Limits and troubleshooting

Limits

• State in memory. The queue lives in the memory of each middleware instance. Several Traefik replicas do not share it, and a restart empties it. A dynamic configuration change may also recreate the middleware with an empty queue: change the configuration outside peak hours.
• Abandoned places. A visitor who closes the waiting page keeps their place in the queue. When their turn comes, the slot stays reserved until inactivityTimeoutSeconds runs out. The queue moves slower than its size suggests when many visitors give up.
• Approximate wait time. The wait shown is computed from the position, not measured from real departures.
• Cookie without Secure behind a TLS proxy. The cookie gets the Secure flag only when the TLS connection ends at Traefik.
• Reload URL. The default page reloads with <meta http-equiv="refresh" content="…;url=./"> and a script that reloads the current path without its query string. On a deep path such as /shop/item, the meta refresh goes to /shop/. Edit the template if visitors must come back to the exact URL.

Troubleshooting

Symptom	Cause	Fix
Traefik refuses the middleware: invalid QueueManager configuration	A value fails the checks	Fix the value given in the message
The built-in English page shows instead of yours	Template not found or invalid	Check queuePageFile and the volume; the log says Could not load queue page template
Empty texts on the waiting page	Language missing from the translations file, or file not found	Add the language, check queueTranslationsFile
Changes to the template or translations do not show	Files are read at startup	Restart Traefik
JSON {"error":"capacity overload"} without detail	Rate limit on requests without the cookie	Keep cookies, or raise rateLimitTimes
Visitors go back to the queue while browsing	inactivityTimeoutSeconds too short, or cookie expired	Raise inactivityTimeoutSeconds or cookieMaxAgeSeconds

Logs

The plugin writes to the Traefik standard error, or to logFile, with the prefix [Loch-Queue]. Set debug=true to see each decision (client, position, promotions) while troubleshooting, and turn it off afterwards: it is verbose.