Setup Cassandra

Run cassandra in cluster, single data-center mode on every mesos slave.

  1. cassandra configuration file

    Following the DATASTAX doc, a modified version of cassandra.yaml is placed in /opt/shared/cassandra.yaml as a template. The only thing need to change is the seeds’ ip address setting.

    We will use mesos-slave-1 & mesos-slave-2 as the seeds in cassandra cluster. This script set the proper seed setting in cassandra.yaml:

cp -f /opt/shared/cassandra.yaml /opt/cassandra/current/conf/
# set the 2 seeds' ip address in cassandra.yaml
SEED_IP=`getent hosts mesos-slave-1 | awk '{ print $1 }'`; sed -i "s/seed1_ip_addr/$SEED_IP/g" /opt/cassandra/current/conf/cassandra.yaml
SEED_IP=`getent hosts mesos-slave-2 | awk '{ print $1 }'`; sed -i "s/seed2_ip_addr/$SEED_IP/g" /opt/cassandra/current/conf/cassandra.yaml

  1. Bring up cassandra as marathon application

    Once the cassandra.yaml is configured, let’s launch cassandra application on each slave node:

# content of marathon setting for cassandra application.
$ cat def-tasks/marathon-cassandra.json 
{
    "id": "cassandra",
    "cmd": "/opt/cassandra/current/bin/cassandra -f",
    "mem": 2048,
    "cpus": 1,
    "instances": 3,
    "constraints": [["hostname", "UNIQUE"]]
}
	
# launch the cassandra on each slave node.
$ curl -i -H 'Content-Type: application/json' \
  -d@./def-tasks/marathon-cassandra.json mesos-master-1:8080/v2/apps

Mesos UI shows cassandra is running on each slave node.

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