docmirror/dev-sidecar · warning

[speed] test error: ${this.hostname} ➜ ${item.host}:${this

Error message

[speed] test error:   ${this.hostname} ➜ ${item.host}:${this.port} from DNS '${item.dns}', errorMsg: ${e.message}

What it means

SpeedTester._doTest logs a warning when testing a candidate IP (host:port for a domain, via a specific DNS provider) throws and the failure is not a timeout. The candidate item is marked status 'failed' with the error as its title; the tester then moves on to other backups, so overall IP selection usually still succeeds.

Source

Thrown at packages/mitmproxy/src/lib/speed/SpeedTester.js:224

    } finally {
      this.isTestingBackups = false
    }
  }

  async _doTest (item, aliveList) {
    try {
      const ret = await this.testOne(item)
      item.title = `${ret.by}测速成功：${ret.target}`
      log.info(`[speed] test success: ${this.hostname} ➜ ${item.host}:${this.port} from DNS '${item.dns}'`)
      _.merge(item, ret)
      aliveList.push({ ...ret, ...item })
    } catch (e) {
      if (item.time == null) {
        item.title = e.message
        item.status = 'failed'
      }
      if (!e.message.includes('timeout')) {
        log.warn(`[speed] test error:   ${this.hostname} ➜ ${item.host}:${this.port} from DNS '${item.dns}', errorMsg: ${e.message}`)
      }
    }
  }

  testByTCP (item) {
    return new Promise((resolve, reject) => {
      const { host, dns } = item
      const startTime = Date.now()

      let isOver = false
      const timeout = 5000
      let timeoutId = null

      const client = net.createConnection({ host, port: this.port, family: host.includes(':') ? 6 : 4 }, () => {
        isOver = true
        clearTimeout(timeoutId)

        const connectionTime = Date.now()

View on GitHub (pinned to 7710cd56cc)

Solutions

1. Check the errorMsg in the log: ECONNREFUSED/EHOSTUNREACH means the candidate IP is dead — remove or update it in dns/providers or preset IP config
2. If the DNS provider failed, switch to a reachable one (e.g. aliyun/google) in config
3. Verify no local firewall blocks outbound connections to the tested port
4. Nothing to fix if other backups pass — this is expected failover behavior; the fastest working IP is still chosen

try {
  await tester.testOne(candidate)
} catch (e) {
  if (!String(e.message).includes('timeout')) {
    log.warn('candidate unreachable, trying next backup', e.message)
  }
  // tester already marks item failed; proceed to next backup
}

When it happens

Trigger: During testBackups → _doTest, connecting to a candidate IP throws a non-timeout error: ECONNREFUSED (IP dead/blocked), EHOSTUNREACH, TLS handshake failure for https probes, or DNS resolution failure for item.dns.

Common situations: Preset/backup IP lists going stale (IPs no longer serving the domain); GFW/ISP blocking certain IPs; DoH/DoT provider unreachable; firewall on the local network blocking the probe port.

Related errors

• [speed] test by TCP error:
• [speed] test by TCP timeout:
• 下载远程配置成功，但内容为空:
• 下载远程 domestic-domain-allowlist.txt 文件成功，但内容为空或内容太短，判断为无效的 do
• IPv6 地址 ${ip} 多次不可达（ENETUNREACH），已自动禁用 IPv6 DNS 解析

AI-assisted analysis of docmirror/dev-sidecar@7710cd56cc (2026-08-31). Data as JSON: /api/errors/57991e635b983933. Report an issue: GitHub.