I went away on holiday with the servers running very well. Our average CPU was hovering about 4% and the peak was close to 10%. When I came back, the average was at about 40% and the peak was in the neighborhood of 90%. I was not out of the office that...

Yesterday I posted a way to do negative DB unit testing . Essentially you wrapped your negative case in a TRY/CATCH block in SQL. There is another way to do this that is a little bit more work but, in my opinion, a little bit more correct. In the example...

Rescently I began using VS testing facilities to create test cases. Its pretty nice, but there is one thing that bothered me when I discovered it wasn't in the UI. Here is the case: You add a new database unit test to your project. You open the...

Here is a little 'feature' I hit while building some database unit tests in Visual Studio. The symptom is you get a message that says something along the lines of: The item "obj\Debug\DbTestPrj.testName.resources" was specified more than once...

I recently wrote about some issues that we had to diagnose in our production environment. I wanted to take a moment to document an interesting problem that had significant performance impact, had interesting symptoms, and was a rather easy fix once it...

I have not had a chance to post much since I started this blog. My intent was to lay some ground work for building scale-out, high perf systems for medium scale sites. It seems like the best laid plans are always interrupted and my vision for this blog...

One of the first things to do when you have performance issues is to find the low hanging fruit. My definition of low hanging fruit is any change that does not affect business or application logic. For example: Adding a much needed index on a table for...

Divide and conquer Many times you start scaling out without knowing it and this type of scale out is the opposite of consolidation. You identify those parts of your system that are resource intensive and move them off to be on their own. Its just that...

This week I attended a day of training on some of the new features for SQL 2008. I mention this because one of the presenters made a 'joke' about problems with databases being related to 'needing more ram'. The reason this is of interested is it touches...

Chaos Fosters Opportunity For the last 6 or so years, I have been working almost exclusively on technologies related to data storage and retrieval. This has included things like object persistence technology (Object Spaces), data warehousing for billion...