Cross-System Coupling Facility (XCF) enhancements for z/OS V2R2
- List services enhancements: XES List services
IXLLIST, IXLLSTE, and IXLLSTC are updated to return both the current
in-use number of entries and current in-use elements for a specific
list. READ, WRITE, MOVE, and DELETE (IXLLIST and IXLLSTE) and READ_LCONTROLS,
MONITOR_LIST, and MONITOR_KEYRANGE requests return both in-use entry
and in-use element counts in the List Services Answer Area (IXLYLAA
macro). For more information, see z/OS MVS Programming: Sysplex Services Guide.
When change was introduced: z/OS V2R2.
Transport Class simplification (Member Isolation): The
XCF member monitors are enhanced to detect ill-behaved members accumulating
a large backlog of signals impeding the ability of XCF to send and
receive messages on behalf of other XCF group members. When this condition
is detected, XCF will "message isolate" the ill-behaved member and
not send messages to that member until the backlog of signals is reduced
to a reasonable level. The XCF Message-Out service (IXCMSGO, IXCMSGOX)
will delay or reject messages targeted to a member that is "message
isolated". For more information, see
When change was introduced: z/OS V2R2.
- IXCQUERY enhancements: The IXCQUERY query
service is modified to provide function to return information for
couple data sets and policy information contained in the couple data
sets, if policy data exists. For more information, see z/OS MVS Programming: Sysplex Services Reference .
When change was introduced: z/OS V2R2.
- CFSite enhancements: The structure definition
in the CFRM policy allows for the specification of a preference list
which specifies an ordered list of coupling facility names from which
the system is to choose when allocating a structure in a coupling
facility. The system attempts to allocate the structure in the first
coupling facility in the preference list that meets a specified allocation
criteria.
To help with defining the preference list, especially across duplexed structures, a new keyword is introduced to the CFRM policy for structure definitions. An additional parameter is introduced that indicates how coupling facilities should be chosen based on their specified site for the structure or structures that should be duplexed.
The DISPLAY XCF and IXCQUERY commands are updated. For more information, see z/OS MVS System Commands. The CFRM Policy Utility, IXCMIAPU, is updated. For more information, see z/OS MVS Setting Up a Sysplex.
When change was introduced: z/OS V2R2.
- Gain ownership enhancements: This support
will remove prompts for system messages IXC501A and IXC560A to avoid
human interaction and prevent an error leading to a sysplex outage.
A new keyword, CFRMTAKEOVERCF, is added to the COUPLExx parmlib member.
The default is CFRMTAKEOVERCF(NO) and changes the behavior from previous
releases. The previous behavior can be achieved by specifying CFRMTAKEOVERCF(PROMPT).
For more information, see z/OS MVS Initialization and Tuning Reference.
When change was introduced: z/OS V2R2.
- 64Bit VSCR Support: Common storage is becoming
constrained below the 2GB bar. XES, in support of Virtual Storage
Constraint Relief (VSCR) in z/OS V2R2, implements the next step in
reducing the usage of 31-bit common storage below 2GB. This support
also includes RAS items to assist in providing better analysis for
problem determination. For more information on the HVCOMMON system
parameter, see z/OS MVS Initialization and Tuning Reference.
In support of VSCR, select XES common storage control blocks are moved to 64-bit common storage above the 2GB bar.
In support of Serviceability, XES provides enhancements to XES IPCS component trace reports. For more information on requesting SYSXES component tracing reports, see z/OS MVS Diagnosis: Tools and Service Aids.
When change was introduced: z/OS V2R2.