Note: For applications exploiting the service for defining application
environments (IWM4AEDF), you may not need to define the application
environment manually. For further information, refer to the appropriate
product documentation.
To define an application environment, specify:
- The subsystem type under which the applications are running.
- The JCL procedure to start server address spaces if you wish workload management to automatically
manage the number of servers.
- If a JCL procedure is specified, any required start parameters.
- Whether requests can execute in multiple server address spaces
and on multiple systems.
| Defining application environments |
|---|
- Application Environment
- Application environment name.
- Description (optional)
- Description of the application environment.
- Subsystem Type
- The subsystem type associated with the application environment,
such as SOM, DB2®, or IWEB.
- Procedure Name (optional)
- The name of the JCL procedure for starting the address space.
The procedure name may be omitted.
- Start Parameters (optional)
- Parameters required by the JCL procedure to start the address
space.
- Starting of address spaces
- Specify whether workload management can start multiple or single
server address spaces for a subsystem instance.
|
- Application Environment
- (Required) One to 32 character name of the application
environment. You must use this name when specifying to the subsystem
how to map work to the application environments. You also use this
name in operator commands when performing actions on the application
environment. The name cannot begin with the letters SYS.
For
guidance in mapping subsystem work to application
environments, see
the subsystem reference information.
If you check
the authorization of application environment server address spaces
through a SAF product, such as RACF®,
or if you plan to do so, choose an application environment name that
does not exceed 27 characters. There is a restriction with respect
to the maximum length of a server profile name passed to the SAF
product (see also Authorizing application environment servers).
- Description
- (Optional) Up to 32 characters describing the application
environment.
- Subsystem Type
- (Required) Subsystem type is the one to four character
name of the subsystem using application environments. This subsystem
type is provided to workload management when the
subsystem initializes. The types currently in use are listed in Table 1. For a subsystem
not listed, refer to the subsystem's documentation for the required
information.
Note: If you are using DB2 stored
procedures, note that the subsystem type DB2 specified
here for an
application
environment is
used only for identifying the DB2 subsystem
when it begins to use the
application
environment. There
is no connection between this value and classification. For more information
on classification, see
Defining classification rules.
- Procedure Name
- (Optional) Procedure name is the one to eight character
name of the JCL procedure that workload management uses to start a
server for the application environment work requests. Refer to the
appropriate subsystem documentation for sample JCL procedures to use.
To ensure that an application environment uses the same JCL procedure
across the sysplex, either (1) identical procedure proclibs must be
maintained across the sysplex or (2) all the procedures must be stored
in a single, shared proclib.
If you specify a procedure name,
“automatic” control is in effect, and workload management manages
the number of servers. If you do not specify a procedure name, manual
control is in effect, and servers must be started manually or by automation.
In either case, workload management processes
work requests from the application environment according to the goals
defined for the work once a server address space is available.
- Start Parameters
- (Optional) Start parameters are the parameters required
for the JCL procedure defined in Procedure Name. These parameters
define how workload management should start the server address spaces.
Specify parameters here that you would use for starting a server address
space with an MVS™ START command.
Note that any parameters you specify here override the parameters
specified in the JCL procedure for that server.
If you specify
the symbol &IWMSSNM, workload management substitutes
the subsystem instance name provided to workload management when the
subsystem connected to it. Refer to the subsystem reference information
to determine the instance name and the appropriate parameters to specify.
- Starting of server address spaces for a subsystem instance
- (Required)You can limit the number of servers for a subsystem
instance. Reasons for limiting the number of servers might be a need
to serialize or limit application
environment server
activity while testing, or a restriction in the subsystem itself.
There are three options:
- Managed by WLM
- Limited to a single server address space per system
- Limited to a single server address space per sysplex
The options that are valid for a subsystem depend on its scope
as described in the next section. For guidance on deciding which
options to use, and to find out which options are valid for subsystems
not explicitly covered in the next section, see the subsystem reference
information.
Example of an application environment
To
enable workload management to dynamically start server address spaces
to process work from a DB2 payroll
application environment, do the following:
- Define the application environment
- Application Environment
- PAYROLL
- Description
- DB2 Payroll APPLENV
- Subsystem Type
- DB2
- Procedure Name
- PAYPROC
- Start Parameters
- DB2SSN=&IWMSSNM
- Server Start
- Managed by WLM
When payroll work arrives into the system, workload
management manages system resources to meet the goals defined for
the work, and dynamically starts and stops server address spaces to
process the work.