PostgreSQL 12 High Availability Cookbook - Third Edition

Minimizing Downtime

Every piece of software has bugs. All hardware eventually fails or becomes obsolete. No environment is perfect. As a consequence, even a perfectly healthy database will require downtime periodically. So, how do we reconcile this need with client expectations that demand data is always available no matter the circumstances?

As users ourselves, we can relate to the frustration associated with attempting to use an application or website that isn't responding. Perhaps the only impediment is a message indicating maintenance. No matter the cause, we have to remember to come back later and hope everything is working normally by then. Even with our knowledge about the complexity of software and databases, it is sometimes difficult ...