Application Metrics
Last updated
Last updated
It's important to monitor your application because the first step to fixing a problem is knowing it exists. For example, without monitoring, you may not know when your database server is overloaded or when a new feature has broken something in an older part of the system.
System monitoring tools can help you track many different aspects of your software: CPU utilization, memory footprint, I/O wait times, latency, throughput, errors, and so on. Most applications have at least some metric that can be useful for performance tuning or debugging purposes (although it's easy to get overwhelmed by the number of metrics available). The trick is figuring out which ones are most relevant for your particular situation and understanding how they fit into the big picture.
OpenShift Container Platform includes a preconfigured, preinstalled, and self-updating monitoring stack that provides monitoring for core platform components. You also have the option to enable monitoring for user-defined projects.
A cluster administrator can configure the monitoring stack with the supported configurations. OpenShift Container Platform delivers monitoring best practices out of the box.
In OpenShift Container Platform, cluster components are monitored by scraping metrics exposed through service endpoints. You can also configure metrics collection for user-defined projects.
You can define the metrics that you want to provide for your own workloads by using Prometheus client libraries at the application level.
In OpenShift Container Platform, metrics are exposed through an HTTP service endpoint under the /metrics canonical name. You can list all available metrics for a service by running a curl query against http://<endpoint>/metrics. For instance, you can expose a route to the prometheus-example-app example service and then run the following to view all of its available metrics:
Example output:
The OpenShift Container Platform monitoring stack is based on the Prometheus open source project and its wider ecosystem. The monitoring stack includes the following:
Default platform monitoring components. A set of platform monitoring components are installed in the openshift-monitoring project by default during an OpenShift Container Platform installation. This provides monitoring for core OpenShift Container Platform components including Kubernetes services. The default monitoring stack also enables remote health monitoring for clusters. These components are illustrated in the Installed by default section in the following diagram.
Components for monitoring user-defined projects. After optionally enabling monitoring for user-defined projects, additional monitoring components are installed in the openshift-user-workload-monitoring project. This provides monitoring for user-defined projects. These components are illustrated in the User section in the following diagram.
