Monitoring structures on a coupling facility

The DISPLAY XCF,STRUCTURE and DISPLAY XCF,STRUCTURE,STRNAME=z/OS® operator commands are especially useful in monitoring structure activity.

These commands let you look at structures on a coupling facility to determine resource status and, for failures, gather information for problem determination.

For detailed information on these commands, see the appropriate z/OS publication.

DISPLAY XCF,STRUCTURE command

Use this command to display the status of structures defined in your active policy.

The following example shows an example of output from this command.

IXC359I  11.09.26  DISPLAY XCF 376
STRNAME           ALLOCATION TIME  STATUS
CF01             02/17/96 17:03:49 ALLOCATED
CF02                --       --    NOT ALLOCATED
CF03                --       --    NOT ALLOCATED
CF04                --       --    NOT ALLOCATED
OSAMSESXI        02/17/96 17:02:54 ALLOCATED
                                   REBUILDING
                                   REBUILD PHASE: QUIESCE
VSAMSESXI        02/17/96 17:03:03 ALLOCATED

In the example:

STRNAME: Is the name of a structure.
ALLOCATION TIME: Is a time stamp indicating when the structure was allocated in the coupling facility.
STATUS: Is the current status of the structure. A structure can be in a number of different states, such as ALLOCATED, NOT ALLOCATED, or ALLOCATED REBUILDING.

The displayed information can help you determine whether the appropriate IRLM, OSAM, VSAM, shared MSGQ, and shared EMHQ structures have been defined and allocated. If not, check that the structure names on your CFNAMES control statement match the structure names that are displayed. If they do not match, change the names in either the coupling facility resource manager (CFRM) policy or the CFNAMES control statement.

In the example, six structures are defined (CF01-CF04, OSAMSESXI, and VSAMSESXI). Three of the structures are allocated (CF01, OSAMSESXI, and VSAMSESXI). The status of the OSAM structure is that it is currently being rebuilt after a structure failure.

DISPLAY XCF,STRUCTURE,STRNAME= command

Use this command to display detailed information about a specific structure. The three structures of importance to IMS are the IRLM, OSAM, VSAM, shared MSGQ, and shared EMHQ structures.

The following example shows an example of output from this command, specifying an OSAM structure named OSAMSESXI.

 IXC360I  17.30.46  DISPLAY XCF 677
 STRNAME: OSAMSESXI
  STATUS: ALLOCATED
   POLICY SIZE    : 2048 K
   PREFERENCE LIST: CF02     CF01
   EXCLUSION LIST IS EMPTY
 
  ACTIVE STRUCTURE
  ----------------
   ALLOCATION TIME: 02/17/96 17:02:54
   CFNAME         : CF02
   COUPLING FACILITY: ND02...
                      PARTITION: 0    CPCID: 00
   ACTUAL SIZE    : 2048 K
   STORAGE INCREMENT SIZE: 256 K
   VERSION        : A8DAC970 15774B04
   DISPOSITION    : DELETE
   ACCESS TIME    : 0
   MAX CONNECTIONS: 32
   # CONNECTIONS  : 5
 
  CONNECTION NAME  ID VERSION  SYSNAME  JOBNAME  ASID STATE
  ---------------- -- -------- -------- -------- ---- ------
  DLI11            04 00040001 MVS1     DLI11    0031 ACTIVE
  DLI12            05 00050001 MVS1     DLI12    0033 ACTIVE
  IMS1             01 00010013 MVS1     DLIOCSA8 0036 ACTIVE
  IMS2             02 00020012 MVS2     DLIOCSB8 0035 ACTIVE
  IMS3             03 00030011 MVS3     DLIOCSC8 0038 ACTIVE

There are three parts to the output. The first part shows the status of the structure and information about the active policy. The following information from the display is especially useful:

STRNAME: Is the name of the structure, as specified in the command.
STATUS: Is the current status of the structure. A structure can be in a number of different states, such as ALLOCATED, NOT ALLOCATED, or ALLOCATED REBUILDING.
POLICY SIZE: Is the size of the structure as specified in the policy.
PREFERENCE LIST: Shows the coupling facility on which MVS allocates the structure. z/OS tries to allocate the structure on the first coupling facility listed (CF02 in the example), then the second one (CF01), and so on.

The second part of the output shows more detailed status information for the structure.

ALLOCATION TIME: Is the time the structure was allocated.
CFNAME: Is the name of the coupling facility on which the structure was allocated.
COUPLING FACILITY: Is the name of the coupling facility on which the structure resides.
ACTUAL SIZE: Is the actual size of the structure.
DISPOSITION: Is what the system will do with the structure in a failure situation. The IRLM structure always has a disposition of KEEP. The OSAM and VSAM structures always have a disposition of DELETE.
MAX CONNECTIONS: Is the maximum number of connections that can be made to the OSAM, VSAM, IRLM, shared MSGQ, or shared EMHQ structure. The maximum is 255 connections for any structure.
# CONNECTIONS: Is the current number of IMS systems connected to the structure.

Other information in the second part of the output is not needed for monitoring and problem determination for IMS sysplex data sharing.

The third part of the output shows which z/OS systems are connected to the structure and gives information about each use.

CONNECTION NAME

Is the name of a connection. z/OS will repeat the connection message text in a table to report all connections. If there are no connections, no connection table is displayed.

ID

Is the connection identifier.

VERSION

Is the version number of the z/OS system that is connected.

SYSNAME

Is the name of the z/OS system that is connected.

JOBNAME

Is the name of the job associated with the connection.

ASID

Is the ID of the address space associated with the connection.

STATE

Is the status of the structure, which can be one of the following:

FAILED PERSISTENT: The failed persistent status occurs if the disposition of a structure is KEEP and connection to the structure is lost.
DISCONNECTING: IMS is in the process of disconnecting from the structure.
FAILING: IMS is in the process of abnormally terminating.
ACTIVE: IMS is connected.
ACTIVE &: IMS is connected, but has physically lost connectivity to the structure.
ACTIVE OLD: The structure is being rebuilt. IMS is connected to the old structure.
ACTIVE &OLD: The structure is being rebuilt. IMS is connected to the old structure, but has physically lost connectivity to it.
ACTIVE NEW,OLD: The structure is being rebuilt. IMS is connected to both the old and the new structure.
ACTIVE NEW,&OLD: The structure is being rebuilt. IMS is connected to both the old and the new structure, but has physically lost connectivity to the old structure.
ACTIVE &NEW,OLD: The structure is being rebuilt. IMS is connected to both the old and the new structure, but has physically lost connectivity to the new structure.
ACTIVE &NEW,&OLD: The structure is being rebuilt. IMS is connected to both the old and the new structure, but has physically lost connectivity to both structures.