01 November 2021
Apache Cassandra is a NoSQL database with flexible deployment options that’s highly performant (especially for writes), scalable, fault-tolerant, and proven in production. Alternative NoSQL databases include Amazon DynamoDB, Apache HBase, and MongoDB.
Assuming we have the following servers
Hostname Public IP Private IP
----------- ----------- ----------
cassandra01 10.10.10.10 1.1.1.1
cassandra02 11.11.11.11 2.2.2.2
cassandra03 12.12.12.12 3.3.3.3
Install Cassandra on the first three servers
$ sudo apt update
$ sudo apt upgrade -y
$ sudo apt install openjdk-8-jdk apt-transport-https -y
$ java -version
$ sudo sh -c 'echo "deb http://www.apache.org/dist/cassandra/debian 40x main" > /etc/apt/sources.list.d/cassandra.list'
$ wget -q -O - https://www.apache.org/dist/cassandra/KEYS | sudo apt-key add -
$ sudo apt update
$ sudo apt install cassandra
$ sudo systemctl enable cassandra
Adjust the /etc/cassandra/cassandra.yaml on the first three servers.
. . .
cluster_name: 'ProdCassandraCluster'
. . .
seed_provider:
- class_name: org.apache.cassandra.locator.SimpleSeedProvider
parameters:
- seeds: "1.1.1.1:7000,2.2.2.2:7000,3.3.3.3:7000"
. . .
listen_address: node_private_ip
. . .
rpc_address: node_private_ip
. . .
endpoint_snitch: GossipingPropertyFileSnitch
. . .
auto_bootstrap: false
After adjusting the three cassandra nodes, stop the three, delete system files and start them again
$ service cassandra stop
$ sudo rm -rf /var/lib/cassandra/data/system/*
$ service cassandra start
Please note that: Datastax Cassandra drivers supports connection pooling and load balancing so they are recommended over HAProxy.
If you still want to run cassandra behind an HAProxy that’s part of the nodes private network, please follow the following steps:
$ apt-get install haproxy
$ service haproxy start
Edit HAProxy config file /etc/haproxy/haproxy.cfg and restart afterwards.
defaults
mode tcp
frontend stats
bind *:8404
stats enable
mode http
stats uri /stats
stats refresh 10s
stats admin if LOCALHOST
frontend cassandra-cql
description "Cassandra CQL"
bind *:9042
mode tcp
option tcplog
default_backend cassandra-cql
backend cassandra-cql
description "Cassandra CQL"
balance leastconn
mode tcp
server 1.1.1.1 1.1.1.1:9042 check
server 2.2.2.2 2.2.2.2:9042 check
server 3.3.3.3 3.3.3.3:9042 check
You should be able to reach cassandra nodes through HAProxy (Public IP 13.13.13.13)
$ cqlsh 13.13.13.13 9042
HAProxy dashboard will be available via this link http://13.13.13.13:8404/stats
References