New to KubeDB? Please start here.

Upgrading Postgres version Overview

This guide will give you an overview of how KubeDB ops manager upgrades the version of Postgres database.

Before You Begin

• You should be familiar with the following KubeDB concepts:
  • Postgres
  • PostgresOpsRequest

How Upgrade Process Works

The following diagram shows how KubeDB KubeDB ops manager used to upgrade the version of Postgres. Open the image in a new tab to see the enlarged version.

The upgrading process consists of the following steps:

1. At first, a user creates a Postgres cr.

2. KubeDB-Provisioner operator watches for the Postgres cr.

3. When it finds one, it creates a StatefulSet and related necessary stuff like secret, service, etc.

4. Then, in order to upgrade the version of the Postgres database the user creates a PostgresOpsRequest cr with the desired version.

5. KubeDB-ops-manager operator watches for PostgresOpsRequest.

6. When it finds one, it Pauses the Postgres object so that the KubeDB-Provisioner operator doesn’t perform any operation on the Postgres during the upgrading process.

7. By looking at the target version from PostgresOpsRequest cr, In case of major upgrade KubeDB-ops-manager does some pre-upgrade steps as we need old bin and lib files to upgrade from current to target Postgres version.

8. Then By looking at the target version from PostgresOpsRequest cr, KubeDB-ops-manager operator updates the images of the StatefulSet for upgrading versions.

9. After successful upgradation of the StatefulSet and its Pod images, the KubeDB-ops-manager updates the image of the Postgres object to reflect the updated cluster state.

10. After successful upgradation of Postgres object, the KubeDB ops manager resumes the Postgres object so that the KubeDB-provisioner can resume its usual operations.

In the next doc, we are going to show a step by step guide on upgrading of a Postgres database using upgrade operation.