Compute Topology for Oracle Java Cloud Service Instances

Each instance of Oracle Java Cloud Service is hosted on one or more Oracle Linux compute nodes. The number of compute nodes that an instance has depends on the number of WebLogic Servers and the load-balancer configuration.

The first node contains the WebLogic Administration Server and the first Managed Server. Each of the other Managed Servers runs on a separate node.

If Oracle Traffic Director is used as the load balancer, then the Oracle Traffic Director administration server and the first load-balancer node are on one compute node. If the instance has a second load-balancer node, then that node is on a separate compute node.

The following table summarizes the number of Managed Servers you can have in the WebLogic Server cluster, and the corresponding nodes:

Compute Node 1–Node Cluster 2–Node Cluster 4–Node Cluster

1st node

Contains WebLogic Administration Server and Managed Server 1

Contains WebLogic Administration Server and Managed Server 1

Contains WebLogic Administration Server and Managed Server 1

2nd node

Contains Managed Server 2

Contains Managed Server 2

3rd node

Contains Managed Server 3

4th node

Contains Managed Server 4

5th node

If present, this node contains the load balancer’s administration server

If present, this node contains the load balancer’s administration server

If present, this node contains the load balancer’s administration server

6th node

If present, this node contains a second load balancer

If present, this node contains a second load balancer

If present, this node contains a second load balancer

Note:

By default a load balancer is not enabled for an instance that has a single-node WebLogic cluster, so the Oracle Traffic Director node won't be present. When you create a service instance that consists of a multinode cluster in the domain, Oracle recommends that you enable a load balancer for the service instance. If enabled, the Oracle Traffic Director node would be present.

When Oracle Coherence is enabled for a service instance, a node on the Coherence data tier can have one or more storage-enabled Managed Servers. You configure the initial number of Coherence nodes and the number of Managed Servers per node when you create the service instance.

The following table summarizes the number of nodes on the application tier and Coherence data tier, and the corresponding Managed Servers contained in the nodes for an Oracle Java Cloud Service—Coherence instance. The example in the table shows a configuration consisting of a 2-node application tier cluster (storage-disabled), and a 3-node Coherence data tier cluster (storage-enabled) in which one Managed Server is running on each node:

Compute Node Contains WebLogic Server Cluster
1st node WebLogic Administration Server, Managed Server 1(storage-disabled) Application Tier
2nd node Managed Server 2 (storage-disabled) Application Tier
3rd node Managed Server 3_DG (storage-enabled) Coherence Data Tier
4th node Managed Server 4_DG (storage-enabled) Coherence Data Tier
5th node Managed Server 5_DG (storage-enabled) Coherence Data Tier

Appropriate security rules are configured on the Oracle Java Cloud Service nodes to enable communication among the different nodes hosting the WebLogic managed servers, and also with the Oracle Traffic Director nodes and the Oracle Database Cloud Service nodes.

You have access to all the compute nodes, including the node on which the WebLogic Administration Server is running. You can use a Secure Shell (SSH) client to log into a node, as described in Access a Node with a Secure Shell (SSH).