SMF records for the channel initiator

The channel initiator (CHINIT) can produce SMF statistics records and accounting records with information on tasks and channels.

The CHINIT can produce SMF statistics records and accounting records with the following types of information:

• The tasks: dispatcher, adapter, Domain Name Server (DNS), and SSL. These tasks form what is called CHINIT statistics.
• Channels: provides accounting information similar to that available with the DIS CHSTATUS command. This is called channel accounting.

IBM MQ for Multiplatforms provides similar information by writing PCF messages to the SYSTEM.ADMIN.STATISTICS.QUEUE. See Channel statistics message data for further information on how statistics information is recorded on IBM MQ for Multiplatforms.

Statistics data

We can use this information to find out the following information:

• Whether we need more of the CHINIT tasks, such as number of SSL TCBs and how much CPU is used by these tasks.
• The average time for requests on these tasks.
• The longest duration request in the interval, and the time of day this occurred, for DNS and SSL tasks. We can correlate this time of day with problems you may experience with the channel.

Accounting data

We can use this information to monitor channel usage and find out the following information:

• The channels with the highest throughput.
• The rate at which messages were sent, and the rate of sending data in MB/second.
• The achieved batch size. If the achieved batch size is close to the batch size specified for the channel, the channel might be close to its limit for sending messages.

You use the START TRACE and STOP TRACE commands to control the collection of the accounting trace and the statistics trace. We can use the STATCHL and STATACLS options on the channel and queue manager to control whether channels produce SMF data.

Parent topic: The channel initiator on z/OS