We have many applications running (consider all of them run on Java Platform) and we need to check which ones were used in the last, say, 3 months, and, among those active applications, which parts/functionalities (and how often) are still being used. Is that possible?
The goal here is to detect applications or funcionalities which no longer are relevant to the business and remove them, so that we end up having less code to maintain and monitor.
Is there any tool which could help us achieving that?
We DO use agile methods, so when a new application gets into production it has only the funcionalities which are important to the business, but sometimes some features of this application expires (for different reasons), so we would like to have a way of identifying that.
There are at least two tools you can deploy along your application and collect some statistics, even in production:
AspectJ – weave all classes and somehow log every method execution.
JaCoCo – essentially does the same thing but automatically with a help of a Java agent. Executed methods/branches (in fact, this is a code coverage tool) are saved in a file for future processing. Should solve your problem pretty easy.
Both approaches should work with any JVM language (I see jruby in your question) as they work on bytecode level. I once used JaCoCo to measure code coverage (think: which methods/branches were execured) during Selenium test run.