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 the same definitions, and agree on them. Make sure talking about the same version and of course about similar circumstances. When you start giving answers in general be sure to work with facts and not some assumptions which might be wrong. So you should always think about the information, about the circumstances and the assumptions you do, it means “Continuous Thinking”.
During the years I heard lots of stories about sizing the Oracle Database Buffer Cache. Oracle introduced in Oracle 8i (8.1.7) the view V$DB _CACHE_ADVICE. According the documentation this view shows IO’s that would be performed at various cache sizes from 10% to 200% of the current size. For example (GV$DB_CACHE_ADVISE):
The thing what is crossing my mind all the time is the question, will a system really react the way the advisor is predicting? This question is a very obvious question of course and in this post I like to place a nice little discussion in place.
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