Issue
Workflows within SharePoint Online will randomly suspend or terminate, and within the Instance Information panel (accessed through the blue 'i' on the Workflow Status page) is the message: 'HTTP status code 429'
Resolution
- Reduce the number of requests that are being made into the SharePoint Online environment by the workflow
- Review Handling Workflow Throttling
Error Code
HTTP status code 429
Additional Information
Microsoft's documentation on avoiding workflow throttling within SharePoint Online
