As part of a proof-of-concept, we are trying to set up an eat-your-own-dog-food sort of scenario in which we can publish Google Public Alerts to a hub (for testing purposes, we're just using http://pubsubhubbub.appspot.com/) and then subscribe to and be notified by that hub as well. We had some initial problems getting subscriptions to verify, but we have confirmed that we are indeed subscribed to the hub at this point. The problem is, it appears that we are getting a response of 204 back whenever we publish an alert to said hub, but our callback URL is not being sent any notifications whatsoever.
We have enough logging enabled that we would know if a notification had at least hit the URL at all, and nothing is arriving to us from the hub. We know the callback URL is not an issue, though, because it at least appears that we were able to get our subscription verified. The same callback URL handles subscriptions and notifications. Fearing we had done something wrong somewhere, we set up an open-source hub (Wolverine, for those interested) and tested our publishing / subscribing code on that. We were able to subscribe to the Wolverine hub, and upon publishing to it, our notification callback URL was hit with a notification. This worked flawlessly, so I know at this point that our code is at least good enough for Wolverine. What could we possibly be missing at this point? Here are a few more pointed questions: 1. What in particular would make the PSHS hub refuse to send notifications to a callback URL? Is it possible to find out where our notifications are going? Is it possible to find out if the hub really has accepted our published updates? We have used both the Publisher PHP client library as well as the PSHS publish link, and neither results in any updates being pushed to our callback URL. We know that the hub is able to reach the callback URL with the subscription confirmation request, ruling out firewall issues. 2. Some of our subscription details (callback URL omitted for privacy reasons) include: State: verified Confirmation failures: 3 Delivery to domain: OK Delivery short-term: 0% errors What does "confirmation failures: 3" mean? Does delivery to domain mean what I think it means, i.e. the hub at least thinks it is pushing notifications to our callback URL?
