t8y2/dbx · error

start RocketMQ endpoint proxy: %w

Error message

start RocketMQ endpoint proxy: %w

What it means

Returned by proxyManager.ProxyFor in the rocketmq driver when binding a new local TCP listener (127.0.0.1:0) for routing a remote broker endpoint fails at net.Listen. Without the local listener the proxy cannot forward traffic, so endpoint setup fails with the OS-level cause wrapped.

Source

Thrown at agents/drivers/rocketmq/routing.go:78

	if endpoint := manager.byOriginal[original]; endpoint != nil {
		address := endpoint.listener.Addr().String()
		manager.mu.RUnlock()
		return address, nil
	}
	manager.mu.RUnlock()

	manager.mu.Lock()
	defer manager.mu.Unlock()
	if manager.closed {
		return "", fmt.Errorf("RocketMQ proxy manager is closed")
	}
	if endpoint := manager.byOriginal[original]; endpoint != nil {
		return endpoint.listener.Addr().String(), nil
	}
	targets, fallback := manager.routeTargetsLocked(original, kind)
	listener, err := net.Listen("tcp", "127.0.0.1:0")
	if err != nil {
		return "", fmt.Errorf("start RocketMQ endpoint proxy: %w", err)
	}
	endpoint := &proxyEndpoint{original: original, targets: targets, fallback: fallback, listener: listener, manager: manager}
	local := listener.Addr().String()
	manager.byOriginal[original] = endpoint
	manager.originalByLocal[local] = original
	go endpoint.serve()
	return local, nil
}

func (manager *proxyManager) routeTargetsLocked(original string, kind proxyTargetKind) ([]string, bool) {
	if kind == proxyTargetNameServer || manager.config.SocksProxy != nil {
		return []string{original}, false
	}
	if manager.config.BrokerAddr != "" {
		return []string{manager.config.BrokerAddr}, false
	}
	host, port := parseSocketAddress(original)
	if port == "" || !isLikelyUnreachableBrokerHost(host) {

View on GitHub (pinned to c0390bff16)

Solutions

1. Check the wrapped error for the bind cause (fd exhaustion, memory limits)
2. Reduce the number of distinct broker endpoints being proxied
3. Free file descriptors / raise ulimit if many endpoints are in use
4. Retry after clearing leaked listeners from previous runs

When it happens

Trigger: Thrown at agents/drivers/rocketmq/routing.go:78 when the library encounters an invalid state.

Common situations: See trigger scenarios.

AI-assisted analysis of t8y2/dbx@c0390bff16 (2026-09-05). Data as JSON: /api/errors/9944ebaedefc57bd. Report an issue: GitHub.