Diagnosing and resolving UPark API Error 500 related to concurrent requests. Focus on TLS/SSL, API response codes, and rate limiting in kiosk environments.
Review the server-side logging for specific exceptions.
Consult the API documentation and configuration files for rate limits.
Examine the kiosk software to determine the queuing mechanism.
HTTP 500 errors typically indicate a failure in the API server's application logic. This can arise from resource exhaustion (CPU, memory, database connections), unhandled exceptions in the code, or temporary inability to access external services. TLS/SSL handshake failures or certificate validation issues can also trigger this error if the API server is unable to establish secure connections with its dependencies. Rate limiting mechanisms not properly configured or exceeded can also cause 500 errors.
Ensure all network cables and power cords connected to the kiosk are properly secured to prevent accidental disconnections. Although no internal access is permitted, ensure external surfaces are free of debris. Follow standard electrical safety procedures. Do not attempt to bypass or disable any security features of the kiosk or API.
Regularly monitor API server performance metrics (CPU utilization, memory usage, database connection count, request latency) to identify potential bottlenecks before they cause errors. Conduct load testing to determine the API server's capacity and identify the breaking point. Proactively review and update rate limiting configurations based on evolving usage patterns. Implement comprehensive logging and monitoring to quickly diagnose and resolve issues.
Utilize browser developer tools (Network tab) on a test kiosk to examine the API request/response headers and payloads when a 500 error occurs. This can provide valuable clues about the nature of the error, such as invalid data being sent in the request or an unexpected response from the server. Verify TLS/SSL certificate validity on both client (kiosk) and server sides. Consider implementing client-side caching of API responses where appropriate to reduce the number of requests sent to the server. Implement exponential backoff with jitter on the client-side when retrying failed API requests.