https://www.knowledgetrail.xyz/ Practical notes on software, systems, and the web. en-us https://www.knowledgetrail.xyz/posts/container-networking.html https://www.knowledgetrail.xyz/posts/container-networking.html Wed, 10 Jun 2026 09:00:00 +0000 A practical walk through how Linux network namespaces, veth pairs, bridges, NAT, DNS, and overlay networks combine to give containers their networking, and when to choose bridge, host, or none. https://www.knowledgetrail.xyz/posts/rate-limiting.html https://www.knowledgetrail.xyz/posts/rate-limiting.html Thu, 21 May 2026 09:00:00 +0000 A practical tour of the five core rate limiting algorithms, their burst and memory tradeoffs, where to enforce limits, and how to make them work across a distributed fleet. https://www.knowledgetrail.xyz/posts/git-internals.html https://www.knowledgetrail.xyz/posts/git-internals.html Sat, 02 May 2026 09:00:00 +0000 A look under the hood of Git's object model, content addressing, the index, and refs to explain exactly what a commit is and why branching is so cheap. https://www.knowledgetrail.xyz/posts/caching-strategies.html https://www.knowledgetrail.xyz/posts/caching-strategies.html Tue, 14 Apr 2026 09:00:00 +0000 A practical tour of cache patterns, eviction and TTL, invalidation, stampede mitigation, and the layered caches that sit between your users and your database. https://www.knowledgetrail.xyz/posts/robust-shell-scripts.html https://www.knowledgetrail.xyz/posts/robust-shell-scripts.html Mon, 30 Mar 2026 09:00:00 +0000 A practical guide to writing reliable Bash scripts using strict mode, traps for cleanup, careful quoting, idempotent operations, and correct handling of exit codes, pipelines, and command substitution. https://www.knowledgetrail.xyz/posts/tls-handshake.html https://www.knowledgetrail.xyz/posts/tls-handshake.html Mon, 16 Mar 2026 09:00:00 +0000 A step-by-step walkthrough of the TLS 1.3 handshake, covering ClientHello/ServerHello, ECDHE key exchange and forward secrecy, the certificate chain of trust, SNI, ALPN, and the tradeoffs of 0-RTT session resumption. https://www.knowledgetrail.xyz/posts/database-indexing.html https://www.knowledgetrail.xyz/posts/database-indexing.html Fri, 27 Feb 2026 09:00:00 +0000 A working developer's guide to how B-tree indexes work, when they help or hurt, how to design composite and covering indexes, and how to read query plans to validate your choices. https://www.knowledgetrail.xyz/posts/tcp-vs-udp.html https://www.knowledgetrail.xyz/posts/tcp-vs-udp.html Mon, 09 Feb 2026 09:00:00 +0000 A practical guide to choosing between TCP and UDP, covering reliability, ordering, head-of-line blocking, handshake overhead, real-world use cases, and where QUIC fits in.