The job type Subnetwork (NET) allows you to define a whole network as a job. The subnetwork must already be defined. It must have an input condition NET-BEGIN and an output condition NET-END as illustrated in the following example:

The same subnetwork can be defined in different jobs of the main network.

The subnetwork can be activated together with the calling network (or job of the type NET) or at the moment the job of the type NET is started.

On activation, each active subnetwork is assigned a unique run number.

This document covers the following topics:

• Link to the Main Network

• Subnetwork Activation and Execution

• Restrictions for Subnetworks

• Adding or Modifying a Subnetwork Definition

• Listing Jobs of a Subnetwork

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Link to the Main Network

The following reserved conditions are used to link a subnetwork to a main network and control the connection between the calling NET job and the subnetwork called.

Reserved Condition	Description
NET-BEGIN	You must specify NET-BEGIN to start the subnetwork and run the first job of the subnetwork.
NET-END	You must specify NET-END to run the last job of the subnetwork and indicate the end of the subnetwork.
NET-END-NOTOK	This condition is optional. If specified and fulfilled during subnetwork termination, the job is treated as ended not ok. If NET-END-NOTOK is specified in the subnetwork but NET-END is missing, the status of the NET job changes to Sub-NW executing - error indicated. In this case, the global message Job ended not ok is sent if the corresponding option is enabled in the Global Messages for Events settings (see the Administration documentation). If NET-END-NOTOK is reset in the subnetwork, the status of the NET job changes back to Subnetwork executing. In this case, the global message mentioned above is sent again.
NET-END-OK	This condition is optional. If specified at least once in your subnetwork and fulfilled during subnetwork termination, the NET job (that is, the whole subnetwork) is treated as ended ok. This has an impact on the release of resources, which are allocated on the network level. You can force the resource release by setting this condition. See also the deallocation mode set in the prerequisite resource definition.

Notes on Subnetwork Usage

1. If the condition NET-END-NOTOK is found together with NET-END, the calling job is set to the status not ok.

2. Jobs of the type NET can use all kinds of prerequisite checks and can have all kinds of End-of-Job actions.

3. The scheduling parameters of a job of the type NET are passed on to the subnetwork. See the section Scheduling a Job.

4. The calling job of a subnetwork (job of type NET) should have an own symbol table definition.

Subnetwork Activation and Execution

A subnetwork is activated together with the main network. The subnetwork is assigned its own run numbers.

If the calling job of the type Subnetwork (NET) becomes a temporary dummy job due to any reason, no subnetwork activation is performed (if the subnetwork was not activated already).

Reserved symbols pass information to the jobs of the subnetwork about which job invoked the subnetwork. These symbols are described in Predefined Symbols for Subnetworks and Recovery Jobs in the section Symbol Table and Symbol Maintenance.

If the subnetwork has a standard symbol table, these values are entered as symbols in the active copy of this table.

This enables you to trace, even through several steps, from where the subnetwork was invoked.

If the job of the type NET can be activated (satisfies all input conditions), the condition NET-BEGIN of the subnetwork is set and the subnetwork starts to work: the NET job is then executing. It remains in this status until the subnetwork has set the condition NET-END. Only at this point are the End-of-Job checking and actions performed which are defined in the invoking network.

If an execution error occurs in the subnetwork, the execution of the invoking network is also blocked. If the subnetwork sets the condition NET-END before its actual termination (or at its very start), the invoking network continues to run, and a parallel asynchronous execution of the networks is possible. However, the user him/herself then becomes responsible for later synchronizing the subnetwork with the invoking network.

This section covers the following topics:

Time of Activation of a Subnetwork

Subnetworks can be activated at two different times:

• After the activation time of the calling network

  The subnetwork is always activated (i.e., with the job type NET) after the calling network has been activated. The time discrepancy depends on the Monitor activation cycle. The subnetwork will be available from this point in time with run number and active JCL. This is the default.

• At the start time (submission) of the calling job of the type NET

  The subnetwork is only activated if the calling job of the type NET is really started. This can prevent a subnetwork from even being activated if the calling job is not executed at all later on. Moreover, the effort for job activations and loading the JCL is thus compensated for, and the waiting-time for prerequisites within the subnetwork is shorter.

The subnetwork activation mode can be defined as follows:

• As a global default value (see Subnetwork activation mode in Defaults for Network Options in the Administration documentation).

• In the definition of the calling job of the type NET (see Activation mode).

Symbol Table Activation for Subnetworks

The order of symbol table activation for subnetworks is:

1. Set caller info into the active table (P-C-... symbols).

2. Activate symbol table(s).

3. Perform symbol modification exit.

The order of symbol table activation for subnetworks is the same as for main networks.

Restrictions for Subnetworks

This section covers the following topics:

• Recursion Checking

• Maximum Nesting Level

Recursion Checking

Subnetworks can in turn be invoked within subnetworks; however, a subnetwork cannot invoke itself, because this can cause an infinite recursion.

The definition of a network as its own subnetwork is prohibited. If this is attempted, the error message Recursive Subnetwork Definition prohibited is issued.

Maximum Nesting Level

The maximal supported nesting level for subnetworks is 5.

Adding or Modifying a Subnetwork Definition

To display or modify a subnetwork definition

1. From a Job Master node in the object workspace, select a job of the type Subnetwork (NET), and choose Display or Open from the context menu.

   Or:
   From the table in a Job Master List window, select a job of the Type NET, and choose Display or Open from the context menu.

   A Maintenance Job Master window opens.

2. Open the tabbed page Subnet.

   The fields on the page are described in Fields: Job Type Specific Execution Features.

To add a subnetwork definition

1. From the Job Master window, select Subnetwork from the Job type drop-down list box.

   The tab Subnet appears.

2. Open the tabbed page Subnet similar to the example below:

   

3. Make your definitions. The input fields available on the page are described in Fields: Job Type Specific Execution Features.

4. Choose OK when you are finished.

Listing Jobs of a Subnetwork

If a master or active job has the type NET, and if the subnetwork is defined properly, you can invoke the master or active job list of the defined subnetwork directly.

If the subnetwork was not defined yet, the subnetwork definition screen is invoked instead.

To list the jobs of a subnetwork

• From a Job Master or Job Active node, select a job of the type Subnetwork (NET), and choose Zoom Subnetwork from the context menu.

  Or:
  From the table in a Job Master List or an Active Job List window, select a job of the Type NET, and choose Zoom Subnetwork from the context menu.

  The jobs of the subnetwork defined for the selected NET job are listed in a (separate) Job Master List or Active Job List window, as shown in the following example: