Single data center deployment

A deployment scenario with a mixed workload cluster has only one data center for each type of workload.

This configuration example describes installing a six node cluster spanning two racks in a single data center.

Set properties for each node in the cassandra.yaml file. This file is located in different places depending on the type of installation:

• Packaged installs: /etc/dse/cassandra/cassandra.yaml
• Tarball installs: install_location/resources/cassandra/conf/cassandra.yaml

1. Suppose the nodes have the following IPs and one node per rack will serve as a seed:
   • node0 110.82.155.0 (Cassandra seed)
   • node1 110.82.155.1 (Cassandra)
   • node2 110.82.155.2 (Cassandra)
   • node3 110.82.155.3 (Analytics seed)
   • node4 110.82.155.4 (Analytics)
   • node5 110.82.155.5 (Analytics)
   • node6 110.82.155.6 (Search - seed nodes are not required for Solr.)
   • node7 110.82.155.7 (Search)
2. If the nodes are behind a firewall, open the required ports for internal/external communication. See Configuring firewall port access.
3. If DataStax Enterprise is running, stop the nodes and clear the data:
   • Packaged installs:

     $ sudo service dse stop
     $ sudo rm -rf /var/lib/cassandra/* ## Clears the data from the  default directories

   • Tarball installs:

     From the install directory:

     $ sudo bin/dse cassandra-stop
     $ sudo rm -rf /var/lib/cassandra/* ## Clears the data from the default directories

     Note: If you are clearing data from an AMI installation for restart, you need to preserve the log files.
4. Modify the following property settings in the cassandra.yaml file for each node:
   • num_tokens: 256 for Cassandra nodes
   • num_tokens: 1 for Hadoop and Solr nodes
   • -seeds: internal_IP_address of each seed node
   • listen_address: localhost_IP_address
   • auto_bootstrap: false (Add this setting only when initializing a fresh cluster with no data.)
   • Make sure that the following options are disabled, as they are no longer supported by DataStax Enterprise:

     ## Replication strategy to use for the auth keyspace.
     #auth_replication_strategy: org.apache.cassandra.locator.SimpleStrategy
     
     #auth_replication_options:
     #replication_factor: 1
     

     Note: If you have not disabled both auth_replication_strategy and replication_factor, you will see an error. For information about correcting this error, see Issues in the DataStax Enterprise 3.2.5 release notes.

   node0:

   cluster_name: 'MyDemoCluster'
   num_tokens: 256
   seed_provider:
     - class_name: org.apache.cassandra.locator.SimpleSeedProvider
       parameters:
            - seeds: "110.82.155.0,110.82.155.3"
   listen_address: 110.82.155.0

   The properties for rest of the nodes are the same as node0 except for the listen_address:

   Node	listen_address
   node1	110.82.155.1
   node2	110.82.155.2
   node3	110.82.155.3
   node4	110.82.155.4
   node5	110.82.155.5
   node6	110.82.155.6
   node7	110.82.155.7

5. After you have installed and configured DataStax Enterprise on all nodes, start the seed nodes one at a time, and then start the rest of the nodes:
   • Packaged installs: See Starting DataStax Enterprise as a service.
   • Tarball installs: See Starting DataStax Enterprise as a stand-alone process.
   Note: If the node has restarted because of automatic restart, you must stop the node and clear the data directories, as described above.
6. Check that your cluster is up and running:
   • Packaged installs: $ nodetool status
   • Tarball installs: $ install_location/bin/nodetool status

Results