PingRoutingStrategy

Overview

The PingRoutingStrategy is a wrapper strategy that performs a HEAD check on the gateway returned from a provided routing strategy. This ensures that the selected gateway is healthy and responsive before using it for requests, adding an extra layer of reliability to any routing strategy.

How It Works

Delegate to Inner Strategy: Use the provided routing strategy to select a gateway
Perform Health Check: Send a HEAD request to the selected gateway
Validate Response: Check if the gateway responds successfully
Return Gateway: If healthy, return the selected gateway; if unhealthy, the strategy may retry or fail

Basic Usage

import {
  PingRoutingStrategy,
  RandomRoutingStrategy,
} from '@ar.io/wayfinder-core'

const strategy = new PingRoutingStrategy({
  routingStrategy: new RandomRoutingStrategy(),
  timeoutMs: 1000,
})

const selectedGateway = await strategy.selectGateway({
  gateways: [
    'https://arweave.net',
    'https://permagate.io',
    'https://arweave.dev',
  ],
})

// Performs a HEAD check on the randomly selected gateway before returning it

Parameters

Parameter	Type	Default	Description
`routingStrategy`	`RoutingStrategy`	required	The routing strategy to wrap with health checks
`timeoutMs`	`number`	`1000`	Timeout for HEAD requests in milliseconds
`logger`	`Logger`	`defaultLogger`	Optional logger instance

Advanced Usage

Combining with Other Strategies

import {
  PingRoutingStrategy,
  FastestPingRoutingStrategy,
  PreferredWithFallbackRoutingStrategy,
} from '@ar.io/wayfinder-core'

// Add health checks to fastest ping strategy
const healthCheckedFastest = new PingRoutingStrategy({
  routingStrategy: new FastestPingRoutingStrategy({ timeoutMs: 500 }),
  timeoutMs: 1000,
})

// Add health checks to preferred with fallback strategy
const healthCheckedPreferred = new PingRoutingStrategy({
  routingStrategy: new PreferredWithFallbackRoutingStrategy({
    preferredGateway: 'https://my-gateway.com',
    fallbackStrategy: new FastestPingRoutingStrategy({ timeoutMs: 500 }),
  }),
  timeoutMs: 1000,
})

Custom Timeout Configuration

const strategy = new PingRoutingStrategy({
  routingStrategy: new RandomRoutingStrategy(),
  timeoutMs: 2000, // 2 second timeout for health checks
})

Use Cases

Production Applications: Add health checks to any routing strategy for increased reliability
Critical Systems: Ensure gateways are responsive before making important requests
High Availability: Combine with other strategies to create robust routing systems
Monitoring: Track gateway health through the ping checks

FastestPingRoutingStrategy: Network-based gateway discovery
PreferredWithFallbackRoutingStrategy: Static gateway configuration
RoundRobinRoutingStrategy: Even distribution across gateways
RandomRoutingStrategy: Randomized gateway selection
StaticRoutingStrategy: Always use a single, fixed gateway