text: (cid:2) Hawkular Metrics: A metrics engine that stores the data persistently in a Cassandra 
  database. 
  
  (cid:2) Cassandra: Database where the metrics data is stored. 
  
  Red Hat OpenShift Container Platform metrics components can be customized for longer 
  data persistence, pods limits, replicas of individual components, custom certificates, and so 
  on. 
  
  As a best practice, persistent storage must be used to allow for metric data to be preserved 
  when metrics are deployed. Node selectors must be used to specify where the metrics 
  components must run. 
  
  **5.3.3 Reference architecture**
  
  This section describes a reference architecture for running OpenShift Container Platform 3.11 
  on PowerVC. In this reference architecture the OpenShift Container Platform is installed on 
  virtual machines that are provisioned by PowerVC to the IBM Power Systems, as shown in 
  Figure 5-11. The architecture is highly available and suitable for production. 
  
  This document describes the reference architecture as it was deployed and tested in a lab 
  environment. 