As per the documentation, Instances are created on demand to handle requests and automatically turned down when idle. However, the time interval varies based on multiple facotrs including system load/idle time, scaling type etc.
Following link provided details on that. https://cloud.google.com/appengine/docs/standard/go/how-instances-are-managed -- You received this message because you are subscribed to the Google Groups "Google App Engine" group. To unsubscribe from this group and stop receiving emails from it, send an email to google-appengine+unsubscr...@googlegroups.com. To view this discussion on the web visit https://groups.google.com/d/msgid/google-appengine/272e2613-4412-412c-a73a-e6a9b498189ao%40googlegroups.com.
