---
title: "Hyperdrive"
description: "1 posts about Hyperdrive, summarised, each linking to the original."
---

# Hyperdrive
> 1 posts about Hyperdrive, summarised, each linking to the original.

## Articles

### [Inside Hyperdrive: How we solved a rare Hyperdrive MySQL caching bug](https://yomu.fyi/post/inside-hyperdrive-how-we-solved-a-rare-hyperdrive-mysql-caching-bug.md)
- Company: [Cloudflare](https://yomu.fyi/company/cloudflare.md)
- Author: Pranoy Dutta
- Published: Oct 14, 2026
- Type: Incident / postmortem

Hyperdrive is Cloudflare’s distributed database connection pooler for Workers; its MySQL support became GA after a beta that uncovered over 20 bugs, including a rare caching issue. The most challenging bug caused consistently empty query responses 0.001% of the time on cache-enabled instances, requiring deep protocol analysis. The root cause was that the Client and Endpoint nodes share a data center cache but use different MySQL capability flags, so a cache entry written by one node could be encoded with capabilities that the other node cannot correctly translate. When the reading node encountered such a mismatched entry, it either sent an early EOF or hung, resulting in empty rows for the Worker. The fix was to always write a canonical version of the query result bytes encoded with Hyperdrive’s own capabilities, regardless of which node stored it, which resolved the issue and raised reliability to the 99.99% target.