Before You Begin

This 20-minute tutorial shows you how to add and remove nodes for the cluster of an Oracle Java Cloud Service instance. It also describes how to add storage to a node.

Background

Scaling a cluster is the process of adjusting the cluster size by adding a node to the cluster ("scaling out") or by deleting a node from the cluster ("scaling in"). Scaling a node is the process of adding block storage to an existing volume or creating and attaching a new storage volume to the node. Scaling a node also could mean changing the current shape of the node by using a larger shape ("scaling up") or a smaller shape ("scaling down"); this function is available only for Oracle Java Cloud Service instances provisioned on Oracle Cloud Infrastructure Classic.

Note: If Oracle Coherence is enabled for your service instance and you intend to scale the data tier cluster, see Scaling the Data Grid Cluster of an Oracle Java Cloud Service Instance.

What Do You Need?

• An Oracle Java Cloud Service instance. This tutorial uses a service instance provisioned on Oracle Cloud Infrastructure. (See Creating a Custom Oracle Java Cloud Service Instance)
• Java Administrator role.

Scale Out the Cluster

1. Sign in to Oracle Cloud at https://cloud.oracle.com/en_US/sign-in.
2. From the My Services dashboard, click Navigation menu , expand Services, and select Java.
3. From the Oracle Java Cloud Service console, click the name of your service instance. In this tutorial example, the service instance name is ExampleInstance.

   

4. On the Instance Overview page, note the number of nodes on the Overview tile. The number of nodes you have in your service instance is the cluster size. In this tutorial example, the cluster size is 1.

   

5. To scale out the cluster, click the plus (+) button on the service instance toolbar.

   

6. In the Scale Out dialog, confirm that WLS is selected, then click Scale Out.

   

   A message is displayed on the page, showing that the scale request has been submitted. The Yield icon () indicates that the instance is in maintenance and cannot be used at this time. On the Overview tile, you'll also see the message "Scaling out..."

   

7. After a few moments, click (Refresh) just below the service instance toolbar.

   

   When the Instance Overview page is refreshed, a line item for the node you are adding is displayed under the existing node. (You might have to click more than once.) There is an hour glass symbol on the newly added node icon.

   

8. On the banner, click and select View Activity.

   

9. On the results table, expand the scale out operation to see the progress of the request.

   

10. Return to the Instance Overview page by clicking the Instances tab and then the service instance name.
11. If necessary, click to refresh the Instance Overview page until the scale out operation completes. (You might have to do this more than once).

    When the scale out operation is completed, observe the following:

    • The maintenance mode icon has disappeared.
    • The hour glass symbol is no longer displayed on the new node icon.
    • The Overview tile indicates that the number of nodes has increased by one. In this tutorial example, the cluster size or number of nodes is now 2.

    

Scale In the Cluster

1. On the Instance Overview page, locate the node you added in the preceding task. Click and then click Remove Node.

   

2. In the Remove Node dialog, select the Force scale in the VMs checkbox, and then click Remove Node. Selecting the checkbox allows Oracle Java Cloud Service to remove the node even if the VM or Managed Server instance is unresponsive.

   

   A message is displayed on the page, showing that the scale request has been submitted. The Yield icon () indicates that the instance is in maintenance and cannot be used at this time. On the Overview tile, you'll also see the message "Scaling in..."

   

3. After a few moments, click to refresh the Instance Overview page.

   When the Instance Overview page is refreshed, note the symbol on the icon of the node you are removing.

   

4. In the In-Progress Operation Messages area, expand the item Scale In In Progress to see the progress of the activity.

   

5. Click to refresh the Instance Overview page until the scale in operation completes. (You might have to do this more than once).

   When the scale in operation is completed, observe the following:

   • The maintenance mode icon has disappeared.
   • The line item for the node you added in the preceding task has been removed from the page.
   • The Overview tile indicates that the number of nodes has decreased by one. In this tutorial example, the cluster size or number of nodes is now 1.

   

Scale a Node

Scaling a node has two aspects: adding storage or changing the compute shape. Adding storage is shown in this tutorial example since you cannot change the node compute shape of a service instance created on Oracle Cloud Infrastructure.

To scale a node by adding block storage:

1. On the Instance Overview page, locate the node you want to scale by adding block storage. In this tutorial example, the exampleinstance-wls-1 node will be scaled. Note the Storage value for the node.

   

2. Click and then click Add Storage.

   

3. In the Add Storage dialog, select Additional Partition Size GB and enter 50 to create a new storage volume with the minimum size. Then click Yes, Add Storage.

   

   A message is displayed on the page, showing that the request has been submitted. The Yield icon () indicates that the instance is in maintenance and cannot be used at this time. On the Overview tile, you'll also see the message "Adding Storage..."

   

4. After a few moments, click to refresh the Instance Overview page.

   When the Instance Overview page is refreshed, note the hour glass symbol on the icon of the node you are scaling.

5. In the In-Progress Operation Messages area, expand the item Add Storage In Progress to see the progress of the operation.

   

6. Click to refresh the Instance Overview page until the operation completes. (You might have to do this more than once).

   When the add storage operation is completed, observe the following:

   • The maintenance mode icon has disappeared.
   • The hour glass symbol is no longer displayed on the node icon.
   • The Storage value on the node has increased.

   

Want to Learn More?

• Oracle Java Cloud Service Tutorials
• Oracle Java Cloud Service Documentation