Overview

Associations provide the capability to specify directed service associations and enforce them in runtime. Associations define a usage model for services in and across architectures/deployments. Associations are created during the design/modeling phase and enforced during runtime. Associations can be either:

• Uses – a weak association relationship where if A uses B exists then, then B may be present for A.
• Requires – a stronger association relationship where if A requires B exists then B must be present for A.
• Colocated – an association which requires that A be colocated with B in the same JVM. If B does not exist, or cannot be located, A shall not be created without B.
• Opposed – an association which requires that A exist in a different JVM then B.

New in GigaSpace 5.2 The Requires and the Colocated associations are available in GigaSpaces version 5.2 and onwards.

As Associations are discovered, a service is notified allowing an associated service to be used. If the Association type is Requires and the service
has not been advertised, the service will be advertised. If an associated service connection is broken (as determined by the associated service's Fault Detection Handler) and the Association type is Requires, the service will be unadvertised.

Association declaration is straightforward:

• An association to a service within the same deployment descriptor. Once discovered, the service will be injected using the setSpace method.

<Association Type="uses" Name="The Space" Property="space"/>

• An association to a service in an included deployment descriptor, pointed to by the refid. Once discovered, the service will be injected using the setSpace method.

<Association refid="dd.ref" Type="uses"  Name="The Space" Property="theSpace"/>

• An association to any discovered service which implements the ClassName. Once discovered, the service will be injected using the setSpace method.

<Association Type="uses" Name="The Space" Property="space" ClassName="net.jini.space.JavaSpace" MatchOnName="no"/>

For more details on how the Service Grid handles associations to services which are GigaSpaces spaces, see Space Services Handling in Service Grid Associations.

RELATED TOPICS

Declaring Elements Globally in Deployment Descriptor

Declaring Service UI in Deployment Descriptor

Deployment Descriptor Codebase Element

Deployment Descriptor DeploymentSchedule Element

Deployment Descriptor Parameters and Configuration Elements

Deployment Descriptor SharedComponent Element

Deployment Descriptor SLA Element

deploy - Service Grid CLI

Fixed and Dynamic ServiceBean ProvisionType

Injecting Deployment Descriptor Properties into POJOs

POJO Lifecycle in Service Grid

Proactive Cache

redeploy - Service Grid CLI

Rio OperationalString

Service Associations

Service Deployment Descriptor

Service Grid ClassLoader Hierarchy

undeploy - Service Grid CLI

Using Service Grid to Deploy Partitioned Space

Using Service Grid to Deploy Partitioned Space with Backup

Using Service Grid to Deploy Replicated Space

Using Service Grid to Deploy Space

Using Service Grid to Deploy Spring Applications

Using System Properties for Deployment Descriptor Element Values