It much better to hunt down the specific request that generated the error. When you get “Backend fetch failed” in the browser, take note of “XID: 12345” at the bottom of the page. Use that number to get relevant requests quickly. The “Backend fetch failed” may be triggered before communicating the backend, or after.
What is Error 503 backend fetch failed?
Error 503 Backend Fetch Failed is displayed when the HTTP cache fails to fetch the requested data from the webserver.
What if backend fetch failed in varnish?
The “Backend fetch failed” may be triggered before communicating the backend, or after. First, you will get client side request using the following command: This will display the client-side request to Varnish. Investigate it for the ID of the backend request. Find a line that looks like this: Now you can investigate actual errors.
