IS-Notification
Contents
Design
The IS-Notification is a library that provides a subscription/notification mechanism based on Remote Events. This library helps the clients to interact with the Notifier Service and allows:
- for a Client or a Service (Subscriber) to subscribe for a Topic and receiving notifications
- for a Service (producer) to register its own topic and sending notification.
Interface
- public <T extends BaseNotificationConsumer> void registerToISNotification(T consumer,List<GCUBENotificationTopic> notifications, GCUBESecurityManager manager, GCUBEScope ... scope) throws ISNotifierException – this method registers a entity of type T (consumer) for a list of GCUBENotificationTopic in selected Scopes (scope) with a GCUBESecurityManager (manager) in the IS-Notifier;
- public void unregisterFromISNotification( GCUBESecurityManager manager, List<GCUBENotificationTopic> notifications, GCUBEScope ... scope) throws ISNotifierException – this method unregisters the consumer for a list of GCUBENotificationTopic from the IS-Notifier in the selected scopes (scope) with a GCUBESecurityManager (manager);
- public void registerISNotification (EndpointReferenceType producerEPR, List<? extends Topic> notifications, GCUBESecurityManager manager, GCUBEScope ... scope) throws ISNotifierException – this method registers the reference to a resource (producerEPR) that produces a list of topics (notifications) in the IS-Notifier in the selected scopes (scope) with a GCUBESecurityManager (manager);
- public void unregisterISNotification (EndpointReferenceType producerEPR, List<? extends Topic> notifications, GCUBESecurityManager manager, GCUBEScope ... scope) throws ISNotifierException – this method unregister the reference to a resource (producerEPR) for a list of topics (notifications) in the IS-Notifier in the selected scopes (scope) with a GCUBESecurityManager (manager);
- public boolean[] isTopicRegistered(GCUBESecurityManager securityManager, GCUBEScope scope, List<TopicData> topics) throws ISNotifierException - this methods checks if a topic (topic) registration is completed or not for a producer (producerEpr) in the IS-Notifier in the selected scopes (scope) with a GCUBESecurityManager (manager);
New Features
From version 1.4 this library contains new features:
- the possibility to register for a client running outside a gcore container;
- the possibility to register to a Topic specifying a 'precodition'. The 'precodition' is represented by an XPath specified at Topic creation time an evaluated producer-side. This feature reduces the number of messages exchanged between producer and consumer.
How to configure clients running outside the gCore container
To register a Topic outside a gCore cotnainer this library requires 2 steps of configuration:
- modify the file $GLOBUS_LOCATION/etc/globus_wsrf_core/client-server-config.wsdd adding in the globalConfiguration session the parameter logicalHost
... <globalConfiguration> <parameter name="containerThreads" value="1"/> <parameter name="containerThreadsMax" value="3"/> <!-- add the following line --> <parameter name="logicalHost" value="yourhost"/> <parameter name="sendXsiTypes" value="true"/> <parameter name="authenticationService" value="gsi/AuthenticationService"/> ...
- start the client setting the GLOBUS_LOCATION system property
java -DGLOBUS_LOCATION=$GLOBUS_LOCATION RegistrationTest
How to register a producer for a topic
To make a GCUBEService capable to produce notifcation for a topic we have, first of all, configure it.
In the deploy-server.wsdd for each port-type that represent a resource that will produce a notification add at the providers SubscribeProvider and GetCurrentMessageProvider:
<parameter name="providers" value="GCUBEProvider SubscribeProvider GetCurrentMessageProvider"/>
In the wsdl of such port-type add in the portType tag wsntw:NotificationProducer:
<portType name="ReadManagerPortType" wsdlpp:extends="wsntw:NotificationProducer provider:GCUBEProvider">
In your GCUBEWSResource declare the topic
... Resource extends GCUBEWSResource { ... private SimpleTopic updateTopic= new SimpleTopic(new QName(NS, "UpdateTopic");
add it to the list of topics of the GCUBEWSResource (it can be done on the overriding the initialiContainer() method)
.. @Override protected void initialiseContainers() throws Exception { super.initialiseContainers(); ... getTopicList().addTopic(updateTopic); } ...
In this way the topic is automatically registered by gcore at container start-up. After this we need to notify the event: