Monitoring is installed optionally (yet strongly recommended). ADCM monitoring is based on three services: Diamond, Graphite, and Grafana.
For offline installation, there is no need for a separate monitoring cluster, as the Enterprise Tools (ET) cluster plays its role. The steps for installing monitoring in this case are listed below. You can perform them both before and after the ADB cluster installation, except the last step Integrate with ADB cluster, that can be executed only when the ADB cluster already exists.