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.
Probably because Twitter is big, and LemmyWorld is small and also the fact that the rate limits are probably reasonable in LemmyWorld, compared to twitter.
There is nothing in theory wrong with a rate limit as long as its not set so absurdly low or to such a long amount of time as to impact actual users. The problem is implementing them stupidly.