Hey lemmings!

I wanted to share a quick update about our recent performance issues and how I have addressed them.

The last 24h have been a bit rough for lemm.ee.

Last night, I spent some time debugging federation issues with lemmy.world. We managed to significantly improve the situation - lemmy.world content is now reaching lemm.ee with a very high success rate - but this has had the effect of increasing incoming federation traffic on our servers significantly.

Additionally, we have been seeing steadily increasing normal user traffic over the past week, which is awesome from a community standpoint, but of course means that our servers have to do more work to keep up with all the new people.

To top things off, today there appeared a badly configured instance in the network, which was effectively launching a DoS attack against lemm.ee for several hours. Most likely it was unintentional, but unfortunately the end result was a sudden increase in our server load.

All these factors combined resulted in a really bad experience for most lemm.ee users today. Page load times have consistently been spiking into as much as 10 seconds or more for the whole day:

In fact, a lot of page loads just timed out with errors.

Fortunately, it seems I have managed to clear up the problems!

I have put a bunch of mitigations in place, and after monitoring the situation for the past hour, it seems that our performance issues have been resolved for now. So hopefully, you can enjoy browsing lemm.ee again without it feeling like torture!

Here are specific steps I took:

• I have doubled the hardware resources for our backend servers and database.
• I purchased a Cloudflare pro subscription for lemm.ee for 1 year. This took out a considerable chunk of my budget for lemm.ee, but in return it will allow me to analyze and optimize our cache usage to a far greater extent. I am already seeing vastly reduced load times for cacheable content (try opening https://lemm.ee a few times in a row as a logged out user - it should be blazing fast now!)
• I have configured a rate limiter which will prevent future DoS from the specific method that was used against us today.

Of course, all of the above is costly. Luckily, lemm.ee users have been very generous with donations in the month of June, and in fact a significant amount of donors have opted for monthly recurring contributions. This all gives me the confidence to increase our spending for now, and I am currently expecting to NOT increase my personal planned contribution of 150€/month, as the increased costs so far are entirely being covered by donations!

Let me take this opportunity to thank the sponsors who made the upgrades possible! All lemm.ee users are now enjoying better performance thanks to you, I could not have done it without you awesome people.

On a final note, I just want to say that I hope a lot of these issues can be solved by optimizations in Lemmy software itself in the future. I have been personally contributing several optimizations to the Lemmy codebase, and I know many others are focused on optimizations as well. Just throwing extra resources at the problem will probably not be a sustainable solution for very long 😅. But I am optimistic that we are moving in the right direction with the software changes, and we’ll be enjoying reduced resource needs before long.

That’s all I wanted to share today, I wish you all a great weekend!