Using OpenMPI 1.2.6 with on-demand clouds

OpenMPI seems to require and test all the nodes to be on the same subnet, before running MPI jobs on them. I was shocked to see the observation about OpenMPI, mentioned in this[1] paper.

But when one requests for several VMs from EC2, most of the time, the VMs booted are not in the same subnet. So this can be a show stopper if you are trying to use OpenMPI within clouds, especially the commercial ones.

[1] : Cloud Computing for Parallel Scientific HPC Applications : Feasibility of Running Coupled Atmospheric-Ocean Climate Models on Amazon's EC2

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Life with the two year old

(No this is not technical :) )

We were worried because we were having lots of trouble thinking Dihini is very naughty. But I was stunned by the reply Dihini's play school teacher gave me, when I explained Dihini's behavior to her. Her answer was "You are explaining about a typical two-year old". Since I seemed not convniced, she asked me to read "Is this a phase?". Having read that, now I'm convinced.

When Dihini wants something, she wants it immediately. If not, she will cry and do anything to get it. But when we prepare it and give that to her, she had forgotten what she wanted and now she wants something else. According to the book, this is a problem of a present-timers. They have no past or future, only think about the current time. When they imagine having it, they need it NOW !!

Also when she is reading a book, she wants to read that book same way, same place she read it the first time. Even where we sit, the orientation, everything has to be same. This was irritating for us. Sometimes we have to move the furnitures here and there to get to the same environment. But it seems (unfortunately for us) this is a phase in the imagination.
She hates when we have a conversation or talk on the phone. If we ignore her, she knows how to get the attention doing all sorts of things. Also when she does a thing we encouraged her not to do, she knows how to please us and even try to make us forget that act.

It is unbelievable how she develops her senses and behavior. Even though its irritating and hard for us sometimes, I think its a fact that everyone must go through these stages. At least my parents must have been in the same situ long time back :D

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Getting upto speed with Latex

(This is a blog I wrote about two year ago, when I was using bloglines. But recently I followed it thought I should put here too).

If you are thinking of writing a paper or academic paper, latex will be one of the great tools to use.
These days, I am using it for couple of reports and thought of writing down the things I did, for some one to get upto speed with Latex soon. For me it took some time for me to get all things working, but I hope following instructions will help you to be familiar with latex within about 30 minutes.

Step 1
Obviously you need to install Latex in your system. I am using Ubuntu edgy and it doesn't come with Latex pre-installed. So its is the time to install it. (If you have different OS, you might wanna look at this)

sudo apt-get install tetex-base tetex-bin tetex-extra

Step 2
You can write latex without an editor or you can use a basic tool like emacs. BUT ... I am not that expert so I got a very good eclipse plugin for latex. TeXlipse is a very good eclipse plugin which has syntax highlighting/prediction, generating docs, links to frequently used symbols, etc.,
You can install it using Eclipse "Software Updates". Follow the comprehensive installation instructions here.
There are couple of configs you need to do after that, especially to give paths to latex. Some times the TeXlips installation automatically pick them for you.
Having installed the plugin, try creating a sample project following these instructions.

Step 3
Now it is the time to dig in to latex. You might wanna start following the very basic tutorial from wikipaedia and then follow this.
There are lots and lots of guides for more information on latex, on the web.

You are done !! This is a great tool, especially when you are dealing with references and maths symbols.

Update : My friend Ajith has something to add in to this, which I think will be a good suggestion to this. Thanks Ajith.

"There is a tool called texmaker (both for windows and linux) and as for Ubuntu linux can be installed easily through synaptic/aptget , just search for texmaker and it should be there."

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Why do we have war in Sri Lanka?

Lots of my friends here ask me this question so often. So thought of writing down the explanation in one place.

How it started

After we got independence from British, one of our political leaders made a mistake by making Sinhala, the only official language in Sri Lanka. This happened during the end of 1960s. Due to various reasons this aroused a conflict between Sinhala and Tamil leaders. Tamil leaders started a movement around TULF. But in 1977, with the election of the new president, JR Jayawardane, he corrected this problem by giving equal rights to all the ethnic groups.
But LTTE, a militant group formed in northern parts of the Sri Lanka, led by the cruel and political leader Prabhakaran. Eventhough they started the movement to get equal rights for tamils, they continued operate even after tamils getting equal rights. The reason I think was that once you get the taste of power, you don't want to give it up, even the cause is gone. They killed people opposing their movement, including both Tamils and Sinhalese. When they killed 13 soldiers, invane, rest of the people replied with the black july, killing lots of tamils in Colombo.
But that is past. Now there is no problem as such for about 2 decades. Since then tamils gained lots of rights and freedom in Sri Lanka.

Why there is a problem still

As one can see there are no problems for Tamils in Sri Lanka. They can go *anywhere* in Sri Lanka. Actually its the Sinhalese and Muslims that can not go anywhere they want due to these terrorists. If tamils are ill-treated, look at the following few examples.

1. Wellawatta, Kotahena, and many other major parts of Colombo itself were mainly populated by tamils. Even if we go outside of Colombo, there are lots of tamils everywhere.
2. In our undergrad intake to University of Moratuwa, engineering faculty in 1998, one of the most prestigious and prominent universities in Sri Lanka, there were 110 tamils out of the total intake of 350. Almost 1/3 of the batch.
3. Any tamil can go to any part of Sri Lanka without trouble. But muslims have trouble living in north-east and Sinhalese can not even go to north or east without trouble.

Those are simple examples.

It is obvious that its LTTE that is the enemy of tamils. They killed their leaders, their own people at a rate. They separated small children from their parents and trained them to fight against their own people, rather than letting them go to school. They are threatening all the tamils in Europe, Canada and other countries to donate money. (This video exposes how LTTE henchmen are/were forcing innocent people to contribute).
In nothern part of the country, LTTE is forcing their people to stay with them making them as baits for their fight. This has gone to an extent for UN to appeal to LTTE to allow those people to seek safety.
LTTE has killed so many innocent people in Sri Lanka, since 1983. They have also forcibly expelled Muslims from north, violated human rights.

But after all, we are about to see an end to this war. SL govt army is making the dream of peace a reality (see the battle progress map here). I wish if I could be with the brave Sri Lankans at this last moment.

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