Thanks for the suggestion of long polling. I'm definitely going to look into that as an option.
On Sat, Mar 14, 2015 at 6:51 PM, bradleyland <[email protected]> wrote: > Our app also has a "real-time" interface. Our app is a procurement app > that orchestrates real-time reverse auctions. Many users sit down, log in, > and participate in an auction at the same time. There are events that > appear to update in real time to the user, but are actually updated by > simple polling. We considered going web sockets until we looked at what > we'd gain and what we'd lose. > > Polling actually scales out really well. With a socket, your users' > connection is always consuming a socket, which is considered a resource. > Scaling of resources with web sockets is 1:1 with concurrent users. With > polling, you're essentially using time division to serve (potentially) many > more users with lower actual concurrency. App server concurrency is usually > the first bottleneck. If your app requests are served quickly, say 100ms, > you can serve 10 requests per second with a single app server > process/thread. If users are happy to get updates in one second, you have > the ability to serve 10 users with a single app sever process/thread. We > use a polling interval of 3 seconds and the illusion of real-time is > upheld. People simply expect things to take some time. > > Once you go web sockets, the server handling the web socket based requests > must have a socket available per user. Fortunately, there are Rails app > servers that offer better concurrency these days, but that concurrency can > still be put to good use with polling. The other option, which it looks > like you've already identified, is to use a PaaS provider to outsource that > bit. As you can see by Pusher's pricing, concurrency with web sockets gets > expensive quickly. > > Just food for thought. > > On Friday, March 13, 2015 at 8:58:13 PM UTC-4, Chris McCann wrote: >> >> I'm trying to put together a design for showing realtime data updates in >> a Rails app in response to calls to an API from mobile devices. >> >> We recently released an Android and iOS version of our first app, Vor >> Vision, which allows people to scan images that have an invisible code >> embedded in them. Think "invisible QR code", only without the ugly. You >> can check it out here: vorvision.com >> >> I've built a Rails backend app that hosts the API and allows a user to >> see scans of their images in realtime. Currently I just do simple Ajax >> polling but I want to significantly improve the app via a websockets-type >> updating system. >> >> When a mobile user scans an image, the owner of that image, if they are >> looking at the dashboard at that moment, should see the scan count for that >> image increment, along with the geolocation of the latest scan, possibly >> with a little highlighting or other chrome to call the user's attention to >> the update. >> >> I haven't used React.js, Angular.js or any of the other client-side JS >> frameworks, but one of these seems like a good fit for elegantly updating >> the client side data elements. The Flux-style architecture (from Facebook) >> seems possibly useful, if it's not overkill. >> >> Using server sent events (SSE) or websockets (via Pusher) seems like a >> good fit for the server side. >> >> Our local Planning Center Online published this: http://developers. >> planningcenteronline.com/2014/09/23/live-updating-rails- >> with-react.js-and-pusher.html >> >> Has anyone else done this or something similar? If so, what technology >> stack did you use? Got any pointers for me? >> >> Thanks all, >> >> Chris >> > -- > -- > SD Ruby mailing list > [email protected] > http://groups.google.com/group/sdruby > --- > You received this message because you are subscribed to a topic in the > Google Groups "SD Ruby" group. > To unsubscribe from this topic, visit > https://groups.google.com/d/topic/sdruby/sBP7M1n4j1U/unsubscribe. > To unsubscribe from this group and all its topics, send an email to > [email protected]. > For more options, visit https://groups.google.com/d/optout. > -- -- SD Ruby mailing list [email protected] http://groups.google.com/group/sdruby --- You received this message because you are subscribed to the Google Groups "SD Ruby" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. For more options, visit https://groups.google.com/d/optout.
