Job variables (JVs) are storage areas where information is exchanged between jobs and between operating systems and jobs. They can be addressed at command and at program level.
JVs are stored in the file catalog. They are addressed in accordance with a syntax which is analogous with the path names for files (catalog ID, user ID, job variable name), and analogous name completion.
User can modify JVs themselves or instruct the operating system to set JVs to agreed values when certain events occur. The values of the JVs can be queried via commands and program interfaces.
The catalog ID in the path name of a JV defines the storage location of the JV in the MSCF network. If the catalog is accessible, JVs can be created, modified, read or deleted from any processor on any pubset in the MSCF network, i.e. JVs are available to all processors in the network.
Changes made to JVs anywhere in the MSCF network can elicit a response throughout the entire network, i.e. interdependencies can be defined between jobs and programs across all the processors.
JVs thus permit flexible job control in the MSCF network. They enable the simple definition of mutual interdependencies between complex job systems. The job variable concept is the basis of the condition-dependent job control (see "Job checking").
A distinction is made between the following JV types:
User JVs
User JVs are created by BS2000 users and can be influenced (i.e created, modified, deleted etc.) by the commands and macros described below.Monitoring JVs (abbreviated to MONJVs)
MONJVs are JVs linked to certain objects (e.g. batch jobs, executing programs) or even complete applications. As long as the object exists to which an MONJV is linked, the system protects it against modification or deletion by the user. If the object no longer exists (i.e the batch job or program is finished), the MONJV becomes a normal user JV.Special JVs
Special JVs are not stored in the file catalog. They are not genuine JVs because they can only be accessed in read mode and locally (i.e. not from all the processors). The purpose of special JVs is to be able to have read access to certain system information (e.g. the current date) and to genuine JVs.
The job variable concept is described in detail in the "Job Variables" manual [9 (Related publications)].
Application example illustrating job variables
In this example, the MSCF network consists of a BS2000XC processor with catalog Z and a BS2000XA processor with catalog B (see diagram below).
Figure 8: MSCF network with processors BS2000XA and BS2000XC
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/CREATE-JV JV-NAME=:Z:JV.1 |
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