DirectAdmin gives each user one PHP-FPM pool, not each site. That single design fact explains most of the 502s on a busy shared box. Here is how to find the pool files, size pm.max_children from real memory numbers, set per-site limits that WordPress cannot override, and make the changes survive the next rewrite_confs.
Benchmarks pick the wrong winner. Here is how Nginx, Apache and Caddy actually differ in production: how each one fails under load, who owns certificate renewal, and where configuration lives when a developer needs to change it. Includes a decision procedure and the mistakes I see most.
MySQL was gone in the morning because the kernel picked it to reclaim memory from Redis. Redis ships configured as a durable datastore, and you are using it as a cache. Setup takes ten minutes; the gotchas are memory limits, shared namespaces and the one enormous key nobody mentions.
Your homepage loads instantly and your dashboard takes eight seconds. That is not a contradiction: wp-admin is the only part of your site that never gets cached. Here is where the time actually goes, in the order worth checking.
Learn how to debug WordPress like a professional. Discover how to fix common WordPress errors, optimize performance, improve security, troubleshoot plugins, themes, databases, and server issues with this complete step-by-step guide.