What are the main signs that help identify the cause of a 500 error on the server?

A 500 Internal Server Error indicates a problem on the server side. Key signs for diagnosing the cause:

• Server logs: examining logs (for example, using the log package in Go) often shows the call stack and the specific error location.
• Panic in Go: an unhandled panic results in a 500 error. Checking the code for potential panics and handling them with recover helps identify the cause.
• Errors in HTTP handlers: improper data handling, nil pointers, database errors.
• Incorrect server or dependency configuration.

Example of panic handling in Go:

func handler(w http.ResponseWriter, r *http.Request) {
    defer func() {
        if err := recover(); err != nil {
            http.Error(w, "Internal Server Error", http.StatusInternalServerError)
            // log err
        }
    }()
    // main handler code
}