Chapter 7. Application Management
In this chapter we are going to explore common management and monitoring tools, procedures, and practices when running and operating container workloads on OpenShift. This includes topics such as logging and metrics, as well as resource scheduling and how we can set quota and limits to help improve the utilization of compute resources across all the nodes in our OpenShift cluster.
To help understand the operational layers, we define three here:
- Operating system infrastructure operations
Deals with compute, network, storage, and operating systems
- Cluster operations
This is all about OpenShift and Kubernetes cluster management
- Application operations
Instrumenting and monitoring deployments, telemetry, logging, etc.
While we will focus on the third layer, in our DevOps world some of these concerns may in fact be carried out by developers with operational sensibilities!
The first place to look when troubleshooting software issues is normally in the log files. OpenShift provides access to logs for infrastructure, builds, deployments, and running applications. Container-based application architectures have multitiered logs that consist of container application logs, daemon logs, and general operating system logs.
Container Logs Are Transient
With transient containers, it is considered an anti-pattern to log to ephemeral storage within the container itself. Generally, the filesystem that the container mounts is recreated ...