minutes -- which explains the slow decay.  But why the sudden
jump?  I've always attributed it to 'update' ('syncer' on some
systems), and ignored it.