Chapter 1. Introduction

This document discusses how best to deploy CloudForms 4.6 to manage large OpenShift Container Platform (OCP) installations. The term "large" in this case infers several thousand managed nodes, projects, services, containers or pods, in possibly several OCP clusters

Experience shows that the most effective way to deploy CloudForms in large OpenShift Container Platform environments is to start with a minimal set of features enabled, and go through an iterative process of monitoring, tuning and expanding. Understanding the architecture of the product and the various components is an essential part of this process. Although by default a CloudForms Management Engine (CFME) appliance or CloudForms OpenShift project is tuned for relatively small environments, the product is scalable to manage many thousands of managed pods or containers. Achieving this level of scale however generally requires some customization of the core components for the specific environment being managed. This might include increasing the virtual machine or StatefulSet resources such as vCPUs and memory, or tuning the CFME workers; their numbers, placement, or memory thresholds for example.

This guide seeks to explain the architecture of CloudForms, particularly with reference to managing large OpenShift providers. Several 'rules of thumb' such as guidelines for CFME appliance to pod/container ratios are offered, along with the rationale behind the numbers, and when they can be adjusted. The principal source of monitoring and tuning data is the evm.log file, and many examples of log lines for various workers and strings to search for have been included, along with sample scripts to extract real-time timings for activities such as EMS refresh.

The document is divided into three sections, as follows:

Part I - Architecture and Design

  • Architecture discusses the principal architectural components that influence scaling: appliances, server roles, workers and messages.
  • Regions and Zones discusses the considerations and options for region and zone design.
  • Database Sizing and Optimization presents some guidelines for sizing and optimizing the PostgreSQL database for larger-scale operations.

Part II - Component Scaling

  • Inventory Refresh discusses the mechanism of extracting and saving the inventory of objects - pods, nodes or containers for example - from an OpenShift Container Platform cluster.
  • Capacity and Utilization explains how the three types of C&U worker interact to extract and process performance metrics from an OpenShift Container Platform cluster.
  • Kubernetes Event Handling describes the three workers that combine to process events from an OpenShift Container Platform cluster, and how to scale them.
  • SmartState Analysis and OpenSCAP Compliance Checking decsribes the SmartState Analysis process for container images, and takes a look at some of the tuning options available to scale SmartState Analysis in larger environments.
  • Monitoring describes some of the in-built monitoring capabilities for both OpenShift Container Platform and CloudForms.
  • Web User Interface discusses how to scale WebUI appliances behind load balancers.

Part III - Design Scenario

  • Design Scenario describes a typical region, zone and CFME appliance layout for a large multi-cluster OpenShift Container Platform installation.