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Support for Kathy

All my support and best wishes to Kathy Sierra. I sincerely hope she come back stronger.

Kathy, I’m a passionate reader of your blog.

QCon 2007 summary – Part 2

A bit late, I know, but here it is the second part of the summary (1st and 2nd day):

“Modifiability: Or is there Design in Agility?“: Martin Fowler lead some ThoughtWorks architects through a discussion of design in an agile context. He started talking about a misconception: “Agility means to start coding directly, without designing”. So he remarked that it’s very important to start designing at the beginning of the project, although it can be modified during the rest of the project. He also stated that simple doesn’t mean stupid, simple means that it’s simple to use and it has sense.

“Operational Manageability“: Dan Pritchett (eBay Technical Fellow) talked about designing for operations and how operational scalability is a software problem. He point out some recommendations about managing configuration in a large enterprise, deploying without taking down the site and avoiding SPOF. He also presented a fact: “Power and cooling are now the primary constraint to growth”, a fallacy: “Hardware will provide the performance improvements needed to keep pace with transaction growth”, and a reality: Inefficient software has driven datacenters to the brink of municipal power delivery capabilities”. He recommends trying to measure power efficiency using (and improving) metrics as for example page views per second / Watts. Dan has also a great post about scaling where he mentions all of the vectors you must consider.

“Test Driven Development: How do we know we’re done?“: Steve Freeman presented this introductory session about TDD. He started with some basic cyclical examples: implementing a test just enough to pass and then Refactor! He said TDD is a design technique and we must test the features not the methods. He also said that unit test code could be half of the source code.

“Agile Project Management: Lessons learned at Google“: Jeff Sutherland started comparing The Toyota way and the Agile Principles, and then the Google way. After that, he described how the Adwords project leader introduced Scrum into Google (an environment that does not have an affinity to processes in general). He talked about some problems that they have found (resistance, late deliveries, …) and how Google reinvented some Lean practices (work in progress). He concluded saying that “[Google] teams embraced the process enough to continue it even without any reinforcement”. At this Google Tech Talk, you will find Jeff explaining the same presentation that he showed at Qcon.

And finally, infoQ has posted a great article where they present the main takeway points and lessons learned by attendees who blogged about QCon.

links for 2007-03-22

• IASA – Skillset
  IASA has developed a full skills library for the IT architect. The library currently contains articles for each primary skill of the IT architect.
  (tags: architecture software)
• Edward Ort’s Blog: Notes from TheServerSide Java Symposium
  One interesting thing though is that the Jazz team found that in developng software you can’t collaborate closely all the time.
  (tags: eclipse jazz ibm rational collaboration)

links for 2007-03-21

• A Periodic Table of Visualization Methods
  (tags: visualization methodology)

QCon 2007 summary – Part 1

Finally I found some time to write about the QCon 2007 conference held last week in London. I think it was a great conference. As usual, there were some poor sessions (I had high expectations about some speakers and contents), but there were also some interesting ones.

So, here it is the first part of the summary (3rd day):

“The eBay Architecture – Striking a balance between site stability, feature velocity, performance and cost“: Dan Pritchett (eBay Technical Fellow) talked about some interesting eBay’s architecture features, as how they deal with vertical DB segmentation (by functional areas) and horizontal DB splits (date, location, …), and, how they don’t use stored procedures, triggers and, amazing, nor transactions (Martin Fowler is talking about this in his post Transactionless). This means that all business logic is executed by the application (sorts, joins, referential integrity, …). They use intensively prepared statements an bind variables (cached by datasources). They also scales using a rewritten connection pool and an internally developed ORM solution called DAL (Data Access Layer). All CRUD operations are executed through this infrastructure. If you are interested in reading the full presentation, Dan has posted it (PDF) at his site.

“Developing Expertise: Herding Racehorses, Racing Sheep“: Dave Thomas (The Pragmatic Programmers), started his speech asserting that process improvement requieres PEOPLE improvement (he recommends to read Capers Jones assessments and benchmarks). Using the Dreyfus Model of Skills Acquisition, he described, on a funny way, the characteristics of people on different stages (Novice, Advanced beginner, Competent, Proficient, Expert). He stated that the vast majority of developers are on Stage 2, and we need to raise the bar. He advocates to use Dreyfus to fix companies and to fix our careers, and also, learn and apply financial management to our daily work (have a plan, diversify, look for value, be active, …).

I have also uploaded some photos to Flickr, although you will find more photos, including my photos, at the QCon 2007 Group Photo Pool.

Comments

Comment by diana plesa on 2007-03-22 10:47:23 +0000

Thanks for blogging about QCon! I just wanted to let you know that we quoted and linked from this entry on the over all QCon 2007 blogger’s key takeaway points and lessons learned article: http://www.infoq.com/articles/qcon-2007-bloggers-summary

Feel free to link to it and of course blogging about this articles existence would help even more people learn from your and other bloggers takeaways.

Thanks again!

Diana

InfoQ/QCon