The attributes are described in the categories:
The general attributes of a DB2CONN are:
The connection attributes of a DB2CONN are:
A protected thread is not terminated immediately when it is released. It is terminated only after two completed purge cycles, if it has not been reused in the meantime. Therefore, if the purge cycle is set to 30 seconds, a protected thread is purged 30 - 60 seconds after it is released. The first purge cycle after the attachment facility starts is always 5 minutes. After that the purgecycle values are applied. An unprotected thread is terminated when it is released (at syncpoint or end of task) if there are no other transactions waiting for a thread on that DB2ENTRY. Only threads belonging to a DB2ENTRY can be protected. Pool threads and command threads cannot be protected.
Specifies the maximum number of TCBs that can be used to process DB2 requests. The default is 12. The minimum number is 4 and the maximum is 2000. When connected to DB2 Version 5 or earlier, the CICS DB2 attachment facility creates the TCBs in the form of subtasks up to the limit specified by TCBLIMIT. Each of these subtasks identifies to DB2 and creates a connection into DB2. When connected to DB2 Version 6 or later, CICS creates open TCBs (up to the limit specified by the system initialization parameter MAXOPENTCBS). The TCBLIMIT attribute of the DB2CONN definition governs how many of the open TCBs can be used to access DB2 -- that is, how many of them can identify to DB2 and create a connection into DB2.
The TCBLIMIT value controls the total number of threads for the CICS region. For this reason, the recommended value for TCBLIMIT is the sum of all the thread limit values (that is, the sum of all THREADLIMIT attributes on the DB2 connection and DB2 entry resource definitions, plus the COMTHREADLIMIT value on the DB2 connection definition) up to the limit of 2000. The value you choose for TCBLIMIT can be exceeded by increasing THREADLIMIT values for selected subtasks.
When determining the number for TCBLIMIT, you must consider the amount you specified for the MAX USERS parameter on DB2 installation panel DSNTIPE.
The pool thread attributes of a DB2CONN are:
When the DB2 sample sign-on exit DSN3@SGN is used with AUTHTYPE(USERID), the exit sends the user ID to DB2 as the primary authorization ID and the RACF® group ID to DB2 as the secondary ID. When the sample sign-on exit is used, there is no difference between AUTHTYPE(USERID) and AUTHTYPE(GROUP).
To use the GROUP option, the CICS system must have SEC=YES specified in the CICS system initialization table (SIT).
If no RACF group ID is available for this USERID, an 8-character field of blanks is passed to DB2 as the group ID.
If the transaction is not associated with a terminal (for example, if it is initiated with a START command), do not specify AUTHTYPE(TERM).
Do not specify YES if the pool is used by transactions running enterprise beans as part of an OTS transaction; CICS syncpoint rollback is not allowed in an OTS transaction. Consider defining a DB2ENTRY which specifies DROLLBACK(NO) for use by transactions which run enterprise beans as part of an OTS transaction.
The CICS DB2 attachment issues a unique abend code AD3T, message DFHDB2011, when THREADWAIT=NO is coded and the number of pool threads is exceeded.
The DB2 connection definition command thread attribute descriptions are:
When the DB2 sample sign-on exit DSN3@SGN is used with AUTHTYPE(USERID), the exit sends the USERID to DB2 as the primary authorization ID and the RACF group ID to DB2 as the secondary ID. When the sample sign-on exit is used, there is no difference between COMAUTHTYPE(USERID) and COMAUTHTYPE(GROUP).
To use the CGROUP option the CICS system must have SEC=YES specified in the CICS system initialization table (SIT).
If no RACF group ID is available for this USERID, an 8-character field of blanks is passed to DB2 as the group ID.
If a transaction is started (using a CICS command) and has no terminal associated with it, the COMAUTHTYPE(TERM) should not be used.