Sorry about the long downtime everyone. What happened is sometime around 20:00 yesterday the instance went down. I wouldn't be able to ssh into the server until the morning, so I tried restarting the server through our hosting's web interface, but this didn't work.
When I got home I found the reason Lemmy wasn't working was because the database had suffered some corruption. Thankfully, the only lost data was 3 posts, but some data got duplicated in random tables that shouldn't be and this wasn't the easiest thing to track down.
Why did the server go down in the first place?
I don't actually know the real reason, what I suspect happened is that the frontend got taken down by the rampant scraping we've been subject to. To put it into prospective, just look at the jump in the size of our web logs:
These are compressed plain text, like it's unreal.
But back to the server, I think when I restarted the server to get everything back up, docker killed the database before it had shutdown properly hence the corruption.
Anyway, it's sorted now. It's going to be a bit quiet until we've caught up with the activities we've missed, so enjoy the quiet while you can.
Do you have anything in place for detecting and mitigating DOS attacks? I wonder if you were to grep the logs by IP address you'd see the offending IP addresses. Though if you're using a load balancer or some other kind of proxy and don't have IP address forwarding configured, all requests might come through as the same IP address.
I'd also check that there's plenty of disk space spare, given that the log files are so large, as I've seen environments start to behave unusually once disk space has ran out, including SSH locking up.