About the Oracle Compute Cloud Service Environment in Oracle Java Cloud Service

Oracle Java Cloud Service is built on top of infrastructure and functionality that are provided by Oracle Compute Cloud Service. The work involved in setting up and managing the compute virtual machines and storage resources for your Java EE applications is done for you.

Topics:

About the Deployment Topology of Virtual Machines

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

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

Note:

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

As shown in the illustration, an Oracle Java 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.

When Oracle Coherence is enabled for a service instance, there is a second WebLogic Server cluster of Managed Servers for storing Coherence data. Both WebLogic Server clusters are associated with the single Coherence cluster in the domain. For information about the VM deployment topology when Oracle Coherence is enabled for a service instance in Oracle Java Cloud Service, see About Oracle Coherence and the Compute Environment in Oracle Java Cloud Service.

About the Virtual Machines

The Oracle Compute virtual machines in an Oracle Java Cloud Service environment are based on the Oracle Linux 6 (OEL6) 60-GB disk image. These virtual machines are highly available and the underlying infrastructure contains built-in capabilities to migrate an unhealthy virtual machine (VM) to a separate hardware cluster.

Each Oracle Java Cloud Service instance that you create can contain one or more Oracle Compute VM instances. The first VM always contains the WebLogic Administration Server and the first Managed Server. Each remaining Managed Server is hosted on its own VM. When the service instance is scaled out, each additional Managed Server is also on its own VM.

If a load balancer is enabled for a service instance, the Oracle Traffic Director (OTD) administration server is hosted on one VM. A second OTD node can optionally be hosted on another VM.

When using the wizard to provision an Oracle Java Cloud Service instance, you can create up to four Managed Servers in the cluster. You can also create up to two load balancers VMs. The following table summarizes the number of Managed Servers you can have in the WebLogic Server cluster, and the corresponding VMs:

VM Instance 1–Node Cluster 2–Node Cluster 4–Node Cluster

1st VM

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 VM

 

Contains Managed Server 2

Contains Managed Server 2

3rd VM

   

Contains Managed Server 3

4th VM

   

Contains Managed Server 4

5th VM

If present, the VM contains the OTD administration server

If present, the VM contains the OTD administration server

If present, the VM contains the OTD administration server

6th VM

If present, the VM contains a second OTD node

If present, the VM contains a second OTD node

If present, the VM contains a second OTD node

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 VM 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 VM would be present.

When Oracle Coherence is enabled for a service instance, a VM on the Coherence data tier can have one or more storage-enabled Managed Servers. The number of Coherence VMs and the number of Managed Servers configured per VM are based on the capacity unit definition that was declared for the service instance during initial provisioning.

The following table summarizes the number of VMs on the application tier and Coherence data tier, and the corresponding Managed Servers contained in the VMs 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) that’s created when you use a default capacity unit defined with three VMs and one Managed Server running on each VM:

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

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

You have access to all VM instances, including the VM on which the WebLogic Administration Server is running. You can use a Secure Shell (SSH) client to log into a VM, as described in Accessing a VM Through a Secure Shell (SSH).

For information about all Oracle Compute VM objects that are created or configured in an Oracle Java Cloud Service instance, see About Compute Virtual Machine Objects in Oracle Java Cloud Service.

About the Disk Volumes

You have access to all Oracle Compute Cloud Service virtual machine instances created for Oracle Java 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 Java 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 Java 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 OTD binaries.

/u01/app/oracle/middleware

JCS_RESERVED

Contains files required by Oracle Java Cloud Service, that is, any binaries and related metadata that are required by the Oracle Java Cloud Service management layer.

/u01/app/oracle/tools

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 a service instance is persistent. Content added to a persistent Boot/OS volume is retained if the service instance is restarted.