This topic contains sections marked as revised for this release
An execution group is a named grouping of message flows that have been assigned to a broker. The broker enforces a degree of isolation between message flows in distinct execution groups by ensuring that they execute in separate address spaces, or as unique processes.
Each execution group is started as a separate operating system process, providing an isolated runtime environment for a set of deployed message flows. Within an execution group, the assigned message flows run in different thread pools. You can specify the size of the thread pool (that is, the number of threads) that are assigned for each message flow by specifying the number of additional instances of each message flow.
A single default execution group is set up ready for use when you create a reference to a broker in the workbench. By setting up additional execution groups, you can isolate message flows that handle sensitive data such as payroll records, or security information, or unannounced product information, from other non-sensitive message flows.
If you create additional execution groups, you must give each group a name that is unique within the broker, and assign and deploy one or more message flows to each one.
You can create and deploy execution groups either in the workbench, or using commands.
An execution group process is also known as a DataFlowEngine (DFE); this term is typically used in problem determination scenarios (trace contents, diagnostic messages, and so on). A DFE is created as an operating system process, and has a one-to-one relationship with the named execution group. If more than one message flow runs within an execution group, multiple threads are created within the DFE process.
When you create an execution group, you can specify whether you want to create a 32-bit execution group or a 64-bit execution group.
Why create 64-bit execution groups?When you deploy the first message flow to a new 64-bit execution group, the broker determines whether a 64-bit execution group is supported on that broker; if not, the deployment fails with error message BIP2825.
See Enabling connections to the databases to check whether you need to define 32-bit data source names (DSNs), 64-bit DSNs, or both when you are using a 64-bit execution group or when you configure global coordination of message flows that are deployed to a 64-bit execution group.
Considerations when using 64-bit execution groups