Conviva

Part 2 of 2. Part 1: We replaced mmap with io_uring in our Rust query engine. It got slower. Part 1 left us stuck: a compio-based io_uring rewrite running 60% slower than the mmap baseline it was supposed to replace. We'd added O_DIRECT and worked around

Why Conviva replaced mmap with io_uring in its Rust query engine, what went wrong under real production load, and why the first rewrite ended up 60% slower.

In the beginning, there was mmap. It was convenient: it let us lazily read huge numbers of Arrow IPC files from disk without managing memory ourselves. It fit our file format perfectly - Arrow IPC's layout is designed for zero-copy random access, and mmap

A shopper is using a brand's AI agent to find wide-fit running shoes to train for a marathon. The agent recommends three pairs, answers every follow-up with confidence, and closes the conversation. Score that transcript on helpfulness, relevance, and clar

Around 2010, one of the first major broadcasters to launch a streaming product had a problem nobody could name. The apps loaded. The streams played. Every dashboard was green. And viewers were disappearing before a single frame appeared on screen. The met