The predefined situations in this category monitor the internal resources of CICS regions. These resources include storage, files, queues, and enqueues. A description and formula for each of these situations follow.
If many AIDs have accumulated, response time can be adversely affected because CICS attempts to start each AID on every dispatch of the Terminal Control Program. If a required terminal is unavailable because a task currently running on the terminal is not completing, you can kill the task with Tivoli OMEGAMON XE for CICS on z/OS and allow the scheduled AID to execute. If the AID is waiting on a remote system, check that the remote system is available and that the connections are in service.
Formula
If the value of the attribute AIDs is greater than 100 and the value of the attribute AIDs is less than or equal to 300 then the situation is true.
If many AIDs have accumulated, response time can be adversely affected because CICS attempts to start each AID on every dispatch of the Terminal Control Program. If a required terminal is unavailable because a task currently running on the terminal is not completing, you can kill the task with Tivoli OMEGAMON XE for CICS on z/OS and allow the scheduled AID to execute. If the AID is waiting on a remote system, check that the remote system is available and that the connections are in service.
Formula
If the value of the attribute AIDs is greater than 300 then the situation CICSRegion_AIDSCrit is true.
An excessive number of ICEs for the same transaction ID can indicate that the issuing task is looping. When ICEs are scheduled for a task which you do not want to run or are associated with a terminal that is not available, Tivoli OMEGAMON XE for CICS on z/OS allows you to view and kill these ICEs. Check whether the expiry time and date for the ICE has passed. If so, CICS can be in a stress situation such as short-on-storage or at the maximum task limit. Remedying that problem allows the ICEs to be processed.
Formula
If the value of the attribute ICEs is greater than 50 and the value of the attribute ICEs is less than or equal to 100 then the situation is true.
An excessive number of ICEs for the same transaction ID can indicate that the issuing task is looping. When ICEs are scheduled for a task which you do not to run or are associated with a terminal that is not available, Tivoli OMEGAMON XE for CICS on z/OS allows you to view and kill these ICEs. Check whether the expiry time and date for the ICE has passed. If so, CICS can be in a stress situation such as short-on-storage or at the maximum task limit. Remedying that problem allows the ICEs to be processed.
Formula
If the value of the attribute ICEs is greater than 100 then the situation is true.
When CICS is at the MXT limit, no new tasks will be dispatched. Use the Transaction Analysis report to determine whether there is a problem that is preventing tasks from completing in a timely manner. For example, tasks can be waiting for an enqueue, or CICS can be short-on-storage. To alleviate a bottleneck, you can use Tivoli OMEGAMON XE for CICS on z/OS to kill the task s causing degradation. The initial MXT limit is defined in the SIT and can be changed dynamically using the CEMT transaction.
Formula
If the value of the attribute Maximum_Tasks_Percent is greater than 80 and the value of the attribute Maximum_Tasks_Percent is less than or equal to 90 then the situation is true.
When CICS is at the MXT limit, no new tasks will be dispatched. Use the Transaction Analysis report to determine whether there is a problem that is preventing tasks from completing in a timely manner. For example, tasks can be waiting for an enqueue, or CICS can be short-on-storage. To alleviate a bottleneck, you can use Tivoli OMEGAMON XE for CICS on z/OS to kill the task s causing degradation. The initial MXT limit is defined in the SIT and can be changed dynamically using the CEMT transaction.
Formula
If the value of the attribute Maximum_Tasks_Percent is greater than 90 then the situation is true.
When CICS is at the MXT limit, no new tasks will be dispatched. Use the Transaction Analysis report to determine whether there is a problem that is preventing tasks from completing in a timely manner. For example, tasks can be waiting for an enqueue, or CICS can be short-on-storage. To alleviate a bottleneck, you can use Tivoli OMEGAMON XE for CICS on z/OS to kill the task s causing degradation. The initial MXT limit is defined in the SIT and can be changed dynamically using the CEMT transaction.
Formula
If the value of the attribute Maximum_Tasks_Percent is greater than or equal to 100 then the situation is true.
When CICS is at the MXT limit, no new tasks will be dispatched. Use the Transaction Analysis report to determine whether there is a problem that is preventing tasks from completing in a timely manner. For example, tasks can be waiting for an enqueue, or CICS can be short-on-storage. To alleviate a bottleneck, you can use Tivoli OMEGAMON XE for CICS on z/OS to kill the task s causing degradation. The initial MXT limit is defined in the SIT and can be changed dynamically using the CEMT transaction.
Formula
If the value of the attribute Maximum_Tasks_Percent is greater than or equal to 100 then the situation is true.
If the total transaction rate is high and the rate for transactions completing is low, check the navigation tree for situations that can identify other problems preventing tasks from completing.
Formula
If the value of the attribute Transaction_Rate is greater than 100 and the value of the attribute Transaction_Rate is less than or equal to 200 then the situation is true.
If the total transaction rate is high and the rate for transactions completing is low, check the navigation tree for situations that can identify other problems preventing tasks from completing.
Formula
If the value of the attribute Transaction_Rate is greater than 200 then the situation is true.
If the total transaction rate is low, check the navigation tree for situations that can identify other problems preventing tasks from being attached. For example, CICS can be short-on-storage or in a stall condition.
Formula
If the value of the attribute Transaction_Rate is less than 10 and the value of the attribute Transaction_Rate is greater than or equal to 5 then the situation is true.
If the total transaction rate is low, check the navigation tree for situations that can identify other problems preventing tasks from being attached. For example, CICS can be short-on-storage or in a stall condition.
Formula
If the value of the attribute Transaction_Rate is less than 5 then the situation is true.
CICS can be using more CPU than normal. Additional diagnostics can be obtained by generating a Region Overview report and checking whether the CICS time-of-day clock is being updated. The Transaction Analysis report can be used to locate looping tasks, or those that have exceeded their Global CPU usage limit, MAXR.
Formula
If the value of the attribute CPU_Utilization is greater than 70 and the value of the attribute CPU_Utilization is less than or equal to 90 then the situation is true.
CICS can be using more CPU than normal. Additional diagnostics can be obtained by generating a Region Overview report and checking whether the CICS time-of-day clock is being updated. The Transaction Analysis report can be used to locate looping tasks, or those that have exceeded their Global CPU usage limit (MAXR.
Formula
If the value of the attribute CPU_Utilization is greater than 90 then the situation is true.
CICS can be requiring fewer CPU cycles than normal for the expected transaction rate. If response time is unacceptable, check the transaction rate display in the Region Overview report to see if the rate is lower than normal. Next, see if Transaction Analysis is showing active task activity, and if so, use the Impact Analysis function of Tivoli OMEGAMON XE for CICS on z/OS to determine why CICS is not being dispatched. If there is no contention, check the network to see if terminals are active.
Formula
If the value of the attribute CPU_Utilization is less than 10 and the value of the attribute CPU_Utilization is greater than or equal to 5 then the situation is true.
CICS can be requiring fewer CPU cycles than normal for the expected transaction rate. If response time is unacceptable, check the transaction rate display in the Region Overview report to see if the rate is lower than normal. Next, see if Transaction Analysis is showing active task activity, and if so, use the Impact Analysis function of OMEGAMON XE for CICS to determine why CICS is not being dispatched. If there is no contention, check the network to see if terminals are active.
Formula
If the value of the attribute CPU_Utilization is less than 5 then the situation is true.
A page-in can cause the CICS job to wait for the page fault to resolve. Any delay during this process, regardless of the cause, degrades response time for all CICS tasks. Use the Region Overview report to view the CICS page-in rate and working set size. Consider the use of storage isolation. For multiple CICS regions, use the LPA option for CICS nucleus modules.
Formula
If the value of the attribute Page_Rate is greater than 3 and the value of the attribute Page_Rate is less than or equal to 5 then the situation is true.
A page-in can cause the CICS job to wait for the page fault to resolve. Any delay during this process, regardless of the cause, degrades response time for all CICS tasks. Use the Region Overview report to view the CICS page-in rate and working set size. Consider the use of storage isolation. For multiple CICS regions, use the LPA option for CICS nucleus modules.
Formula
If the value of the attribute Page_Rate is greater than 5 then the situation is true.
Storage isolation values can be examined with the system summary display provided by Tivoli OMEGAMON XE for CICS on z/OS. If the working set size must be reduced, consider lowering the MXT value for CICS, using shared libraries, LPA residency options, VSAM LSR pools, or Max class limits.
Formula
If the value of the attribute Working_Set_Size is greater than 6000 and the value of the attribute Working_Set_Size is less than or equal to 7500 then the situation is true.
Storage isolation values can be examined with the system summary display provided by Tivoli OMEGAMON XE for CICS on z/OS. If the working set size must be reduced, consider lowering the MXT value for CICS, using shared libraries, LPA residency options, VSAM LSR pools, or class max limits.
Formula
If the value of the attribute Working_Set_Size is greater than 7500 then the situation is true.
Use the Transaction Analysis report to check whether there are any active transactions. If there is task activity, monitor the page-in rate with the Region Overview report. A low working set can be caused by frequent variations in the number of page-ins that CICS is doing. Consider storage isolation (set in the z/OS IPS to control the average CICS working set size.
Formula
If the value of the attribute Working_Set_Size is less than 256 and the value of the attribute Working_Set_Size is greater than or equal to 128 then the situation is true.
Use the Transaction Analysis report to check whether there are any active transactions. If there is task activity, monitor the page-in rate with the Region Overview report. A low working set can be caused by frequent variations in the number of page-ins that CICS is doing. Consider storage isolation (set in the z/OS IPS to control the average CICS working set size.
Formula
If the value of the attribute Working_Set_Size is less than 128 then the situation is true.
If the OSCOR value remains consistently large, consider increasing the size of the CICS Dynamic Storage Area for your expected transaction rate.
Formula
If the value of the attribute Largest_Contiguous_Available_OSCOR is greater than 500 and the value of the attribute Largest_Contiguous_Available_OSCOR is less than or equal to 1000 then the situation is true.
If the OSCOR value remains consistently large, consider increasing the size of the CICS Dynamic Storage Area for your expected transaction rate.
Formula
If the value of the attribute Largest_Contiguous_Available_OSCOR is greater than 1000 then the situation is true.
Shortages of OSCOR will cause S80A abends. Also, CICS applications should not execute functions that bypass CICS to make operating system calls. Review the region size of CICS, and consider reducing the size of the DSA to ensure enough OSCOR is available for z/OS system functions.
Formula
If the value of the attribute Largest_Contiguous_Available_OSCOR is less than 48 and the value of the attribute Largest_Contiguous_Available_OSCOR is greater than or equal to 24 then the situation is true.
Shortages of OSCOR will cause S80A abends. Also, CICS applications should not execute functions that bypass CICS to make operating system calls. Review the region size of CICS, and consider reducing the size of the DSA to ensure enough OSCOR is available for z/OS system functions.
Formula
If the value of the attribute Largest_Contiguous_Available_OSCOR is less than 24 then the situation is true.
Allocation of private storage within CICS can be viewed with the Tivoli OMEGAMON XE for CICS on z/OS CSYS command. If a request for Local System Queue Area (LSQA is made and cannot be satisfied, an S40D abend might result. Consider lowering the region size of CICS to increase available LSQA.
Formula
If the value of the attribute Largest_Contiguous_Available_LSQA is less than 48 and the value of the attribute Largest_Contiguous_Available_LSQA is greater than or equal to 24 then the situation is true.
Allocation of private storage within CICS can be viewed with the Tivoli OMEGAMON XE for CICS on z/OS CSYS command. If a request for Local System Queue Area (LSQA is made and cannot be satisfied, an S40D abend might result. Consider lowering the region size of CICS to increase available LSQA.
Formula
If the value of the attribute Largest_Contiguous_Available_LSQA is less than 24 then the situation is true.
Use the Transaction Storage Violations report to determine which tasks are responsible for corrupting memory in CICS. Consider disabling the transactions until the problem is resolved.
Formula
If the value of the attribute Storage_Violations is greater than 0 and the value of the attribute Storage_Violations is less than or equal to 1 then the situation is true.
Use the Transaction Storage Violations report to determine which tasks are responsible for corrupting memory in CICS. Consider disabling the transactions until the problem is resolved.
Formula
If the value of the attribute Storage_Violations is greater than 1 then the situation is true.
Inspect the Transaction Analysis report for any possibility of a looping transaction. The Bottleneck Analysis report can be used to check whether CICS is waiting for CPU cycles or page data set activity.
Formula
If the value of the attribute CICS_TOD_Updated equals No then the situation is true.
Inspect the Transaction Analysis report for any possibility of a looping transaction. The Bottleneck Analysis report can be used to check whether CICS is waiting for CPU cycles or page data set activity.
Formula
If the value of the attribute CICS_TOD_Updated equals No then the situation is true.
Use the CDEV command in Tivoli OMEGAMON XE for CICS on z/OS to determine whether a particular volume is causing the high I/O rate. Bottleneck Analysis, VSAM displays, and current and historical transaction displays in Tivoli OMEGAMON XE for CICS on z/OS can all be used to decide if there is contention for a particular file, a s well as identifying the transaction responsible for the I/O activity.
Formula
If the value of the attribute I/O_Rate is greater than 90 and the value of the attribute I/O_Rate is less than or equal to 100 then the situation is true.
Use the CDEV command in Tivoli OMEGAMON XE for CICS on z/OS to determine whether a particular volume is causing the high I/O rate. Bottleneck Analysis, VSAM displays, and current and historical transaction displays in Tivoli OMEGAMON XE for CICS on z/OS can all be used to decide if there is contention for a particular file, a s well as identifying the transaction responsible for the I/O activity.
Formula
If the value of the attribute I/O_Rate is greater than 100 then the situation is true.
Check the startup messages in the CICS job log for an explanation of why the VTAM ACB failed to open. Check to make sure that the CICS VTAM ACB is active. If it is not, vary the ACB active with the VTAM vary command and issue the CEMT SET,VTAM,OPEN transaction in CICS to establish VTAM communications. If you are still having difficulty, contact the staff responsible for VTAM at your installation.
Formula
If the value of the attribute VTAM_ACB_Open equals No then the situation is true.
Check the startup messages in the CICS job log for an explanation of why the VTAM ACB failed to open. Check to make sure that the CICS VTAM ACB is active. If it is not, vary the ACB active with the VTAM vary command and issue the CEMT SET,VTAM,OPEN transaction in CICS to establish VTAM communications. If you are still having difficulty, contact the staff responsible for VTAM at your installation.
Formula
If the value of the attribute VTAM_ACB_Open equals No then the situation is true.
See also the CICSplex Region Overview attribute group.