Your pod is shown in the first portion of the site URL after signing in. Example: https://10az.online.tableau.com is the United States - West (10AZ) pod.
For service status related to Licensing and Registration, Webstore and Checkout, TableauID, community forums, or customer and partner portals: Please visit the Tableau Customer Support Trust at https://cs-trust.ea.tableau.com.
Between the times of 4:15 and 4:30 pm PT some users of Tableau Online may have experienced an inability to sign in. Tableau Engineers identified the root cause and successfully restored service at 4:30pm PT.