Potential use of IMS commands
Although the primary purpose of end-user procedures is to describe transaction input, you might also allow the users to enter a subset of IMS commands so that they can make more informed use of IMS resources.
For example, if the end users can choose the order in which transactions are submitted, they can use a /DISPLAY command to gauge the current queue levels.
ALL keyword to
minimize the effect of these commands. The following table presents a list of IMS commands and evaluates their potential use by a remote terminal operator. The /DISPLAY TRAN and QUERY TRAN commands are especially appropriate. However, because of the many keyword choices for these commands, you should specify individual keywords. For convenient entry, include command abbreviations.
The commands in the table that are marked with an asterisk (*) are available to the remote terminal operator using default command security. To allow the remote terminal operator to use other commands, you need to declare the full list of commands for that terminal through RACF® (or an equivalent product). You can also use the DFSCCMD0 exit routine for command security.
| Command group | Command | Default security | End-user use | Comments |
|---|---|---|---|---|
| End-user specific | /RCLSDST | * | YES | Acts as remote VARY offline (for VTAM® terminals). |
| /RCOMPT | * | YES | Decentralizes control of VTAM component. | |
| /BROADCAST | * | YES | Provides convenient user interaction; use of message switching is preferred. | |
| /SET | * | YES | Provides convenient entry for batched transactions. | |
| /RESET | * | YES | Used with /SET. | |
| /RDISPLAY | * | YES | Identifies MTO location; used with /BROADCAST. | |
| /CANCEL | * | YES | Cancels both single- and multisegment messages. | |
| /EXCLUSIVE | * | YES | Safeguards discrete application usage. | |
| Connection commands | /OPNDST | NO | Allows access to VTAM network. | |
| /CLSDST | NO | Restricts access to VTAM network. | ||
| /QUIESCE | NO | Restricts access to VTAM network. | ||
| /SIGN | * | YES | Allows access to IMS resources; required for signon verification. | |
| /RSTART | YES | Starts IMS resources; allowed if /STOP allowed. | ||
| /MSASSIGN | NO | Alters assignments for IMS resources; required for MFS transactions. | ||
| /FORMAT | * | YES | Formats a screen; required for conversation terminations. | |
| /EXIT | * | YES | Terminates conversations; required for non-VTAM switched terminals. | |
| /HOLD | * | YES | Suspends conversations. | |
| /RELEASE | * | YES | Resumes conversations. | |
| Connection commands for MTO | /START | NO | Starts IMS resources. | |
| /STOP | NO | Stops IMS resources. | ||
| /CHANGE | NO | Allows changes to mode table and automatic session restart. Immediate termination best handled by the MTO. | ||
| /IDLE | NO | Allows control of multiple systems. | ||
| Device control | /COMPT | NO | Sets terminal components; also available through /RCOMPT. | |
| /MONITOR | NO | Stops programmable remote stations; best handled by MTO. | ||
| Monitoring | /DISPLAY | YES | Displays information about IMS resources; convenient for status of queues and terminals. | |
| /TRACE | NO | Allows IMS to trace resource activity; IMS Monitor and traces affect system performance. | ||
| /LOG | * | YES | Records user text on IMS system log. | |
| Serviceability | /DIAG | NO | Retrieves diagnostic information for system resources (for example, IMS control blocks) without taking console dump. | |
| Testing | /TEST | * | YES | Sets test mode; limit use for remote terminal operators. |
| /LOOPTEST | * | NO | Tests I/O for terminal. | |
| /END | * | YES | Terminates test, looptest, or exclusive mode. | |
| /MSVERIFY | NO | Verifies IMS resources; used by administrator of multiple systems. | ||
| Resource control | /ASSIGN | NO | Assigns IMS resources; prime control of resources for MTO. | |
| /PSTOP | NO | Restricts use of resources. | ||
| /PURGE | NO | Restricts input to resources. | ||
| /LOCK | * | NO | Restricts resource use; use only for supervisor remote terminal operators. | |
| /UNLOCK | * | NO | Unlocks IMS resources. | |
| /RMxxxxxx | NO | Allows control of DBRC resources; database availability should be controlled by MTO. | ||
| /SMCOPY | NO | Controls the logging of system messages, commands, and command responses to the secondary master terminal. | ||
| /MODIFY | NO | Allows online changes to IMS system. | ||
| Recovery | /DBRECOVERY or UPDATE | NO | Controls database availability; restrict to MTO. | |
| /DBDUMP or UPDATE | NO | Controls database availability; restrict to MTO. | ||
| /DEQUEUE | NO | Controls integrity of message queues; restrict to MTO. | ||
| /CHECKPOINT | NO | Shuts down IMS; restrict to MTO; simple checkpoints can have a performance impact. | ||
| /ERESTART | NO | Restarts IMS; restrict to MTO. | ||
| /RECOVER | NO | Recovers full-function databases and Fast Path areas; restrict to a DBA or the MTO. | ||
| /SWITCH | NO | Switches data sets used in an XRF environment; restrict to MTO. |