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!
What a phenomenal response. Every single day makes me happy that I chose lemme.ee as my home instance. Truly appreciate all of the hard work you are pouring into this. And we can see how difficult it is based off of your total transparency. Thank you!
Yo, I'm a simple Reddit refugee, just trying to figure out how to make my way in the fediverse, and I signed up to lemm.ee not long after this post went up. I honestly chose this instance on a whim, and after a bit of exploring and learning about how Lemmy works, boy does this post make me glad I landed here!
Thanks for running this instance, and for housing us reddit noobs :)
Can you tell me what you've cached? I'm not using cloudflare but I am using haproxy which has frontend caching builtin. It was next on my plan but if you share your caching setup I can try to replicate it on lemmy.dbzer0.com
Mostly all images are served through a cache. I would like to also cache some static HTML (such as pages for unauthenticated users), but it breaks due to some users requesting these pages with an Accept header for an activitystream content-type, and I haven't had time to figure out a solution for accounting for the content type in my cache key unfortunately 😅. But if you can do that easily in your cache then for sure you could also cache any static pages for a minute or so.
Thank you @sunaurus@lemm.ee for all of your work. I am continually realizing that I chose the right instance with how transparent and responsive you have been.
I've just joined up to lemme.ee and subscribed to a community on another instance. I can see the posts in that community, but they all show up with zero comments. If I view the community on the web, there are several comments there. Is this a bug?
Just to add to the other reply, if there's an old comment chain you really want to reply to you can grab the URL of the last comment, search for it through your home instance and that'll force an index of the comment you searched for plus any parents.
The DoS was responsible for about 10-20% increased load on our system - it wasn't the root cause of the slowdowns, it was more like a nice cherry on top of the cake 😅 The bigger issue is the constantly increasing federation load.
I hope years from now you get to look back on these times as the beginning of something great not only for you, but also for the future of social media on the internet. Your dedication to this project has been admirable, and you are absolutely crushing it.
On a side note, really liking this 0.18.1 release candidate version, the 0.18.1 official release is going to be brilliant. The new compact view is beautiful and it scales with window width nicely. They just need to drop the post header size a bit and the compact view will be perfect. This release candidate seems to be pretty solid, only seeing fixes, no new bugs.
I mean protocol buffers might be more efficient, but json is nice and readable. Much nicer than XML for an example. And significantly more readable than protobuf!
Yeah the slowdown was a bit rough, been browsing off and on all day today. Thanks for fixing that. Seems to be working a lot better now. That's a bummer you had to increase expenses though.
Agreed! I was hopping around trying to figure out how to choose an instance (and only somewhat understanding how the site works so far lol), but these super transparent posts and the effort clearly being put in to keep things running smoothly + be welcoming to reddit "refugees" is what made it easy to pick this instance to sign up on first! Thank you for all the hard work!! :)
You are awesome man. I wanted to wait until the instance matured before committing to a monthly donation but I am signing up now. You're the best instance admin anyone can hope for. Glad to see your patch make it to 0.18
I joined this instance after reading this post. My inclination is to operate my own instance; but it seems best to wait until some of the dust settles and some of the bugs get discovered and fixed, first. The admins here seem capable of doing just that, while providing a stable platform.
I just joined up too after having lots of issues on lemmy.world, which is not surprising with how many people are flooding over. Someone commented about lemm.ee and I'm also really liking it. The performance difference is huge! I also love how the owner/dev talks about the instance. Seems like this will be a good one to stick with and use as primary.
I am curious about membership counts on communities though. On other instances I'll see a community member count of around 1000 and on here, it shows the (same community) is nowhere near that high. Are you saying that the lower number is more accurate? Or maybe it's a syncing issue and with all the signups happening the numbers just haven't had a chance to get caught up?
The instance its hosted on is probably the most accurate. The reason I said this one was more accurate is because the old one I used had many posts without any comments and some posts were missing completely while this was showing most if not all of them. It will probably never be 100% synced due how lemmy works I guess.
If you're viewing a community through an instance that isn't the one it's actually hosted on, you'll see a lower subscriber count because as far as I'm aware it's showing the number of subscribers from the instance you're viewing it on rather than the total.
Yeah @sunaurus@lemm.ee is really optimizing the hell out of this instance. A driver for me right now is he's running the release candidate for 0.18.1 and it's a huge improvement for me over 0.18.0. He's also a dev on the project so he's getting fixes in as well.
I'm so grateful for your knowledge and persistence. My donation finally went through after fighting with my bank. Maybe I don't have to give up my Gen X card afterall.
Alrighty, I had a browse around and I've settled on lemm.ee + Jerboa and it's looking good. Thanks for all your hard work handling the influx of reddfugees like myself. This gives me hope ❤️
Thank you very much. I've been made to feel very welcome and have joined on of the many support groups, that his helping me remove typing r/ from my muscle memory. Have a great weekend.
Thank you for using your time and resources to create this space! Reading updates on server performance in main, gives me a tingly homey feeling I haven't felt in a loooong time
I would like to see a create a sub for dummies video or post. I followed the link to create a sub, and I’m a dummy. I don’t get it. Once subs can be created easily, this community will grow much faster now that Apollo is gone. RIP
I've not created any communities myself, but looking at the form it seems pretty straightforward. Is there a particular field that could be better explained, or are you getting some sort of error?
Awesome news! I did make a small fix to a localization bug in Lemmy-ui, which was causing some people to not see posts, so it could have been that. But in any case, I'm glad it's sorted for you!
I know what you mean! The good news is that there are some huge improvements for federation in 0.18.1. These improvements depend on instances at both ends being on 0.18.1, so we'll start seeing it kick in shortly as more of the network upgrades.
I'm definitely seeing an increase in speed. I think at some point there will be a market for servers that users must pay to use. For the time being, I'm more than happy to contribute to a server that is open to all, but good speed needs to be there.
Connect is great, nicest app I've used for Lemmy so far. I do wish it had a way to swap instances quicker without an account, as I get the need for posters, but I don't like posting.