About the Infrastructure Resources Used by Oracle SOA Cloud Service

About the Deployment Topology of Virtual Machines

Using Oracle SOA Cloud Service simplifies the work you've to do in order to provision and configure an Oracle WebLogic Server domain and cluster, and Oracle Traffic Director as the software load balancer.

The following illustration shows an example of the Oracle SOA Cloud Service virtual machine (VM) deployment topology that is set up and configured for you when you provision an Oracle SOA Cloud Service instance with two Managed Servers and also enable a load balancer:

Description of soacs_diagram_topology.png follows

Description of the illustration soacs_diagram_topology.png

Note:

For information about the network protocols and default ports that can be used from within Oracle Cloud and from outside Oracle Cloud, see About the Default Access Ports. Note that the HTTP port is disabled if you created the Oracle SOA Cloud Service instance by using the service instance creation wizard available through the Oracle SOA Cloud Service Console.

As shown in the illustration, an Oracle SOA Cloud Service instance is a single Oracle WebLogic Server domain that consists of one WebLogic Administration Server and one WebLogic Server cluster of Managed Servers for hosting applications. The example in the topology illustration shows a cluster of two Managed Servers.

About the Compute Nodes

The compute nodes in an Oracle SOA Cloud Service instance run Oracle Linux 6. These virtual machines are highly available and the underlying infrastructure contains built-in capabilities to migrate an unhealthy node to a separate hardware cluster.

Each Oracle SOA Cloud Service instance that you create can contain one or more nodes. The first node always contains the WebLogic Administration Server and the first Managed Server. Each remaining Managed Server runs in its own node. When the service instance is scaled out, each additional Managed Server is also on its own node.

If a local load balancer is enabled for a service instance, the Oracle Traffic Director administration server is in a separate node.

When using the Oracle SOA Cloud Service web console to create an instance, you can create up to four Managed Servers in the cluster. 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

Note:

By default a load balancer is not enabled for a service instance that has a single-node cluster in the WebLogic Server domain, 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.

Appropriate security rules are configured on the Oracle SOA 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 Classic 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 VM Through a Secure Shell (SSH).

About the Disk Volumes

You have access to all the virtual machine instances created for Oracle SOA Cloud Service, including the virtual machine on which the WebLogic Administration Server is running.

The following table lists the disk volumes that are attached to Oracle SOA Cloud Service virtual machines and the mount points:

Disk Volume	Purpose	Mount Point
Boot/OS volume	The boot volume as provided by the machine image. Contains the OS binaries.	Local disk, no mount point
Backup volume	Contains a copy of backups up to seven days old.	`/u01/data/backup`
`DOMAIN_HOME`	Contains data for the domain corresponding to the Oracle SOA Cloud Service instance.	`/u01/data/domains`
`APPLICATION_HOME`	Contains deployed applications and application configuration files.	`/u01/data/domains`
`MW_HOME`	Contains Oracle WebLogic Server binaries and Oracle Traffic Director binaries.	`/u01/app/oracle/middleware`
`JCS_RESERVED`	Contains files required by Oracle SOA Cloud Service, that is, any binaries and related metadata that are required by the Oracle SOA Cloud Service management layer.	`/u01/app/oracle/tools` Caution: Do not modify any scripts in the `/u01/app/oracle/tools` directory.
`JDK_HOME`	Contains JDK binaries.	`/u01/jdk`

Note:

All volumes under /u01, except DOMAIN_HOME and APPLICATION_HOME, should be treated as read-only volumes.
The Backup volume is writable by the oracle user; the opc user has read-only access.
The Boot/OS volume of any service instance provisioned before the mid-August 2015 update to Oracle SOA Cloud Service is an ephemeral disk volume. Content added to an ephemeral Boot/OS volume does not persist if the service instance is restarted. If the Boot/OS volume is ephemeral, the entire Boot/OS volume, including the home directory of the opc user, might be recreated from the machine image (for example, when an infrastructure patch is applied or the service instance is restarted).
The Boot/OS volume of any service instance provisioned before the mid-August 2015 update to Oracle SOA Cloud Service is persistent. Content added to a persistent Boot/OS volume is retained if the service instance is restarted.