DNS

import * as dns from "node:dns";

const addrs = await dns.promises.resolve4("bun.sh", { ttl: true });
console.log(addrs);
// => [{ address: "172.67.161.226", family: 4, ttl: 0 }, ...]

import {dns} from "bun";

dns.prefetch("my.database-host.com", 5432);

dns.prefetch(hostname: string, port: number): void;

import {dns} from "bun";

dns.prefetch("bun.sh", 443);
//
// ... sometime later ...
await fetch("https://bun.net.cn");

{
  // Cache hits 
  cacheHitsCompleted: number;
  cacheHitsInflight: number;
  cacheMisses: number;
  // Number of items in the DNS cache
  size: number;

  // Number of times a connection failed
  errors: number;

  // Number of times a connection was requested at all (including cache hits and misses)
  totalCount: number;
}

import {dns} from "bun";

const stats = dns.getCacheStats();
console.log(stats);
// => { cacheHitsCompleted: 0, cacheHitsInflight: 0, cacheMisses: 0, size: 0, errors: 0, totalCount: 0 }

BUN_CONFIG_DNS_TIME_TO_LIVE_SECONDS=5 bun run my-script.ts