Posts

EMR master instance is not reachable

I faced a rare issue today.  My EMR cluster was not resizing. Apparently, the master node was facing issue in communicating with EMR. The cluster status showed "Master instance is not reachable. Please check your master instance status". But I was able to login into master node and use hadoop and HDFS without any issues. Just that the cluster was not resizing. Searching on the internet just gave one relevant result. https://forums.aws.amazon.com/thread.jspa?messageID=695687 Although it mentioned that the issue was with the emr 3.x amis and my cluster was a 4.x, I thought this was the same issue. For verifying I checked on my other clusters if any such service was running on them. $ ps awux | grep instancecontroller hadoop    2389  0.4  2.0 3584132 309980 ?      Sl   Apr13  97:41 /etc/alternatives/jre/bin/java -Xmx1024m -XX:OnOutOfMemoryError=kill -9 %p -XX:MinHeapFreeRatio=10 -server -cp /usr/share/aws/emr/instance-controller/lib/*:/home/hadoop/conf -Dl

Writing BOLD text in Gmail Chat

Did you ever felt the need to write something in BOLD when chatting on Gmail. Now, here's a simple trick. Just add asterisk on both sides of the *word*. Want to bold a phrase or complete text. Just put * in the beginning and at the end *. Its as simple as that!!!!!! Now be BOLD and CHAT .

Compiz Desktop Effects Keyboard Shortcuts

I had been seaching the keys for a long time. Even when I had everything installed, I just didn't knew how to activate, say, the Desktop Cube. So, here's a list of useful shortcut keys to compiz. Alt + Tab = switch between open windows Win + Tab = switch between open windows with Shift Switcher or Ring Switcher effect Win + E = Expo, show all workspace Ctrl + Alt + Down = Film Effect Ctrl + Alt + Left mouse button or Mousewheel on Desktop = Rotate Desktop Cube Alt + Shift + Up = Scale Windows Ctrl + Alt + D = Show Desktop Win + Left mouse button = take screenshot on selected area Win + Mousewheel = Zoom In/Out Alt + Mousewheel = Transparent Window Alt + F8 = Resize Window Alt + F7 = Move Window Win + P = Add Helper F9 = show widget layer Shift + F9 = show water effects Win + Shift + Left mouse button = Fire Effects Win + Shift + C = Clear Fire Effects Win + Left mouse button = Annotate: Draw Win + 1 = Start annotation Win + 3 = End annotation Win + S = sel

Adding jar files to weka

Recently, I had to implement a machine learning algorithm called MLRules. I found the code on the author's webpage but there was a big problem. It was in Java using the WEKA environment. I had never worked in the Java before. Above that, I had another alien named 'weka'. Initially everything seemed out of the world. I tried different things, searched on google, read wiki after wiki but there doesn't seem to be a working solution of adding new classifiers in form of .jar files to run in weka. My search on google began with query 'adding jar files to weka'. I searched and searched till the query became 'cannot add jar file to weka'. I was nearly ending an unsuccessful pursuit of the 'WEKA' when one of the results came up from the 'google code' site about adding thier code to weka. The steps were well documented. I tried working it out and ALAS!!! it started working. It took a week's time just to do a simple thing. I ran the code and it

Matlab 32-bit on ubuntu 64-bit

I was bugged to install Matlab 32-bit on my system that had a newly installed Ubuntu 64bit Linux. Matlab couldn't find the right JRE for the 64-bit architecture and ran only in command-prompt. After lot of wandering on the net, i found a simple solution the the problem. I had to manually set the JAVA path for matlab. For this i used the command : export MATLAB_JAVA='/usr/lib/jvm/ia32-java-6-sun-1.6.0.06/jre' After this i just ran the command to start matlab : matlab -glnx86 Remmber to put it in .bashrc to get it done every time you start matlab from bash.

Check Your Adobe Flash Player Version!!!!!

Wanted to know which version of the leading online video player - Adobe Flash Player - is installed on your system. Whether it is working properly or not??? Here's a simple solution and from the Adobe's site itself. Just go to http://kb.adobe.com/selfservice/viewContent.do?externalId=tn_15507 Here, if the player is correctly installed, you will see the version no. of the player and also details such as - is it a shipping version or a debug version, OS details etc. So, install the flash player and enjoy the sites likes YOUTUBE.

PDF Split and Merge

Recently, I had lots of problem in joining or merging different pdfs. There are many licensed softwares available. On using them as shareware would work but almost all made the pages of thus generated pdfs really unusable by putting large remarks that you need to register. After lots of roaming around the web and googling, I found a very neat and simple solution to all my problems. This is the PDF Split and Merge or PDF-SAM as it is called. It is a project going on sourceforge.net. That means "ITS COMPLETELY FREE". And above all, we can access even the source code of the project. This doesn't seem that interesting but considering the power of open-source softwares, this may be very helpful. I don't think it needs any more explanation as it is very simple to use, say for merging: 1: Choose the tab "MERGE" 2: Add as many files as you want 3: Set the path. Be little careful here and give the whole path or it throws back an error. Or simply, just press browse an