DevDay is a one-day long event, organized by ABB.
There were 12 speakers and around 300 participants.
For example, in java,
double d = 0.3d is actually 0.299999999
Also, Jon pointed to interesting facts about dates. For example:
- CST is the name for 3 different timezones
- There are dates which exist in one country only – February 30, 1712
So, as Patrick suggests, we should :
- Release often
- Make no breaking changes – this becomes easier if you release frequently, because each release becomes a minor change.
- Make Ops and Dev teams work together
He also reminded about the power of HTTP protocol, whch is often undertaken by the developers. The suggestion is to use HTTP not only as a transport protocol, but an application protocol, which it really is.
Full text search with Apache Lucene
The author of Raven DB in action explained the fundamentals of full text search and how Lucene helps to solve the problem.
He also recommended the ElasticSearch, which is build on top of Lucene and has clustering support out of the box. Apart from ability to scale to many servers, there’s also a REST API, which, looks to be easy to learn and use.
The Architecture of StackOverflow
Software engineer from StackExchange, Marco Cecconi gave an overview of the infrastructure and architecture, which lies behind one of the most popluar web-sites in the world – StackOverflow.
- There are only 23 servers handling all the load – it is ~10 times less then sites with similar traffic usually have.
- Everything is cahced – database servers have ~300GB of RAM memory.
- At StackOverflow, they scale-up. When everyone is saying that applications should run on cheap comodity hardware, SO runs on big servers, without any cloud platforms.
- All the server are located in the US.
“I don’t usually test my code, but when I do – I do it in production”.
Well organized, with interesting talks, nice venue and a lot of fun. And it was all free!