Apache Cassandra Cluster Setup

Apache Cassandra Cluster Setup

This tutorial is to build a 3-node cassandra cluster.

Step1: Download apache-cassandra and install it on your operating system.[more details in the previous tutorial]

Step2: Modify configuration fils, cassandra.yaml.
You can find it is under ../conf/cassandra.yaml
There are only three things you need to focus on if you just want to build a simple cassandra cluster:
     1. listen_address
     2. rpc_address
     3. seeds
     we'll take a glance at those one by one.
1. listen_address, Here is the description about it: 

# Address to bind to and tell other Cassandra nodes to connect to. You
# _must_ change this if you want multiple nodes to be able to
# communicate!
# 
# Leaving it blank leaves it up to InetAddress.getLocalHost(). This
# will always do the Right Thing *if* the node is properly configured
# (hostname, name resolution, etc), and the Right Thing is to use the
# address associated with the hostname (it might not be).
#
# Setting this to 0.0.0.0 is always wrong.
listen_address: 

So, leave listen_address blank is a good choice.

2. rpc_address, here is the description:

# Address to broadcast to other Cassandra nodes

# Leaving this blank will set it to the same value as listen_address

# broadcast_address: 1.2.3.4

# The address to bind the Thrift RPC service to -- clients connect

# here. Unlike ListenAddress above, you *can* specify 0.0.0.0 here if

# you want Thrift to listen on all interfaces.

# 

# Leaving this blank has the same effect it does for ListenAddress,

# (i.e. it will be based on the configured hostname of the node).

rpc_address: 

After reading the description, leave it blank it good.

3. seeds, this part you have to edit it, the description of it:

# any class that implements the SeedProvider interface and has a

# constructor that takes a Map of parameters will do.

seed_provider:

    # Addresses of hosts that are deemed contact points. 

    # Cassandra nodes use this list of hosts to find each other and learn

    # the topology of the ring.  You must change this if you are running

    # multiple nodes!

    - class_name: org.apache.cassandra.locator.SimpleSeedProvider

      parameters:

          # seeds is actually a comma-delimited list of addresses.

          # Ex: ",,"

          - seeds: "127.0.0.1"

You only need to change the last line "- seeds: "127.0.0.1", if your 3 IP address are 192.168.0.1, 192.168.0.2, and 192.168.0.3, your last line should be 

- seeds:"192.168.0.1, 192.168.0.2, 192.168.0.3"

Step3: restart cassandra, and be sure that the port can access to other servers.
you can turn iptables off using the command in terminal:
# sudo service iptables stop

Step4: Now to check whether it works, using Cassandra-CLI(command line interface):

# ../bin/nodetool -h 192.168.1.0.1 -p 7199 ring

Address         DC      Rack    Status State   Load        Owns    Token                                       
                                                                   127605887595351923798765477786913079296     
192.168.0.1    DC1     r1      Up     Normal  17.3 MB     33.33%  0                                           
192.168.0.2    DC1     r1      Up     Normal  17.4 MB     33.33%  42535295865117307932921825928971026432      
192.168.0.3    DC1     r1      Up     Normal  37.2 MB     33.33%  85070591730234615865843651857942052864 

Step5: Write new info to your cassandra database, and check all servers get the same date.