Point-to-Point

Point-to-Point

Two nodes, both write, both sync. The simplest topology — one --peer flag each.

Node A ←→ Node B

When to Use

• Simple active-active replica (2 servers)
• Dev/test setup
• Read scale-out with write scale-out (both nodes accept writes)

Setup

# Node A
./hook-sync-go -id node1 -db node1.db -listen :9001 \
  -peer http://localhost:9002

# Node B
./hook-sync-go -id node2 -db node2.db -listen :9002 \
  -peer http://localhost:9001

// Node A
const mgr = attach(db, {
  id: "node1",
  peers: ["http://localhost:9002"],
  batchMs: 50,
}, ["items"]);

// Node B — change port to 9002, peer to 9001

// Node A
const mgr = attach(db, {
  id: "node1",
  peers: ["http://localhost:9002"],
  batchMs: 50,
}, ["items"]);

// Node B — change port to 9002, peer to 9001

How It Works

1. Node A writes to SQLite → trigger captures to _changes
2. Background timer ships changes to Node B every 50ms
3. Node B applies with INSERT OR REPLACE + timestamp check
4. Node B returns ACK → Node A deletes from _changes
5. Same flow in reverse (Node B → Node A)

Both nodes accept writes independently. Conflicts resolve via last-write-wins by updated_at timestamp on reconnect.

Characteristics

Property	Value
Connections	1
Hops	1
Redundancy	None
SPOF	No
Write penalty	0% (sync is background)
Sync latency	Batch interval (50ms default)

Benchmark

10 runs × 100 concurrent requests per node (200 total per run):

Runtime	QPS median	QPS min	QPS max	Integrity
Go	9,149	3,705	15,063	10/10 PASS
Bun	10,476	3,004	14,159	10/10 PASS
Node	8,393	3,458	10,068	10/10 PASS

Run with: bash bench-dual-ack.sh