Service Execution Process (SEP)

Describes the role of a Service Execution Process (SEP) component, detailing its purpose, how it communicates with other Enterprise Server for .NET components, and hosting details.

SEPs

A SEP is an isolated container inside which a single CICS transaction or JES program runs.

SEP pools

Multiple SEPs are hosted within a SEP pool.

A SEP pool is a collection of application domains.

Each SEP is responsible for the execution of a single request. When a request completes, the SEP is returned to the pool and made available for a subsequent request execution.

SEPs are removed from the pool when the associated client disconnects, or when the SEP needs to be shutdown prematurely due to a timeout.

The following diagram represents SEP pool layout architecture:

Hosting

A SEP is hosted as follows:

Default: WAS-hosted

Started by	Event Monitor, Dispatcher, or SEP
Process¹	w3wp.exe

Exception: In some cases, such as during startup routines and when running the debugger, Enterprise Server for .NET creates self-hosted SEPs by default. You can override this by starting the region using the seestart -was flag. See seestart: start a region for details.

Alternative: Self-hosted

Process¹

seesep.exe

¹ To keep SEPs isolated, they operate in Enterprise Server for .NET as discrete application domains within a process.