19 May 2011

neo4j open source nosql graph database »

Design Meeting Patterns/Antipatterns | Javalobby

Design Meeting Patterns/Antipatterns | Javalobby

  • Understand the Problem vs. Jump to the Solution
  • Assume the Worst vs. Assume the Best
  • Basing Decisions on the Current Situation vs. Basing Decisions on History
  • Shooting for the “Best” Solution vs. the “Easiest” Solution
  • Present Possible Solutions Objectively vs. My Solution is the Best
  • Validating from Code vs. Validating from Memory

07 May 2011

Rambo Architecture

Amazon’s EC2 & EBS outage | Cloud Zone
I just read a post in Coding Horror which refers to a year old post in Netflix’s blog called “5 lessons we’ve learned using AWS [Amazon WebSevices]“. Netflix, in case you’re wondering survived Amazon’s outage and indeed, in lesson #3 they explain that if you want to survive failures you have to plan and constantly test for it:

3. The best way to avoid failure is to fail constantly. We’ve sometimes referred to the Netflix software architecture in AWS as our Rambo Architecture. Each system has to be able to succeed, no matter what, even all on its own. We’re designing each distributed system to expect and tolerate failure from other systems on which it depends. If our recommendations system is down, we degrade the quality of our responses to our customers, but we still respond. We’ll show popular titles instead of personalized picks. If our search system is intolerably slow, streaming should still work perfectly fine.

That's a great quote. You got to build systems that expect dependencies to fail and test those scenarios.

02 May 2011

Rooting Nexus S problems

Anyone who has rooted their Nexus S using 1.0-XXJK8-nexuss-superboot and found that their camera and wifi stops working.  Its because you need to use the correct version of superboot.  Instructions can be found here http://forum.xda-developers.com/archive/index.php/t-882333.html.  You can correct the problem by rerooting with the correct version.  Also anyone who finds that on windows, the cmd line stays in "waiting for device" during fastboot mode, installing PDANet for Android fixes the problem as per http://forum.xda-developers.com/showthread.php?t=875580.  Hope this saves you some time and heartache :)