// Module included in the following assemblies:

// *scalability_and_performance/cluster-compare/understanding-the-cluster-compare-plugin.adoc

:_mod-docs-content-type: CONCEPT

[id="cluster-compare-overview_{context}"]
= Overview of the cluster-compare plugin

[role="_abstract"]
Clusters deployed at scale typically use a validated set of baseline custom resources (CRs) to configure clusters to meet use-case requirements and ensure consistency when deploying across different environments. 

In live clusters, some variation from the validated set of CRs is expected. For example, configurations might differ because of variable substitution, optional components, or hardware-specific fields. This variation makes it difficult to accurately assess if a cluster is compliant with the baseline configuration.

Using the `cluster-compare` plugin with the `oc` command, you can compare the configuration from a live cluster with a reference configuration. A reference configuration represents the baseline configuration but uses the various plugin features to suppresses expected variation during a comparison. For example, you can apply validation rules, specify optional and required resources, and define relationships between resources. By reducing irrelevant differences, the plugin makes it easier to assess cluster compliance with baseline configurations, and across environments.

The ability to intelligently compare a configuration from a cluster with a reference configuration has the following example use-cases:

*Production:* Ensure compliance with a reference configuration across service updates, upgrades and changes to the reference configuration.

*Development:* Ensure compliance with a reference configuration in test pipelines.

*Design:* Compare configurations with a partner lab reference configuration to ensure consistency.

*Support:* Compare the reference configuration to `must-gather` data from a live cluster to troubleshoot configuration issues.

.Cluster-compare plugin overview
image::493-OpenShift-0125.png[Cluster-compare plugin overview]
