PoolConfig

Options for the underlying http.Agent / https.Agent connection pool.

interface PoolConfig {
  maxSockets?: number
  maxFreeSockets?: number
  keepAlive?: boolean
  keepAliveMsecs?: number
  timeout?: number
  socketTimeoutMs?: number
  maxContentLength?: number
  maxBodyLength?: number
}

---

Options

maxSockets

• Type: number
• Default: 200
• Must be >= 1 — Node reads 0 as unlimited, the opposite of what it looks like, so it is rejected.

Maximum number of concurrent open sockets per host. Requests beyond this limit are queued.

Sized for burst headroom, not average load: steady-state demand is rps × latencySeconds, so 58 rps at 200 ms needs only about 12 sockets. The default matters when latency degrades.

maxFreeSockets

• Type: number
• Default: 50

Maximum number of idle (keep-alive) sockets to keep open. Sockets above this limit are destroyed when idle.

keepAlive

• Type: boolean
• Default: true

Enables TCP keep-alive. Strongly recommended — prevents ECONNRESET when servers close idle connections.

keepAliveMsecs

• Type: number
• Default: 1000

Interval in milliseconds between TCP keep-alive probes. Lower values detect dead connections sooner but increase network overhead.

timeout

• Type: number
• Default: 30000

Response timeout in milliseconds — how long to wait for the upstream to answer. Can be overridden per-request via config.timeout or policy.timeout.

This bounds a single attempt. To bound a whole call (queue waits + all attempts + all backoff), use client.deadline(ms).

socketTimeoutMs

• Type: number
• Default: same as timeout

Socket inactivity timeout passed to the agent itself. Without it, a connection silently dropped by a NAT or firewall is only noticed by the response timeout. Node's http.Agent exposes no separate connect timeout, so inactivity covers a stuck connect too.

maxContentLength

• Type: number
• Default: 33554432 (32 MiB)

Maximum response body accepted. Axios itself defaults to unlimited, so a runaway upstream could exhaust the client's memory.

maxBodyLength

• Type: number
• Default: 33554432 (32 MiB)

Maximum request body sent.

---

Usage

import { HttpClientFactory } from 'super-http'

const client = HttpClientFactory.create('https://api.example.com', {}, {
  maxSockets: 200,
  maxFreeSockets: 50,
  keepAlive: true,
  keepAliveMsecs: 2_000,
  timeout: 15_000,
  socketTimeoutMs: 15_000,
})