Jms

Front 1

Base concepts of JMS?

Back 1

● Topic: A destination used in publish/subscribe messaging. If a topic has several subscribed listeners, each message published to that topic is delivered to all listeners.
●Queue: A destination used for point-to-point messaging.

Front 2

Name interfaces of the javax.jms package?

Back 2

● QueueSender
● QueueReceiver
● TopicPublisher
● TopicSubscriber

Front 3

Describe Dynamo implementation of JMS?

Back 3

Dynamo Messaging System (DMS):
● Two JMS providers, Local JMS and SQL JMS.
● Patch Bay is an API and configuration system layered on top of JMS. Allows Nucleus components to send and receive messages. The configuration system uses an XML file to specify how these components should be connected.

Front 4

How create Local JMS Destinations?

Back 4

Configure /atg/dynamo/messaging/MessagingManager:

localJMSQueueNames+=/Orders

Reference it in Java:
localdms:/local/Orders

Front 5

Creating and Accessing SQL JMS Destinations

Back 5

By using the requiredQueueNames and requiredTopicNames properties of the /atg/dynamo/messaging/SqlJmsProvider component. For example:

requiredQueueNames+=MyApp/Orders
requiredTopicNames+=MyApp/RegistrationEvents,MyApp/FinancialEvents

To access an SQL JMS destination in your Java:

sqldms:/MyApp/RegistrationEvents

Front 6

What are possibilitues of administering SQL JMS?

Back 6

● Configuring Databases and Data Sources
● Adjusting the SQL JMS Polling Interval
● Removing SQL JMS Destinations and Subscriptions
● Monitoring Message Buildup
● Using the SQL-JMS Administration Interface

Front 7

What is Patch bay component name and class?

Back 7

Component:
/atg/dynamo/messaging/MessagingManager
Class: atg.dms.patchbay.PatchBayManager

Front 8

What Patch Bay API includes?

Back 8

● Message source: A component that can send messages. A message source must implement the atg.dms.patchbay.MessageSource interface.
● Message sink: a component that can receive messages. A message sink must implement the atg.dms.patchbay.MessageSink interface.
● Message filter: a component that implements both interfaces, and can send and receive messages.

All message sources, sinks, and filters must have global scope.

Patch Bay does not have separate interfaces for objects that communicate with topics and those that communicate with queues.

Front 9

Describe creating message sources in Patch Bay

Back 9

A message source must implement the atg.dms.patchbay.MessageSource interface.

Implement setMessageSourceContext, startMessageSource, and stopMessageSource methods.

Example:
public void sendOneMessage ()
throws JMSException
{
if (mStarted && mContext != null) {
TextMessage msg = mContext.createTextMessage ();
msg.setJMSType ("atg.test.Test1");
msg.setText ("Test text string");
mContext.sendMessage (msg);
}

Front 10

Creating Message Sinks

Back 10

A message sink must implement the atg.dms.patchbay.MessageSink interface. defines a single method, receiveMessage, which is called to notify the message sink. Class should be stateless.

Front 11

Creating Message Filters

Back 11

Message filters must implement both the MessageSource and the MessageSink interface. A message filter typically implements receiveMessage by manipulating the message in some way, then sending a new message.

Front 12

Configuring Patch Bay

Back 12

/atg/dynamo/messaging/MessagingManager

definitionFile=/atg/dynamo/messaging/dynamoMessagingSystem.xml.

Definition file path shouldn't be changed. Configuration consists of:
● Declaring JMS Providers
● Declaring Message Sources, Sinks, and Filters
● Connecting to Destinations
● Using Messaging Ports
● Using the Message Registry
● Delaying the Delivery of Messages
● Configuring Failed Message Redelivery

Front 13

Using DMS with Weblogic JMS provider

Back 13

ATG platform provides components of class atg.dms.patchbay.JMSProviderConfiguration that are preconfigured for the WebSphere and WebLogic JMS providers. By default these components are disabled, but you can enable the component for your application server by running the ATG platform with the WebLogic.JMSProvider or WebSphere.

Front 14

Using a Third-Party JMS Provider with DMS

Back 14

Configuring a 3rd-part provider is done through the standard Patch Bay tags.