Defining Nodes in the Deployment
ICM deploys one InterSystems IRIS instance per provisioned node, and the role that each instance plays in an InterSystems IRIS configuration is determined by the Role field value under which the node and the instance on it are provisioned, deployed, and configured.
In preparing to use ICM, you must define your target configuration (see Define the Deployment in the “Using ICM” chapter) by selecting the types and numbers of nodes you want to include. If you want to deploy an InterSystems IRIS sharded cluster, for example, you must decide beforehand how many data nodes and (optionally) compute nodes will be included in the cluster, and whether the data nodes are to be mirrored. The specifications for the desired nodes are then entered in the definitions file (see Configuration, State, and Log Files) to provide the needed input to ICM. This is shown in the following simplified example defining four data nodes and eight compute nodes:
[
{
"Role": "DATA",
"Count": "4",
"LicenseKey": "ubuntu-sharding-iris.key"
},
{
"Role": "COMPUTE",
"Count": "8",
"StartCount": "5",
"LicenseKey": "ubuntu-sharding-iris.key"
}
]
The Mirror field, which determines whether the data nodes are mirrored, appears in the defaults file. Mirror deployment is covered at length in ICM Cluster Topology and Mirroring.
