IBM Integration Bus, Version 9.0.0.5 Operating Systems: AIX, HP-Itanium, Linux, Solaris, Windows, z/OS

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Adding additional instances at message flow level

To change the number of threads that a message flow can use at run time to process messages, you can configure the Additional instances property of a message flow in a BAR file. These instances can be started as you need them or you can choose to start all of them at once when the message flow starts by selecting the Start additional instances when the flow starts property.

The default value of the Additional instances property is 0 threads. The maximum value of the Additional instances property is 256 threads.

The following conditions apply when IBM® Integration Bus allocates threads to a message flow based on your configuration options:
  • By default, one thread is allocated per Input node. The Input node can be defined in the main message flow or within a subflow.
  • You can add more instances or threads by setting the Additional instances property of the message flow that is included in the BAR file to a value greater than 0 and up to 256 threads.
    Note: If you set the value to a number greater than 256, the BAR file will fail to deploy.
  • If you have more than one Input node, the additional instances that you configure can be used by any Input node that receives messages. An additional instance is allocated to an Input node that has its default thread busy processing a previous message and needs to process an incoming message.
  • The number of threads available to process messages when you start a message flow is by default equal to the number of Input nodes. IBM Integration Bus will start additional instances as required.
  • If you want to start all of the threads configured at once, including the ones configured through the Additional instances property, you must select the Start additional instances when the flow starts property associated with the message flow.
  • Additional message flow instances are configured at flow level. If you have a subflow included in a message flow, you cannot configure additional instances for the subflow independently. This condition applies whether the subflow is used as the starting node in a message flow, as a middle node in a message flow, or as the last node in a message flow.

To configure the Additional instances property of a message flow in a BAR file, complete the following steps:

  1. Open the BAR file that contains the message flow and subflows for which you want to set the Additional instances property. In the Application Development view, identify the project that contains the BAR file, and double-click the file to open it.
  2. Set the Additional instances property of a message flow that is included in the BAR file to a value greater than 0 and up to 256.

    The following figure outlines the configuration properties of a message flow:

    This figure shows the message flow properties that you can configure when creating a BAR file.

    Note: If you set the value to a number greater than 256, the BAR file will fail to deploy.

Based on your message flow design and configuration, the following tables summarize the number of threads available when running the message flow in IBM Integration Bus:

Table 1. Sample summary table of parallel threads available when running a message flow in an integration node
Number of Input nodes in a message flow Number of default instances or threads per message flow (1 thread per input node in a message flow) Additional instances property (set at message flow level) Maximum number of threads that can process messages in parallel
1 1 0 1
1 1 1 2
1 1 2 3
2 2 0 2
2 2 1 3
2 2 2 4
3 3 2 5
Table 2. Sample summary table of parallel threads available when running a message flow in an integration node that contains a subflow with Input nodes
Number of Input nodes in a message flow (not included in a subflow) Number of Input nodes modeled in a subflow that is included in a message flow Number of default instances or threads per message flow (1 thread per input node in a message flow) Additional instances property (set at message flow level) Maximum number of threads that can process messages in parallel
0 1 1 0 1
1 1 2 0 2
0 1 1 1 2
1 1 2 1 3
0 1 1 2 3
1 1 2 2 4
0 2 2 0 2
2 2 4 2 6
0 2 2 1 3
0 2 2 2 4
0 3 3 2 5

Return to Configuring a message flow that includes subflows.

Parent topic: Configuring a message flow that includes subflows
scnsubflows_01_28_.htm | Last updated: Last updated: 2016-08-12 11:20:28