https://xuzhang.site/ Notes on Linux, networking and self-hosting. en Tue, 20 Oct 2026 08:00:00 +0000 https://xuzhang.site/posts/http2-multiplexing/ https://xuzhang.site/posts/http2-multiplexing/ Tue, 20 Oct 2026 08:00:00 +0000 How streams share one TCP connection, why browsers stopped opening six connections per host, and where head-of-line blocking still bites. https://xuzhang.site/posts/caddy-static-site/ https://xuzhang.site/posts/caddy-static-site/ Wed, 02 Sep 2026 08:00:00 +0000 A small Caddyfile that serves a static site with automatic HTTPS, compression, sensible headers and a custom 404 page. https://xuzhang.site/posts/debian-12-checklist/ https://xuzhang.site/posts/debian-12-checklist/ Wed, 15 Jul 2026 08:00:00 +0000 The short list of things I do on every fresh Debian 12 VPS before putting anything on it. https://xuzhang.site/posts/tls13-handshake/ https://xuzhang.site/posts/tls13-handshake/ Thu, 28 May 2026 08:00:00 +0000 What actually goes over the wire in a TLS 1.3 handshake, why it takes one round trip, and what changed with hybrid post-quantum key exchange. https://xuzhang.site/posts/systemd-timers/ https://xuzhang.site/posts/systemd-timers/ Wed, 11 Mar 2026 08:00:00 +0000 Timers take two small files instead of one crontab line, but you get logging, missed-run catch-up and dependency handling for free.