After having a good sleep I attended the first session in the morning from George Djerdj Srdanov with a presentation called “How to Get the Most Out of Your I/O Subsystem?”. George dived deep into the I/O subsystem, with the following important subjects:
- Different RAID configurations (Read and Write (more...)
Due to a cold or “the bug” some at the symposium called it, I had a very bad night sleep. In the morning I was not able to follow the sessions and I ended up having a good breakfast and released the new white paper and latest presentation to Hotsos (more...)
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 (more...)
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 (more...)
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 (more...)
Since I am working on my method-GAPP (see method-GAPP overview presentation) I have been challenged with the task to model a real system and not a Lab system with a programmed load profile. The big issue with a real system is that the load profile is changing all the time and the only thing we can recognize are periods of time we have a not to changing workload profile. For example an OLTP system will do during production hours from 9:30 in the morning till 11:30 and from 14:00 till 16:00 in the afternoon comparable things, but will (more...)
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 (more...)
Since a long time I am busy using queuing formula’s to be able to calculate cpu queue’s and I/O queues. One of the big problems I was facing that the formula’s I like to use on big data sets with my GAPP analysis were only available in perl. For a long time I was using proximity functions to avoid the perl programmed Erlang-C formula and some other. Last weekend I just had the time to start programming the formula’s in PLSQL, just to have them easily accessible in my database. After finish programming the package I realized that the package (more...)
As always Hotsos started off with a nice keynote, this time done by Tom Kyte. Tom Kyte was introduced by Hotsos president Gary Goodman after the HOTSOS 2010 opening. Tom’s keynote theme was “Should we be less smart some times”. Tom told about own experiences, that he in the past gave sometimes too fast an answer. It is very important to think about an answer before giving it… Why? Well some things applied in the past or for a specific version, and now they don’t anymore… this can be a problem, a real issue. Always make sure you talk about (more...)