I'm writing this as I'm waiting for the the presentation "Agile Development Metrics" by Neal Ford to begin. I attended a presentation on Selenium that he did yesterday, and that was one of the better ones so far. The overall quality of the sessions has been mixed, ranging from fairly shallow (Rod on "Spring 2.0 and beyond") or way too basic (Mark Richards on "Advanced (bah!) JPA", Adrian Colyer on "Simplifying Enterprise development with AOP") to very good. Hani biled the JPA session, and my feelings were exactly the same. "Hey, if you add fetch=FetchType.EAGER to your annotation, the relation is no longer lazy!". Duh. Also, showing how to make a POJO transactional using AOP isn't exactly jaw-dropping in 2007.
What is jaw-dropping however is the scale of operations run by investment banks, that John Davis talked about this morning. Java is widely used in the banking world, and outperforms C/C++ a lot of the time, but a 50 ms garbage collection run is unacceptable since it would mean missing business opportunities worth millions of dollars. The solution: hardware garbage collection. He also explained that the speed of light was a limiting factor for performance. Yes, that's right. The speed of light. A theoretical best-case roundtrip for light to travel between New York to Chicago is around 8 ms, which is enough to motivate moving the physical system from NY to Chicago if you need to talk to another system in Chicago, for example. XML isn't widely adopted either, for performance reasons. If it's used at all, you often have a situation with a single element with 4000 attributes, to minimize the number of angle brackets to parse. And when it comes to reliable messaging, no JMS vendor can match the SWIFT system, used by 8000 banks world-wide to transfer money between them. They guarantee 100% reliability, to the point where they will refund any amount submitted to the system that is lost. However, in the 30 years that they've been operating, they haven't yet lost a single message. They average around 12 million messages a day. The particular investment bank that John talked about handled around $500,000,000,000 (five hundred thousand million dollars, or half a trillion) a day, so that's why even milliseconds matter. Quite a few "whoooa!" moments during the speech :-).
The second half of TSSJS contains a few sessions that I hope will be interesting, mainly around clustering and JVM and XML performance and scalability, which will be relevant in my current work assignment right away. There's one presentation held by a Swedish developer, Jonas Bonér of Terracotta fame which I'll be watching. Terracotta has gotten quite a few mentions in other presentations, and it seems really useful in some situations.
Next up is Cameron Purdy from Tangosol. I'll be back with a review of the second half on Saturday, I think.