Failed to get access token by using service principal ADAL Error service unavailable while trying copy activity using datafactory

Question

While performing a copy activity using Azure datafactory, Copy activity fail with the following error:

Failed to get access token by using service principal.
ADAL Error: service_unavailable, The remote server returned an error: (503) Server Unavailable.

What is the cause for this? and how should I resolve it? please help.

Answer 1

When the Service Token Server (STS) owned by Azure Active Directory is not unavailable, i.e., too busy to handle requests, it returns an HTTP error 503 which says that service is unavailable.

Rerun the copy activity after several minutes. This should resolve the error.