Parameters for TYPE=CACHE

,ADJUNCT=NO

,ADJUNCT=YES

Use this input parameter to specify whether adjunct data areas are associated with each cache entry in the coupling facility cache structure. Each adjunct data area is 64 bytes.

NO: Indicates that adjunct data areas should not be allocated for the cache structure.
YES: Indicates that adjunct data areas should be allocated for each entry in the cache structure.

,DIRRATIO=1

,DIRRATIO=dirratio

Use this input parameter to specify a value to express the directory portion of the directory-to-element ratio of the coupling facility cache structure. The value of DIRRATIO must be greater than zero.

To Code: Specify the RS-type name or address (using a register from 2 to 12) of the 2-byte input field that contains a value to express the directory portion of the directory-to-element ratio of the coupling facility cache structure.

,ELEMCHAR=0

,ELEMCHAR=elemchar

Use this input parameter to specify the value of an element characteristic used to determine the element size. The element size is calculated with the formula Start of change

256×(2^ELEMCHAR) End of change

, where ELEMCHAR is used as the power of 2. For example, if ELEMCHAR=0, then the size of each element is 256 bytes.

The valid values for ELEMCHAR range from zero to a maximum determined by the coupling facility limitation on element size.

To Code: Specify the RS-type name or address (using a register from 2 to 12) of the 1-byte input field that contains the value of the element characteristic, used to determine the cache structure element size.

Note: The element size, in combination with the maximum number of elements (MAXELEMNUM parameter), determines the size of the data entry — the data written to and read from the cache structure. With a coupling facility of CFLEVEL=0, a data entry can be up to 16 times the data element size, as indicated by the element characteristic. With a coupling facility of CFLEVEL=1 or higher, a data entry can be up to 255 times the data element size.

Use either ELEMCHAR or ELEMINCRNUM to define the element size. You can specify either an element characteristic or an element increment number for element size determination.

,ELEMENTRATIO=1

,ELEMENTRATIO=elementratio

Use this input parameter to specify a value to express the element portion of the directory-to-element ratio of the coupling facility cache structure. If ELEMENTRATIO is zero, the structure is allocated without data elements.

To Code: Specify the RS-type name or address (using a register from 2 to 12) of the 2-byte input field that contains a value to express the element portion of the directory-to-element ratio of the coupling facility cache structure.

,ELEMINCRNUM=elemincrnum

Use this input parameter to specify the element increment number. The element size is calculated with the formula Start of change

256×ELEMINCRNUM End of change

. For example, if ELEMINCRNUM=1, then the size of each element is 256 bytes.

The valid values for ELEMINCRNUM range from 1 to a maximum determined by the coupling facility limitation on element size. The value of ELEMINCRNUM must be a power of 2.

To Code: Specify the RS-type name or address (using a register from 2 to 12) of the 1-byte input field that contains the value of the element increment number, used to determine the cache structure element size.

Note: The element size, in combination with the maximum number of elements (MAXELEMNUM parameter), determines the size of the data entry — the data written to and read from the cache structure. With a coupling facility of CFLEVEL=0, a data entry can be up to 16 times the data element size, as indicated by the element increment number. With a coupling facility of CFLEVEL=1 or higher, a data entry can be up to 255 times the data element size.

Use either ELEMCHAR or ELEMINCRNUM to define the element size. You can specify either an element characteristic or an element increment number for element size determination.

,MAXELEMNUM=16

,MAXELEMNUM=maxelemnum

Use this input parameter to specify a value to determine the maximum number of data elements for each data entry in the coupling facility cache structure.

With a coupling facility of CFLEVEL=0 or higher, you can specify from 1 to 16 for MAXELEMNUM.
With a coupling facility of CFLEVEL=1 or higher, you can specify from 1 to 255 for MAXELEMNUM.

The maximum data entry size in bytes equals MAXELEMNUM multiplied by the element size obtained from the value specified for ELEMCHAR or ELEMINCRNUM.

For example, if ELEMCHAR=0 and MAXELEMNUM=1, the maximum data entry size in bytes is 256. If ELEMCHAR=4 and MAXELEMNUM=16, the maximum data entry size in bytes is Start of change 4096×16 End of change , or 65,536.

To ensure that the system can assign all possible data elements allocated in a structure to a directory entry, MAXELEMNUM must be greater than or equal to ELEMENTRATIO divided by DIRRATIO. MAXELEMNUM is ignored if ELEMENTRATIO is zero.

To Code: Specify the RS-type name or address (using a register from 2 to 12) of the 1-byte input field that contains the maximum number of data elements for each data entry in the coupling facility cache structure.

,NAMECLASSMASK=0

,NAMECLASSMASK=nameclassmask

Use this input parameter to specify the name class mask pattern definition to be applied to entry names for the purpose of assigning entries to name classes in the structure. Name classes may be used to improve the efficiency of processing for commands such as IXLCACHE REQUEST=DELETE_NAME.

The position of each bit in the name class mask corresponds to the same relative character position in an entry name. If a bit in the name class mask is a one, then the corresponding position in the entry name is applied in the masking operation to determine the name class to which the entry will be assigned. If a bit is a zero, then the corresponding position in the entry name is not applied to assigning the entry to a name class.

Specifying or defaulting to a name class mask of 0 (X'0000'), or specifying a name class mask of all binary ones (X'FFFF'), will result in name classes not being used for the structure. A CFLEVEL of 7 or greater must be specified when any other name class mask is specified, implying that name classes are to be used.

To Code: Specify the RS-type name or address (using a register from 2 to 12) of the 16-bit input field that contains the name class mask pattern definition.

,NUMCOCLASS=numcoclass

Use this input parameter to specify the number of cast-out classes for named data entries used with the coupling facility cache structure. You must specify at least 1 cast-out class.

To Code: Specify the RS-type name or address (using a register from 2 to 12) of the fullword input field that contains the number of cast-out classes.

,NUMSTGCLASS=numstgclass

Use this input parameter to specify the number of storage classes for named data entries used with the coupling facility cache structure. You must specify at least 1 storage class.

To Code: Specify the RS-type name or address (using a register from 2 to 12) of the fullword input field that contains the number of storage classes.

,SUPPRESSEVENTS=NO

,SUPPRESSEVENTS=YES

Use this input parameter to indicate whether the origination of user connection events (New Connection, Existing Connection, Rebuild New Connection, Rebuild Existing Connection), and user disconnection/failure events (Disconnected or Failed Connection), should be suppressed for this connection. Suppression of these events may provide a significant performance benefit at connect or disconnect time to connectors who do not need the information presented in these events.

Note that suppression of these events is on a per-connection basis, where it is the ORIGINATION of the event that is suppressed, not the RECEIPT of the event. Therefore, the following cases are possible:

A connection that is suppressing the origination of events may nevertheless receive such events for another connection to the structure that is NOT suppressing the origination of events. In the case of response-required events, this connection is still required to provide responses to any such event that is presented to it, regardless of whether it is suppressing events itself.
When a connection is suppressing the origination of events, other connections will not receive the suppressed events for that connection, even if the other connections themselves are NOT suppressing events.

Also note that, depending on whether the system on which the connection is running is at OS/390® Release 9 or higher or has OW38840 installed, a request to suppress events may or may not be honored for the current connection.

NO: Indicates that connection and disconnection related events will be originated normally for this connection.
YES: Indicates that the origination of connection and disconnection related events may be suppressed for this connection. (Dependent on the level of the system on which the connection is running.)

,UDFORDER=NO

,UDFORDER=YES

Use this input parameter to indicate whether a user data field (UDF) order queue should be maintained for each cast-out class for the structure. A coupling facility with CFLEVEL=5 or higher is required when UDFORDER=YES.

Depending on whether UDF-order queues are maintained, a READ_COSTATS request to retrieve cast-out class statistics will include the following information:

If a UDF-order queue is maintained, the system will return the user data field of the first entry on the UDF-order queue.
If a UDF-order queue is not maintained, the system will return the user data field of the first entry on the cast-out class queue.

,VECTORLEN=vectorlen

Use this input parameter to specify the number of cache buffers in the requestor's local storage which require concurrent registration. The requestor uses the vector length to map each local cache buffer to a named data entry in the coupling facility cache structure. The value of VECTORLEN must be a multiple of 32 or the system will round the value up to a multiple of 32.

To Code: Specify the RS-type name or address (using a register from 2 to 12) of the fullword input field that contains the number of cache buffers in the requestor's local storage.