Users are getting "Service Unavailable" message from time to time, sometime when logging in or when navigating through the pages. Here is the detailed error from developer mode:
503 Service Unavailable
The database user for the connection pool named |apex|rt|, is not able to proxy to the schema named ASR_APEX.
This could be a configured restriction on the maximum number of database sessions or an authorization failure.
Any idea why? How do we fix it?