ZIIP - zIIP Processing (z/OS Only)

This Natural profile parameter can be used to configure zIIP processing under Natural. It corresponds to the NTZIIP macro in the Natural parameter module.

Note:
The ZIIP setting takes effect only if Natural Batch for zIIP, Natural for CICS for zIIP, Natural for Com-plete for zIIP or Natural for IMS for zIIP has been installed in your z/OS environment. For further information, refer to Installing Natural for zIIP in the Installation for z/OS documentation.

Possible settings	See ZIIP Parameter Syntax.
Default setting	`AUTO`	See ZIIP Parameter Syntax and Keyword Subparameters.
Dynamic specification	yes	The parameter `ZIIP` can be specified dynamically only. In the Natural parameter module, use the macro `NTZIIP`.
Specification within session	yes	By means of the system command `ZIIP`, the zIIP component switch statistics can be controlled and information about zIIP processing can be displayed.

The following topics are covered below:

ZIIP Parameter Syntax
NTZIIP Macro Syntax
Keyword Subparameters
Example of ZIIP Parameter
Example of NTZIIP Macro

ZIIP Parameter Syntax

The ZIIP parameter is specified as follows:

ZIIP=(state,keyword-subparameter=value,keyword-subparameter=value,...)

Or:

ZIIP=state

Where state can be ON, OFF or AUTO.

Value	Explanation
`ON`	zIIP support will be activated.
`OFF`	zIIP support will not be activated.
`AUTO`	zIIP support will be activated only if there is at least one zIIP online, or if the z/OS parameter `PROJECTCPU=YES` is set in the `SYS1.PARMLIB` member `IEAOPT`. This is the default value.
`keyword-subparameter`	See Keyword Subparameters.

Note:
If specified as a list within brackets, ON, OFF or AUTO must be the first value.

NTZIIP Macro Syntax

The NTZIIP macro is specified as follows:

         NTZIIP state,                                                 *
               IMSG=value,                                             *
               IOCSIZE=value,                                          *
               PNR=value,                                              *
               PRINT=value,                                            *
               PWCSIZE=value,                                          *
               PWCXAM=value,                                           *
               STAT=value,                                             *
               TMSG=value

See Keyword Subparameters.

For a description of state, see ZIIP Parameter Syntax.

Keyword Subparameters

IMSG – Natural zIIP Support Message

This keyword subparameter determines whether Natural issues a NAT7070 system message after Natural zIIP support has been successfully enabled during session initialization.

Value	Explanation
`ON`	The zIIP support message is issued. This is the default value.
`OFF`	The zIIP support message is not issued.

IOCSIZE - Cache Size for Primary Batch I/O Files

This keyword subparameter can be used to determine the cache sizes for processing the primary batch I/O files CMSYNIN, CMOBJIN and CMPRINT. This can be useful when running Natural in zIIP mode because it reduces the overhead caused by switching from zIIP to GCP (general central processor) and vice versa. There is one cache for each file, the CMSYNIN input file, the CMOBJIN input file and the CMPRINT output file.

The advantage of the cache is that all I/O data is collected in the cache instead of accessing a file immediately. When the cache for the CMPRINT file fills up, the cache is flushed, that is, all records are written at once.

In order not to hide the data for too long inside the CMPRINT cache buffer, a time slice mechanism triggers an automatic flush. The flush will be triggered when both of the following conditions are met:

You enter a new record into the nonempty CMPRINT cache buffer.
The first record in the CMPRINT cache buffer was written more than 60 seconds ago.

For a CMSYNIN or CMOBJIN input file, respectively, all records for the given file are read and stored in the input cache for this file. Subsequently, Natural reads the input records directly from the input cache.

Warning:
The usage of IOCSIZE may delay the appearance of output sent to CMPRINT.

IOCSIZE Parameter Syntax

The subparameter IOCSIZE is specified as follows:

IOCSIZE=(CMSYNIN-cache-size, CMOBJIN-cache-size, CMPRINT-cache-size)

Where:

Syntax Element	Value	Explanation
`CMSYNIN-cache-size`	`1 - 2097151`	The `CMSYNIN-cache-size` in KB is used to allocate the cache for the CMSYNIN input file.
`CMSYNIN-cache-size`	`0`	No cache for the CMSYNIN input file is allocated. This is the default value.
`CMOBJIN-cache-size`	`1 - 2097151`	The `CMOBJIN-cache-size` in KB is used to allocate the cache for the CMOBJIN input file.
`CMOBJIN-cache-size`	`0`	No cache for the CMOBJIN input file is allocated. This is the default value.
`CMPRINT-cache-size`	`64 - 2097151`	The `CMPRINT-cache-size` in KB is used to allocate the cache for the CMPRINT output file.
`CMPRINT-cache-size`	`0`	No cache for the CMPRINT output file is allocated. This is the default value.

Notes:

The default setting is IOCSIZE=(0,0,0). If you want to change a default value, you only need to specify the size to be changed, for example, IOCSIZE=(,200) to allocate 200 KB for the CMOBJIN cache file only.
You cannot change the IOCSIZE setting during a session.

PNR – Print File for zIIP Processing Information (in Batch Sessions only)

This keyword subparameter can be used to determine the file where the information about zIIP processing (see the keyword subparameter PRINT) is printed at the end of a batch session. PNR is ignored in server and TSO sessions.

Value	Explanation
`0`	The information about zIIP processing is routed to the standard printer (CMPRINT). This is the default value.
`1 - 31`	The information about zIIP processing is routed to the specified print file. If the specified print file is unavailable during session termination, Natural returns an error message. For more information about the definition of Natural print files, see the profile parameter `PRINT`.

PRINT – Print zIIP Processing Information (in Batch Sessions only)

This keyword subparameter can be used to get information printed about zIIP processing automatically at the end of a batch session. It is ignored in server and TSO sessions.

Value	Explanation
`INFO`	Print zIIP processing general information only.
`STAT`	Print zIIP switch component statistics only.
`ALL`	Print both: zIIP processing general information and zIIP switch component statistics.
`OFF`	No print of zIIP processing information is generated at the end of the session. This is the default value.

PWCSIZE - Size of the Cache for Print and Work Files

This keyword subparameter can be used to determine the cache sizes for print and work file I/O processing. This may be useful when running Natural in zIIP mode, because it reduces the overhead caused by switching from zIIP to GCP (general central processor) and vice versa. There is one cache for print files, one for output work files, and one for each input work file.

The advantage of the cache is that all I/O data is collected in the cache instead of accessing the file immediately. When the cache for print files or output work files fills up, the cache is flushed, that is, all records are written to their respective files at once. In case of work file input, all records for a given file are read and stored in the input cache for this file. Subsequently, Natural reads the input records directly from the input cache.

Warning:
The usage of PWCSIZE can have a negative impact on your application flow. For example, an application may receive sent records at a later point of time since the records are not written immediately to the desired media. Moreover, the error behavior can be different. Example: If the error "NAT1507 - The work/print file is full." occurs, it is not displayed immediately. Instead, the error message "NAT1532 - Error(s) during flush of print/work file cache." is displayed later during the cache flush. The error that actually occurred can then only be displayed with the system command LASTMSG. This means that an ON ERROR clause for NAT1507 no longer works.

PWCSIZE Parameter Syntax

The subparameter PWCSIZE is specified as follows:

PWCSIZE=(print-size,work-input-size,work-output-size)

Where:

Syntax Element	Value	Explanation
`print-cache-size`	`1 - 2097151`	The `print-cache-size` in KB is used to allocate the cache for all print files.
`print-cache-size`	`0`	No cache for all print files is allocated. This is the default value.
`work-input-cache-size`	`1 - 2097151`	The `work-input-cache-size` in KB is used to allocate a cache for each input work file.
`work-input-cache-size`	`0`	No cache for each input work file is allocated. This is the default value.
`work-output-cache-size`	`1 - 2097151`	The `work-output-cache-size` in KB is used to allocate the cache for all output work files.
`work-output-cache-size`	`0`	No cache for all output work files is allocated. This is the default value.

Notes:

The default setting is PWCSIZE=(0,0,0). If you want to change a default value, you only need to specify the size to be changed, for example, PWCSIZE=(,200) to allocate 200 KB for the input cache only.
You cannot change the PWCSIZE setting during a session.

PWCXAM - Disable Caching for Print and Work Files

This keyword subparameter can be used to disable the caching for print and work files (defined with the PWCSIZE keyword subparameter) for single or multiple access methods defined for the files.

Disabling caching for file access methods can be useful if you want to avoid negative impact on the logical flow of your application (see also the Warning for the PWCSIZE subparameter).

PWCXAM Parameter Syntax

The subparameter PWCXAM is specified as follows:

For a single access method:

PWCXAM=access-method

For multiple access methods:

PWCXAM=(access-method1,access-method2,...)

The syntax above only applies to the NTZIIP macro in the Natural parameter module. If you want to define more than one value dynamically, specify PWCXAM multiple times.

access-method defines the type of access method to be used. The values you can specify correspond to the values of the AM subparameter of the PRINT profile parameter and the AM subparameter of the WORK profile parameter, respectively.

STAT – zIIP Switch Component Statistics

This keyword subparameter controls the collection of component statistics for the switches into TCB-mode. The statistics can be displayed by the system command ZIIP during the session, or the report can be triggered by the subparameter PRINT automatically at the end of the session (batch only). Moreover, it is possible to control the statistics by means of the ZIIP command.

Value	Explanation
`ON`	Activate zIIP switch component statistics.
`OFF`	Deactivate zIIP switch component statistics. This is the default value.

Note:
The setting of STAT can be overridden by the STAT option of the ZIIP system command and the application programming interface USR8204N which performs ZIIP command functions. See the relevant sections in the System Commands documentation.

TMSG – Destination for Natural zIIP Support Initialization Messages

This keyword subparameter determines whether Natural sends zIIP support initialization messages to the job log or the Natural standard output device, for example, a user terminal for online environments or CMPRINT for batch. This can be helpful for testing purposes.

Value	Explanation
`ON`	All zIIP support initialization messages are sent to the Natural standard output device.
`OFF`	All zIIP support initialization messages are sent to the job log. This is the default value.

Example of ZIIP Parameter

ZIIP=(ON,STAT=ON,PWCSIZE=(200,,300),IOCSIZE=(100,100,500))

Example of NTZIIP Macro

         NTZIIP AUTO,                                                  *
               STAT=ON,                                                *
               PWCSIZE=(500,),                                         *
               IOCSIZE=(,,2000),                                       *
               PRINT=ALL