Thursday, February 4, 2010

Running Java in debug mode using Apache Ant

Configure your Java task as given below;



<java classname="org.zero.Main" fork="true" failonerror="true">
            <sysproperty key="DEBUG" value="true" />
            <jvmarg value="-Xdebug" />
            <jvmarg value="-Xrunjdwp:transport=dt_socket,server=y,suspend=n,address=8999" />
            <jvmarg value="-Xnoagent" />
            <jvmarg value="-Djava.compiler=none" />
            <arg value="${project.root}/conf/preferences.xml" />
            <classpath refid="project.classpath" />
        </java>

Further,  configure your eclipse debug remote application to listen to the specified port (8999 in this case).

Also, add Thread.sleep(1000); as the first line in your main method.

Execute Java task and try connecting from eclipse, you may need to increase the thread sleep time.

Saturday, January 30, 2010

Bug fix: Eclipse springsource on UBuntu 9.10

...so u have upgraded to UBuntu 9.10 and you are really impressed with its new features and you cannot control your excitement to check out your development environment and launch eclipse .. but oops! you are not able to create a new project.. none of the buttons seem to work chances are you are also suffering from the same bug follow the link for the fix  

This issue is resolved in eclipse 3.5.2 M2 release. Hope that helps.

Friday, October 16, 2009

Who created God?


Who created God? or Is it our own invention? It is an age-old question that has plagued all those who like to think about the big questions.

Just last fortnight, I visited Puri, Orissa for the pilgrimage to Jagannath temple. As much as it was spiritually "satisfying" for my parents I was irritated with the chaos and mayhem created by 'pandas' there. I was wondering if indeed visitors are able to offer their prayers in peace. It is after all every Hindus long cherished wish to do their 'char-dham-yatra' but was that the only purpose or the reason lies in creating another money spinning business in the name of God? Is God our own creation? may be I don't know and neither do I have the patience or time or inclination or competence to read and understand the philosphical content of all the books on the subject. But, here was this craftsman on the Grand Road - famous for the 'Rathyatra' conducted here every year, focussed on giving final touches to idols. His frentic fingure movement was a feast to watch and I was still wondering if he created the God!! Shy of me taking his photos he asked me 'Babu, humari photo kyun le rahe ho?' I told him, I never saw any one creating God to which he replies 'Babu, murti nahin banayenge to ghar kaise chalayenge aur bhagwan to haathon mein hai to khana khila raha hai.. humara to bass itna hi kaam hai'

Soon I realised why do we say 'Apna haath Jagannath'. I guess it is very important to be focussed and do our duty religiously.. rest shall follow. I guess I learn some thing from him.

Saturday, August 15, 2009

Maya tumko itna bhi samajh mein nahin aaya!!

Dalit ki beti has done it again... this time she harps back on Manuwadis for targeting her for being partial.. why is it that congress is not targeted for creating 'brand' by naming every little thing after Nehru-Gandhi family member... Read more

I believe instead of crying foul, she can take a lesson here and help creating lets say an IT park in the name of Dr. Ambedkar (hmm.. that will not help BSP) or Kansiram (hmm.. that will help her) Maya Pragat Sangadak Sansthan etc as a matter of fact it doesn't matter if you are trying to bring token benefit for your party provided it brings considerable tangible benefit to people and help them improve their living... get creative Maya you can earn much more by helping people create wealth.. and you can really be in good history books.

Friday, July 24, 2009

Finally spotted the 'Tiger'

Once upon a time long, long, long ago SCJP 5 was newly released and it was a proud moment in my life to secure a distinction in the same. I felt like I 'Tamed the Tiger' never ask how did I feel working on versions 1.4 and 1.3! all these years. Never mind, the 'Tiger' will soon be a sunset technology from Sun's stable... never mind 'Mustang' is galloping faster and faster... Today I spotted the 'Tiger'. I'm happy with the opportunities at hand to experiment... looking forward to play with the beast...

Tuesday, July 21, 2009

School chalein hum...

Coming from a modest middle-class background I understand and appreciate the importance of education in securing one's future. Not that people from other background don't appreciate education or that careers in other fields do not exist. But, pragmatically speaking education can help you achieve sustainable living and it is crucial in managing one's self esteem, specially for those from related backgrounds. Probably, that sets the pretext for the heightened stress that parents and children undergo to secure better grades, which has even led to suicides etc in some really unfortunate cases.

The recent education policy aims to abolish school board exams quoting the need to remove [reduce?] the stress for school going children. A welcome step? Well, depends where are you coming from.. In case you feel it is a welcome step because it help reduce stress I'm not with you. My question is who are you trying to help? are you saying you can make their life a bed of roses? they are not going to have any stress? ever? May be your new system allows them to pass certain public exam 'without failing' but what next? are they going to spend their lives at school alone, studying? I believe, No.. some time or the other they need to face the industry, the real world.. believe me all that school work will look like a cake walk...

But, in case you do believe that abolishing public exams at school level is welcome step because now students do not have to study to get grades. Yes, as much as it sounds strange it is good. It is important to understand that education is not some material object [read grades/marks] that one gets upon completion of education. The real education is the state of mind. It is that great heritage of common sense that has been brought down to us over the ages. Now, with that material motivation removed students can now focus on learning rather than getting good grades, which makes them seeker. The motivation to learn is now from within, there are no socially defined pressures.

I understand what many of us might go through as a result of this void created in our lives. There are no 'goals' which might distract our 'normal' student and he may eventually loose his interest in studies and compromises on a lesser education ... which is good isn't it?!! think about it!!... he was not liking it any ways and at best would have remained a mediocre all his life even after a 'highly-rated-degree'. Only those who really appreciate their learning will continue thus saving a lot of resources.

In either case there are certain risk factors which need to be mitigated to avoid chaos:
  • The 'normal' student who settled for a lesser education as a result of his ever increasing committment to his 'other-than-education' activities should be able to leave his education without any penalties
  • He should be able to find an employment opportunity fit to his calibre.
  • He should be able to return to his education in case he gets frustrated with his 'boring' work to seek creativity to gain theoretical understanding of THE World around him.
Learning should be fun.

Monday, July 13, 2009

Imagining Female Foeticide and Gay marriages and Prostitution

All along I was tagged as a happy-go-lucky person who would go out of his way to have fun.. for that one moment of 'nirmal anand' and the best compliment to me was when some called me a 'stress buster' and further asked what's your source of energy? how do you do that? In reply to which I would say I'm happy as I'm gay!!! and then everyone would burst out to laughter.. I dare say that again and people would take it really seariously .. thanks to the recent turn of events in our society. Recent court judgements have 'legalised' the gay/lesbian marriages leading to nationwide celebrations for their newly acquired "freedom". I was wondering what's the real cause for their inclination to the unantural carnalness... Is that their utmost frustration in finding the right girl? Is it because of acute gender imbalance in their community? Is it THE result of female foeticide in our country? I mean I'm also not in favor of moral poilicing but then isn't it banal and disgusting or may be I don't understand... so what's next? Let's legalize prostitution and earn more money for governement coffers..

The whole point is such act of recognition will only encourage impressionable minds to follow the next 'IN' thing to prove them to be 'COOL' and the by the time they will realize their mistakes it will be to late...

Sunday, June 21, 2009

Complete idiot's guide to Debugging

Time and again I have learnt much to my displeasure that I'm not efficient while debugging. Most often than otherwise, I would just miss the point and keep 'searching' for the issues. Sitting back I found one fundamental flaw in my approach to debugging a problem that there was no structure in my method! Instead of narrowing the cause-effect scenarios I was simply 'searching for the needle in the hay stack'. This would obviously take more time than expected and would lead to sheer wastage of my resources.

Learning about the scientific method of experimentation I found that solution of problems too complex for common sense to solve are achieved by mixture of inductive and deductive techniques.

The inductive logic demands us to start observing the 'system' and arrive at general conclusions. Make a mental note of your observations and try finding explanations to them chances are you would hit few observations which are not clearly understood in the given context, some thing which is kind of a 'mystery' and you find it tough to explain it the first time, hold on and do not get distracted collect information. Having done that now try to break your thoughts and write them under following heads;
  1. Problem statement: The biggest mistake to avoid here is to write too much, things which you are not sure of.. just an assumption. Rather, it is much better to state the problem straight. It might sound dumb in he beginning but would save from making dumb efforts based on incorrect assumptions later ..
  2. Hypotheses to he problem; typically list down possible reasons for the failure
  3. Experiments to test your hypotheses: The most important mistake to avoid here is that the experiments must be designed to test the hypotheses nothing more nothing less. This step would help you narrow down your solution/problem area.
  4. Expected outcomes will help you draw a base line for your experimentations.
  5. Actual outcomes must be compared and contrasted with the expected outcome for rigour in the testing process. Any deviations must be carefully studied and isolated to ensure that the anomaly is not because of some mistakes/incorrect measurements this will save one from drawing incorrect conclusions.
  6. Conclusion, here again care must be taken to state no more than the experiment proves/disproves.
By asking the right questions, conducting the right tests and drawing the right conclusions one might drill down the hierarchical structure of the problem to isolate the point of failure and fix it so that the system no longer fails at this point.

One might need to-fro between the two logical techniques to reach a plausible solution. Need to put this learning in practice now...

Thursday, April 23, 2009

Debugging

This is funny, this is not funny for me.

During this debugging session, I'm continuously guilt ridden for the technical failure is delaying the delivery and it was increasingly time consuming because I needed to question each of my assumptions, that sucks!

After my stress-profile-code-profile-stress cycles I did however learned a bit more about various JVM GC tuning options. Also, that in an overzealous attempt to gain customer delight the code was doing far more than required. I moved a step back and thinking from the usability perspective the problem immediately visible. Thanks to right encapsulation none of the interfaces are breaking and the affected code module could be refactored to fix the performance issue at hand. Further, tweaking the data structure to collect data for generating the performance reports helped us achieve performance gains. Now, we are able to do more with less. The trick is finding the application of technology that makes the most sense for solving your problem at hand.

Looks like my build is complete, let me profile my code again..

Tuesday, April 21, 2009

Java: Heap crunch

Profile-code-deploy-load was all that I did yesterday and yes it did improve the system performance and technically it did survived the brutal four hour load test without causing OOOE (out of memory exception). The primary hypothesis under which I'm working is that their the certain long living references have retained a sizable of memory. But, I'm sure I'm not exactly able to find the root cause for the system degradation under load. The important observations are;
  • We are loading the system using a pattern where we ramp up the load in x minutes and maintain the peak load for y hours and hen ramp down to zero in x minutes.
  • The heap usage percentage follows the similar pattern during ramp up, but although the load has plateaued the heap usage percentages continues go higher, while ramp down it eases a bit but never follows the decrease in load and never actually reaches zero or minimum even though there is no activity in the application.
  • CPU times in GC increases almost linearly albeit with a low gradient and decreases to zero after load completes.
I plan to study GC logs today to understand the system characteristics and fine tune the JVM fit for our purpose and I am sill not sure if I have a memory leak... more later.

Sunday, April 19, 2009

Java: Memory leak

Around two years back, when I encountered an article mentioning memory leak in Java, it was little surprising for me and may be author knew about his audience and went ahead to provide one demo program. It surely made me aware of the issue and certain anti-patterns to avoid. Then, I encountered my very own first Java memory leak, and that I my skills are not adequate to handle them. Here, in the current case, when I first observed this phenomenon I went ahead and explicitly 'nulled' my references, which are other wise supposed to go out of scope any ways and hence eligible for garbage collection, but to my frustration this has only marginally helped as the changes have only reduced the rate of memory leak and has not eliminated it. Now I plan to work to work associated anti-patterns like that weak references or references to small living objects held by long living objects etc. Will keep you posted.

Monday, April 13, 2009

Just like that...

We Indians have a tendency to generalize thing so much so that it hardly takes any effort from our side to paint the world in one color. Often as an extension to this exercise to tend o extract particular characteristics of people from a city, and I quite believe that any self respecting engineer from a decent engineering college in India must have had great fun using them to describe their friends. Almost every where you can find 'Baba', 'Guru', 'Ziddi Jat', 'Sirfira Sardar', 'Bihari', 'Taant', 'Gulti', 'Kannadiga', 'Khatta', 'Ghatan'... and the list goes on and on... while I was siting wih some of my senior friends we happened to discuss the changing times.. the arch typical '... those were the day, ...' and one of my senior friend was quite amused and interested to learn the diversity, he then told us that back then during his times such richness and variety was unheard of and as a result of which he would often be referred to as 'Madrasi', now that was real bad as this could be the worst form of identity crisis... he complained that all those from 'North India' used to refer any one down south with the same term and he would never be able to take that... and in order to have revenge on them he would paint them (Northies) as 'Bihari' and that had far reaching affect on them and upon complain he would highlight the similar difference to them... and that probably sowed the seed to heightened verbosity currently in use... seems like this is what is referred to as evolution of language ;)

Disclaimer: With malice to no one... have fun, n'joy!

Thursday, April 9, 2009

Failed to connect to remote VM. Connection refused. Connection refused: connect

A lot of time was wasted to resolve the above mentioned error, while I was trying to connect to a remote server using my eclipse IDE in debug mode. Here is the solution;

  1. Compile your application using '-g' option. This will generate all the debugging related information, including local variables. By default, only line number and source file information is generated.
  2. Launch a new Java Virtual Machine (VM) with the main class of the application to be debugged. For e.g. Launch a new Java Virtual Machine (VM) with the main class of the application to be debugged. For e.g. $> gt; java -Xdebug -Xnoagent -Xrunjdwp:transport=dt_socket, server=y, suspend=n, address=8000
Hope that helps.