Cassandra - Installing Cassandra

1. First Download the Cassandra installable tarball (as I am going to install in Red Hat Linus machine) from the official Cassandra website to the location in your machine where you want to install it - http://cassandra.apache.org/download/

2. Cassandra is written in Java and it requires Java 7 or above is to be installed before we install Cassandra. Ensure in your machine java 7 or above is installed.  Java version 7 naming looks like 1.7.x.x
The command to check what version of java installed is simple, in the terminal type in :   java –version as shown below

3. Cassandra installation is very simple – untaring the tarball makes the cassandra installed (or all the executables and tools are available to get started with Cassandra ) and the installable is of around 22MB size only.

Once the tarball is downloaded in the machine where you want to install it, make a directory named – cassandra in your home directory and place the tarball in it.

To untar the tarball use the below command

$ tar -xvzf apache-cassandra-2.1.2-bin.tar.gz

[rvalusa@ol6-11gGG ~]$ cd cassandra/
[rvalusa@ol6-11gGG cassandra]$ ls
apache-cassandra-2.1.2-bin.tar.gz
[rvalusa@ol6-11gGG cassandra]$ tar -xvzf apache-cassandra-2.1.2-bin.tar.gz
apache-cassandra-2.1.2/bin/
apache-cassandra-2.1.2/conf/
apache-cassandra-2.1.2/conf/triggers/
apache-cassandra-2.1.2/interface/
apache-cassandra-2.1.2/javadoc/
apache-cassandra-2.1.2/javadoc/org/
apache-cassandra-2.1.2/javadoc/org/apache/
apache-cassandra-2.1.2/javadoc/org/apache/cassandra/
apache-cassandra-2.1.2/javadoc/org/apache/cassandra/auth/
apache-cassandra-2.1.2/javadoc/org/apache/cassandra/auth/class-use/
apache-cassandra-2.1.2/javadoc/org/apache/cassandra/cache/
apache-cassandra-2.1.2/javadoc/org/apache/cassandra/cache/class-use/
apache-cassandra-2.1.2/javadoc/org/apache/cassandra/cli/
apache-cassandra-2.1.2/javadoc/org/apache/cassandra/cli/class-use/
..........
..........
..........
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apache-cassandra-2.1.2/tools/bin/cassandra-stress.bat
apache-cassandra-2.1.2/tools/bin/cassandra-stressd
apache-cassandra-2.1.2/tools/bin/cassandra.in.bat
apache-cassandra-2.1.2/tools/bin/cassandra.in.sh
apache-cassandra-2.1.2/tools/bin/json2sstable
apache-cassandra-2.1.2/tools/bin/json2sstable.bat
apache-cassandra-2.1.2/tools/bin/sstable2json
apache-cassandra-2.1.2/tools/bin/sstable2json.bat
apache-cassandra-2.1.2/tools/bin/sstablelevelreset
apache-cassandra-2.1.2/tools/bin/sstablemetadata
apache-cassandra-2.1.2/tools/bin/sstablemetadata.bat
apache-cassandra-2.1.2/tools/bin/sstablerepairedset
apache-cassandra-2.1.2/tools/bin/sstablesplit
apache-cassandra-2.1.2/tools/bin/sstablesplit.bat
apache-cassandra-2.1.2/tools/bin/token-generator

[rvalusa@ol6-11gGG cassandra]$ ls
apache-cassandra-2.1.2  apache-cassandra-2.1.2-bin.tar.gz
[rvalusa@ol6-11gGG cassandra]$ cd apache-cassandra-2.1.2
[rvalusa@ol6-11gGG apache-cassandra-2.1.2]$ ls
bin          conf       javadoc  LICENSE.txt  NOTICE.txt  tools
CHANGES.txt  interface  lib      NEWS.txt     pylib
[rvalusa@ol6-11gGG apache-cassandra-2.1.2]$

Viewing The Main Configuration File:
Cassandra has a main configuration named – cassandra.yaml in conf directory.
Details on YAML are in here - http://en.wikipedia.org/wiki/YAML.  It is a recursive acronym – Yaml Ain’t Markup Language

Below are some of the parameter properties set in the cassandra.yaml config file

[rvalusa@ol6-11gGG conf]$ pwd
/home/rvalusa/cassandra/apache-cassandra-2.1.2/conf
[rvalusa@ol6-11gGG conf]$ cd cassandra.yaml

cluster_name: 'Test Cluster'
num_tokens: 256
partitioner: org.apache.cassandra.dht.Murmur3Partitioner
endpoint_snitch: SimpleSnitch

Providing Permissions to Cassandra directories:
[rvalusa@ol6-11gGG lib]$ su -
Password:
[root@ol6-11gGG ~]# mkdir /var/lib/cassandra <== In here cassandra data files will be residing
[root@ol6-11gGG ~]# mkdir /var/log/cassandra <== In here cassandra system logs will be residing
[root@ol6-11gGG ~]# chown -R rvalusa /var/lib/cassandra
[root@ol6-11gGG ~]# chown -R rvausa /var/log/cassandra