Web app becomes unresponsive when deploying new version to staging slot

Question

We have an Azure App Service, running two virtual applications: an ApiServer and a Web application.

Since a few weeks it seems we have a problem when we run a deployment from an Azure Devops Release pipeline to the staging slot. The Web application in the production slot becomes unresponsive. The apiserver stays responsive during deployment.

Normally the staging slot is stopped. When a new version is deployed, the staging slot is also stopped. When we are ready to swap, the staging slot is started, a swap is performed and the slot is stopped again. This is to prevent a running process which might be out of sync with our database.

We are running this way of almost a year now, without any problems and performed upgrades every two to four weeks.

Any ideas what can be the problem?

Answer 1

Hi Andre Konijnendijk ,

Apologies for the delay in response. How long does the Web app in the production slot unresponsive for? When you looked at the deployment logs did you see any errors or warnings that could be causing the issue? because it seems like there might be an issue with the deployment process.

You can try swapping the slots manually instead of using the automated process to see if that resolves the issue. If the problem persists, you can try redeploying the application to the staging slot and then swapping it with the production slot to see if that fixes the issue.

Please let us know if the issue persists.

Best,

Grace