Does lemmy federation sync old posts or just posts that have been updated since a user subscribed?

Ice@lemmy.icyserver.eu to Fediverse@lemmy.world – 55 points –
15

🧟John is a 🍎lemm.app user, he subscribes to 🐢turtle community on 🍌lemm.ban

he is the first ever to do this on 🍎lemm.app

so 🍎lemm.app creates a copy with the last 20 posts and now will always keep in sync with future posts

👩‍🚀Jill is also a user on🍎 lemm.app, she subscribes to the same 🐢turtle community but a year later.

she will be able to see all the posts of that year all the way up to those 20 posts.

According to their documentation:

  • If you search for a community for the first time (no user ever subscribe to that community in your instance), 20 posts are fetched initially.
  • After you subscribed, the community will send updates to your instance. So new posts, comments, etc will be federated going forward.
  • If you want to pull older posts or comments to your instance, you can paste their url into the search field and wait a few seconds to pull them. If you're pulling a comment, sibling comments are not fetched, only parent comments got included automatically.

https://join-lemmy.org/docs/administration/federation_getting_started.html

I have my own instance and that first bullet point hardly ever works. I usually get a complete empty community. Occasionally I'll get one or two posts, but they will have no comments or votes. Very rarely everything comes through as expected.

In my experience, it usually happen when you try to subscribe to a community from lemmy.ml. Their server's datacenter appear to have a shitty peering and often timeouts depending on your location/ISP. If your instance is in US, it'll usually load but not always.

I have had it happen equally on lemmy.ml, lemmy.world, and beehaw.org. I am in the US.

Strange, it usually loads 20 posts on my instance after a minute or so, unless if the community is from lemmy.ml.

It's been a while since I pulled a community. It's very possible it has improved recently.