7th April 2026
Research
SQLite WAL Mode Across Docker Containers Sharing a Volume
— SQLite’s WAL mode reliably supports concurrent access when two Docker containers share a volume on the same host, due to shared kernel and filesystem semantics. The experiment, using Docker Desktop for macOS and a named volume, demonstrated real-time propagation of database changes and effective memory-mapped file sharing by monitoring `.db-shm`.
Inspired by this conversation on Hacker News about whether two SQLite processes in separate Docker containers that share the same volume might run into problems due to WAL shared memory. The answer is that everything works fine - Docker containers on the same host and filesystem share the same shared memory in a way that allows WAL to collaborate as it should.
Recent articles
- Running Python code in a sandbox with MicroPython and WASM - 6th June 2026
- Claude Opus 4.8: "a modest but tangible improvement" - 28th May 2026
- I think Anthropic and OpenAI have found product-market fit - 27th May 2026