503 Service Unavailable
Situations in the vault where SharePoint, SPFx, Microsoft Graph or the Azure services around them answer with HTTP 503. Each one explains why it happens and how to fix it.
- A fixed WEBSITE_CONTENTSHARE in your template can break production on the first template redeploy after a slot swapgotchas / azure-functionsOn a function app with deployment slots, WEBSITE_CONTENTSHARE isn't slot-sticky: a swap moves it together with the code. A template that pins the production value (say toLower(appName)) would point production back at…
- Retry only fast failures — a gateway error after 230 seconds is a timeout, not a hiccupgotchas / azure-functionsThe 502/503/504 a client rightly retries for transient failures also comes back when a request ran out of time (Azure Load Balancer returns 502 after 230 s), and retrying that multiplies the wait (3 × ~230 s) and the…
- Windows Functions — zip deploy onto a running app corrupts it (whole app 503)gotchas / azure-functionsLive wwwroot file locks → whole app 503; re-run the deploy, prevent with WEBSITE_RUN_FROM_PACKAGE=1