CICS actions on a warm start

A warm start restores certain elements of the CICS® components to the status that was recorded in the previous warm keypoint. The recorded status is determined from their definitions or commands rather than their actual status at shutdown.

A partial warm start is similar to a complete warm start, except that some selected CICS facilities are started cold, as specified in the system initialization parameters. Information is obtained for those facilities from the warm keypoint only if they are not specified for a cold start.

In a warm start:
  • Resource definition information is obtained as follows:
    • Tables specified by system initialization parameters, such as MCT=xx, are obtained from the program library. Information contained in the warm keypoint of the previous run is used to update the information from the program library.
    • Information in the groups in the list named by the GRPLIST system initialization parameter for this initialization is ignored.
    • Information in the groups in the list named by the GRPLIST system initialization parameter for the previous initialization is obtained from the warm keypoint and the global catalog.
    • Information in groups that have been installed since the last cold start is obtained from the warm keypoint and the global catalog.
    • Information in groups that have been defined or added to group lists is taken from the CSD.
    • All dynamic LIBRARY resource definitions will be restored from the catalog, and the actual search order through the list of LIBRARY resources that was active at the time of the preceding shutdown will be preserved. If a library that is defined as critical is restored from the catalog and an error occurs in enabling the LIBRARY, such as one of the data sets in its concatenation no longer being available, a Go or Cancel message will be issued to allow the operator to choose whether to continue the CICS startup regardless, or to fail the startup. The message will be preceded by a set of messages providing information on any data sets which are not available. For non critical LIBRARY resources, this condition will not cause CICS startup to fail, but a warning message will be issued and the library will not be reinstalled.
    • Information about any autoinstalled terminal that has an automatic-initiate descriptor (AID) outstanding is retrieved from the global catalog.
  • Selected fields from the CSA are restored from the warm keypoint, including:
    • Region exit time interval value
    • Runaway time interval value
    • Maximum number of tasks
    • High watermark number of the unit of recovery descriptor.
  • The following pieces of information relating to logically recoverable, physically recoverable and non-recoverable intrapartition transient data queues are restored:
    • All data defining the queues. This information is restored from the global catalog, including trigger level information, ATI transaction IDs, ATI terminal IDs and so on.
    • All state-related data. This information is retrieved from the warm keypoint which was written to the log, including:
      • Record count
      • Read pointer value
      • Write pointer value
      • Information about whether or not a trigger transaction has been attached.

      All intrapartition transient data queues are installed as ENABLED. Trigger transactions are rescheduled if required.

      Extrapartition transient data queues are opened if OPENTIME=INITIAL is specified in the queue definition.

  • The following FCT information is restored to what it was at the time of the warm shutdown, using information from the global catalog:
    • The ENABLED/DISABLED/UNENABLED status
    • The SERVREQ options (UPDATE, DELETE and so on)
    • Any alterations made to the DSNAME.
  • Files defined as initially OPEN are opened irrespective of their other attributes. If the file state recovered during initialization is ENABLED or UNENABLED, the file becomes OPEN, ENABLED after the OPEN. If the file state recovered is DISABLED, the file becomes OPEN, DISABLED.
  • Installed transaction and profile definitions are obtained from:
    • The groups specified in the GRPLIST system initialization parameter at the last cold start
    • The groups that have been installed since the last cold or emergency start.
    The following attributes of the installed transactions and profiles are restored from the warm keypoint:
    • ENABLED/DISABLED status
    • Transaction priority.
  • Installed program and mapset definitions are obtained from these sources:
    • The groups specified in the GRPLIST system initialization parameters at the last cold start
    • The groups that have been installed since the last cold start or emergency restart
    • The changes (such as LPA-eligibility) made by CEMT or EXEC CICS SET PROGRAM commands in the last run.

    The ENABLED/DISABLED status of each installed program and mapset is restored from the warm keypoint. Directory information is obtained for each program and mapset during CICS initialization.

  • The following TCT information is restored from the warm keypoint information:
    • Processing status (transaction, transceive, input, or receive)
    • Service status (INSERVICE or OUTSERVICE)
    • Extended attributes supported (color, programmed symbols, and so on)
    • Partition support
    • Magnetic-stripe-reader support
    • Outboard formatting support
    • Coded graphic character set identifiers
    • APL/TEXT keyboard.
    If any outstanding work was scheduled for an autoinstalled terminal at the last warm shutdown, the terminal entry is recovered. (Terminal entries for autoinstalled terminals with no work outstanding are deleted at shutdown.)
  • The following auxiliary temporary storage information is restored from the warm keypoint:
    • All data in the auxiliary temporary storage queues
    • The temporary storage use map.
  • Interval control elements (ICEs) for outstanding START TRANSID commands are restored from the warm keypoint.
  • The BMS logical messages that were created by the functions listed below but have not yet been viewed by the terminal operator are restored:
    • Message switching transaction (CMSG).
    • ROUTE command.
    • SEND MAP ACCUM and SEND TEXT ACCUM commands, except for those messages terminated by SEND PAGE without specifying RELEASE or RETAIN. In those cases, the message might already have been viewed by the operator, but can be viewed again following the warm start.
  • All unit of recovery descriptors (APPC log name, APPC resynchronization, and external resource manager) are restored from the warm keypoint, together with any associated deferred work elements (DWEs).
  • The STORECLOCK value is restored from the warm keypoint.
  • The intervals at which statistics were collected and status and the logical end-of-day time are restored from the global catalog.
  • The monitoring status, class status and monitoring control table suffix are restored from the global catalog.
  • Transaction and system dump table options are held in the global catalog and reapplied at a warm start.
  • Journals and journal models are restored from the catalog.
  • The version of Java™ in use for the CICS region (supported by the IBM® 64-bit SDK for z/OS®, Java Technology Edition) is restored from the global catalog.