What is Lemmy?
Lemmy is a self-hosted social link aggregation and discussion platform. It is completely free and open, and not controlled by any company. This means that there is no advertising, tracking, or secret algorithms. Content is organized into communities, so it is easy to subscribe to topics that you are interested in, and ignore others. Voting is used to bring the most interesting items to the top.
Major Changes
This version brings major optimizations to the database queries, which significantly reduces CPU usage. There is also a change to the way federation activities are stored, which reduces database size by around 80%. Special thanks to @phiresky for their work on DB optimizations.
The federation code now includes a check for dead instances which is used when sending activities. This helps to reduce the amount of outgoing POST requests, and also reduce server load.
In terms of security, Lemmy now performs HTML sanitization on all messages which are submitted through the API or received via federation. Together with the tightened content-security-policy from 0.18.2, cross-site scripting attacks are now much more difficult.
Other than that, there are numerous bug fixes and minor enhancements.
Support development
@dessalines and @nutomic are working full-time on Lemmy to integrate community contributions, fix bugs, optimize performance and much more. This work is funded exclusively through donations.
If you like using Lemmy, and want to make sure that we will always be available to work full time building it, consider donating to support its development. No one likes recurring donations, but they’ve proven to be the only way that open-source software like Lemmy can stay independent and alive.
- Liberapay (preferred option)
- Open Collective
- Patreon
- Cryptocurrency (scroll to bottom of page)
Upgrade instructions
Follow the upgrade instructions for ansible or docker. There are no config or API changes with this release.
This upgrade takes ~5 minutes for the database migrations to complete.
You may need to run sudo chown 1000:1000 lemmy.hjson if you have any permissions errors.
If you need help with the upgrade, you can ask in our support forum or on the Matrix Chat.
Yes, I had to upgrade from Postgres 13 to get this working. I’m not sure if there’s a minimum Postgres version specified anywhere in the docs, I took a quick look but couldn’t find it.
For anyone else running Debian like me, you can add the official Postgres repo and use the pg_upgrade script to migrate to the new version.
I do not find it in the "From Scratch Install" documentation. I will work to revise those documents this weekend to warn people that 0.18.3 and later is incompatible. Thank you again for sharing.