WebSphere Event Broker includes a large number
of message processing nodes that you can use within your message flows. You can also choose from user-defined nodes that
have been created and supplied by users,
or other vendors and companies.
Your decision about which nodes to use depends on the processing
that you want to perform on your messages. The
built-in nodes can be considered in several categories, and are displayed
in the workbench grouped in those categories
(although this grouping has no effect on their operation). You can also categorize
user-defined nodes in the same way. The categories are:
- Input and output
- Input and output nodes define points in the message flow to which clients
send messages (input nodes such as MQInput) and from which clients receive
messages (output nodes such as MQOutput). Client applications interact with
these nodes by putting messages to, or getting messages from, the I/O resource
that is specified by the node as the source or target of the messages. Although
a message flow must include at least one input node, it does not have to include
an output node.
- If you are creating a message flow that you want to deploy to a broker,
you must include at least one input node to receive messages. The input node
that you choose depends on the source of the input messages and where
in the flow you want to receive the messages:
- MQInput
- If the messages arrive at the broker on a WebSphere
MQ queue
and the node is to be at the start of a message flow.
The
use of message flows that contain MQeInput nodes in WebSphere
Event Broker Version 6.0 is
deprecated. Redesign your message flows to remove the MQe nodes and replace
them with MQ nodes that are configured to your own specifications and coordinated
with your MQe Gateway configuration. For more details, see Migrating a message flow that contains WebSphere MQ Everyplace nodes.
- MQGet
- If the messages arrive at the broker on a WebSphere MQ queue and the
node is not to be at the start of a message flow.
- SCADAInput
- If the messages are sent by a telemetry device.
- Real-timeInput or Real-timeOptimizedFlow
If the messages are sent by a JMS or multicast application. The
Real-timeInput node is an input node and the Real-timeOptimizedFlow node is
a complete message flow that provides a high performance publish/subscribe message
flow.
JMSInput
If the messages are sent by a JMS application.
- User-defined input node
- If the message source is a client or application that uses a different
protocol or transport.
- Input node
- If you are creating a message flow that you want to embed in another message
flow (a subflow) that you will not deploy as a standalone message flow, you
must include at least one Input node to receive messages into the subflow.
An
instance of the Input node represents an in terminal. For example, if you
have included one instance of the Input node, the subflow icon shows one in
terminal that you can connect to other nodes in the main flow in the same
way that you connect any other node.
You can deploy only message flows
that have at least one input node. If your message flow does not contain an
input node, you are prevented from adding it to the broker archive file. The
input node can be in the main flow, or in a message flow that is embedded
in the main flow.
You can use more than one input node in a message
flow. For more information, see Using more than one input node.
- If you want to send the messages produced by the message flow to a target
application, you can include one or more output nodes. The one that you choose
depends on the transport across which the target application expects to receive
those messages:
- Publication
- If you want to distribute the messages using the publish/subscribe network
for applications that subscribe to the broker across all supported protocols.
A Publication node is an output node that use output destinations that are
identified by subscribers whose subscriptions match the characteristics of
the current message.
- MQOutput
- If the target application expects to receive messages on a WebSphere
MQ queue,
or on the WebSphere
MQ reply-to queue specified
in the input message MQMD.
The use of message flows
that contain MQeOutput nodes in WebSphere
Event Broker Version 6.0 is
deprecated. Redesign your message flows to remove the MQe nodes and replace
them with MQ nodes that are configured to your own specifications and coordinated
with your MQe Gateway configuration. For more details, see Migrating a message flow that contains WebSphere MQ Everyplace nodes.
- MQReply
- If the target application expects to receive messages on the WebSphere
MQ reply-to
queue specified in the input message MQMD
- SCADAOutput
- If a telemetry device is the target of the output messages, and the Publication
node is not suitable
- Real-timeOptimizedFlow
- If the target application is a JMS or multicast application
JMSOutput
If the messages are for a JMS destination.
- User-defined output node
- If the target is a client or application that uses a different protocol
or transport
- Output node
- If you are creating a message flow that you want to embed in another message
flow (a subflow) that you will not deploy as a standalone message flow, you
must include at least one Output node to propagate messages to subsequent
nodes that you connect to the subflow.
An instance of the Output node represents
an out terminal. For example, if you have included two instances of the Output
node, the subflow icon shows two out terminals that you can connect to other
nodes in the main flow in the same way that you connect any other node.