To record the monitored data SM2 requires the resources CPU and disk storage. The requirement depends on:
the type of monitoring programs and their parameters
the hardware configuration
the load profile (principally the number of tasks and the I/O intensity)
In all the resource utilization by SM2 is relatively low. Occasionally a check should be made to see whether a restriction of the monitoring programs is necessary or possible. However, a restriction of the monitoring programs is detrimental to the quality of performance monitoring.
Monitored data
The resource requirement of SM2 was measured in a laboratory test under a typical OLTP load which utilizes approx. 70% of the server capacity.
The following CPU requirement for SM2 in absolute percentage values was measured:
0.5 - 1% for basic monitoring (standard and SYSTEM monitoring programs)
Additional 1% for recording response times and the UTM monitoring program
Additional 1% for utilization of the PERIODIC-TASK and TASK monitoring programs
Additional 1% for utilization of the STORAGE-SYSTEM monitoring program with:
//SET-STORAGE-SYSTEM-PARAMETERS ADDITIONAL-DATA=*SYMMETRIX(TYPE=(*PHYSICAL-DISK,*DIRECTOR)and activation of I/O time monitoring of the disk devices with:
//SET-SAMPLING-DEVICE-PARAMETERS DISK-SERVICETIME=*ON)
These values were monitored using the standard sampling period of 800 ms. When the sampling period is changed, the CPU requirement of SM2 changes linearly with the share of periodically recorded data. For example, in basic monitoring with recording of response times and the UTM monitoring program, the CPU requirement of SM2 drops from 1.5% to just under 1% when the sampling period is changed to 2000 ms.
Disk storage space is required to store the monitored data. It is not possible to specify standard values in absolute measures as the requirement is too heavily dependent on the relevant hardware and software load and the configuration of the monitoring programs. However, it must be borne in mind that in particular the PERIODIC-TASK monitoring program (and still more the DISK monitoring program, which is no longer recommended) makes the output file increase by 50% or more compared to basic monitoring.