About Oracle Java Cloud Service—Coherence Instances

You can enable Oracle Coherence when you create a service instance in Oracle Java Cloud Service using the Oracle Java Cloud Service Console or the REST API. For clarification purposes in this document and others, service instances provisioned to use Oracle Coherence in Oracle Java Cloud Service are referred to as Oracle Java Cloud Service—Coherence instances.

When you provision a service instance using the Create Java Cloud Service wizard, there are certain options you must select and specific Coherence details you must specify, so that an environment for using Oracle Coherence in Oracle Java Cloud Service is correctly provisioned and configured for you.

Note:

You can enable Oracle Coherence on any service instance but only those running Oracle WebLogic Server 12c (12.1.3 or 12.2.1) provide tooling to provision and manage your cache capacity. If the service instance is running Oracle WebLogic Server 11g you must manually configure and start Oracle Coherence by directly accessing the VMs that comprise the service instance.

To enable Oracle Coherence for an Oracle Java Cloud Service instance that’s already been provisioned and configured, you have to use the REST API. Note that you can add Oracle Coherence only to a service instance that's configured to run Oracle WebLogic Server 12c (12.1.3) or Oracle WebLogic Server 12c (12.2.1), and Enterprise Edition with Coherence. For information about using the REST API to enable Coherence for a service instance, see Add a Coherence Data Tier Cluster in REST API for Oracle Java Cloud Service.

Before creating an Oracle Java Cloud Service—Coherence instance, ensure you're familiar with capacity units. See About Capacity Units for Oracle Java Cloud Service—Coherence Instances for information about using default and custom capacity units.

Service Level and Software Choices

The following table describes the service level and software choices, and the selections you must make when using the wizard to create an Oracle Java Cloud Service—Coherence instance:

Choice Select This Description

Service Level

Oracle Java Cloud Service or Oracle Java Cloud Service—Virtual Image

If you select Oracle Java Cloud Service—Virtual Image, you won’t be able to use advanced tooling in the Oracle Java Cloud Service Console for major service lifecycle operations such as scaling, backup and restoration, and patching.

Use Oracle Java Cloud Service—Virtual Image if you’re planning to create an environment for development purposes.

Software Release

Oracle WebLogic Server 12c (12.1.3) or Oracle WebLogic Server 12c (12.2.1)

To use all of the capabilities provided for Oracle Coherence in Oracle Java Cloud Service, you must run Oracle WebLogic Server 12c on the service instance.

Software Edition

Enterprise Edition with Coherence

To use Oracle Coherence in Oracle Java Cloud Service, you must run Enterprise Edition with Coherence.

Coherence Data Tier Details

When configuring details for the Coherence data tier, you can use a default capacity unit or define your own custom capacity unit. The following table describes the Coherence data tier choices and the selections you can make when using the wizard to create an Oracle Java Cloud Service—Coherence instance:

Choice Select Description

Capacity Unit

Select:

  • A default capacity unit definition that provides the best combination of processing power and cache capacity for your Coherence application and workflow requirements.

  • Advanced to define your own configuration for a custom capacity unit (instead of using a default capacity unit), to get the processing power and cache capacity your business needs.

A default capacity unit comprises one virtual machine (VM) or three virtual machines (VMs) with a predefined shape, running a number of JVMs or Managed Coherence Servers to provide a predefined amount of primary cache storage for Coherence. A shape defines the processing power of the virtual machines to provision, and the amount of memory that would be available for JVM heap.

Coherence high availability is achieved when you select a default capacity unit that has three VMs. See About Default Capacity Units for Oracle Java Cloud Service—Coherence Instances for information about the different configurations provided by default capacity unit definitions.

When defining a custom capacity unit: You must specify a number for VMs and JVMs, and a compute shape for the VMs.

Note that after a service instance has been provisioned, you can’t change the default capacity unit you used or the configuration of a custom capacity unit you defined.

Cache Size

A display-only field. The field is displayed when you select a default capacity unit or Advanced from the Capacity Unit dropdown list.

Whether you’re using a default capacity unit or defining a custom capacity unit, each capacity unit provides an amount of cache, which is the primary cache storage to allocate for Coherence in the domain.

The primary cache storage to allocate is based on the general rule of splitting the JVM heap size into thirds, using 1/3rd for primary cache storage, 1/3rd for backup storage, and 1/3rd for scratch space.

See About Capacity Units for Oracle Java Cloud Service—Coherence Instances for more information about default and custom capacity units.

Shape

Select a VM compute shape that provides the best combination of processing power and RAM.

Advanced configuration only: A shape represents the number of Oracle Compute Units (OCPUs) and amount of RAM (system memory) available for a VM instance. All VMs in a capacity unit have the same shape. For a list of available shapes you can use, see About Machine Images and Shapes in Using Oracle Compute Cloud Service (for PaaS).

Nodes

Select the number of VMs to create per capacity unit.

Advanced configuration only: The number of VMs to create when a capacity unit is provisioned. Coherence high availability is achieved when you specify three VMs per custom unit. See About Custom Capacity Units and Advanced Configuration for Oracle Java Cloud Service—Coherence Instances for more information.

Managed Servers Per Node

Select the number of JVMs to configure per VM.

Advanced configuration only: The number of Managed Coherence Servers to configure per VM.

Note that the maximum heap size that will be configured is 16 GB.

See About Custom Capacity Units and Advanced Configuration for Oracle Java Cloud Service—Coherence Instances for more information.