Administering DBCTL

This information shows you how to connect to DBCTL and issue operator commands.

Connecting to DBCTL: overview
You can perform CICS and DBCTL startup from a TSO terminal or an MVS™ console.
Connecting DBCTL to CICS automatically
You can specify that CICS is connected automatically to either the same or a different DBCTL.
Connection, disconnection, and inquiry transactions for the CICS DBCTL interface
There are two CICS transactions that you can use to connect to, disconnect from, and inquire on the status of the CICS-DBCTL interface.
Operator communication with DBCTL: overview
IMS operations can be done from an IMS main terminal operator console, which is usually the primary MVS console.
DBCTL operator commands
The operator commands you can use to communicate with DBCTL are a subset of IMS operator commands.
Summary of DBCTL operator commands
The following tables show you the CICS operator commands, corresponding DBCTL operator commands, and which DBCTL commands can be issued using the CICS-supplied transaction CDBM. Also shown are the IMS operator commands and keywords valid with DBCTL.
CDBM operator transaction
You can use CDBM to issue most of the IMS operator commands that are valid for DBCTL across the DRA interface to DBCTL to display and change the state of selected resources.
Issuing DBRC commands
With DBCTL, you must issue DBRC commands by using DBCTL console commands (/RMxxxxxx) because DBRC runs outside the CICS address space. You can issue the /RMxxxxxx commands by using the CICS-supplied transaction CDBM.
IMS password security
Use the Resource Access Control Facility (RACF®) to protect your databases and program specification blocks (PSBs).
Controlling tracing of DBCTL events
To start and stop tracing of internal DBCTL events dynamically, and define activities to be monitored by the IMS monitor, use the /TRACE command.
Finding out current status of DBCTL activities
To find out the status of particular DBCTL activities, use the /DISPLAY command.
Specifying messages to be logged on IMS log
Use the /LOG command to specify any alphanumeric character message to be logged on the IMS log.
Changing DBCTL resources online
The /MODIFY command is a part of the online change process used to control the modification of DBCTL resources online.
Preventing programs and transactions from updating DBCTL databases
You can use the /DBDUMP command with the DATABASE keyword to prevent programs from updating DL/I full function databases.
Switching to a new OLDS
Specifying /SWITCH OLDS causes the IMS log to switch to the next OLDS. This switch to the next OLDS is marked as a recovery point for log archiving purposes. If you also specify the (optional) CHECKPOINT keyword, IMS issues a simple checkpoint after the active log data set has been switched to the next OLDS.
Entering external subsystem commands from DBCTL
If you are using DBCTL to access Db2 databases via BMPs, you can use certain DBCTL operator commands to enter external subsystem commands (where Db2 is the external subsystem).
Making DBCTL resources available
To make DBCTL resources available to refer to and use, enter the /START command.
Preventing scheduling of PSBs and use of DBCTL databases
You can use the /STOP command to stop the scheduling of specific PSBs and the use of a given database.
Purging a transaction that is using DBCTL
You can query and purge tasks that use DBCTL using the CICS CEMT transaction as for any CICS task. However, if a transaction has hung in DBCTL, and you need to purge it, you must use the DBCTL command /STOP THREAD.
Stopping DBCTL normally
To stop DBCTL normally and disconnect it from CICS, use the /CHECKPOINT command with the FREEZE or PURGE keywords.
Stopping DBCTL abnormally
There is no equivalent of a CICS immediate shutdown in DBCTL. If you need to force termination of DBCTL, the MVS console operator has to issue an MVS MODIFY jobname STOP command.
Dealing with messages from DBCTL and CICS
Messages from DBCTL (in the form DFSnnnn) are sent to one or more consoles as specified in the MCS parameter of the IMSCTRL macro in the IMS generation. These messages include notification of change in status and of abnormal events.
Recovery and restart operations for DBCTL
Covers recovery and restart, commit protocols and resolving indoubt units of work.

Parent topic: Administering connections to other systems