Today, like the past few days, we have had some downtime. Apparently some script kids are enjoying themselves by targeting our server (and others). Sorry for the inconvenience.
Most of these 'attacks' are targeted at the database, but some are more ddos-like and can be mitigated by using a CDN.
Some other Lemmy servers are using Cloudflare, so we know that works. Therefore we have chosen Cloudflare as CDN / DDOS protection platform for now. We will look into other options, but we needed something to be implemented asap.
For the other attacks, we are using them to investigate and implement measures like rate limiting etc.
That doesn't help with volumes of otherwise legit looking traffic right? The problem that Cloudflare and Akamai etc address is usually content that is otherwise static that can be cached. Say the front page of hot lemmy.world is updated every few minutes with the newest hot item. That page is otherwise distributed by the CDN so the CDN can just direct the traffic to access it, and no requests are made to lemmy.world.
nginx would be helpful for any attacks located from a single address trying to making large numbers of connections, but without reading more into the attack I can suspect that this isn't what the attacker did.