Refactor Node::run() with strategy pattern (Learner/Voter bootstrap)

[JoshuaChi]

Changes

Refactored Node::run() to eliminate scattered control flow and improve code clarity:

Before: Multiple is_learner() checks scattered throughout, mixed Learner/Voter logic
After: Strategy pattern with clear separation:

• run_as_learner() - Learner-specific bootstrap
• run_as_voter() - Voter-specific bootstrap
• warmup_with_shutdown() - Extracted common shutdown handling
• start_raft_loop() - Shutdown-aware main loop entry

Benefits

• Single point of role branching (one is_learner() check)
• Eliminates code duplication in shutdown handling
• Clear, linear bootstrap flow for each node type
• Fixes potential race: shutdown check before raft.run()
• Better reflects Raft protocol semantics (Learners don't need cluster quorum)

[coderabbitai]

📝 CodeRabbit Plan Mode

Generate an implementation plan and prompts that you can use with your favorite coding agent.

• Create Plan

Examples

• Example 1
• Example 2

---

🔗 Similar Issues

Related Issues

• Fix ClusterMembership API: Separate static role from dynamic leader info #201
• fix: Learner promotion stuck due to voter count and missing role transition #212
• Fix remove_node() to Allow Leader Self-Removal #200

👤 Suggested Assignees

• JoshuaChi

---

🧪 Issue enrichment is currently in open beta.

You can configure auto-planning by selecting labels in the issue_enrichment configuration.

To disable automatic issue enrichment, add the following to your .coderabbit.yaml:

issue_enrichment:
  auto_enrich:
    enabled: false

💬 Have feedback or questions? Drop into our discord!