juicedata/juicefs · error

load worker config: %s

Error message

load worker config: %s

What it means

In doSync, when the process runs as a sync worker (--worker), it reads its src/dst URLs and environment from the master via loadClusterWorkerConfig(os.Stdin). Any failure in that handshake (including bad config format, I/O errors on stdin, or env-setting failures from error 310) is re-wrapped as 'load worker config: %s'. The worker cannot proceed without this config, so the command exits.

Source

Thrown at cmd/sync.go:537

		return "", "", err
	}
	for key, value := range env {
		if err := os.Setenv(key, value); err != nil {
			return "", "", fmt.Errorf("set worker environment %q: %s", key, err)
		}
	}
	return src, dst, nil
}

func doSync(c *cli.Context) error {
	isWorker := c.String("manager") != ""
	var workerSrcURL, workerDstURL string
	if isWorker {
		var err error
		// need init before NewConfigFromCli, otherwise the env will not be applied(umask)
		workerSrcURL, workerDstURL, err = loadClusterWorkerConfig(os.Stdin)
		if err != nil {
			return fmt.Errorf("load worker config: %s", err)
		}
	}
	setup(c, 2)
	if c.IsSet("include") && !c.IsSet("exclude") {
		logger.Warnf("The include option needs to be used with the exclude option, otherwise the result of the current sync may not match your expectations")
	}
	config := sync.NewConfigFromCli(c)
	cliCtx = c
	if config.Manager != "" {
		logger.Debugf("worker process start")
	}
	// Windows support `\` and `/` as its separator, Unix only use `/`
	srcURL, dstURL := c.Args().Get(0), c.Args().Get(1)
	if isWorker {
		srcURL, dstURL = workerSrcURL, workerDstURL
	} else {
		config.SetClusterStorage(srcURL, dstURL)
	}

View on GitHub (pinned to c9a67b23e8)

Solutions

1. Read the inner error after 'load worker config:' to find the root cause.
2. Verify the worker was launched by the master (with --worker) so stdin carries the cluster config; do not run --worker manually with a terminal stdin.
3. Check that the master is running and reachable, and that it printed no errors when distributing the job.
4. If running under a supervisor, ensure stdin is a pipe connected to the master, not /dev/null.

if err := runSyncWorker(); err != nil {
    if strings.Contains(err.Error(), "load worker config") {
        // verify master connectivity and that stdin carries the config pipe
    }
    return err
}

When it happens

Trigger: `juicefs sync ... --worker` where loadClusterWorkerConfig returns an error: stdin closed/empty, malformed cluster config line, or a setenv failure inside the worker env application loop.

Common situations: Worker launched without the master piping the config into stdin; master crashed or disconnected mid-handshake; master sent malformed config; stdin redirected by a process manager (systemd/docker) so the worker never receives the config.

Understand the failure class

Background: "X is required", "must be set", "cannot be empty": the missing-required-config error family, from Vertex AI project/location to WeChat keys — this error's family across 18 libraries.

Related errors

• set worker environment %q: %s
• Unsupported ByteMultiple " + sMultiple
• wrong type
• random, backward, skip are only valid under read
• random, backward, skip are mutually exclusive

AI-assisted analysis of juicedata/juicefs@c9a67b23e8 (2026-09-06). Data as JSON: /api/errors/8b8bc59a776ab5f7. Report an issue: GitHub.