Single datacenter deployment per workload type
Steps for configuring nodes in a deployment scenario in a mixed workload cluster that has only one datacenter for each type of workload.
In this scenario, a mixed workload cluster has only one datacenter for each type of workload. For example, if the cluster has 3 analytics nodes, 3 Cassandra nodes, and 2 DSE Search nodes, the cluster has 3 datacenters, one for each type of workload. In contrast, a multiple data-center cluster has more than one datacenter for each type of workload.
In Cassandra, a datacenter can be a physical datacenter or
virtual datacenter. Different workloads must always use separate datacenters,
either physical or virtual. In a single datacenter deployment, data is
replicated within its datacenter. For more information about replication:
- Choosing keyspace replication options
- Configuring replication
- Single-token architecture deployment
- Data replication (Applies only to the single-token-per-node architecture.)
Prerequisites
- A good understanding of how Cassandra works. Be sure to read at least Understanding the architecture, Data Replication, and Cassandra's rack feature.
- Ensure DataStax Enterprise is installed on each node.
- Choose a name for the cluster.
- For a mixed-workload cluster, determine the purpose of each node.
- Determine the snitch and replication strategy. The GossipingPropertyFileSnitch and NetworkTopologyStrategy are recommended for production environments.
- Get the IP address of each node.
- Determine which nodes are seed nodes. Do not make all nodes seed nodes. Seed nodes are not required for DSE Search datacenters. Read Internode communications (gossip).
- Use the yaml_diff
tool to review and make appropriate changes to the
cassandra.yaml configuration file.The location of the cassandra.yaml file depends on the type of installation:
Package installations /etc/dse/cassandra/cassandra.yaml Tarball installations install_location/resources/cassandra/conf/cassandra.yaml - Review and make appropriate changes to other property files, such as cassandra-rackdc.properties.
- Set virtual nodes correctly for the type of datacenter. DataStax does not recommend using virtual nodes on datacenters running BYOH or DSE Hadoop. See Virtual nodes.
Procedure
This configuration example describes installing an 8 node cluster spanning 2 racks in a single datacenter. The default consistency level is QUORUM.
Results
Datacenter: Cassandra
=======================
Status=Up/Down
|/ State=Normal/Leaving/Joining/Moving
-- Address Load Tokens Owns Host ID Rack
UN 110.82.155.0 21.33 KB 256 33.3% a9fa31c7-f3c0-... RAC1
UN 110.82.155.1 21.33 KB 256 33.3% f5bb416c-db51-... RAC1
UN 110.82.155.2 21.33 KB 256 16.7% b836748f-c94f-... RAC1
Datacenter: Analytics
=======================
Status=Up/Down
|/ State=Normal/Leaving/Joining/Moving
-- Address Load Owns Host ID Tokens Rack
UN 110.82.155.3 28.44 KB 13.0.% e2451cdf-f070- ... -922337.... RAC1
UN 110.82.155.4 44.47 KB 16.7% f9fa427c-a2c5- ... 30745512... RAC1
UN 110.82.155.5 54.33 KB 23.6% b9fc31c7-3bc0- ..- 45674488... RAC1
Datacenter: Solr
=======================
Status=Up/Down
|/ State=Normal/Leaving/Joining/Moving
-- Address Load Owns Host ID Tokens Rack
UN 110.82.155.6 15.44 KB 50.2.% e2451cdf-f070- ... 9243578.... RAC1
UN 110.82.155.7 18.78 KB 49.8.% e2451cdf-f070- ... 10000 RAC1