Resolved
The incident has been resolved. This impact end time would be 11:10 UTC.
Issue
Upon further investigation, our engineers found the issue started at 06:58 UTC. Our engineers are working with the upstream provider for a resolution.
Investigating
We see increased failure rates to resolve DNS on *.herokuapp.com domains and custom domains in the Common Runtime environment. This is causing failed requests to customers' apps. Engineers are actively investigating this issue and we'll provide an update shortly.