WEBSITES_ENABLE_APP_CACHE actually read only volume?

[enghaug90]

When using WEBSITES_ENABLE_APP_CACHE is it actually a read only volume that is mounted to /home/site/wwwroot?

I'm testing out the WEBSITES_ENABLE_APP_CACHE app setting on a App service hosting a NextJS application on App service on linux. Because we are experiencing some serious latency on cold start, which we suspect is latency related to fetching module files from Azure Storage. The NextJS cache folder is deleted on publish or restart of site, but the site recreates the folder and add files (images) to the folder.
If the volume was read only this should not be possible, but maybe for some reason the setting is not activating the cache in my App service? Ho can I tell that the cache is active? Other than the environment setting.

The cache folder is located at /home/site/wwwroot/.next/cache.

I'm also facing av problem with disable the feature. After removing the setting, it is not possible to deploy new versions of the app. The deployment looks successfully i Azure DevOps release pipeline, but the web application still serves the old version. I had to re enable the cache by adding the app setting WEBSITES_ENABLE_APP_CACHE back, then do a new deploy, an finally the new version was served by the app service.

[guiihlopes]

Hey @enghaug90 were you able to resolve this cold start latency issue somehow?

[markoharness]

@enghaug90 Did you maybe have some luck in figuring out a solution to your issue?