Recording statistics to SMF

CICS® Transaction Server, TXSeries, and WebSphere® support the recording of statistics to SMF. The z/OS® based products write SMF records. CICS Transaction Gateway provides similar function on the z/OS platform using type 111 SMF record format.

End-of-day and shutdown statistics

An attempt is always made to write end-of-day and shutdown statistics to SMF regardless of whether the statsrecording parameter is set to on or off. A message is logged if this attempt fails.

Interval correlation number

Interval statistics are captured at predefined intervals by issuing requests for them to be recorded at the correct time.

The interval statistics component periodically requests the SMF recording facility to record statistics information. The interval statistics component takes a snapshot of all current statistics and sends them to the SMF recorder. The SMF recorder formats the statistics into the documented SMF record format. This data is then sent to the SMF facility. Every time the interval statistics component issues a request to record statistics, a unique number is generated. This number is known as the interval correlation number and is unique, for a specific CICS Transaction Gateway instance, over the lifetime of that CICS Transaction Gateway.

The interval correlation number is included as an external field in every SMF record header.

The SMF subsystem allows a maximum of 30 KB per record. If the formatted data for a statistics request exceeds 30 KB, the data is split across multiple SMF records. Each SMF record is given the same interval correlation number. This correlation allows the records relevant to an individual statistics interval to be linked.

Correlating multiple SMF records within the same interval

The timestamp and datestamp fields, CTG_COLTIME and CTG_COLDATE, are used to correlate records for a specific CICS Transaction Gateway APPLID. A CICS Transaction Gateway instance cannot have intervals of less than 1 minute, so these fields can be used to identify the record. This correlation is valid if the CICS Transaction Gateway is stopped and restarted, whereas the interval count is reset at a stop and restart.

You do not need multiple records unless you have a large number of servers, because CICS Transaction Gateway writes data of greater than 30 KB in size.

For more information about configuring recording statistics to SMF, see Configuring monitoring and statistics

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Correlating multiple SMF records from the same Gateway daemon

The CTG_STARTDATE and CTG_STARTTIME fields are used to correlate records for a specific instance of a CICS Transaction Gateway daemon. The fields are described in SMF product section data structure

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Timestamp icon Last updated: Tuesday, 19 November 2013


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