cMulticast

Routes messages to a number of endpoints at one go and process them in different
ways.

cMulticast Standard properties

These properties are used to configure cMulticast running in the Standard Job framework.

The Standard
cMulticast component belongs to the Routing family.

Basic settings

URIS	Add as many lines as needed in the URIs table to define the endpoints to route the message(s) to.
Use ParallelProcessing	Select this check box to multicast the message(s) to the specified endpoints simultaneously.
set timeout	Select this check box and set a timeout in the Timeout field, in milliseconds. If cMulticast fails to send and process all the messages within the set timeframe, it breaks out and continues. Note that this check box appears only when the Use ParallelProcessing check box is selected.
Use Aggregation Strategy	Select this check box to refer to a predefined Java bean as an aggregation strategy for assembling the messages from the message source into a single outgoing message. By default, the last message acts as the outgoing message.
Stop On Exception	Select this check box to stop the processing immediately when an exception occurred.

Usage

Usage rule	cMulticast can be used as a middle or end component in a Route.
Connections	Route: Select this link to route the message(s) from the sender to the next endpoint.
	EndBlock: Select this link to route the message(s) from the end block of the Route to the next endpoint.
Limitation	n/a

Route a message to multiple endpoints and set a new body for each

This scenario applies only to Talend Open Studio for ESB, Talend Data Services Platform and Talend Data Fabric.

In this scenario, a cMulticast component is used to
route a message to two endpoints. The source message and the message on each endpoint is
then set a new body. The cProcessor component is used
to monitor the messages.

Dropping and linking the components

From the Palette, expand the Connectivity folder. Drag and drop a cFile and two cMessagingEndpoint components onto the design
workspace.
From the Routing folder, drag and drop a
cMulticast component onto the design
workspace.
From the Custom folder, drag and drop four cProcessor components onto the design
workspace.
From the Core folder, drag and drop three cSetBody components onto the design
workspace.
Label the components as shown above to better identify their roles in the
Route.
Right-click the cMulticast component,
select Row > EndBlock in the context menu and click the cProcessor component labeled Monitor_endblock.
Right-click the cFile component, select
Row > Route in the context menu and click the cMulticast component. Repeat this step to link
the rest components in the Route as shown above using the Row > Route
connection.

Configuring the components

Double-click the cFile component labeled
Source_file to open its Basic settings view in the Component tab.
In the Path field, fill in or browse to
the path where the source file Hello.txt
is located. Keep the default settings for other fields.
Double-click the cMulticast component
labeled Multicast to open its Basic settings view in the Component tab.
In the URIS table, click the plus button
to add two lines and specify the URIs of the endpoints where the message
will be sent, “direct:a” and “direct:b” in this use case.
Double-click the cMessagingEndpoint
component labeled direct_a to open its
Basic settings view in the Component tab.
In the URI field, enter the endpoint URI,
“direct:a” in this use case.

Repeat this step to set the endpoint URI for direct_b as “direct:b”.
Double-click the cProcessor component
labeled Monitor_source to open its
Basic settings view in the Component tab.
In the Code box, enter the code below to
print the source message in the console.

System.out.println("The source message is: " + exchange.getIn().getBody(String.class));

1

System.out.println("The source message is: " + exchange.getIn().getBody(String.class));

Repeat this step to customize the code of Monitor_endblock, Monitor_direct_a, and Monitor_direct_b as shown below to print the message of each
endpoint.

Monitor_endblock:

System.out.println("The endblock message is: " + exchange.getIn().getBody(String.class));

1

System.out.println("The endblock message is: " + exchange.getIn().getBody(String.class));

Monitor_direct_a:

System.out.println("direct a just downloaded: "+exchange.getIn().getBody(String.class));

1

System.out.println("direct a just downloaded: "+exchange.getIn().getBody(String.class));

Monitor_direct_b:

System.out.println("direct b just downloaded: "+exchange.getIn().getBody(String.class));

1

System.out.println("direct b just downloaded: "+exchange.getIn().getBody(String.class));
Double-click the cSetBody component
labeled Set_new_body to open its
Basic settings view in the Component tab.
Select SIMPLE in the Language list.

In the Expression field, enter “New message” as the new message body.

Repeat this step to set the message body for direct:a and direct:b as
“message A” and “message B” respectively.
Press Ctrl+S to save your Route.

Viewing code and executing the Route

Click the Code tab at the bottom of the
design workspace to check the generated code.

In the partially shown code, the source message is routed
from
"Source_file_cFile_1"
.to
direct:a and direct:b via
"cMulticast_1". The message is then processed by
"cProcessor_1" and given the message body "New message" by "cSetBody_3". The .end
block of the route is processed by "cProcessor_2". The message
from
"direct_a_cMessagingEndpoint_1" is set the message body
"message A" by "cSetBody_1" and processed by
"cProcessor_3". The message from direct:b is
processed similarly.
Click the Run view to display it and
click the Run button to launch the
execution of your Route. You can also press F6 to execute it.

RESULT: The source file message is Hello
world!. The message routed to direct:a and direct:b is
set the message body message A and message
B respectively. The end block message of this Route is
New message that is set by the
component labeled Set_new_body.

Document get from Talend https://help.talend.com

Thank you for watching.

Docs 7.x

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cMulticast – Docs for ESB ESB 7.x