USRDELAY

The USRDELAY system initialization parameter specifies the maximum time, in the range 0 - 10080 minutes (up to seven days), that an eligible user ID and its associated attributes are cached in the CICS® region after use. A user ID that is retained in the user table can be reused.

USRDELAY={30|number}
For a user ID to be retained in the CICS region and eligible for reuse in the USRDELAY period, one of the following statements must apply to the user ID:
  • The user ID was received from remote systems.
  • The user ID was specified on the SECURITYNAME attribute in the CONNECTION resource.
  • The user ID was specified on the USERID attribute in the SESSIONS resource.
  • The user ID was specified on the USERID attribute in the definition of an intrapartition transient data queue.
  • The user ID was specified on the USERID option on a START command.
  • The user ID was specified on the USERID attribute for a non-terminal task, such as the alias tasks that are attached for processing HTTP requests.

Within the USRDELAY period, a user ID in any one of these categories can be reused in one of the other categories, provided that the request for reuse has the same qualifiers. If a user ID is qualified by a different group ID, APPLID, or terminal ID, a retained entry is not reused, except when changing the terminal ID on LU6.2 when the retained entry is used.

If a user ID is unused for more than the USRDELAY limit, it is removed from the system, and the message DFHUS0200 is issued. You can suppress this message in an XMEOUT global user exit program.

If you specify USRDELAY=0, all eligible user IDs are deleted immediately after use and cannot be reused. With USRDELAY=0 set, the message DFHUS0200 is not issued.

When you specify USRDELAY=0, CICS drives a full sign-on for each incoming request (with I/O to RACF) and a full sign-off at the end of each transaction. This setting provides the highest level of security, but in some scenarios performance might be a higher priority. For example, if the CICS region communicates with other CICS regions and the connections carry high volumes of transaction routing or function shipping activity, multiple instances of sign-on and sign-off might be required for a single task. Select a USRDELAY value that gives the optimum balance of performance and security for the type of work that is carried out in each CICS region.

When a value other than 0 is specified for USRDELAY, the user ID and its attributes are retained in the region until the USRDELAY value has expired. For example, if you specified USRDELAY=30 for a user ID, but that user ID continues to run transactions every 25 minutes, the USRDELAY value never expires and any changes made to the user ID never come into effect.

Note: If RACFSYNC=YES, all cached user tokens for the user ID are flushed irrespective of the setting of the USRDELAY parameter for that user ID. A type 71 ENF event occurs when a user ID is added or removed from a group, or revoked. Learn more about RACFSYNC.

If you previously specified low values for the USRDELAY system initialization parameter in your CICS regions to ensure that CICS detected changes to RACF® profiles quickly, you might want to increase this value, because CICS is notified immediately if RACF profile changes occur. The primary impact of a high USRDELAY value is that the amount of storage used for RACF control blocks is increased.