The predefined situations in this category monitor DB2 task activity.
It is not detrimental to reach a high percentage of the maximum active thread limit. However, when the ratio frequently nears 100%, increase the value specified in the THRDA keyword of the DSNCRCT macro used to define the CICS DB2 Resource Control Table for the transaction. You can also increase it dynamically using the MODIFY option of the DSNC transaction. Increasing the number of threads increases the overhead of the z/OS dispatcher scanning the TCB chain.
Formula
If the value of the attribute Maximum_Active_Threads is greater than 20 and the value of the attribute Maximum_Active_Threads is less than or equal to 54
It is not detrimental to reach a high percentage of the maximum active thread limit. However, when the ratio frequently nears 100%, increase the value specified in the THRDA keyword of the DSNCRCT macro used to define the CICS DB2 Resource Control for the transaction. You can also increase it dynamically using the MODIFY option of the DSNC transaction. Increasing the number of threads increases the overhead of the z/OS dispatcher scanning the TCB chain.
Formula
If the value of the attribute Maximum_Active_Threads is greater than 54
Consider changing the WAIT parameter in the DSNCRCT table to specify WAIT=YES or WAIT=POOL for this transaction. WAIT=YES allows a task to be queued when no threads are available; WAIT=POOL allows a task to use a pool thread. Increase the value specified in the THRDA keyword of the DSNCRCT macro used to define the CICS DB2 Resource Control for the transaction, or increase it dynamically using the MODIFY option of the DSNC transaction. Increasing the number of threads will increase the overhead of the z/OS dispatcher scanning the TCB chain.
Formula
If the value of the attribute Abort_Percent is greater than 40 and the value of the attribute Abort_Percent is less than or equal to 65
Consider changing the TWAIT parameter in the DSNCRCT table to specify WAIT=YES or WAIT=POOL for this transaction. WAIT=YES allows a task to be queued when no threads are available; WAIT=POOL allows a task to use a pool thread. Increase the value specified in the THRDA keyword of the DSNCRCT macro used to define the CICS DB2 Resource Control for the transaction, or increase it dynamically using the MODIFY option of the DSNC transaction. Increasing the number of threads will increase the overhead of the z/OS dispatcher scanning the TCB chain.
Formula
If the value of the attribute Abort_Percent is greater than 65
To reduce the percentage of waits, you can increase the maximum number of active threads for this transaction temporarily using either the MODIFY option of the DSNC transaction, or permanently by changing the THRDA parameter in the DSNCRCT. Increasing the number of threads, however, increases the overhead of the z/OS dispatcher scanning the TCB chain.
Formula
If the value of the attribute Wait_Percent is greater than 40 and the value of the attribute Wait_Percent is less than or equal to 65
To reduce the percentage of waits, you can increase the maximum number of active threads for this transaction temporarily using either the MODIFY option of the DSNC transaction, or permanently by changing the THRDA parameter in the DSNCRCT. Increasing the number of threads, however, increases the overhead of the z/OS dispatcher scanning the TCB chain.
Formula
If the value of the attribute Wait_Percent is greater than 65
If the problem is intermittent, you can increase the maximum number of active tasks for this transaction temporarily with the MODIFY option of the DSNC transaction. If the threshold is exceeded frequently, consider raising the maximum number of active threads by changing the THRDA parameter in the DSNCRCT. Increasing the number of threads, however, increases the overhead of the z/OS dispatcher scanning the TCB chain.
Formula
If the value of the attribute Threads_in_Use_Percent_HWM is greater than 70 and the value of the attribute Threads_in_Use_Percent_HWM is less than or equal to 90
If the problem is intermittent, you can increase the maximum number of active tasks for this transaction temporarily with the MODIFY option of the DSNC transaction. If the threshold is exceeded frequently, consider raising the maximum number of active threads by changing the THRDA parameter in the DSNCRCT. Increasing the number of threads, however, increases the overhead of the z/OS dispatcher scanning the TCB chain.
Formula
If the value of the attribute Threads_in_Use_Percent_HWM is greater than 90
If the problem is intermittent, you can increase the maximum number of active tasks for this transaction temporarily with the MODIFY option of the DSNC transaction. If the threshold is exceeded frequently, consider raising the maximum number of active threads by changing the THRDA parameter in the DSNCRCT. Increasing the number of threads, however, increases the overhead of the z/OS dispatcher scanning the TCB chain.
Formula
If the value of the attribute Threads_in_Use_Percent is greater than 70 and the value of the attribute Threads_in_Use_Percent is less than or equal to 90
If the problem is intermittent, you can increase the maximum number of active tasks for this transaction temporarily with the MODIFY option of the DSNC transaction. If the threshold is exceeded frequently, consider raising the maximum number of active threads by changing the THRDA parameter in the DSNCRCT. Increasing the number of threads, however, increases the overhead of the z/OS dispatcher scanning the TCB chain.
Formula
If the value of the attribute Threads_in_Use_Percent is greater than 90
Verify that DB2 is required for this CICS region. If DB2 is needed, attach DB2 for this region using DSNC STRTc, wherec is the appropriate RCT suffix. Include the DB2 startup program in the CICS startup PLT.
Formula
If the value of the attribute CICSplex_DB2_Summary.Attached_to_DB2 equals No
Verify that DB2 is required for this CICS region. If DB2 is needed, attach DB2 for this region using DSNC STRTc, wherec is the appropriate RCT suffix. Include the DB2 startup program in the CICS startup PLT.
Formula
If the value of the attribute CICSplex_DB2_Summary.Attached_to_DB2 equals No
Use the CICS transaction CDBC to connect CICS to DBCTL.
Formula
If the value of the attribute CICSplex_DBCTL_Summary.DBCTL_Active equals No
Use the CICS transaction CDBC to connect CICS to DBCTL.
Formula
If the value of the attribute CICSplex_DBCTL_Summary.DBCTL_Active equals No
See also the: