Avoiding polling on services like Heroku and Google App Engine?

I do not think there's a way to do this but I thought I'd ask to see what workarounds p开发者_Go百科eople are using to avoid polling on Heroku and/or GAE.

How are you sending out notifications in somewhat real-time from these apps?

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GAE can use one of the following to notify another system:

• xmpp
• urlfetch to a callback url
  • like to pubsubhubbub
• send email

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With Heroku's new Cedar stack you can do long polling.

There's a link to some long polling example code here.

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As @dar mentions, you can use PubSubHubbub to do realtime notification without polling. Nick Johnson has an excellent tutorial on using an existing PubSubHubbub server, or even including a server with your application.

This will let you publish feeds and subscribe to them in realtime without polling.