I've successfully subscribed to a Google Alert feed using PubSubHubbub and the appspot hub and received updates to my callback regularly, but now the updates have stopped. I've verified the subscription is still valid using the Subscriber Diagnostics.
The updates stopped 30 days after the Expiration time in the Subscription Details. I did not specify lease_seconds in my original subscription request so the hub responded 432000 (5 days). According to the PubSubHubbub Core Working Draft, a recheck should have occurred after those 5 days, but I cannot find one in my logs.
Should I send another subscription request? Do I need to monitor rechecks and re-subscribe in the future if they don't come?