Type of Upgrades for Deployments in Kubernetes

There are two ways to do upgrades for deployments in Kubernetes:

1. Rolling upgrades - default
2. Recreate

Recreate

All existing pods are killed before new pods are created.

Rolling Upgrades

It replaces some pods at a time (controlled via maxUnavailable and maxSurge).

maxUnavailable specifies the max number of pods that can be unavailable during an upgrade. It can be a number (like 2) or a percentage (like 25%)

maxSurge specifies the max number of pods that can be created during the upgrade. It can be a number of a percentage.

Default value for both is 25%.