Editing CICS (section)

==CICS Recovery/Restart==
The objective of recovery/restart in CICS is to minimize and if possible eliminate damage done to Online System when a failure occurs, so that system and data integrity is maintained.<ref>{{cite web|url=https://www.ibm.com/support/knowledgecenter/SSGMCP_latest/administering/recovery/dfht219.html|title=IBM Knowledge Center|website=publib.boulder.ibm.com|access-date=2 February 2021|archive-date=15 June 2021|archive-url=https://web.archive.org/web/20210615130445/https://www.ibm.com/docs/en/cics-ts/5.6?topic=recovery-cics-warm-restart|url-status=live}}</ref> If the CICS region was shut down instead of failing it will perform a "Warm" start exploiting the checkpoint written at shutdown. The CICS region can also be forced to "Cold" start which reloads all definitions and wipes out the log, leaving the resources in whatever state they are in.

Under CICS, following are some of the resources which are considered recoverable. If one wishes these resources to be recoverable then special options must be specified in relevant CICS definitions:

* VSAM files
* CMT CICS-maintained data tables
* Intrapartition TDQ
* Temporary Storage Queue in auxiliary storage
* I/O messages from/to transactions in a VTAM network
* Other database/queuing resources connected to CICS that support XA two-phase commit protocol (like IMS/DB, Db2, VSAM/RLS)

CICS also offers extensive recovery/restart facilities for users to establish their own recovery/restart capability in their CICS system. Commonly used recovery/restart facilities include:

* Dynamic Transaction Backout (DTB)
* Automatic Transaction Restart
* Resource Recovery using System Log
* Resource Recovery using Journal
* System Restart
* Extended Recovery Facility