Techno Stuff

Start and access Amazon EC2 micro ubuntu instance.

2011-11-14T13:28:00.000-08:00

Log no/sign in: http://aws.amazon.com/ec2/

Start an ubuntu micro-image, Eg:
ebs/ubuntu-images-milestone/ubuntu-oneiric-alpha2-amd64-server-2011*** (ami-00b14b69)

create a keypair:_ something.pem

change the permission of something.pem to 400:
sudo chmod 600 something.pem

create security group:
- open ssh, tcp - in the security group, by editing/adding rules.

access the virtual machine using ssh, using public DNS of instance:
For ubuntu machines, default user is ubuntu:

So, access it like:
ssh -i something.pem ubuntu@ec2-67-202-**-***.compute-1.amazonaws.com

To install gcc/openmpi

sudo apt-cache search make g++ libopenmpi-dev openmpi-bin openmpi-doc build-essential gcc-multilib libstdc++6
sudo apt-get -y update
sudo apt-get -y install make libopenmpi-dev openmpi-bin openmpi-doc build-essential gcc-multilib libstdc++6

iweb parsing error - fix

2011-03-13T19:37:00.000-07:00

If there is a Parse error: syntax error, unexpected T_STRING, etc in publishing a website developed using iweb on web hosting servers, try the following. I got it fixed.

create a file named ".htaccess", where you put "index.html" (or folder called "public", some say - I havent tried this).

Add either of the following line to that file:

php_flag short_open_tag off
-- OR --
php_value short_open_tag 0

That should fix the problem. I got the tip from the following link. It works for me.

http://answers.yahoo.com/question/index?qid=20081022040450AAY1T8u

BACKUP USING RSYNC & CRON

2011-02-10T17:30:00.000-08:00

This link is quite useful:

Backups using Rsync, Bash & Cron:

http://linuxbasement.com/content/backups-using-rsync-bash-cron

Follow this link to create loginless ssh:
http://blogs.sun.com/jkini/entry/how_to_scp_scp_and

apt-get - how to update, upgrade

2011-01-28T15:03:00.000-08:00

It is not necessary that apt-get fetches the latest versions you needed always. You have to update the list of places from where new versions can be fetched.

It works like this:

apt-get looks at:

/etc/apt/sources.list

You have to update that file with proper links:

This post explains it well: https://help.ubuntu.com/community/Repositories/CommandLine

remember Ubundu 8.xx is called hardy, other versions have got different names.. find out and use accordingly.
use: "cat /etc/issue" or "lsb_release -a" to find out the version of linux u r running

once updated the list use
man apt-get to know how to update and upgrade the version list.

then use apt-get install .... to update your libraries with the new versions.

Installing different versions of open mpi - NFS cluster

2011-01-28T14:27:00.000-08:00

It can be bit tricky.

Basically we can have different versions of open mpi running on the same machine, because they can work independent if we install them in different folders.

choose an NSF folder which is common to all machines. Eg: /opt
create a folder called /opt/mpi
create a folder for the version you are planning to install. Eg: /opt/mpi/ompi-4.3.1
(u need root privileges)

Now download tar (.gz) file of the version u r planning to install from openmpi site.

http://www.open-mpi.org/software

(better not to build from the svn checkout version. get the native one)

Now make sure that your system has got the correct versions of autoconf, automake, libtool, gcc, ffortran, g++ etc
(this link will help you to know the requirements: http://www.open-mpi.org/svn/building.php)

if apt-get does not get you the latest or the right version, manually install them.
Eg: from the gnu site: ftp://ftp.gnu.org/gnu/

(manual installation tips:
./configure,
./make all install

you may have to set the correct symbolic links using "ln -s" command at: /usr/bin/ as well.

check versions using --version command. Eg: gcc --version
)

Once your env is ready, start installing open-mpi.

Unzip the tar file

(in the below step, adding prefix is important, otherwise the installation will conflict with the previous or next version installations)

./configure --prefix=/opt/mpi/ompi-4.3.1

(a lot of output)

./make all install

(a lot of output)

If you are lucky, your new open mpi will be installed at /opt/mpi/ompi-xxx folder, without any fuss. Or address the bugs :( and install.

Now, set the PATH and LD_LIBRARY_PATH at .bashrc file to /opt/mpi/ompi-xxx/bin and /opt/mpi/ompi-xxx/lib as follows:

PATH=/opt/mpi/ompi-1.4.3/bin:$PATH
export PATH

LD_LIBRARY_PATH=/opt/mpi/ompi-1.4.3/lib
export LD_LIBRARY_PATH

Logout and login again....

Now this open mpi version should be accessible by all nodes in the NFS cluster. Happy open-mping..

Solve Conflict between IEEEtran class and 'listings' in creating captions

2010-03-14T16:16:00.000-07:00

This tip works like a charm.

Use this patch code after IEEEtran loads:

\makeatletter
\let\@ORGmakecaption\@makecaption
\long\def\@makecaption#1#2{\@ORGmakecaption{#1}{#2}\vskip\belowcaptionskip\relax}
\makeatother

mpirun and "test"

2009-10-05T16:38:00.000-07:00

I had a great revelation today! I was unable to run my MPI program named "test.cpp" using mpirun (Open MPI) 1.3.2

I was stuck up for 3 days!

I couldnt find any problem with my code. I tried, tried, tired. It didnt work!

I changed the name of file to "client.cpp"

Alleluia! It worked. It seems that "test" is a reserved word/file in MPI. Dont mess with it, ever!

Differences between C++ Classes and Structs

2009-08-26T17:39:00.000-07:00

Quoted from Ref:

Probably the most frequently asked interview question that I have received is one that explores the difference between C++ classes and structs. Such a question was asked by a Northrop Grumman recruiter during a career fair at UC Irvine. I was also asked this sort of question during an on-site interview at Heavy Iron Studios. Recently, it has been asked during a phone interview with Amazon.com.

My answer typically states that members of a class are private by default, whereas members of a struct are public by default. Inheritance between classes is also private by default, and inheritance between structs is public by default. The interviewer was usually satisfied with this answer, which Dr. Raymond Klefstad fed to my first computer science class. Lately, I was interested in the nontrivial cases that bring me uncertainty: a struct inheriting from a class and a class inheriting from a struct.

IEEEtran latex - url in reference

2009-03-10T04:02:00.000-07:00

The url representation in reference (using bibtex in latex) may break up. U can avoid that by using:

usepackage{hyperref}

in latex file.

Installing Husband.

2009-02-16T14:11:00.000-08:00

I got this email from one of my friends.. hilarious.

------------------------------------------------------------------
A desperate woman writes to the Technical support Guy,

Dear Tech Support,

Last year I upgraded from Boyfriend 5.0 to Husband 1.0 and I noticed a distinct slowdown in the overall system performance, particularly in the flower and jewellery applications, which operated flawlessly under Boyfriend 5.0.

In addition, Husband 1.0 uninstalled many other valuable programs, such as
Romance 9.5 and Personal Attention 6.5, and then installed undesirable programs such as NEWS 5.0, MONEY 3.0 and CRICKET 4.1.

Conversation 8.0 no longer runs, and Housecleaning 2.6 simply crashes the system.

Please note that I have tried running Nagging 5.3 to fix these problems, but to no avail.

What can I do?

Signed,

Desperate Woman

DEAR DESPERATE Madam,

First, keep in mind, Boyfriend 5.0 is an Entertainment Package, while Husband 1.0 is an operating system.

Please enter command: ithoughtyoulovedme.htmland try to download Tears 6.2 and do not forget to install the Guilt 3.0 update.
If that application works as designed, Husband1.0should then automatically run the applications Jewellery 2.0 and Flowers 3.5.

However, remember, overuse of the above application can cause Husband 1.0 to default to Silence 2.5, Happy Hour 7.0 or Beer 6.1.
Please note that Beer 6. 1 is a very bad program that will download the Farting and Snoring Loudly Beta.

Whatever you do, DO NOT under any circumstances install Mother-In-Law 1.0 (it runs a virus in the background that will eventually seize control of all your system resources.)

In addition, please do not attempt to reinstall the Boyfriend 5.0 program. These are unsupported applications and will crash Husband 1.0.

In summary, Husband 1.0 is a great program, but it does have limited memory and cannot learn new applications quickly.
You might consider buying additional software to improve memory and performance.
We recommend: Cooking 3.0 and Hot Looks 7..7.

Good Luck

Tech Support .

Find the disk space usage in Mac and Linux

2009-01-31T19:36:00.000-08:00

To find the total space usage of all the files/folders in a particular folder, in human readable form, use:

du -sh *

(on Terminal)

Find free disk space

2008-09-04T21:28:00.000-07:00

Use

df -h

or

df -k

To Increase the hard disk size of OS in Parallels (Mac OSX)

2008-09-04T20:35:00.000-07:00

Refer the link:

In case, if you dont find it there:

1. Find your hard disk image file on the host machine (in this case Mac OS). Run the Parallels Image Tool.app on it and expand it to the desired size.

My Parallels disk image is located in:

~/Library/Parallels/Microsoft Windows XP/winxp.hdd

These days, Parallels is installing that image in:

~/Documents/Parallels

2. Use the Finder to duplicate the hard disk image you wish to expand.

3. Open Parallels but do not start Windows. Open the Parallels Preferences for the virtual machine. Change the hard disk image path to the duplicate image. (Note, this is not the "Default Folder for Virtual Machine" setting you first see. It is the Hard Disk setting, lower on the Preferences screen.)

4. Add a new hard disk via the Add button at the bottom of the screen. Set the new hard disk's path to the original image. The purpose of this and the above step is to boot from the duplicate disk, so that Windows can have full access to the disk (original image) you wish to expand.

5. Boot up Windows. Windows will report that it has identified new hardware. After that is finished, then navigate to Start -> Run. Type (no and no quotes), and press Run/Enter.

6. In the new window that appears type:

7. After that process runs, a list of disks appears. Notice that Volume 1 and Volume 2 look identical. Note: Volume 2 should be the original hard disk image.

8. Select Volume 2 by typing: select return. Then extend it by typing . Once that is complete type exit return. Then shut down Windows.

9. Before starting Windows, clean up the Virtual Machine preferences by using the Parallels preferences to delete the second hard disk, and to switch the Hard Disk 1 path back to the original hard disk image. You can put the duplicated Win XP hard disk image into the Mac Trash.

10. Restart Windows. Rebooting may be necessary if Windows "detects new hardware."

Create shared folders between Mac OSX and Parallels Linux OS

2008-09-04T19:31:00.000-07:00

Follow the link:

http://ubuntuforums.org/archive/index.php/t-325768.html

To install a new version of gcc in RHEL (any linux)

2008-09-04T18:55:00.000-07:00

Ref:

http://www.tellurian.com.au/whitepapers/multiplegcc.php

To find Dir sizes in sorted order in Linux

2008-09-04T18:54:00.000-07:00

just use du command(disk utility)

du -skh * | sort

It's time for Microsoft

2007-09-17T15:48:00.000-07:00

Microsoft lost half a billion Euro case against it by the European Commission. The case is about Monopoly, as everyone could imagine! Microsoft uses it's monopoly over Windows Operating system to extend it's market over other services (like media players, in this case). Their strategy is simple: hide some core protocols called "server interoperability protocols". Now others cannot operate on Windows - as smoothly as Windows applications do!

It's only a tip of an iceberg. Somehow there should be an end to this monopoly of companies like Microsoft in IT field

What the 'hackers' did!

2007-09-06T03:06:00.000-07:00

go to HOME

The continuation of the story of iPhone.. Look what the 'hackers' have done!

Sales spike expected from iPhone price cut

Some experts:

"Australian sellers of iPhone unlock hacks are bracing themselves for a deluge of orders after Apple cut the iPhone's price tag by a whopping $US200 ($240).

The 8GB and 4GB models now retail for $US399 and $US299, respectively, but the latter will be discontinued once existing stocks sell out.

The price drop is expected to infuriate those who paid $US599 for the iPhone around its launch just over two months ago..."

whopping $US200 ($240) per Phone within 2 months! That's phenomenal. What' s the reson could be? Apple fears loss of monopoly over its 'locking with a particular network'.

How do we judge the scenario?

Little more about iPhone

2007-09-04T17:04:00.000-07:00

After reading my previous post the parent wrote to me to have a look at the following issues too..

the two issues which i expected you would address was

1. the media hype given - which to my opinion is not good for modern world

2. he having to trade it to a competitor company - he could have informed iPod about it

I will address the second question first. The hacker didnt trade it to Apple. Instead he went to a competitor. What's its implication?

Of course he could have informed Apple and could get remuneration for his work. It would be of great interest to Apple too. They would like to know how their code could be hacked - as another piece of intellectual work.

But the hacker didnt do that. He preferred a competitor. His motive may be to challenge Apple's monopoly.

I do believe that Apple has got all the rights over their product (iPhone). But the issue here is, they are compelling the customers to choose a 'network' to use their product.

Microsoft had the same issues in the past. They used their monopoly over PCs to promote their own other web based services. As we all remember there was fierce legal battle over the issue and finally Microsoft lost it. Now its the term of Apple, that's all.

It's bit complex.

And also the word 'hacking'! It may be like 'sex'.

Is 'sex' bad? answer is 'Yes' and 'No'.

Within the marriage bond it is good and it's good use should be promoted. But it can also be 'bad'. The context and motivation will decide it.

I do try to understand the confusion of a PARENT in this situation. How to guide his siblings? It's a real challenge - to teach him to differentiate between the 'right' and the 'wrong', in this complex world. Good conscience formation with the help of genuine religious values only will help the child to survive positively in this ever changing world.

Media always make hype - especially, if its regarding Mac products! I wish they give at least as importance as this to the suffering people in the world. They wont - especially the Western Media. Sorry.

iPhone Hackers and the moral dilema

2007-09-04T04:09:00.001-07:00

The IPhone has been hacked!

READ THE LINKS:

Teen trades hacked iPhone for new car

Code crack opens the iPhone floodgates

A Concerned parent wrote to me:

"Dear Fr. Jaison,

Living in the modern world on many occasions we get confused reading the stuff like the one below

http://news.yahoo.com/s/ap/20070828/ap_on_re_us/odd_iphone_unlocked

"We grew up listening to the stories of early Christians loosing their life for sake of their beliefs but now he has traded on the flaws of a company's product to get rich, people like you who tech savvy and religious are ones who should address to this....I have a son aged 1 yr 5 months but i am not sure how i am going to impart the values which i gained to him when I myself don't find enough words to explain that what we just read is wrong even though i know it is wrong. How will i be able to justify... seems people no more think about the cardinal sins."

What's the morality behind this event.

The apple has locked their new phone to a particular service provider. It's a business decision. The goal is very clear - giving the monopoly of it's new phone to someone. If someone wants to use iPhone, they have to choose the 'provider' as well. How morally upright that position is?

A BIG QUESTION?

The sole aim is making more profit - by using intellectual property right.

Now, some kids wants to use their brain to show that they can break that code. They may be called hackers! But what they are doing is also intellectual work. They got a right over their skills too... isn't it. We may have to legalize it, that all.

It's an open ended question. A lot of moral principles may come in play. But I would like to side with the kids... The preferential option for the poor!

Examiner Report of my Minor Thesis (its pretty good!)

2007-07-16T17:36:00.000-07:00

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July 4, 2007

Minor Thesis::Jaison Paul Mulerikkal

Dear Sirs,

The minor thesis of Jaison Paul Mulerikkal investigates a very relevant and original research topic. Due to the permanently increasing traffic in the Internet as well as the increasing bandwidth and processing power of end systems, it makes much sense to implement content delivery networks based on end system functionality. The minor thesis proposes an architecture, where systems deployed both in the customer and operator premises are used. The architecture has been evaluated by simulation experiments. The architecture design is rather straight forward and should be considered as a first attempt to develop a good solution for the addressed problem. It would have been nice to see a somewhat more innovative solution, but this was probably not possible due to time constraints. It is somewhat surprising that the author did not really find scenarios, where the benefits of the proposed approach become more obvious. On the other hand, the results also suggest that there is significant need to further investigate the problem. The results presented seem to be quite complete and the reader gets the impression that the evaluation has been performed very carefully.

The thesis is very well written and structured. It is easy to read and understand. The results are presented and discussed in an appropriate way. The conclusions are logical and consequent. The related work has been discussed very well. The author seems to have a very good background on the related research in the field. Overall, the minor thesis is of good quality, the results are interesting, and the student proved to be able to perform research in a systematic way. Therefore, I propose “pass” as the result for the thesis.

Examiner

Distributed Content Delivery Network

2007-06-22T19:12:00.000-07:00

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here is the abstract of my Minor Thesis. bit technical, but will give an idea about what i'm doing.. have a look.. good luck..

Abstract
----------

Commercial Content Delivery Networks create their own network of servers around the globe to effectively deliver Web content to the end-users. The peering of Content Delivery Networks (CDN) would increase the efficiency of commercial CDNs. But still the high rental rates resulting from huge infrastructure cost make it inaccessible to medium and low profile clients . Academic models of peer-to-peer CDNs aim to reduce the financial cost of content distribution by forming volunteer group of servers around the globe. But their efficiency is at the mercy of the volunteer peers whose commitment is not ensured in their design. We propose a new architecture that will make use of the existing resources of common Internet users in terms of storage space, bandwidth and Internet connectivity to create a Distributed Content Delivery Network (DCDN). The profit pool generated by the infrastructure savings will be shared among the participating nodes (DCDN surrogates) which will function as an incentive for them to support DCDN. Since the system uses the limited computing resources of common Internet users, we also propose a suitable load balancing (LB) algorithm so that DCDN surrogates are not burdened with heavy load and requests are fairly assigned to them. Simulations have been carried out and the results show that the proposed architecture (with LB) can offer same or even better performance as that of commercial CDN.

Techno Stuff

2007-06-19T21:08:00.000-07:00

My techinical blogs goes here...