feat: implement batch-based rollout and scaling using RollingUpdateDeployment

[sangheee]

Hi, first of all, I would like to thank you for your positive feedback on my initial suggestions and for taking the time to review this PR.

This PR improves the rollout and scaling performance of Milvus components by implementing batch-based replica adjustment. It replaces the current hardcoded step-by-step (1, -1) approach with a configurable strategy using the standard Kubernetes DeploymentStrategy.

Changes

• Added *appsv1.RollingUpdateDeployment to ComponentSpec.
• Applied surgeStep and unavailableStep in planScaleForRollout for parallel pod replacement.

Even if podReplacementPolicy is introduced to Deployment and twoDeploymentMode is removed in the future, having this RollingUpdate configuration will be helpful as it can work alongside the policy to support both faster and more reliable updates.

Related Issue

Fixes #470

cc. @haorenfsa

[sre-ci-robot]

[APPROVALNOTIFIER] This PR is NOT APPROVED

This pull-request has been approved by: sangheee
To complete the pull request process, please assign yellow-shine after the PR has been reviewed.
You can assign the PR to them by writing /assign @yellow-shine in a comment when ready.

The full list of commands accepted by this bot can be found here.

Details

Needs approval from an approver in each of these files:

• OWNERS

Approvers can indicate their approval by writing /approve in a comment
Approvers can cancel approval by writing /approve cancel in a comment

[codecov]

Codecov Report

❌ Patch coverage is 78.57143% with 9 lines in your changes missing coverage. Please review.
✅ Project coverage is 76.64%. Comparing base (52b5430) to head (9fde88b).

Files with missing lines	Patch %	Lines
pkg/controllers/components.go	68.42%	3 Missing and 3 partials ⚠️
pkg/controllers/deploy_ctrl_util.go	90.00%	1 Missing and 1 partial ⚠️
pkg/controllers/deployment_updater.go	50.00%	1 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main     #472      +/-   ##
==========================================
- Coverage   76.70%   76.64%   -0.06%     
==========================================
  Files          66       66              
  Lines        6176     6196      +20     
==========================================
+ Hits         4737     4749      +12     
- Misses       1176     1180       +4     
- Partials      263      267       +4     

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.

🚀 New features to boost your workflow:

• ❄️ Test Analytics: Detect flaky tests, report on failures, and find test suite problems.

[haorenfsa]

Thank you, @AlintaLu please help review

[Copilot]

Pull request overview

This PR adds configurable Kubernetes-style rolling update parameters (maxSurge / maxUnavailable) to Milvus component specs and uses them to adjust replica changes in larger batches during two-deployment rollouts, improving rollout/scaling performance for large clusters.

Changes:

• Added rollingUpdate (*appsv1.RollingUpdateDeployment) to ComponentSpec and merged it via MergeComponentSpec.
• Updated deployment strategy resolution to accept *v1beta1.MilvusSpec and apply per-component rollingUpdate overrides.
• Updated planScaleForRollout to compute batch steps from maxSurge / maxUnavailable, plus corresponding CRD and test updates.

Reviewed changes

Copilot reviewed 11 out of 11 changed files in this pull request and generated 4 comments.

Show a summary per file

File	Description
pkg/controllers/deployments.go	Minor logging change for deployment diffs.
pkg/controllers/deployment_updater.go	Updates strategy plumbing to pass *MilvusSpec into GetDeploymentStrategy.
pkg/controllers/deploy_ctrl_util.go	Implements batch-based rollout scaling using rollingUpdate-derived step sizes.
pkg/controllers/deploy_ctrl_util_test.go	Sets default rolling update strategy in test fixtures to match new rollout logic dependencies.
pkg/controllers/components.go	Allows per-component rollingUpdate overrides when using RollingUpdate strategy.
pkg/controllers/components_test.go	Adds tests for rollingUpdate merge + custom strategy behavior.
apis/milvus.io/v1beta1/components_types.go	Adds the rollingUpdate API field to ComponentSpec.
apis/milvus.io/v1beta1/zz_generated.deepcopy.go	Updates deepcopy generation for the new rollingUpdate field.
config/crd/bases/milvus.io_milvuses.yaml	Adds rollingUpdate schema to Milvus CRD.
config/crd/bases/milvus.io_milvusclusters.yaml	Adds rollingUpdate schema to MilvusCluster CRD.
charts/milvus-operator/templates/crds.yaml	Propagates CRD schema changes into the Helm chart CRDs.

---

💡 Add Copilot custom instructions for smarter, more guided reviews. Learn how to get started.

[sangheee]

Hi @AlintaLu , I've addressed all the suggestions and the PR is now ready for another look. Could you please take a look when you have a moment? Thanks!