This section describes the types of delays that are specific to CICS. CICS statistics, which can give insight into these delays, are discussed in CICS Summary Statistics and CICS Transaction Statistics. Warning signs and possible tuning measures are also discussed.
With autonavigation, you can go directly from a delay category to a more detailed screen that provides relevant information about the delay. For more information, see "Using Autonavigation".
An overview of the delay types that you see in a CICS environment follows along with recommendations about how to use CA MAT to find out more about why your transactions are experiencing delays.
CA MAT groups delays into major and minor categories. An overview of CICS delay categories follows.
Either CICS locks were held by the application causing delays or a function was shipped to another CICS region running in an MRO configuration.
Transient data delays include all functions that read, write, or delete records to the transient data in VSAM data sets. Delays associated with actually performing I/O to the VSAM cluster also are included in this category.
Storage allocated for the application includes CICS system-acquired storage for the application, such as areas for the program, data records, terminal areas, and messages. It also includes dynamically acquired user storage needed by the application.
This category includes the delays associated with performing I/O to CICS files or database operations. The I/O is directly requested by the application or is performed on behalf of the application by CICS.
Journal control delays are those delays associated with performing any actions to the CICS journals. Journaling is performed on behalf of the applications.
Temporary storage delays are those delays that are incurred because of read/write activity to the Temporary Storage facility of CICS.
This category includes delays incurred by the application when programs are loaded by CICS.
This category includes all delays incurred when reading or writing data to a terminal, all VTAM related delays, and delays caused when an application is waiting for input from the terminal user.
This category includes delays related to application requests to local DL/I resources and to DBCTL regions.
The various types of CICS system delays, and the possible reasons for them are described next.
CICS obtains locks on behalf of the application for a variety of reasons. These locks normally exist for a short period of time. A significant delay can indicate a system definition problem.
If your application uses the multiregion option of CICS, it might be delayed because you are unable to establish a session with the remote system. This delay indicates that too few sessions are available on the remote system, or, if the connection has been made, the other system is responding slowly and your request is delayed. CA MAT attempts to identify the name of the other CICS in its detail data.
The following text describes the various types of CICS transient data delays, and the possible reasons for them.
Application can wait when making a request to an extrapartition transient data queue because some other task is using that destination.
Transient data queues defined in the DCT as logically recoverable can cause delays because a subsequent task that is making a request to the same queue is forced to wait until the first application terminates or issues a synchpoint command.
This delay occurs when all of the buffers for the transient data are in use. The application waits until a buffer becomes available.
This delay occurs when all of the VSAM strings for the transient data queue are in use. The application waits until a VSAM string becomes available.
This delay occurs when the transient data request is waiting for the VSAM I/O to the Transient Data VSAM file to complete processing.
Brief delay that occurs when there is contention for a VSAM control interval.
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