As outlined in a previous blog post, Heroku Data services undergo routine maintenances for security and patching. In this post, we describe the process used to minimize downtime for Heroku Postgres and Heroku Key-Value Store premium ‘High Availability’ plans and how we optimized the process to perform up to 75% faster.
Data Services Architecture
High availability plans for Postgres and Redis are designed to have two database instances running at the same time. One is a writeable primary database server and the other is a read-only hidden standby. Since the standby is hidden, customers cannot access it during normal operations.
Before starting a planned maintenance, we do our best to...