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Show HN: Pushpin, a reverse proxy for real-time web services

49 points by jkarneges 11y ago

fiatjaf 11y ago
This is interesting, but why did you make it? Who is using it? Why isn't it a paid service?
- jkarneges 11y ago
  I created Pushpin because it addressed a problem that I had myself at a previous employer. Namely that I needed to build a realtime API and there were essentially no dev tools available to help with that. We (Fanout) have a paid service too: https://fanout.io/cloud/ https://fanout.io/cloud/ At this time, users are mostly other startups, for example LaunchDarkly (controlled feature rollouts) and Appbase (ElasticSearch-compatible BaaS). We have some promising discussions going on with larger companies as well.
jkarneges 11y ago
Many upvotes and github stars, but not many comments here yet. Guess I did a thorough job on the readme? :) As an example of how powerful Pushpin's transparency is, we were able to build a Bayeux server with it. Bayeux is the open pubsub standard supported by projects such as Faye [1]. For our Bayeux server, we made a backend that uses Pushpin's ZeroMQ interface to set up stateless long-polling and manage stateful WebSockets (eventually I want to figure out how to use Pushpin's stateless WebSockets ability here, but the Bayeux protocol makes this difficult). Session information is stored in Redis. Pushpin's JSONP configuration is tweaked to work exactly like Bayeux's, which is generally needed for the initial handshake. When a message needs to be published to all subscribers of a channel, it is produced once by the backend and Pushpin handles the one-to-many delivery. Long-polling responses use Pushpin's JSON Patch ability, so that they can contain the request-specific ack information without published payloads needing to be client-specific. Thus, we were able to make Pushpin speak Bayeux without it having any direct knowledge of that protocol. Most developers will not need to build such a gnarly service like this, as modern realtime APIs tend to be a lot simpler than the classic Bayeux protocol. But I think it's a cool example of what's possible. [1] http://faye.jcoglan.com/ http://faye.jcoglan.com/

49 points by jkarneges 11y ago

fiatjaf 11y ago

This is interesting, but why did you make it? Who is using it? Why isn't it a paid service?

jkarneges 11y ago
I created Pushpin because it addressed a problem that I had myself at a previous employer. Namely that I needed to build a realtime API and there were essentially no dev tools available to help with that. We (Fanout) have a paid service too: https://fanout.io/cloud/ https://fanout.io/cloud/ At this time, users are mostly other startups, for example LaunchDarkly (controlled feature rollouts) and Appbase (ElasticSearch-compatible BaaS). We have some promising discussions going on with larger companies as well.

jkarneges 11y ago

Many upvotes and github stars, but not many comments here yet. Guess I did a thorough job on the readme? :) As an example of how powerful Pushpin's transparency is, we were able to build a Bayeux server with it. Bayeux is the open pubsub standard supported by projects such as Faye [1]. For our Bayeux server, we made a backend that uses Pushpin's ZeroMQ interface to set up stateless long-polling and manage stateful WebSockets (eventually I want to figure out how to use Pushpin's stateless WebSockets ability here, but the Bayeux protocol makes this difficult). Session information is stored in Redis. Pushpin's JSONP configuration is tweaked to work exactly like Bayeux's, which is generally needed for the initial handshake. When a message needs to be published to all subscribers of a channel, it is produced once by the backend and Pushpin handles the one-to-many delivery. Long-polling responses use Pushpin's JSON Patch ability, so that they can contain the request-specific ack information without published payloads needing to be client-specific. Thus, we were able to make Pushpin speak Bayeux without it having any direct knowledge of that protocol. Most developers will not need to build such a gnarly service like this, as modern realtime APIs tend to be a lot simpler than the classic Bayeux protocol. But I think it's a cool example of what's possible. [1] http://faye.jcoglan.com/ http://faye.jcoglan.com/