OCPBUGS-114888: clarify that bare metal supports 3, 4, or 5 control plane nodes

[agawai]

Summary

Fixes OCPBUGS-114888

The etcd and architecture docs said bare-metal clusters can have "up to 5" control plane nodes. That phrasing is easy to misread as an open range, or as if 5 is the expected size.

This change states that:

• 3 control plane nodes is the standard production design
• On bare metal only, a cluster can have 3, 4, or 5 control plane nodes
• 4-node and 5-node control planes are a supported non-standard HA option
• A 4-node control plane has the same failure tolerance as 3 nodes

Also restates the 3 / 4 / 5 sizes on the replace-unhealthy-etcd-member procedure that support commonly links.

Related: OSDOCS-11570 (original 4.17 4/5-node feature docs)

Test plan

• modules/etcd-node-scaling.adoc lead sentence lists 3, 4, or 5 (included by etcd performance / recommended practices)
• Architecture control-plane note no longer says only "scaled up to five"
• Replace-unhealthy-etcd-member assemblies stay in sync
• Docs preview / peer review of AsciiDoc rendering

Made with Cursor

[openshift-ci-robot]

@agawai: This pull request references Jira Issue OCPBUGS-114888, which is invalid:

• expected the bug to target the "5.1.0" version, but no target version was set

Comment /jira refresh to re-evaluate validity if changes to the Jira bug are made, or edit the title of this pull request to link to a different bug.

The bug has been updated to refer to the pull request using the external bug tracker.

Details

In response to this:

Summary

Fixes OCPBUGS-114888

The etcd and architecture docs said bare-metal clusters can have "up to 5" control plane nodes. That phrasing is easy to misread as an open range, or as if 5 is the expected size.

This change states that:

• 3 control plane nodes is the standard production design
• On bare metal only, a cluster can have 3, 4, or 5 control plane nodes
• 4-node and 5-node control planes are a supported non-standard HA option
• A 4-node control plane has the same failure tolerance as 3 nodes

Also restates the 3 / 4 / 5 sizes on the replace-unhealthy-etcd-member procedure that support commonly links.

Related: OSDOCS-11570 (original 4.17 4/5-node feature docs)

Test plan

• modules/etcd-node-scaling.adoc lead sentence lists 3, 4, or 5 (included by etcd performance / recommended practices)
• Architecture control-plane note no longer says only "scaled up to five"
• Replace-unhealthy-etcd-member assemblies stay in sync
• Docs preview / peer review of AsciiDoc rendering

Made with Cursor

Instructions for interacting with me using PR comments are available here. If you have questions or suggestions related to my behavior, please file an issue against the openshift-eng/jira-lifecycle-plugin repository.

[openshift-ci]

Hi @agawai. Thanks for your PR.

I'm waiting for a openshift member to verify that this patch is reasonable to test. If it is, they should reply with /ok-to-test on its own line. Until that is done, I will not automatically test new commits in this PR, but the usual testing commands by org members will still work.

Regular contributors should join the org to skip this step.

Once the patch is verified, the new status will be reflected by the ok-to-test label.

I understand the commands that are listed here.

Details

Instructions for interacting with me using PR comments are available here. If you have questions or suggestions related to my behavior, please file an issue against the kubernetes-sigs/prow repository.

[agawai]

Closing in favor of #119021. SME LGTM is on that PR.

[openshift-ci-robot]

@agawai: This pull request references Jira Issue OCPBUGS-114888. The bug has been updated to no longer refer to the pull request using the external bug tracker.

Details

In response to this:

Summary

Fixes OCPBUGS-114888

The etcd and architecture docs said bare-metal clusters can have "up to 5" control plane nodes. That phrasing is easy to misread as an open range, or as if 5 is the expected size.

This change states that:

• 3 control plane nodes is the standard production design
• On bare metal only, a cluster can have 3, 4, or 5 control plane nodes
• 4-node and 5-node control planes are a supported non-standard HA option
• A 4-node control plane has the same failure tolerance as 3 nodes

Also restates the 3 / 4 / 5 sizes on the replace-unhealthy-etcd-member procedure that support commonly links.

Related: OSDOCS-11570 (original 4.17 4/5-node feature docs)

Test plan

• modules/etcd-node-scaling.adoc lead sentence lists 3, 4, or 5 (included by etcd performance / recommended practices)
• Architecture control-plane note no longer says only "scaled up to five"
• Replace-unhealthy-etcd-member assemblies stay in sync
• Docs preview / peer review of AsciiDoc rendering

Made with Cursor

Instructions for interacting with me using PR comments are available here. If you have questions or suggestions related to my behavior, please file an issue against the openshift-eng/jira-lifecycle-plugin repository.