My website keeps crashing and giving an "error 503 backend fetch failed" error when you try to go to it. To temporarily fix it I reset my server the website is hosted on, and it seems to fix the problem momentarily. But normally within 8-12 hours the website will crash again and give the same backend fetch failed error. The exact error reads:
Error 503 Backend fetch failed
Backend fetch failed
xid: XXXXXXX<-----(random number every time the error comes up)
Varnish cache server
I changed the config based on suggestions I found in Magento DevDoc but nothing seems to work: https://devdocs.magento.com/guides/v2.3/config-guide/varnish/tshoot-varnish-503.html
Screenshot of error:
Does anyone have any ideas what the problem may be?
Try to fetch the website without varnish to see if the error is in varnish or the webserver, in your case, it seems from the hosting side.
For example, if you have a different hostname for the webserver, load that and find the error, if you can fix that,
Restart varnish and it should resolve your issue.
I have the same problem as you mention. you may want to take a look at this post
Follow this: http://aircartapp.com/fix-error-503-backend-fetch-failed It will surely help you to fix 503 issue.
First of all, you have to identify why this error is occurring again and again. It can be due to various reasons:
1. lack of memory.
2. The varnish is not working from the backend.
3. The extensive number of requests on the server.
4. SSL couldn't configure successfully
How to fix this issue?
look for the scalability if you can or ask the hosting provider to do it for you. Second, remove the maintenance.flag file and hit the URL again.
If it works with you, do let me know!