What is a 503 error?
This error might happen when handling a certain number of concurrent requests. Each datasources have their own limits on API requests per account per period of time. As a result, when you create new or refresh queries and when the limit of the concurrent requests is reached, you might run into this error.
Note that a single Supermetrics query execution can result in many requests to the data source API, depending on the selected metrics and dimensions.
- Supermetrics Team