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Solr Horizontal Scaling

This guide will give an overview on how KubeDB Ops-manager operator scales up or down Solr cluster replicas of various component such as Combined, Broker, Controller.

Before You Begin

• You should be familiar with the following KubeDB concepts:
  • Solr
  • SolrOpsRequest

How Horizontal Scaling Process Works

The following diagram shows how KubeDB Ops-manager operator scales up or down Solr database components. Open the image in a new tab to see the enlarged version.

  

The Horizontal scaling process consists of the following steps:

1. At first, a user creates a Solr Custom Resource (CR).

2. KubeDB Provisioner operator watches the Solr CR.

3. When the operator finds a Solr CR, it creates required number of PetSets and related necessary stuff like secrets, services, etc.

4. Then, in order to scale the various components of the Solr cluster, the user creates a SolrOpsRequest CR with desired information.

5. KubeDB Ops-manager operator watches the SolrOpsRequest CR.

6. When it finds a SolrOpsRequest CR, it halts the Solr object which is referred from the SolrOpsRequest. So, the KubeDB Provisioner operator doesn’t perform any operations on the Solr object during the horizontal scaling process.

7. Then the KubeDB Ops-manager operator will scale the related PetSet Pods to reach the expected number of replicas defined in the SolrOpsRequest CR.

8. After the successfully scaling the replicas of the related PetSet Pods, the KubeDB Ops-manager operator updates the number of replicas in the Solr object to reflect the updated state.

9. After the successful scaling of the Solr replicas, the KubeDB Ops-manager operator resumes the Solr object so that the KubeDB Provisioner operator resumes its usual operations.

In the next docs, we are going to show a step by step guide on horizontal scaling of Solr cluster using SolrOpsRequest CRD.