// Module included in the following assemblies:
//
// * scalability_and_performance/telco_core_ref_design_specs/telco-core-rds.adoc

:_mod-docs-content-type: REFERENCE
[id="telco-core-red-hat-advanced-cluster-management_{context}"]
= Red Hat Advanced Cluster Management

[role="_abstract"]
{rh-rhacm} provides Multi Cluster Engine (MCE) installation and ongoing lifecycle management for deployed clusters.

New in this release::
* There are no reference design updates in this release.

Description::
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{rh-rhacm} provides Multi Cluster Engine (MCE) installation and ongoing {ztp} lifecycle management for deployed clusters.
You manage cluster configuration and upgrades declaratively by applying `Policy` custom resources (CRs) to clusters during maintenance windows.

You apply policies with the {rh-rhacm} policy controller as managed by {cgu-operator}.
Configuration, upgrades, and cluster status are managed through the policy controller.

When installing managed clusters, {rh-rhacm} applies labels and initial ignition configuration to individual nodes in support of custom disk partitioning, allocation of roles, and allocation to machine config pools.
You define these configurations with `SiteConfig` or `ClusterInstance` CRs.
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Limits and requirements::

* Hub cluster sizing is discussed in link:https://docs.redhat.com/en/documentation/red_hat_advanced_cluster_management_for_kubernetes/2.15/html-single/install/index#sizing-your-cluster[Sizing your cluster].

* {rh-rhacm} scaling limits are described in link:https://docs.redhat.com/en/documentation/red_hat_advanced_cluster_management_for_kubernetes/2.15/html-single/install/index#performance-and-scalability[Performance and Scalability].

Engineering considerations::
* When managing multiple clusters with unique content per installation, site, or deployment, using {rh-rhacm} hub templating is strongly recommended.
With {rh-rhacm} hub templating, you can apply a consistent set of policies to clusters while providing unique values per installation.

