milvus-io/milvus · error

Server error

Error message

Server error

What it means

Thrown by the Milvus WebUI telemetry login flow in telemetry.html. After POSTing credentials to GET /_telemetry/clients with the computed Basic auth token, any non-2xx response other than 401 (which is handled separately as a bad-credential message) raises this generic 'Server error'. It means the HTTP request reached a server that refused it for a reason other than authentication: typically 500 (telemetry handler panic or embedded etcd/proxy not ready), 403, or a proxy/gateway in front returning 502/503.

Source

Thrown at internal/http/webui/telemetry.html:1549

            // Create Basic Auth token
            authToken = 'Basic ' + btoa(username + ':' + password);

            // Test auth by making a request
            try {
                const resp = await fetch(`${API_BASE}/_telemetry/clients`, {
                    headers: { 'Authorization': authToken }
                });

                if (resp.status === 401) {
                    errorDiv.textContent = 'Invalid username or password';
                    errorDiv.style.display = 'block';
                    authToken = '';
                    return;
                }

                if (!resp.ok) {
                    throw new Error('Server error');
                }

                // Save auth
                sessionStorage.setItem('milvusAuth', authToken);
                sessionStorage.setItem('milvusUser', username);
                showApp(username);
            } catch (error) {
                errorDiv.textContent = 'Connection error: ' + error.message;
                errorDiv.style.display = 'block';
                authToken = '';
            }
        }

        function showApp(username) {
            document.getElementById('loginPage').style.display = 'none';
            document.getElementById('appContainer').style.display = 'block';
            document.getElementById('currentUser').textContent = username;
            loadData();

View on GitHub (pinned to b43a76673a)

Solutions

1. Open the same URL /_telemetry/clients with curl -u user:pass -i and read the actual status code and body, which the UI discards.
2. If 500: check the Milvus proxy logs for a panic or stack trace around the telemetry handler and restart the component if it crashed.
3. If 403/401-loop: verify web auth settings (common.security.authorizationEnabled, proxy auth) and that the WebUI is served by the same Milvus instance you are authenticating against.
4. If behind a proxy: ensure /_telemetry/* is passed through to Milvus unchanged, including the Authorization header.
5. Retry after Milvus is fully healthy (healthz/metrics endpoints respond).

Example fix

// before
if (!resp.ok) {
    throw new Error('Server error');
}

// after - surface the real status/body so the cause is diagnosable
if (!resp.ok) {
    const body = await resp.text().catch(() => '');
    throw new Error(`Server error: HTTP ${resp.status} ${body.slice(0, 200)}`);
}

try {
  const resp = await fetch(`${API_BASE}/_telemetry/clients`, { headers: { 'Authorization': authToken } });
  if (resp.status === 401) { /* bad credentials */ }
  if (!resp.ok) {
    const body = await resp.text().catch(() => '');
    throw new Error(`Server error: HTTP ${resp.status} ${body.slice(0, 200)}`);
  }
} catch (e) {
  // distinguish network failure (TypeError) from HTTP failure
  showError(e instanceof TypeError ? 'Cannot reach Milvus WebUI endpoint' : e.message);
}

When it happens

Trigger: Calling the WebUI login when the Milvus proxy is up but the telemetry HTTP server has an internal error (500), when the auth config (webui auth username/password or proxy.authEnabled) is inconsistent so the server returns 403, or when a reverse proxy returns 502/503 while Milvus is starting. Any resp.status not in 2xx and not 401 hits this branch.

Common situations: Milvus still starting up (proxy listens before the telemetry handler is fully wired); mismatch between the credentials expected by the server and those typed in; a load balancer / ingress intercepting /_telemetry/* routes; telemetry disabled via config so the handler errors.

Related errors

• HTTP error: ${resp.status}
• Failed to delete command
• Failed to request errors
• HTTP ${response.status}
• Failed to push config

AI-assisted analysis of milvus-io/milvus@b43a76673a (2026-08-15). Data as JSON: /api/errors/b7917be99781c629. Report an issue: GitHub.