Vercel· 11 AugHow we migrated the database behind every Vercel build
Vercel migrated build pool state from Redis to DynamoDB
Vercel migrated the database behind its build warm pool from Redis to DynamoDB.
The state, which tracks container readiness, authentication tokens, and billing mappings, had become too important to keep in an ephemeral cache.
The migration ran live under production traffic in feature-flagged phases, with the container ID as the new sort key and tokens stored as hashes.
From the source
The problem is that the pool never stops. Containers are coming up, polling, picking up work, and expiring around the clock, which meant we couldn't pause the world, copy the data, and restart. The migration had to happen live, under production traffic, in phases, each one behind a flag with a rollback ready if we needed it.
vercel.com