Performance issues with java

Performance issues with java have been a real hazard for application deployment over the years. I was involved in many of the projects as performance engineer where I had to resolve some real time server crashing issues. Many of problems occurred due to improper memory handling with application development. The bottom line of this is application developer has no sense of what its look like during the deployment which apparently leads to many of the problems.

Memory leaks

If your application keeping reference to objects that are no longer used, it leads to memory leaks.

High Memory usage / Insufficient object creations

Modernized applications keep loads of information on user events in order to comfort user in turn it can be an overhead to your application memory space if you don’t manage it properly. Also some applications create very high amount of objects for use of keeping large set of information.

Garbage Collector

GC too can be a problem if you don’t configure it properly. You will need to run lots of profiling tests, loading tests and find optimum configuration for your system. Also if your application creates series of objects in very short period of time, it would be a very costly task for GC to perform its GC operations accordingly. The more frequently it creates, it demands the CPU a big time.

tech-chat-rich-sharples

http://java.dzone.com/videos/tech-chat-rich-sharples

How Do You Convince Your Boss to TDD?

Really good article.

http://java.dzone.com/articles/how-do-you-convince-your-boss

Refactoring legacy system...

Re-factor a legacy system is any passionate developer’s nightmare (I said re-factor NOT re-engineer). Job is really hard to go over chunk of code and try to make them in a correct order most importantly with out touching the flow of the program and with out touching the base design. As I go over it, I happen to find so much of buggy codes...not really bugs… I would say “not properly written” codes. There are number of places I can see where I need to optimize but I’m limited by the time and scope I can change over. On the other hand there is a saying “if something works don’t try to change". Sometimes I really finding it interesting to do things in different ways but other time its very boarded to move codes here and there, change variable names… etc. I work on the heart of the company base system and it really needs concentration to finalize better design.

This is kind of exercise where you get to change your wheels while you are on ride. The most difficult thing is to think through all possible issues with out practice TDD.

Working on Rules Engine ...

Started to design a rules engine that can execute simple rules describe in a XML config. Obviously this will look simpler but idea is to cater dynamic change of requirements on operational flow of an entire business process...
In my mind i have what i needs to achieve but it’s too early to estimate how far this will turn good... Anyway i will do more readings on SOA, ESB and other rules engine standards soon...

Is nothing sacred on the racetrack?

By Himal Kotelawala, The Sunday Times, June 1, 2008

Colombo, Sri Lanka -- Sri Lanka is considering some diplomatic action regarding cases where a horse named ‘Buddhist Monk’ and another named ‘Buddah’ had run in two separate horse races in Yarmouth, England and Tramore, Ireland respectively, last week.
www.racingpost.co.uk. The latter website also carried a summary of ‘Buddhist Monk’s’ performance. It said “ ‘Buddhist Monk’ had a rug for stalls entry but got away well and was soon tracking the leader. He edged left in the closing stages and was only shaken up by his jockey without resorting to the whip and can repay the kindness in a similar contest,”
‘Buddhist Monk’ finished the race in second place on Thursday. Its rider was D O’Donohoe and the horse is owned by Lord Derby. The betting was stated as 10:1, meaning if the horse had won, a prospective bet winner would have made Rs. 10 for a Rs. 1 he bet on it. Meanwhile ‘Buddah’ owned by Joseph A. Shannon and ridden by R.Walsh had come ninth in a field of 14 in a two mile hurdle race on Friday.
When contacted by The Sunday Times, British High Commission media spokesman
http://www.buddhistchannel.tv/index.php?id=43

Lamport's one-time password algorithm (or, don't talk to complete strangers!)

There's a subtle beauty in simple things that present great value. To paraphrase Albert Einstein, a solution to a problem should be as simple as it can be, but no simpler. Applying a one-time password (OTP) scheme between distributed systems makes it more difficult for a would-be intruder to access and gain unauthorized control of restricted resources such as data, physical devices, or service end points. An OTP scheme is obviously a step up from completely open access, or access limited only by physical network barriers. But a solution based on an OTP challenge also has some advantages over static, infrequently changing passwords, because the window of opportunity to gain access to credentials is much smaller. There's a practical place for either type of authentication, or even both used in concert.

Refer : http://www.javaworld.com/javaworld/jw-03-2009/jw-03-lamport-otp.html