Design News Feed

What are the different approaches for sending News Feed contents to the users?

1. Pull: Clients can pull the News Feed contents from the server on a regular basis or manually whenever they need it.

Cons:

Possible problems with this approach are

a) New data might not be shown to the users until clients issue a pull request

b) Most of the time pull requests will result in an empty response if there is no new data.

2. Push: Servers can push new data to the users as soon as it is available.

To efficiently manage this, users have to maintain a Long Poll request with the server for receiving the updates.

Cons:

A possible problem with this approach is, a user who follows a lot of people or a celebrity user who has millions of followers; in this case, the server has to push updates quite frequently.

3. Hybrid: We can adopt a hybrid approach.

We can move all the users who have a high number of follows to a pull-based model and only push data to those users who have a few hundred (or thousand) follows.

Another approach could be that the server pushes updates to all the users not more than a certain frequency, letting users with a lot of follows/updates to regularly pull data.

Reference

Gainlo.co: Design News Feed System (Part 1) | Design News Feed System (Part 2)