/Cassandra-Multi-Data-Center-Setup

Cassandra Multi Data Center Setup and Configuration

#Cassandra Deployment

Cassandra on CentOS

Java Install

yum -y update
yum -y install java

Add the DataStax Community Repository

vim /etc/yum.repos.d/datastax.repo

[datastax]
name = DataStax Repo for Apache Cassandra
baseurl = http://rpm.datastax.com/community
enabled = 1
gpgcheck = 0

Install Apache Cassandra 2

yum -y install dsc20

Basic Configuration

vim /etc/cassandra/conf/cassandra.yaml

cluster_name: 'Name'
initial_token: Token
seed_provider:
    - seeds:  "Seed IP"
listen_address: Droplet's IP
rpc_address: 0.0.0.0
endpoint_snitch: GossipingPropertyFileSnitch

Configure MultiData Center:

cassandra.yaml

Cluster Name update (Cluster name should be same accross all the data center otherwise application will connect to only one datacenter and if that is down apllication wont connect to other datacenter but if cluster name is same it will connect to all the datacanter.)
Cqlsh <<ip>>
UPDATE system.local SET cluster_name = 'NGC DEV Cluster' where key='local';
Exit
nodetool flush (to commit the update and never use remove data files that will messs the cqlsh)

cassandra-rackdc.properties

dc=DC1
rack=rack1

cassandra-topology.properties

# Cassandra Node IP=Data Center:Rack
<<DC2 IP>>=DC2:rack1
<<DC2 IP2>>=DC2:rack1
<<DC1 IP>>=DC1:rack1
<<DC1 IP2>>=DC1:rack1
<<DC1 IP3>>=DC1:rack1

Commands

service cassandra start
service cassandra stop
service cassandra restart

Authentication

vim /etc/cassandra/conf/cassandra.yaml
authenticator: PasswordAuthenticator

User Creation 
CREATE USER <<USERNAME>> WITH PASSWORD '<<PASSWORD>>’;

Cassandra OpsCenter & Agent

1.     Open the Yum repository specification /etc/yum.repos.d for editing. For example:
a.     sudo vi /etc/yum.repos.d/datastax.repo
2.     In this file, add the repository for OpsCenter.
[opscenter]
name = DataStax Repository
baseurl = http://rpm.datastax.com/community
enabled = 1
gpgcheck = 0
3.     Install the OpsCenter package.
a.     sudo yum install opscenter
4.     Start OpsCenter:
a.     sudo service opscenterd start
5.     Connect to OpsCenter in a web browser using the following URL:
a.     http://opscenter-host:8888/

Agent

1.     Add the DataStax Yum repository in the /etc/yum.repos.d/datastax.repo file.
[datastax]
name = DataStax Repo for Apache Cassandra
baseurl = http://rpm.datastax.com/community
enabled = 1
gpgcheck = 0
2.     Install the DataStax agent.
a.     yum install datastax-agent
3.     In address.yaml set stomp_interface to the IP address that OpsCenter is using. You might have to create the file.
a.     echo "stomp_interface: reachable_opscenterd_ip" | sudo tee -a /var/lib/datastax-agent/conf/address.yaml
4.     If SSL communication is enabled in opscenterd.conf, use SSL in address.yaml.
a.     echo "use_ssl: 1" | sudo tee -a /var/lib/datastax-agent/conf/address.yaml
5.     Start the DataStax agent.
a.     sudo service datastax-agent start