502 - Web server received an invalid response while acting as a gateway or proxy server on azure web app

3
votes

I have hosted one web app on azure but suddenly it started to give error. I am not what is the issue previously it was working very fine. Suddenly it stops working.

502 - Web server received an invalid response while acting as a gateway or proxy server. There is a problem with the page you are looking for, and it cannot be displayed. When the Web server (while acting as a gateway or proxy) contacted the upstream content server, it received an invalid response from the content server.

2
azureweb-applicationsserverazure-web-app-service
Try to restart the web app. – Joy Wang-MSFT
I have tried more than 10 times since than but no solution – dipoletechi
May be it will work some day without doing anything about it, I have encountered several cases, no reasonable explanation, but some day the op comes back and says it works without any operation.According to the error message, it may related to the server. – Joy Wang-MSFT
Is there any update on your side? – Nancy Xiong
Hi Nancy, I solved this issue by doing following steps "Scale up the application to Medium in order to change the instance where your application is running. Wait some minutes and check again your site The above change will change the worker instance. This in order to discard a platform issue , or worker affinity issue" – dipoletechi

2 Answers

3
votes

Many reasons could cause 502 errors.

This problem is often caused by application level issues, such as requests taking a long time; application using high memory/CPU; application crashing due to an exception.

You can follow these troubleshooting steps to identify which one as your side. Also, make sure there is no network connection broken on your side. If the web app still does not work, you can try to re-deploy it. You also can open a support ticket to contact the Azure experts.

Hope this helps.

1
votes

Scale up the application to Medium in order to change the instance where your application is running.

Wait some minutes and check again your site

The above change will change the worker instance. This in order to discard a platform issue , or worker affinity issue