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How to Decode TLV Quickly

In TLV, the format is Tag, Length, and Value. The TLV protocol needs this type of data. Here you will know how to decode TLV data. According to IBM , TLV data is three parts. The tag tells what type of data it is. The length field denotes the length of the value. The Value-field denotes the actual value. Structure of TLV. TLV comprises three field values.  Tag Length Value EMV formulated different tags. They have their meanings. Usually, the Tag and Length together takes 1 to 4 bytes. The Best example for TLV. In the below example, you can find the sample TAG, LENGTH, and VALUE fields. [Tag][Value Length][Value] (ex. " 9F4005F000F0A001 ") where Tag Name =  9F40 Value Length (in bytes) =  05  Value (Hex representation of bytes. Example, "F0" – 1-byte) =  F000F0A001 In the above message, tag 9F40 has some meaning designed by EMV company. Here  you can find a list of EMV Tags. How to read the TLV Tag: 1 or 2 bytes Length: Length of the Value. F0-00-F0-A0-01 ==> 5 By

How to Setup Hadoop Cluster Top Ideas

Hadoop cluster setup in Centos Operating System explained in this post. So you can install CentOs either in your Laptop or in Virtual Machine.
Hadoop cluster setup proces
Hadoop Cluster Setup Process

9 Steps Process to Setup Hadoop Cluster

Step 1:  Installing Sun Java on Linux. Commands to execute for the same:
sudo apt-add-repository ppa:flexiondotorg/java
sudo apt-get update
sudo apt-get install sun-java6-jre sun-java6-plugin
sudo update-java-alternatives -s java-6-sun

Step 2:  Create Hadoop User. Commands to execute for the same:
$sudo addgroup hadoop
$sudo adduser —ingroup hadoop hduser

Step 3:  Install SSH Server if not already present. Commands are:
$ sudo apt-get install openssh-server
$ su - hduser
$ ssh-keygen -t rsa -P ""
$ cat $HOME/.ssh/id_rsa.pub >> $HOME/.ssh/authorized_keys

Step 4:  Installing Hadoop. Commands for the same are:
$wget http://www.eng.lsu.edu/mirrors/apache/hadoop/core/hadoop-0.22.0/hadoop-0.22.0.tar.gz
$ cd /home/hduser
$ tar xzf hadoop-0.22.2.tar.gz
$ mv hadoop-0.22.2 hadoop

Step 5:  Edit .bashrc. Commands:
# Set Hadoop-related environment variables
export HADOOP_HOME=/home/hduser/hadoop
# Set JAVA_HOME (we will also configure JAVA_HOME directly for Hadoop later on)
export JAVA_HOME=/usr/lib/jvm/java-6-sun

Step 6:  Update hadoop-env.sh
Here we need to only update the JAVA_HOME variable, we just need to open the file from text editor.
$vi /home/hduser/hadoop/conf/hadoop-env.sh
And update the following:
export JAVA_HOME=/usr/lib/jvm/java-6-sun

Step 7:  Update the files residing in the conf folder.  The three main files are:
Core-site.xml
Mapred-site.xml
Hdfs-site.xml
Here we need to change the value of namenode and jobtracker to where we want to run.

Step 8:  Start the hadoop cluster, using command.
Start-all.sh

Step 9:  Check if all the processes are up and running, using command:
Jps
That’s it. The cluster should be up and running with the following 5 processes:
  • NameNode
  • SecondaryNameNode
  • DataNode
  • JobTracker
  • TaskTracker
If we see all these processes, it means our installation is successful and the cluster is up and running.

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