Forgive the soap box. This is old news. Linux process data in any virtual
environment is
wrong. This was measured and presented in a production environment as off by
order of
magnitude. This is true for all releases and distributions of linux. ibm
claims there is
a fix in sles10, this has never been validated in any presentation. i don't
like claims
that sound suspiciously like vaporware.
Why is this data bad? it's useless.
1) imagine someone doing application tuning and using this data and thinking
they've
improved their app performance - and their data is wrong, leads to wrong
conclusion
2) system utilization high, logon to any linux using linux tools, you might
think top is
the hog, but if the system utilization is high, you will make very poor choices
of what
processes or linux server to kill
3) if you are making poc decisions based on this data, you will think the
mainframe is dog
slow. this is bad for all of us and leads to poor financial decisions.
This gives a very good platform a bad image.
6 years ago when velocity software analyzed this, we found a way to correct and
record the
process data. (for all linux releases and distributions) thus this data is
useful for all
of the above. no other vendor (other than velocity software) has presented a
solution for
this problem - and validated in any public forum.
So when i hear about installations planning on dependancies on garbage data, i
think about
how many people would drive cars without gas gauges or speedometers? was the
used car
salesperson ethical in taking advantage of the naive buyer?
Evans, Kevin R wrote:
Rob,
As we are just switching to Omegamon and almost up to implementation of
our first user to come into a new zLinux front end, can you give ant
further details on your comment below?
Thanks
Kevin
-----Original Message-----
From: Linux on 390 Port [mailto:[EMAIL PROTECTED] On Behalf Of
Rob van der Heij
Sent: Thursday, September 13, 2007 4:07 PM
To: [email protected]
Subject: Re: linux performance behind load balancer
On 9/13/07, Alan Altmark <[EMAIL PROTECTED]> wrote:
Finishing the thought, IBM's OMEGAMON comes to mind as well. There's
more
than one "decent" performance monitor Out There, so shop and compare.
But since that will present incorrect CPU breakdown per Linux process,
it may lead to wrong conclusions. ESALPS will correct the CPU usage
for virtualization effects.
Rob
--
Rob van der Heij
Velocity Software, Inc
http://velocitysoftware.com/
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begin:vcard
fn:Barton Robinson
n:Robinson;Barton
adr;dom:;;PO 390640;Mountain View;CA;94039-0640
email;internet:[EMAIL PROTECTED]
title:Sr. Architect
tel;work:650-964-8867
note:If you can't measure it, I'm just not interested
x-mozilla-html:FALSE
url:http://velocitysoftware.com
version:2.1
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