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 penalties)
Block alignment and recommendation
George Djerdj Srdanov presenting at Hotos 2013
The presentation was good and triggered me to check some things at a customer I am currently working for. In the customer case the block alignment in regard of the online redolog files might be a point of investigation. Continue reading →
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 for distribution.
At 13:00 I attended the presentation of Dr. N.J.G. Gunther titled “Superlinear Scalability: The Perpetual Motion of Parallel Performance”. Because of his subjects I like to be present at his presentations, although on the other track Gwen Shapira had her first presentation titled “Visualizing Database Performance Using R” which was for me also a subject I would love to be present. The presentation from Neil discussed an important topic regarding the effect of increasing the amount of servers giving better throughput than expected on linearity, this phenomenon has been baptized by Neil as “Superlinear Scalability”. During the past couple of years he struggled to have his USL to fit with this phenomenon and at first he just ignored it, but after seeing the phenomenon more he had to admit the fact it really exists and his USL should be able to cope with it. After a long process he came to the conclusion that his USL is still able to apply if he would loosen the limitation of accepting negative numbers for his alpha parameter (Contention) in his USL. It basically means that by increased number of servers you get a kind of hybrid effect temporary (the throughput has increased with a factor more than expected on the number of added threads based on linear scalability). On a certain moment you still have to face the music and throughput degradation starts to appear due to coherency (Beta parameter in the USL formula). Based on the gathered proof, based on different data sets, he concluded that his USL still is valid, also in situations the “Superlinear Scalability” phenomenon is occurring. As usual Neil really showed in a very good scientific way that his claims were accurate and as he always says, “Models come from God and data comes from the devil!”. If you like to read more you can checkout his blog at: http://perfdynamics.blogspot.nl/2012/11/hotsos-2013-superlinear-scalability.html
Dr. N.J.G. Gunther at Hotsos 2013
After the presentation from Neil it was my turn to give my own presentation as I mentioned earlier, titled “”Method GAPP” Used to Mine OEM 12c Repository and AWR Data”. Continue reading →
It is the first of March 2013 finally… I will travel to Dallas for (one of) the best Oracle performance symposia in the world, Hotsos 2013. The flight to get there will be from Amsterdam to Philadelphia and from Philadelphia to Dallas. Against all odds I will not travel alone but an old Amis colleague and friend Marco Gralike with his colleague will be on the same flight (even going back). After departure from Schiphol at 13:00 in the afternoon, and having our stop in Philadelphia we arrive at the Omni Mandalay Hotel in Las Colinas (Irving / Dallas) at 22:30 local time… This is the real start of an awesome time at this great symposium…
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”.
Yesterday I had the opportunity to present the presentation “Gapp in practice”, here at the HOTSOS event 2009. To get the presentation ready I worked the whole weekend in the plane and in the hotel. My biggest challenge was to get the demo for the presentation working. The demo would show how easy GAPP can be used in practice. My goal was very well in my opinion, and I was ready to present it in time…
Than at the moment of truth, my laptop was not willing to display via the beamer and I had to present on another laptop… I apologized towards the audience and almost ten minutes late I started my presentation, with some applause from the audience. Anyway my audience was good and after some minutes of strugle (a little mixed up due to the laptop chalenge), my presentation started to run…
To get people in for my presentation I used some words on my badge…
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.
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.
Dr. N.J. Gunther has received at the annual CMG International Conference in Las Vegas last week the A.A. Michelson Award. Dr. Neil Gunther was the recipient of the prestigious A.A. Michelson Award; the industry’s highest honor for computer performance analysis and capacity planning. As he said in his acceptance speech, it was the fulfillment of a dream he had entertained at his first CMG Conference in 1993.
I really like to congratulate Dr. Neil Gunther with this very big achievement. For further reading you can check out the blog post from Dr. Neil Gunther on his website. Don’t forget to check out the speech presentation with at the end a nice picture of Dr. Neil Gunther and his father.
It is now almost a year ago I came up with the name GAPP to promote my method “General Approach Performance Profiling”. The last couple of months I have been very busy to use the method in practice and was able to fine tune the way to gather data and do the analysis quicker and quicker.
The power of the method comes to its full exposure in situations that a lot of servers are involved and the business process are very hard to be traced in any way. The latest customer I helped with the method had a system with a hardware loadbalancer, 8 application servers, 2 database servers running 30 databases each and a NETAPP storage. In this situation I was able to pinpoint that problems in the garbage collection on the application servers was there mean issue and a second important issue was residing on a synchronization process on the NETAPP.
The used data mining made it possible to find relations in the data, which are very hard to be determined without extensive tracing. Also the capabilities of data mining to predict with a model future bottlenecks, make GAPP very powerfull. Although it is probably a pitty to tell, I had still not the time to finish my whitepaper. There is a version, but is still beta and should be more professional and enriched with more information about the practical use of the method. For now I have put it online, but be aware it is very beta.
I hope I will from this moment on, not again let you wait to get some new content on this blog.