louislam/uptime-kuma · error · Error

${res.data.reason}

Error message

${res.data.reason}

What it means

RabbitMQ's management API returns HTTP 503 when the node/cluster is considered unhealthy and includes a `reason` field in the JSON body (e.g. a resource alarm). checkSingleNode special-cases 503 to surface that reason directly rather than the generic status text. So the message is whatever the RabbitMQ HTTP API put in res.data.reason.

Solutions

1. Resolve the alarm reported in `reason`: free disk space, raise vm_memory_high_watermark, or clear the alarm with `rabbitmqctl clear_resource_alarm <name>`.
2. Inspect cluster state: `rabbitmqctl status`, `rabbitmqctl cluster_status`, and the management UI overview.
3. Confirm the node being queried is the one in alarm; rotate through each node URL.
4. Tune limits (disk_free_limit, vm_memory_high_watermark) so transient load does not trip 503.

Example fix

# before
reason: "memory resource alarm"
# after
rabbitmqctl set_vm_memory_high_watermark absolute=2GB && rabbitmqctl clear_resource_alarm memory

// Pre-flight: call the aliveness endpoint; if 503, surface the reason early.
async function preflightRabbitNode(monitor, baseUrl) {
  const res = await axios.get(`${baseUrl}/api/aliveness-test/%2F`, { auth: { username: monitor.rabbitmqUsername, password: monitor.rabbitmqPassword } });
  if (res.status === 503 && res.data?.reason) {
    throw new Error(res.data.reason);
  }
}

function hasResourceAlarmReason(data) { return !!data && typeof data.reason === 'string'; }

try {
  await checkSingleNode(monitor, baseUrl, nodeInfo);
} catch (e) {
  if (/resource alarm|disk|memory/i.test(e.message)) {
    alertOps('RabbitMQ resource alarm: ' + e.message);
  }
  throw e;
}

When it happens

Trigger: axios.request returns status 503 with a JSON body containing `reason`. Common reasons include resource alarms (disk or memory), node not running, or maintenance mode. The branch at rabbitmq.js:95 throws res.data.reason verbatim.

Common situations: Disk alarm (disk_free < disk_free_limit), memory alarm (mem_above watermark), node paused, or the cluster in a degraded state where the management plugin still answers 503.

Related errors

• ${res.status} - ${res.statusText}
• Accepted status codes must be valid JSON
• All nodes failed because
• Bark notification failed with invalid response!
• Bark notification failed with status code

AI-assisted analysis of louislam/uptime-kuma@6b5ea01557 (2026-08-12). Data as JSON: /api/errors/23abc565cc97bb79. Report an issue: GitHub.

Appendix: source

Thrown at server/monitor-types/rabbitmq.js:95

            signal: axiosAbortSignal((monitor.timeout + 10) * 1000),
            // Capture reason for 503 status
            validateStatus: (status) => status === 200 || status === 503,
        };

        log.debug("monitor", `[${monitor.name}] Checking node ${nodeInfo}: ${baseUrl}`);

        try {
            const res = await axios.request(options);
            log.debug(
                "monitor",
                `[${monitor.name}] Axios Response: status=${res.status} body=${JSON.stringify(res.data)}`
            );

            if (res.status === 200) {
                log.debug("monitor", `[${monitor.name}] Node ${nodeInfo} is healthy`);
                // Success - return without error
            } else if (res.status === 503) {
                throw new Error(res.data.reason);
            } else {
                throw new Error(`${res.status} - ${res.statusText}`);
            }
        } catch (error) {
            if (axios.isCancel(error)) {
                throw new Error("Request timed out");
            } else if (error.response) {
                // Re-throw with the original error message if it's already formatted
                throw error;
            } else {
                throw new Error(error.message);
            }
        }
    }
}

module.exports = {
    RabbitMqMonitorType,

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