Over the last few weeks we've seen a lot of cases of previously low load accounts suddenly getting suspended for high memory usage. Of course, quite a few people have accused us of having inaccurate load monitoring, and we have wasted a great deal of time testing the load monitoring over and over and over and over again. As far as we could see the load monitoring was working perfectly. Since we're going to be launching Morty soon it is very important to us to have accurate load monitoring. Well, we finally figured out the problem. The load monitoring is working perfectly, and since it works so well, it helped us find the actual issue:
People's PHP processes aren't always exiting like they should.
Normally PHP processes fire up, spit out some website after a few milliseconds, and then hang around for a maximum of 30 seconds or so before their memory is reclaimed by the OS. We've been seeing some PHP processes lock up and continue using memory for over 22 hours.
We have already devised and implemented a fix that should make sure this high memory usage doesn't continue, but as always we recommend keeping an eye on your load chart at https://heliohost.org/dashboard/load/ and let us know if anything abnormal is happening. We also recommend taking a look at your web statistics, and blocking any abusive IPs you find. We're also seeing a lot of accounts with 10k to 100k page hits per day from hacker bots, etc. Obviously no human has visited your site ten thousand times in a single day so just block them with .htaccess. We can't block IPs for you because there are legitimate reasons for you to have tons of page hits from a single IP, such as running an API. Let us know if you need help.