I have three boxes using cloudlinux. one of them using lsws 4.1.13, and lsws 4.2.1 for others . but they are all using the same lsapi 6.1. and they are together keep sending 503 error emails. sometimes 503 errors stoped after setting Memory Soft Limit to beyond 650 Mb. but i have to stop raising Memory Soft Limit because more higher value seems doesn't make sense to me (more than 650mb).