Limited mental capacity these days, so I don’t have the spoons to properly research and implement a solution at the moment. I installed Nepenthes last year, but I’ve never managed to get round to integrating it into my site. It’s low priority at the moment.

Around 2010, I used to work at an MSP, and once had a customer that ran a custom LAMP stack website for local radio UK stations web presence. It was a bit slow, running on a dedicated physical server, but every time it snowed, the website would 500 out - because of too many requests to the “School Closures” page. The site had no caching other than Apache’s internal cache, but PHP pages could not be cached because “reasons”, and the original developer was “not available”. I optimised their MySQL indexes, increased the number of Apache workers, and it improved the render time per page and number of concurrent connections. Stress testing looked good.

Anyway, some months later, 2AM one snowy morning, I was on call, and it went down again. This was when I discovered the school closures problem. After diagnosing, and then liaising with the customer to discuss the options, I was told “just make it work”. I ended up modifying the PHP script to add some “on spec” caching that saved the HTML to a temp file in ramdisk, and only re-ran the query-and-render code if the cached copy was more than 5 minutes old. It was hacky, but it did the trick, and I was finished by about 4 AM. This hack was later applied at their request to a number of trouble-points in the source tree, as and when things broke.

We recommended adding a Varnish cache, and found a more generalised caching library but they wouldn’t/couldn’t authorise engineering work for this - they were running on a shoestring - and they already had the tech break-fix contract with us, and decided it was sufficient to just spot fix things as they broke rather than fix the root cause.

I left that MSP in 2012, so I don’t know what happened after that, but as far as I know, the site could still be running… unlikely, but possible.

I have my blog address (which goes to my home server) in my Mastodon profile, and every time I post on Masto, my server gets a request from every Mastodon site that federates with my instance - i.e. hundreds of requests. It’s no problem for my server, because my blog is a static site, but for anything that dynamically generates every single page impression (like worpress or joomla), it could be a problem. Caching settings might help, I suppose.

Truth is, though, I get far more traffic from vulnerability scanners and AI crawlers that don’t honour robots.txt (or aren’t yet listed).