Siemens U3585-J-Z125-8-76 1 manual Monitored data on the system for bottleneck analysis, Cosmos

SM2 monitoring programs COSMOS

COSMOS

Monitored data on the system for bottleneck analysis

COSMOS is an event-driven monitoring program for recording detailed system data that is required particularly for bottleneck analyses of OLTP applications. It collects monitored data for all tasks, for task groups (which can be selected by user ID, category, or job name), or for individual tasks. Because of the high volume of very detailed monitored data involved, COSMOS should only be used for short-term monitoring. Intimate knowledge of the internal workings of the system is required to interpret the monitored data.

COSMOS is an SM2 add-on product and only available on special release. A detailed description is supplied with the product.

DAB

Monitored data on DAB activities

SM2 outputs highly detailed information on DAB activity in all DAB cache areas. Intensive use of DAB in parallel may result in a large volume of data traffic in SM2.

DISK

Monitored data on disk access

The monitoring program for disk statistics permits fine analysis of the frequency with which the cylinders or blocks of a disk are accessed, and of the duration of I/O operations. SM2R1 provides analyses of the records supplied by SM2. These analyses, combined with a knowledge of how files are mapped to cylinder/block areas, make it possible to optimize the mean access time for disk I/O operations.

Monitored variables

The following information is recorded for each completed disk access to a selected disk device:

–mnemonic device name

–cylinder/block number addressed when I/O is started (at the time of the SDV or START- SUBCHANNEL command)

–duration of hardware I/O (time between the initiation of I/O using the SDV or START- SUBCHANNEL command) until termination of I/O (as the result of a channel interrupt)

–I/O identifier specifying read, write or other I/O operations

The monitored data recorded is then written only to an SM2 output file, from which it can be analyzed by SM2R1 (PRINT-DISK-STATISTICS statement).

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