Coupling Facility Usage Summary section
This section of the Coupling Facility Activity report gives a snapshot of coupling facility storage and specific structure data at the end of the reporting interval. It lists all the structures occupying space either in the coupling facility real storage or in storage class memory (SCM), including those with no currently active connections. For asynchronously duplexed secondary structures, it provides a summary on consumed processing times and performance counts related to asynchronous duplexing. Data shown for asynchronous duplex sync up requests are accumulated over all reported systems that have a connector to the structure.
All structure summary data is grouped in the report by structure type (LIST, LOCK, CACHE and UNKN in that order). Within the structure type, the report lines are in alphanumeric order by structure name. This ordering puts the structure data in the same relative position across interval reports.
The report summarizes request activity for active structures. This activity is described in more detail in the Coupling Facility Structure Activity section of the report. It is included in this report to give the customer a quick view of the relative amount of activity among the structures in a coupling facility.
The following table explains the field headings in the Coupling Facility Usage Summary section.
|TOTAL SAMPLES (AVG), (MAX), (MIN)||Average (AVG), the maximum (MAX) and minimum (MIN) sample count for all systems connected to this coupling facility.|
|GENERAL STRUCTURE SUMMARY|
|TYPE||Indicates whether the structure is a list, lock,
or cache structure. The structures being reported are grouped by
UNKN indicates a structure for which there was no activity during the interval but that is still allocated in the coupling facility. There are no structure activity details for UNKN structures.
|STRUCTURE NAME||The name given to the structure by the coupling facility policy specification in the Function Couple Data Set. It is up to 16 characters and is unique within a sysplex.|
|STATUS||Indicates status of the structure at the end of the interval:
The PRIM and SEC indicators of synchronously duplexed structures might not appear if data from one or more systems in the sysplex is missing.
|CHG||X indicates that the status of this structure changed during the reporting interval.|
|ALLOC SIZE||The number of bytes set aside in the coupling facility for this structure by the coupling facility policy in the Function Couple Data Set. Storage is allocated in increments of 4K bytes. This storage consists of both control and data storage.|
|% OF CF STOR||The percentage of the total coupling facility storage allocated to this structure.|
|# REQ||The number of requests processed by the coupling facility against this structure. This is the same number as appears in the TOTAL line of the Coupling Facility Structure Activity report.|
|% OF ALL REQ||The percentage of all requests attributable to this structure. Use this field for a quick idea of where the activity occurred during the interval.|
|% OF CF UTIL||The percentage of CF processor time used by the
structure. The structure execution time is related to the total CF-wide
processor busy time. The sum of the values in this column is less
than 100%, because not all CF processor time is attributable to structures.
|AVG REQ/SEC||The average number of requests per second for this structure.|
| DIR REC/
DIR REC XI'S
|Number of Cache directory reclaims.
Directory reclaims occur when the total number of used unique entities exceeds the total number of directories. Whenever this shortage of directory entries occurs, the coupling facility will reclaim in-use directory entries associated with unchanged data. All users of that data must be notified that their copy of the data is invalid. As a consequence, it may happen that this data must be re-read from DASD and registered to the coupling facility again.
Directory reclaim activity can be avoided by increasing the directory entries for a particular structure.
The second value is the number of reclaims that caused an XI (see XI field in the Structure Activity section). A high value is an indicator for a performance problem in this structure.
|SCM STRUCTURE SUMMARY(See note 2)|
|ALG||Type of algorithm that is used by the coupling
facility to control the movement of structure objects between coupling
facility real storage and storage class memory:
|SCM AUX ENABLED||
|ASYNCHRONOUS CF DUPLEXING SUMMARY(See note 3)|
|ASYNC DUPLEX CF OPERATIONS||
|ASYNC DUPLEX SYNC_UP REQUESTS||
|TOTAL CF STORAGE USED BY STRUCTURES||The total amount of coupling facility storage
that is used by structures and the percentage of the total coupling
facility storage allocated to these structures.
These totals do not necessarily represent 100% of the facility activity for the interval. There is some amount of storage and request activity overhead that is not attributable to individual structures. For example, the total for # REQ will usually be less than the sum of the TOTAL REQ from the Subchannel Activity Report because the subchannel numbers include facility management command counts whereas the structure numbers do not.
|TOTAL CF DUMP STORAGE||Amount and percentage of coupling facility space allocated as dump space.|
|TOTAL CF AUGMENTED SPACE||
|TOTAL CF STORAGE AVAILABLE||The amount and percentage of coupling facility space that is not allocated to any structure, not allocated as dump space, and not allocated as augmented space.|
|TOTAL CF STORAGE SIZE||The total amount of storage in the coupling facility, including both allocated and available space. This value does not include the storage required by the coupling facility code itself, so that it differs from the storage assigned to the coupling facility on the HMC.|
|TOTAL CONTROL STORAGE DEFINED, TOTAL DATA STORAGE DEFINED, % ALLOCATED||The amount of coupling facility storage that is
allowed to be occupied by control information (CONTROL STORAGE) or
data (DATA STORAGE).
For each structure, plus the dump area, a certain amount of control and data storage is allocated. The coupling facility defines an area called control storage; structure control information is restricted to that area. The remaining storage is called data storage and is used for structure data. If the data storage area becomes full, structure data can then be allocated from the control storage area. If TOTAL DATA STORAGE DEFINED is zero, it means control information can reside anywhere on the coupling facility and there are no allocation restrictions.
If the % ALLOCATED field for control storage shows a percentage approaching 100, it means the control storage is close to being completely allocated even though the CF SPACE AVAILABLE field may still show an amount of total free space. Possible customer actions include:
|TOTAL CF STORAGE CLASS MEMORY||
|COUPLING FACILITY||Coupling facility processor type.|
|MODEL||Coupling facility processor model.|
|CFLEVEL||Coupling facility architected function level.|
|DYNDISP(See note 1)||The dynamic CF dispatching status (ON, OFF, or THIN). THIN indicates that coupling thin interrupts are enabled for the coupling facility (only for CFLEVEL 19 or higher).|
|AVERAGE CF UTILIZATION (% BUSY)||Average value of CPU utilizations within the coupling
The utilization of the individual CPs in the coupling facility is recorded in the SMF 74, Subtype 4, Processor Data Section.
In case of a stand-alone coupling facility, the utilization of the individual CPs should be approximately the same. In a PR/SM environment where this CP is shared with other partitions the utilization is the logical utilization of the CP (that is, only the utilization by the coupling facility). The CPU Activity report can be used to determine the total utilization of the CP.
If the average utilization is high, you can take the following actions:
|LOGICAL PROCESSORS DEFINED(See note 1)||Number of logical processors defined for the coupling facility.|
|LOGICAL PROCESSORS EFFECTIVE||Number of effective available logical processors
in a shared environment. This value is only useful in CFCC environment.
CFCC measures the time of real command execution as well as the time
waiting for work. The reported value shows the ratio of the LPAR dispatch
time (CFCC execute and wait time) to the RMF interval length.
For example, if a CFCC CEC contains 6 LPs, and the measured CF LPAR has two logical processors and is limited at 5 % the number of effective LPs is 0.3
Please, refer to the CPU Activity report in case of an ICMF LPAR.
|LOGICAL PROCESSORS SHARED||The number of shared processors defined for the coupling facility.|
|LOGICAL PROCESSORS AVG WEIGHT(See note 1)||The average weight of shared processors, which is the sum of shared processor weights related to the number of shared processors.|
- For CFLEVEL lower than 15, this field is not displayed.
- SCM statistics are included in the SCM Structure Summary only for those structures that can make
use of the SCM storage extension and have set a non-zero maximum SCM size. If none of the structures
is configured to exploit SCM, the SCM Structure Summary displays message:
NO STORAGE CLASS MEMORY DATA AVAILABLE.
- If no structure is configured to exploit asynchronous duplexing, the Asynchronous
CF Duplexing Summary includes an informational message
NO ASYNCHRONOUS CF DUPLEXING DATA AVAILABLE.