You may have experienced a Push subscription fail due to the following error:
Stopped due to too many failed delivery attempts
This is typically caused by DataSift being unable to reach, and successfully deliver data to your Push Destination for over an hour. This may be because we are unable to connect to your Push Destination, or your destination could be returning errors on delivery.
What Can I Do About It?
Check your logs! On the DataSift side you can hit the /push/log API endpoint for this Push subscription to see what errors were logged for this Push subscription; this should give you some insight into why the subscription failed.
Also think about checking the logs in your Push Destination; ensure your endpoint was responsive and available at the time messages appeared in your /push/log.