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 do from 01:00 till 06:00 in the night something totally different. The given example could match maybe some OLTP systems but could be totally different for your OLTP production system. Continue reading
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 can also be very handy for other people, so I decided to create this blog. The created package has the following important functions: Erlang-C, Erlang-B, Response Time in multi-server environments (ErlangR in the package), Queue length in multi-server environments (ErlangQ in the package) and Response Time in multi-queue environments like IO (paratqr in the package).
The formula’s are described in the book “Analyzing Computer System Performance with Perl::PDQ” from Dr. Neil J. Gunther 2005. In the source of the package are the exact locations in the documentation documented. Continue reading
I recently discovered that under certain circumstances, for now it looks to be environment setting depended, that an ORA-25330 is encountered when running dbms_predictive_analytics.predict procedure. I found out of this problem while preparing a demo and certainly the error was comming up in TOAD (I am not a TOAD fan, but it is handy searching through the very big amount of factor columns in a GAPP analysis). When the same command below was executed directly on the server via sqlplus, the error was not encountered.
To investigate I tried to create a errorstack on the error, but without luck. So I started to do a sqltrace and found out that the ORA-25330 is actually on the server translated as ORA-40206. After I found that I created the following small test in TOAD: Continue reading
For some months ago (october 2008) I wrote an abstract for a paper to present at the HOTSOS 2009 symposium. Although I hoped I was selected to give the presentation, I was not selected by Hotsos. This was a pitty but looking at the people and the presentations who made it to the agenda of the HOTSOS 2009 symposium, it would have been very special to be there also. Due to the high quality of the sysmposium and the fact that it is the place to be for every performance geek out there, I planned together with my collegae Marco Gralike a trip to the symposium this year only as an attendee.
Last week I received unexpectedly an email from Cary Millsap with a very special opportunity within. Cary asked me if I was still interested in presenting at the comming symposium and although very little time I said of course YES. So although late I was added to the HOTSOS 2009 symposium agenda to give a presentation called “Practical Use of Method Gapp to Find Performance Bottlenecks for Business Processes in Complex Architectures”
I hope personal that I will give a presentation wich will be equally or even more interresting than the one I gave at the HOTSOS Symposium 2008. As a last word I really like to thank Cary Millsap for this opportunity.
Sunday 21 September 2008 at Oracle Open World, I had the opportunity to present my method “GAPP” once more (HOTSOS 2008 and Planboard may 2008). This time I also mentioned how the method can be used with Service Oriented Architectures (SOA). For people not knowing what “GAPP” is all about I give a small introduction to the method. I also like to tell you why I started with “GAPP” in the first place and what the added value is of the method above other methods.
“GAPP” means General Approach Performance Profiling and can be used to find out where in your architecture the most wait time variance can be explained from your business process. “GAPP” makes it possible with very little data, in higly complex technical infrastructures, still be able to find the performance bottlenecks for a specific business process. The nice thing about the method is that it is not only able to pinpoint a bottleneck which is already there, it is also able to pinpoint a future bottleneck in a normal running system. This is something what only “GAPP” can do.
What makes “GAPP” special:
- The method can analyse the full infrastructure, so from front-end to back-end
- The method is not focussing on one piece of the infrastructure, like only the database
- The method is able to predict how the response time of a business process will react on changes in involved factors
- The method is able to predict when a certain bottleneck will evolve to a real problem
The third of march 2008 I had the opportunity to present my developed performance profiling approach called “GAPP” at the HOTSOS Symposium 2008 in Dallas. “GAPP” is an abbreviation of “General Approach Performance Profiling” and is based on data mining of all kind of gathered system statistics (but also other data is possible).
The presentation went well and a lot of people attended my presentation. I got a lot of nice criticism and was questioned a lot by Dr. Neil Gunther. Before and after the presentation I had a lot of nice discussion with him and he even offered to help me make this approach even bigger. For me this was a real honor and I really was very happy with his input.
Also a lot of other “important” people attended the presentation, like Anjo Kolk, James Morle, Cary Millsap, Jeroen Evers, Toon Koppelaars and many others. I personally was very happy to have the chance to present for such an audience, and was very happy with their reactions and criticism. I personal think that the HOTSOS Symposium is “The Place” for performance in the world. Continue reading