Managing the CICS DB2 attachment facility

You can manage the status of the connection between CICS® and DB2® using CEMT commands and commands provided by the CICS DB2 attachment facility. The same function provided by CEMT is also available via EXEC CICS INQUIRE and SET commands. Below is a summary of the functions available:

CEMT INQUIRE and SET DB2CONN
The global status of the connection and its attributes along with attributes of pool threads and command threads can be inquired upon and set using these commands. See CICS Supplied Transactions and CICS Supplied Transactions.
CEMT INQUIRE and SET DB2ENTRY
The attributes of a particular DB2ENTRY defining threads to be be used by a specific transaction or set of transactions can be inquired upon and set using these commands. See CICS Supplied Transactions and CICS Supplied Transactions.
CEMT INQUIRE and SET DB2TRAN
Use these commands to find out and alter which transaction IDs use which DB2ENTRYs. See CICS Supplied Transactions and CICS Supplied Transactions.
DSNC DISC (disconnect)
This CICS DB2 attachment command can be used to cause currently connected threads to be terminated as soon as they are not being used by a transaction. For active threads, that means when the transaction releases the thread, which is typically at syncpoint time. Protected threads are threads that currently are not being used by a transaction and normally are released if they have not been reused after two protected thread purge cycles. A DSNC DISCONNECT command pre-empts the purge cycles and causes them to be terminated immediately. For more information on the DSNC DISCONNECT command see DSNC DISCONNECT.
DSNC DISP (display)
This CICS DB2 attachment command can be used to display the status of active threads for a particular plan, for a particular transaction, or for all plans and transactions. For more information, see DSNC DISPLAY.

The DSNC DISP command also displays CICS DB2 statistics to a CICS terminal. These statistics are only a subset of the CICS DB2 statistics that you can obtain using the CICS COLLECT STATISTICS and PERFORM STATISTICS commands. These statistics are subject to the same resetting characteristics as all CICS statistics.

For more information on the DSNC DISP STAT command, see DISPLAY STATISTICS output. For more information on the full CICS DB2 statistics available, see the CICS Performance Guide.

DSNC MODI (modify)
This CICS DB2 attachment command can be used to modify where unsolicited messages are sent and the number of threads allowed for a DB2ENTRY or for the pool or command threads. This function is superseded by the CEMT commands described which allow these attributes to be modified and all other attributes of a DB2CONN, DB2ENTRY or DB2TRAN. For more information, see DSNC MODIFY.

Related concepts
Operations with CICS DB2
Starting the CICS DB2 attachment facility
Stopping the CICS DB2 attachment facility
Resolving indoubt units of work (UOWs)
Entering DB2 commands
Purging CICS DB2 transactions
Starting SMF for DB2 accounting, statistics and tuning
Starting GTF for DB2 accounting, statistics and tuning
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