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Joined 2 years ago
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Cake day: July 9th, 2023

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  • If you just make it public it wouldn’t be an announcement, and it wouldn’t have the irreplaceable first impression effect that you fear, because the only people who will see it are the very curious ones like I am.

    At least explain to us what it’s all about if you won’t post it. I would love to know and see if I would be interested in contributing!



  • bringing up RSS feeds is actually very good, because although you can paginate or partition your feeds, I have never seen a feed that does that, even when they have decades of history. But if needed, partioning is an option so you don’t have to pull all of its posts but only recent ones, or by date/time range.

    I would also respectfully disagree that people don’t subscribe to 100’s of RSS feeds. I would bet most people who consistently use RSS feed readers will have more than 100 feeds, me included.

    And last, even if you follow 10,000, yes it would require a lot more time than reading from a single database, but it is still on the order of double digit seconds at most. If you compare 10,000 static file fetches with 10,000 database writes across different instances, I think the static files would fare better. This isn’t to mention that you are more likely to have to write more than read more (users with 100k followers are far more common than users with 100k subscriptions)

    And just to emphasize, I do agree that double digit seconds would be quite long for a user’s loading time, which is why I would expect to fetch regularly so the user logs onto a pre made news feed.




  • Oh my bad, I can explain that.

    Before I do, one benefit of this method is that your timeline is entirely up to your client. Your instance becomes primarily tasked with making your posts available, and clients have the freedom of implementing the reading and news feed / timeline formation.

    Hence, there are a few ways to do this. The best one is probably a mix of those.

    Naive approach: fetch posts and build news feed when user requests it

    This is not a good approach, but I mention it first because it’ll make explaining the next one easier.

    • User opens app or website, thereby requesting their timeline / news feed
    • server fetches list of user’s subscriptions and followees
    • for each followee or subscription, server fetches their content via their static file wherever they are hosted
    • server performs whatever filtering and ordering of content they want
    • user sees the result

    Cons: loading time for the user may be long, depending on how many subscriptions they have it could be several seconds. P90 may even be in double digits.

    Better approach: pre-build user’s timeline periodically.

    Think like a periodic job (hourly, or every 10 min, etc) , which fetches posts in a similar manner as described above, but instead of doing it when user requests it, it is done in advance

    Pros:

    • fast loading time compared to previous solution
    • when the job runs, if users on the same instance share a followee or subscription, we don’t have to query it twice (This benefit already exists on current fediverse implementations) Cons: posts aren’t real-time, delayed by the batch job frequency.

    Best approach: hybrid

    In this approach, we primarily do the second method, to achieve fast loading time. But to get more up-to-date content, we also simultaneously fetch the latest in the background, and interleave or add the latest posts as the user scrolls.

    This way we get both fast initial load times and recent posts.

    Surely there’s other good approaches. As I said in the beginning, clients have the freedom to implement this however they like.


    1. I write a post, and send a request to the server to publish it
    2. The server takes the post and preprends it to the file housing all my posts
    3. Now, when someone requests my posts, they will see my new one

    If a CDN is involved, we would have to properly take care of the invalidations and what not. We would have to run a batch process to update the CDN files, so that we are not doing it too often, but doing it every minute or so is still plenty fast for social media use cases.

    Have to emphasize that I am not expert, so I may be missing a big pitfall here.