@rpckit/cluster

Cluster meta-transport for rpckit. Provides m-of-n quorum consensus across multiple transports.

Installation

npm install @rpckit/core @rpckit/cluster

Usage

import type { ElectrumCashSchema } from '@rpckit/core/electrum-cash'
import { cluster } from '@rpckit/cluster'
import { webSocket } from '@rpckit/websocket'

const transport = cluster<ElectrumCashSchema>(
  [
    webSocket('wss://server1.example.com:50004'),
    webSocket('wss://server2.example.com:50004'),
    webSocket('wss://server3.example.com:50004'),
  ],
  { quorum: 2, timeout: 10000 }, // Require 2-of-3 agreement
)

await transport.connect()

// Only resolves when 2 servers return identical results
const tip = await transport.request('blockchain.headers.get_tip')

await transport.close()

Options

• quorum - Number of identical responses required (must be ≥1 and ≤ number of transports)
• timeout - Timeout in ms for quorum to be reached

How It Works

1. Request is sent to all transports in parallel
2. Responses are compared using deep equality
3. When quorum transports return identical results, that result is returned
4. If quorum cannot be reached (too many errors or different results), an error is thrown

Subscriptions also support quorum - notifications are only forwarded when enough transports agree.

Response Observation

Monitor all requests and responses from individual transports:

const unsub = transport.onResponse(({ method, params, transport, response, error, status }) => {
  console.log(`${method} via ${transport.url}: ${status}`)
})
// Later: unsub()

// Access underlying transports
console.log(transport.transports)