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39 lines
2.2 KiB
Plaintext
39 lines
2.2 KiB
Plaintext
// Module included in the following assemblies:
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//
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// * scalability_and_performance/telco_core_ref_design_specs/telco-core-rds.adoc
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:_mod-docs-content-type: REFERENCE
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[id="telco-core-topology-aware-lifecycle-manager_{context}"]
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= Topology Aware Lifecycle Manager
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New in this release::
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* No reference design updates in this release.
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Description::
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{cgu-operator} is an Operator that runs only on the hub cluster.
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{cgu-operator} manages how changes including cluster and Operator upgrades, configurations, and so on, are rolled out to managed clusters in the network.
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{cgu-operator} has the following core features:
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* Provides sequenced updates of cluster configurations and upgrades ({product-title} and Operators) as defined by cluster policies.
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* Provides for deferred application of cluster updates.
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* Supports progressive rollout of policy updates to sets of clusters in user configurable batches.
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* Allows for per-cluster actions by adding `ztp-done` or similar user-defined labels to clusters.
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Limits and requirements::
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* Supports concurrent cluster deployments in batches of 400
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Engineering considerations::
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* Only policies with the `ran.openshift.io/ztp-deploy-wave` annotation are applied by {cgu-operator} during initial cluster installation.
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* Any policy can be remediated by {cgu-operator} under control of a user created `ClusterGroupUpgrade` CR.
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* Set the `MachineConfigPool` (`mcp`) CR `paused` field to true during a cluster upgrade maintenance window and set the `maxUnavailable` field to the maximum tolerable value.
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This prevents multiple cluster node reboots during upgrade, which results in a shorter overall upgrade.
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When you unpause the `mcp` CR, all the configuration changes are applied with a single reboot.
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+
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[NOTE]
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====
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During installation, custom `mcp` CRs can be paused along with setting `maxUnavailable` to 100% to improve installation times.
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====
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* Orchestration of an upgrade, including {product-title}, day-2 OLM operators, and custom configuration can be done using a `ClusterGroupUpgrade` (CGU) CR containing policies describing these updates.
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** An EUS to EUS upgrade can be orchestrated using chained CGU CRs
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** Control of MCP pause can be managed through policy in the CGU CRs for a full control plane and worker node rollout of upgrades.
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