Module quick_start_standalone 

Quick Start: Standalone Mode in 5 Minutes

Goal: Start 3-node d-engine cluster and verify it works with gRPC.

d-engine uses standard gRPC - works with any language (Go, Python, Java, Node.js, Rust, etc.)

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Prerequisites

• Rust stable (to build d-engine)
• Go 1.20+ (for client example)
• 5 minutes

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Step 1: Start Demo Cluster (1 minute)

What is this?
examples/three-nodes-standalone is a demo project included in d-engine repository. It simulates a production-like 3-node cluster for quick testing.

cd examples/three-nodes-standalone
make start-cluster

What happens:

• Starts 3 d-engine server processes (Node 1/2/3)
• Auto-elects leader (takes ~2s)
• Exposes gRPC endpoints: 127.0.0.1:9081-9083
• Persists data to ./db/1/, ./db/2/, ./db/3/

Verify cluster is ready:

# Check processes
ps aux | grep "target/release/demo"  # Should see 3 processes

# Check logs for leader election
tail -f logs/1/demo.log  # Look for ">>> switch to Leader"

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Step 2: Run Go Client (1 minute)

cd examples/quick-start-standalone
make run

What this does:

1. Connects to any node (tries 127.0.0.1:9081 first)
2. Sends write request
3. If NOT_LEADER error, follows metadata.LeaderAddress to redirect
4. Writes hello=world to leader
5. Reads back with LinearizableRead consistency

Expected output:

Not leader, redirecting to 0.0.0.0:9082
Write success (leader at 0.0.0.0:9082)
Value: world

Note: Leader may be at any node. The client uses Leader Hint from error response to redirect automatically.

Want to see the code? Check the quick-start-standalone example

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What’s Next?

Try other languages:

• Proto files: d-engine-proto/proto/*.proto
• Language guides: https://grpc.io/docs/languages/

Advanced topics:

• Monitor cluster and test failover
• Embedded vs Standalone comparison
• Production deployment example

Clean up:

make stop-cluster && make clean

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Advanced Topics

Monitor Cluster

# Watch node 1 logs
tail -f logs/1/demo.log

# Test failover (kill leader, observe re-election)
pkill -f "demo.*node-id=1"
tail -f logs/2/demo.log  # Watch new leader election

Embedded vs Standalone

Feature	Embedded (Rust)	Standalone (gRPC)
Latency	<0.1ms	1-2ms
Serialization	None	Protobuf
Language	Rust only	Any (Go, Python, Java)
Deployment	1 binary	3 server processes
Setup	EmbeddedEngine::start_with()	make start-cluster

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Created: 2025-12-04
Updated: 2025-12-30