USHIFT-6799: C2CC: Latency measurement between clusters

[pmtk]

Summary by CodeRabbit

• New Features

  • RemoteCluster status now exposes latency statistics: avg, min, max, last, stddev (rolling-window).

• Improvements

  • Probe loop measures RTT and updates status with latency stats; failed probes preserve prior latency values.

• Tests

  • Added unit and end-to-end tests validating latency collection, statistical calculations, wrap-around behavior, and status reporting.

[openshift-ci]

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[openshift-ci-robot]

@pmtk: This pull request references USHIFT-6799 which is a valid jira issue.

Warning: The referenced jira issue has an invalid target version for the target branch this PR targets: expected the story to target the "5.0.0" version, but no target version was set.

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[coderabbitai]

Walkthrough

This PR adds rolling-window latency collection and stats for RemoteCluster probes: a ring buffer computes avg/min/max/last/stddev, probe manager records RTTs and sets status.Latency, CRD and Go types expose the stats, and Robot tests verify end-to-end reporting.

Changes

Latency Tracking Feature

Layer / File(s)	Summary
Data model and CRD pkg/apis/microshift/v1alpha1/types.go, assets/crd/microshift.io_remoteclusters.yaml	RemoteClusterStatus gains optional Latency field and LatencyStats type; CRD status schema added with required avg, last, max, min, stddev string fields.
Latency window ring buffer & unit tests pkg/controllers/c2cc/latency.go, pkg/controllers/c2cc/latency_test.go	Fixed-size circular buffer collects RTT samples with add() and computes avg/min/max/last/stddev via stats(); comprehensive unit tests for empty, single, partial, wrap-around, deterministic, and identical-sample cases.
Probe manager latency integration pkg/controllers/c2cc/probe.go	ProbeManager gains per-cluster latency windows; doProbe returns RTT; probe loop records RTTs, sets status.Latency from window stats, and preserves previous latency on failed probes.
Robot framework integration tests test/suites/c2cc/probe.robot	Tests wait for latency stats and assert avg/min/max/last/stddev are populated for remote clusters; helper keyword queries status.latency fields via jsonpath.

Estimated code review effort

🎯 3 (Moderate) | ⏱️ ~20 minutes

Possibly related PRs

• openshift/microshift#6727: Introduces the initial RemoteCluster CRD and Go types; this PR extends the same resources with latency-specific schema and controller wiring.

Suggested labels

ready-for-human-review

Suggested reviewers

• jogeo
• kasturinarra

---

Caution

Pre-merge checks failed

Please resolve all errors before merging. Addressing warnings is optional.

• Ignore

❌ Failed checks (1 error, 1 warning)

Check name	Status	Explanation	Resolution
No-Sensitive-Data-In-Logs	❌ Error	The logging statement in probe.go logs rc.Spec.ProbeTarget (an internal IP:port address) which is flagged as sensitive internal hostname data.	Remove or redact ProbeTarget from the "Starting probe for" log statement, or change it to Info level only if necessary.
Docstring Coverage	⚠️ Warning	Docstring coverage is 12.50% which is insufficient. The required threshold is 80.00%.	Write docstrings for the functions missing them to satisfy the coverage threshold.

✅ Passed checks (13 passed)

Check name	Status	Explanation
Description Check	✅ Passed	Check skipped - CodeRabbit’s high-level summary is enabled.
Title check	✅ Passed	The title clearly and specifically describes the main change: adding latency measurement for cluster-to-cluster probes, which aligns perfectly with all the file changes.
Linked Issues check	✅ Passed	Check skipped because no linked issues were found for this pull request.
Out of Scope Changes check	✅ Passed	Check skipped because no linked issues were found for this pull request.
Stable And Deterministic Test Names	✅ Passed	PR contains no Ginkgo tests. Go unit tests and Robot Framework tests use static, deterministic names without dynamic content.
Test Structure And Quality	✅ Passed	No Ginkgo tests present in PR. Tests use Go testing package with testify and Robot Framework instead; check is not applicable.
Microshift Test Compatibility	✅ Passed	No Ginkgo e2e tests added. PR contains Go unit tests (latency_test.go using testify) and Robot Framework tests (probe.robot). Check is not applicable.
Single Node Openshift (Sno) Test Compatibility	✅ Passed	No Ginkgo e2e tests added—only Robot Framework tests and standard Go unit tests are present, which fall outside the scope of the SNO compatibility check.
Topology-Aware Scheduling Compatibility	✅ Passed	PR adds latency measurement to C2CC probes via CRD schema, types, ring buffer logic, and tests. No deployment manifests, pod definitions, or scheduling constraints present.
Ote Binary Stdout Contract	✅ Passed	PR adds no direct stdout writes and uses klog (writes to stderr by default). No process-level code, init functions, or top-level initializers with side effects violate OTE stdout contract.
Ipv6 And Disconnected Network Test Compatibility	✅ Passed	No Ginkgo e2e tests added. PR includes unit tests (testify-based) and Robot Framework tests, neither of which fall under the Ginkgo check scope.
No-Weak-Crypto	✅ Passed	PR implements latency measurement (network RTT statistics) with no weak crypto (MD5, SHA1, DES, RC4, 3DES, Blowfish, ECB), custom crypto, or non-constant-time comparisons detected.
Container-Privileges	✅ Passed	PR adds latency measurement for C2CC probes via CRD schema updates, Go types/logic, and tests. No container security settings, privileged modes, or capability escalations introduced.

✨ Finishing Touches

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• Create PR with unit tests

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[openshift-ci]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: pmtk

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[coderabbitai]

Actionable comments posted: 1

🤖 Prompt for all review comments with AI agents

Verify each finding against current code. Fix only still-valid issues, skip the
rest with a brief reason, keep changes minimal, and validate.

Inline comments:
In `@test/suites/c2cc/probe.robot`:
- Around line 88-101: The test "Latency Stats Are Reasonable" currently only
checks presence via Should Not Be Empty for fields retrieved by Get Latency
Field; either rename the test to something like "Latency Stats Present" to
reflect presence-only checks, or add numeric/bounds validation: for each ${avg},
${min}, ${max}, ${last}, ${stddev} convert to numbers (e.g., using Convert To
Number or your helper) and assert ${min} >= 0, ${stddev} >= 0, ${min} <= ${avg}
<= ${max}, ${last} within [${min}, ${max}], and optionally enforce an upper
bound on ${max} (e.g., <200 ms) to reflect "reasonable" for local-network
probes; update the test body accordingly where Get Latency Field and Should Not
Be Empty are used.

🪄 Autofix (Beta)

Fix all unresolved CodeRabbit comments on this PR:

• Push a commit to this branch (recommended)
• Create a new PR with the fixes

---

ℹ️ Review info

⚙️ Run configuration

Configuration used: Repository YAML (base), Central YAML (inherited)

Review profile: CHILL

Plan: Enterprise

Run ID: 282796d3-2f96-4f81-b68f-0c9a5e284a70

📥 Commits

Reviewing files that changed from the base of the PR and between 8d4bf57 and 1c6513e.

⛔ Files ignored due to path filters (1)

• pkg/apis/microshift/v1alpha1/zz_generated.deepcopy.go is excluded by !**/zz_generated*

📒 Files selected for processing (6)

• assets/crd/microshift.io_remoteclusters.yaml
• pkg/apis/microshift/v1alpha1/types.go
• pkg/controllers/c2cc/latency.go
• pkg/controllers/c2cc/latency_test.go
• pkg/controllers/c2cc/probe.go
• test/suites/c2cc/probe.robot

[pmtk]

/test e2e-aws-tests-bootc-arm-el9 e2e-aws-tests-bootc-el10

[pmtk]

/test e2e-aws-tests

[openshift-ci]

@pmtk: all tests passed!

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[agullon]

it looks to me from QE POV