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Comment by jontammeh | Hacker News Reader

Interesting these are coming around now. Some services (i.e. Pubnub) have been doing this (for money) for a long time and what I noticed were at the end of the day, the use cases were actually rather limited.

Apart from stock quotes, bitcoin quotes and multiplayer games - polling just isn't that bad. And it's actually a very good place to start when developing as it's simple.

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Even if you don't need sub-second updates polling is still very wasteful. Your typical HTTP header is 700-800 bytes, so every 100,000 requests you're sending 75 megabytes of data you don't need to.

Websockets require 2 bytes, so those same 100,000 requests send only 200 kilobytes of additional data. Also it's worth noting that with Websockets data is only sent when there is new data to send. Saving you even more bandwidth.

Plus with services like Pubnub & Pusher websockets are really simply to get started with now as well. I would argue they're actually easier to use than polling.

Not to mention things like logging and metrics overhead if you're logging every request at multiple levels (application, NGINX, HAProxy).

Polling can be a fine place to start and is better than nothing. The speed of realtime updates does matter though. Even for seemingly boring use-cases like synchronizing CRM screens or something, it's still best if updates happen within a few seconds. And instant (sub-second) updates add an extra level of polish. Similar to non-flickering graphics and smooth scrolling, fast updates are impressive and can increase the appeal of an app.

Polling works for current use cases, but products of the future aren't built around current use cases ;-)

Programming is akin to woodworking. Lots of tools and all of it is for wood. Use the right tools to craft the right solutions.

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