Starting CICS regions

This section describes how to start CICS® regions. It assumes that you have already carried out any customization of CICS, generated any additional support required, and defined all the necessary CICS system definitions.

About this task

You can start CICS in one of two ways:
  • Use the MVS™ START command to start CICS as a started task.
  • Submit a CICS batch job to the MVS internal reader.

In both methods, you determine how CICS starts, and the facilities and resources that it can use by specifying system initialization parameters that are used by the CICS startup procedure. You would normally specify the system initialization parameters before starting CICS. However, after you have started the initialization of CICS, you can override the system initialization parameters specified before startup; for example, to enable a specific facility for that run of CICS.

Procedure

  1. Specify system initialization parameters before startup.
  2. Start CICS in one of the following ways:
  3. Optional: After the CICS system initialization started, if you want to override any system initialization parameters that are specified before startup, follow the instructions in Overriding system initialization parameters during startup.

Results

When system initialization is completed, the message DFHSI1517 is returned, indicating that control is given to CICS and that CICS is ready to process terminal requests.

Tip:
System warm-up by use of z/OS® Workload Manager health service
Consider allowing CICS to have a warm-up process after the end of system initialization.

Even though DFHSI1517 signals the end of system initialization, the region might not be fully ready to receive work. This is because in some cases initialization continues after this message. For example, some bundle-defined resources are being installed asynchronously; so resources such as JVMSERVERs required for some applications have not completed initialization, even though the TCP/IP listener is open and accepting work. This could cause transactions to abend. For web services, a pipeline scan might not have completed, so use of the web service before the scan completes will fail.

You can allow CICS to have a warm-up process by setting the WLMHEALTH system initialization parameter. If the z/OS Workload Manager health service is active in the region, when the message DFHSI1517 is returned, the warm-up process is started. Then CICS intermittently adjusts the region's z/OS WLM health value to control flow of work into the region until the region is fully capable to process work. For more information about the CICS warm-up process, see CICS warm-up and cool-down by use of z/OS Workload Manager health service.

Inquiry of CICS system startup date and time
To find out the date and time a CICS region last undertook a cold, emergency, initial, or warm startup, you can use the INQUIRE SYSTEM SPI command. For more information, see INQUIRE SYSTEM.