I was reading some newsletter and they recommended some online courses so out of curiosity I looked at this one:
http://www.javapassion.com/j2ee/
I decided to register and we will see if I can follow it all the way through. Certainly looks like the course material is quite exhaustive so I should certainly learn a few things from this.
Until today I was not even aware we were using this IP geolocation service in some of our systems. I guess that you need an outage to get to know what you have.
We do queries to country.netop.org to quickly know which country an IP is from. I am not sure of all the details but it seems quite simple to use. The only catch is that netop.org mentions that they have a single server answering the queries and that it can’t take big loads.
So why do we depend on it?
Someone decided that it was simpler to use this service to add the requested feature. It was probably not highlighted in the dependencies of the system or someone did not understand the full value of the dependencies.
I am not blaming anyone because I am ready to bet that we have many more dependencies like that, some that I have put in place, that we can’t fully value until an outage hits us.
The ITIL CMDB is a useful idea to try to catch these but it is one thing to know a system to help identify these dependencies and an other to make it work in real life.
This is not the first time I do this and it is on the edge of embarrassing except this time I knew I had tools to get me out: lose the source code to a java application.
I have this application that was done a year ago and I guess that in the rush to get it to production I forgot to import the code in SVN.
A year later we have changed a few things and now I have to change a few lines in the code and add a method to it.
I remembered using a command line tool under Linux to decompile but since I could not remember the name of it I had to search for it. In the first few results of my google search for “java decompiler” came this site:
http://java.decompiler.free.fr/
I tried to install the JD-Eclipse but I don’t see how to use it so I simply downloaded and used the JD-Gui for Linux and it works beautifully. I can see my source code in the .class file in 2 seconds and now I can easily change it. This is so convenient.