At the end of a monitoring cycle, the monitored data is summarized into groups which have similar content, extended by the SM2 monitoring task to include additional information (time stamp, host,...), and then written to a central SM2 data buffer.
If a user has activated online monitoring, the monitored data is transferred from the central data buffer to the buffer of the user task. Note that sensitive data is transferred to privileged users only. The monitored data is then processed and output in the address space of the user task.
For background monitoring, the SM2 administrator can open an SM2 output file. At the end of a monitoring cycle, the monitored data is grouped into data records and written to the SM2 output file. The information in the SM2 output file can be used for subsequent problem and trend analyses. Special analysis routines are provided for this purpose.
Methods used for compressed output of monitored data
Mean values
SM2 adds up the sampled values at the end of each sampling cycle and computes a mean value for each monitoring cycle (e.g. the number of tasks) as follows:
Sum of sampled values Average = --------------------- Number of samplesPercentage frequency
At the end of each sampling cycle, SM2 records the occurrence of specific events or conditions and computes the percentage frequency of events (conditions) in relation to the total number of samples (e.g. channel utilization) as follows:
Sum of occurrences Frequency = ------------------ *100 % Number of samplesAscending system counters and SM2 counters
The activity during the monitoring cycle can be determined by calculating the differences between values gathered at the beginning and the end of the monitoring cycle (e.g. idle time).
Computation
SM2 computes some data from monitored data, e.g. the summation values for all categories.
Uninterruptible clock resetting
SM2 works internally with UTC time. During the switch from daylight saving time to winter time and vice versa, SM2 can continue to work without interruption.