Last week I got the great opportunity to present on Method-GAPP again at the UKOUG 2011 (see presentation of the UKOUG2011). This time the focus in the presentation was partly on the multi linear regression and for the other part especially on AWR data. The multi linear regression makes it possible to get a linear equation to calculate the end user response time, what makes it possible to get a complete breakdown of all involved components in the end user response time as show in the graph below. In the graph the test and modelling from the white paper is shown:
Breakdown of all the involved components for the end-user response time
In the breakdown, the UTILR80 is the utilization of the I/O and the UTILRAU is the utilization of the CPU. The breakdown shows that basically the REST is time which is always there but might be split out in more components if the involved model is enhanced. So more time is explained from the found variance of the end-user (R) response time. Continue reading →
In a lot of cases you like to know which SQL, wait-events, metrics, etc. in AWR is important for your specific end-user process response time. So it could be very well possible that the most important SQL, wait-events, metrics, etc. are show-in up in your “Top Activity” in your OEM grid control and AWR reports are actually not the most important for your end-user process response time.
After you know the share of time of your end-user process is taken by the database server (Method-GAPP primary components), you actual can use all the AWR (and ASH) information as secondary components as input in Method-GAPP (see the white paper). Basically we simply can use the “Data Mining – Explain” step in the method and create a factorial analyses as shown below (see the white paper).
After a long time of not able to finish my whitepaper, I finally finished it. Just struggling with time constraints made it hard to get my whole method on paper. I really wanted to have it finished before I would present the new improvements on the method at the HOTSOS Symposium 2011. In a couple of hours at 13:00 Dallas time I will do my talk based on the whitepaper and really hope I get a packed room of people.
Of course I hope the audience will see it’s potential and I will be able to put the message in the presentation as good as possible. I am just nervous on the demo I try to give… As some people may recall from HOTSOS 2009 I had a big issue with my laptop and in the end started 10 minutes late without a demo. So really hope this time everything will go smoothly.
The presentation will also become available on the blog, but for now you can download the official Method-GAPP whitepaper in the download section. As a last note I like to thank Cary Millsap and Dr. Neil Gunther for their inspiration and support.
The last couple of months I have worked very hard on method GAPP and have finally made a very big improvement to it. In the past GAPP was only able to pin point where in the architecture the biggest variance in response time was caused. The improvement to GAPP makes it now also possible to find within certain error also the service time per measured component in the architecture. The point is that sometimes the component causing the biggest variance in end user response time is not always the component responsible for the most service time of the total response time.
The second version of GAPP has now an extra step inside the method, which is “data modeling”, the data is first modeled by using normalized response times for different amount of servers by using the Erlang C formula. Next to this data mining is used with a generalized linear model and ridge regression, to solve near collinearities in the data. With this extra step in place the prediction of service time and wait time per measured component became possible. When I first verified it against real system data I was really happy to find out that it works very well. More information will follow soon in blogs and hopefully for the end of this year in a white paper.
I am very happy I get the opportunity from Hotsos to be able to present it next year in march 2011. Via this way I also like to thank everybody who inspired me and made this possible, especially Cary Millsap and Dr. Neil Gunther.