Three years with Java Simon (1)
November 8, 2011 1 Comment
If you wonder what that Java Simon is just check the project site (previously on Google Code). It all started when we got back from TheServerSide Java Symposium in Prague in 2008. One of the many talks given there was about JAMon (don’t mix it with jamon – the text template engine) – simple monitoring API that allowed you to code your monitors into your application and obtain the results later.
JAMon guys used Jarep to store and graph results and what I liked the most was the story how these results available over a long time helped them when they needed it. Story went something like: “We found out that the performance of our web-shop started to be unacceptable sooner then originally calculated. Graph showed us that there was sudden jump half a year ago and since then the application performed worse. Luckily we had also work plan from IT stuff that revealed that the same day new JDBC driver was installed – and that was the reason.” Bottom line – without data you just don’t know. I liked that and it went pretty much along the lines Kirk Pepperdine says all the time – you need proof, you need data, you just need to know – don’t guess. Actually most wise people say that, but I remember Kirk and also that JAMon/JARep story when it comes to performance and monitoring.
A colleague of mine tried to use JAMon for our work project but he was not happy about the API. He was missing some management hierarchy – and that’s how idea of a tree hierarchy (not much different from java.util.logging for instance) for Simons started. Another issue was timer based on ms (JAMon is compatible with J2SE 1.4), I didn’t like that at all. So many things may happen in a single ms – not to mention most Windows changed the timer ever 10 or 16 ms. We decided to write our stopwatch facility and over one August weekend I wrote some basics (our first commits) and we started building on it. We can’t measure anything – like JAMon tries – we focused solely on Stopwatch and Counter. Three years later I’m happy about it – Stopwatch being probably 90% (or more) of all used Simons. Originally I wanted to give our users some way to add another kinds of Simons, but soon I realized how messy it would all become.
JAMon was in version 2.7 when we started the Simon project and the page looked exactly how it looks right now. We finished the first version in December, we were happy about most of it, we cared for the code and for the Javadoc too – and I think it was really obvious from the look at the project. These are ideas we still care for and quality Javadoc is undisputed part of the project.
TSS press release: Java Simon 1.0, monitoring API, released
Simon gained some initial attention and one particular developer even blogged a few times about us – check Evaluating Simon – Java monitoring or other Erik’s posts related to monitoring. Funny – later I’ve heard the name Erik van Oosten mentioned by my colleagues working with Wicket, but I’m 2 years ahead of the story. That’s just how it is with active people. His posts were most appreciated and he also provided AOP based Spring integration. Now – years later – even I use it in our current project (though it went through a few fixes, but the code is essentially still Erik’s).
Soon we discovered that the first version had a few serious issues and redesign was necessary. But more about that in the next installment some other time.