I've recently been experimenting with some different forms of blogging, mostly following the lead of a couple of friends who have invited me to use some of the new blogging web sites out there. Twitter is quite cool for seeing what friends are up to but for me at least doesn't seem like an appealing medium for communicating with a wider audience in the way that a blog does. I guess that's not the point of twitter anyway. Tumblr on the other hand does look interesting and seems to fill the middle ground between blogging and twittering. Tumblr doesn't really seem to be any different from a regular blog technically but it somehow seems more acceptable to use tumblr for short messages or sharing links. Basically, tumblr is a much less formal manner of blogging and suits me well for my personal blog as it's somewhere I can post frequently if I have information I don't want to forget but doesn't require me to switch context from whatever else I'm doing in order to write a more formal blog entry with vaguely acceptable grammar.

Labels: blogging

I just rediscovered a web site I set up for a SQL tool that I wrote a long time ago (1997) called HandySQL . Now that's what I call web design!

Luckily, my web design skills had improved a bit by 1999 when I set up the Orbware web site.

You just can't hide your past on internet!

I've been trying on and off for a while, and without luck, to install Linux on one of my "test lab" machines. These machines have quad-core Intel processors on Asus P5K SE motherboards, which feature a Marvell PATA IDE controller. I'd tried a good number of distributions including the latest RHEL, Fedora, Ubuntu, and Mandriva releases but none of them would recognize the CD/DVD drive during installation. I did eventually manage to install Fedora 7 over the network but applications kept crashing due to kernel panics. After some research it seems that the Linux Kernel needed updating to support this motherboard and its chipset.

This morning I downloaded Fedora 8 Test 2, which was released about a week ago and the install ran absolutely smoothly and I saw it specifically load a "pata_marvell" driver, which was reassuring.

The only problem now is that the final release of FC8 is still about six weeks away so I just hope this test release is stable enough for my needs.

Labels: hardware, linux

I've discovered two very useful tools this week that both have free and commercial versions available. The first, soapUI, is ideal for quickly testing WSDL-based SOAP services without the need to write code. The second, is DBVisualizer, a general-purpose SQL client.

Labels: tools

Hmmm. Looks like the iPhone will be exclusive to O2 when it launches in the UK. O2 certainly seem to have a strategy of being the exclusive operator for some of the more advanced handsets and I've been suckered into becoming an O2 customer twice before for that very reason and ended up very disappointed with service both times. Also, I can barely pick up an O2 signal from my house so I guess I'll be sticking with my trusty BlackBerry on Vodafone.

Labels: mobile

I've been researching some ideas in my spare time over the past couple of weeks where performance is critical so I decided to put together a framework for easily running performance and scalability tests. The idea is to provide a framework that is as easy to use as JUnit and that encourages performance testing as an integral part of the development process, rather than as an afterthought before a product release or deployment.

I've called the framework JPerf and I have made the code available on sourceforge - it's just a few classes at the moment but I will be evolving this as and when I need the functionality myself.

The key interface is PerfTest which provides setUp(), test() and tearDown() methods. The test runners call setUp() once and then repeatedly call test() for the specified period of time and then call tearDown() at the end to free up resources, such as database connections.

There are currently two test runners - PerfTestRunner and ScaleTestRunner, which measure performance and scalability, respectively. Here's some sample output from the example that ships with JPerf.

PerfTestRunner:

[java] org.jperf.example.SimpleDateFormatTest: 243,971 iterations in 500ms (486,968 iterations per second)
[java] org.jperf.example.MyDateFormatTest: 371,968 iterations in 500ms (742,451 iterations per second)

ScaleTestRunner:

[java] With 1 client threads, throughput is 100.0 tps and memory usage is 5137656
[java] With 2 client threads, throughput is 202.0 tps and memory usage is 5175144
[java] With 3 client threads, throughput is 300.0 tps and memory usage is 5223616
[java] With 4 client threads, throughput is 402.0 tps and memory usage is 5271592
[java] With 5 client threads, throughput is 504.0 tps and memory usage is 5330056
[java] With 6 client threads, throughput is 602.0 tps and memory usage is 4888336
[java] With 7 client threads, throughput is 702.0 tps and memory usage is 4979288
[java] With 8 client threads, throughput is 798.0 tps and memory usage is 5057864
[java] With 9 client threads, throughput is 900.0 tps and memory usage is 5137568
[java] With 10 client threads, throughput is 1000.0 tps and memory usage is 5215200


I'd be interested to hear ideas on what features people would like to see in this framework to make it useful for their projects. If you have any requirements please leave a comment here or post a feature request on sourceforge.

Labels: java, performance