Siemens SM2 monitoring system User Manual
U3585-J-Z125-8-76
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Notes on SM2 operation
System resource utilization
The event-driven method is used by the monitoring programs CHANNEL-IO, DISK, DISK-
FILE, ISAM, NET-DEVICE, PERIODIC-TASK, RESPONSETIME, SERVICETIME,
SYSSTAT and TASK, as well as for user task statistics.
FILE, ISAM, NET-DEVICE, PERIODIC-TASK, RESPONSETIME, SERVICETIME,
SYSSTAT and TASK, as well as for user task statistics.
UTM monitoring program
If UTM applications are running on the system and these applications provide data for SM2,
the following additional load occurs in each UTM task: an additional 500 instructions
(approx.) are required at the end of each dialog step and each asynchronous conversation
in order to provide this data. For a typical application, this amounts to considerably less than
1% of the entire processing volume.
the following additional load occurs in each UTM task: an additional 500 instructions
(approx.) are required at the end of each dialog step and each asynchronous conversation
in order to provide this data. For a typical application, this amounts to considerably less than
1% of the entire processing volume.
The resulting additional load on the system thus depends on the throughput in the applica-
tions, but can generally be ignored.
tions, but can generally be ignored.
If values are also provided from the database systems, an additional load arises in these
database systems in order to capture the monitored data. This load depends on the
database system itself and the version used. For this reason, no general rule can be given.
database systems in order to capture the monitored data. This load depends on the
database system itself and the version used. For this reason, no general rule can be given.
Write task and I/O buffer
SM2 creates a write task (system task with TSN=SM2W) for writing to the SM2 output file.
This task exists only from OPEN to CLOSE and is activated only when an I/O buffer is full.
The input/output operation is controlled by the write task, and the CPU is required for task
execution (CPU time for TPR and SIH states). The CPU time required for writing to the I/O
buffer is assigned not to the write task but to the initiating task (system task or SIH
processor state).
This task exists only from OPEN to CLOSE and is activated only when an I/O buffer is full.
The input/output operation is controlled by the write task, and the CPU is required for task
execution (CPU time for TPR and SIH states). The CPU time required for writing to the I/O
buffer is assigned not to the write task but to the initiating task (system task or SIH
processor state).
The data rate for writing to the I/O buffer depends on whether the record is written
–
by the monitoring task at the end of a monitoring cycle,
–
by another task, or
–
in the SIH processor state
In the first case, the data rate depends on the number of active monitoring programs (data
records) and monitored objects, as well as the duration of the monitoring cycle (OFFLINE-
PERIOD operand in the MODIFY-MEASUREMENT-PERIODS statement). If the same data
records remain active during monitoring, the workload is inversely proportional to the
duration of the monitoring cycle. The second and third cases only apply to the monitoring
programs TASK and DISK.
records) and monitored objects, as well as the duration of the monitoring cycle (OFFLINE-
PERIOD operand in the MODIFY-MEASUREMENT-PERIODS statement). If the same data
records remain active during monitoring, the workload is inversely proportional to the
duration of the monitoring cycle. The second and third cases only apply to the monitoring
programs TASK and DISK.