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Tuesday, December 27, 2011

IT/EV-Charts as an Application Signature: CMG'11 Trip Report, Part 1


I have attended the following CMG’11 presentation (see my previous post):

A Way to Identify, Quantify and Report Change
Richard Gimarc Kiran Chennuri
CA Technologies, Inc. Aetna Life Insurance Company

Identifying change in application performance is a time consuming task. Businesses today have
hundreds of applications and each application has hundreds of metrics. How do you wade
through that mass of data to find an indication of change? This paper describes the use of an
Application Signature to identify, quantify and report change. A Signature is a compact
description of application performance that is used much like a template to judge if a change has
occurred. There are a concise set of visual indicators generated by the Signature that supports
the identification of change in a timely manner.

Here are my comments.

I like the idea of building an application characteristic called Application Signature. As described in the paper it is actually based on typical (standard) deviations of Capacity usage during the peak hours of a day.

Looking closely to the approach I see it is similar with one I have developed for SEDS but it is a bit too simplified. Anyway it is great attempt to use SEDS methodology to watch application capacity usage.

I think the weekly IT-CONTROL CHART ( see other previous post ) is a way to compare usual weekly profile with last 168 hours of data (Base-line vs. Actual), so the base-line in the format of IT-Control Charts without actual data IS AN APPLICATION SIGNATURE but in much more accurate way. It even looks like somebody’s signature:

The actual data could be significantly different, as seen below:

And that diference should be automatically captured by SEDS-like system as an exceptions and calculated how much it differs from the "Signature" using EV meta metric as a weekly sum of each hour EV values  or as a EV-Control Charts like showed here.

For instance, in this example week the application had took a bit more than 23 unusual CPU hours as calculated below:

So, if weekly EV number is 0, that means the most recently the application (server or LPAR and so on) stayed within the IT-Signature, which is GOOD – no changes happend!

The paper also shows the “calendar view“ report that consists of set of daily control charts. It is another good idea. I used to use that approach before I switched to weekly IT- charts that cover 1/4 of a month or bi-weekly ones that cover 1/2 of a month. So if you have IT-charts there is no need for the "calendar view" that sometimes is not easy to read.

Another feature could be important for capacity usage estimates: it is a balance of hourly capacity usage for the day or week vs. overall average (e.g. weekdays vs. weekends or daily “cowboy hat” profile with lunch time drop). That is supposed to be an additional IT-Signature feature. There was another CMG’11 paper that presents some interesting approach to analyze/calculate that. I plan to publish my comments about that paper. So please check my next post soon.....