characteristics of that program in terms of resource usage.
spooling considerations, the INDICATE command may produce
results if entered while a program is issuing I/O requests.
Because of
unexpected
The system analyst can identify active users, the queues they are
using, their I/O activity, their paging activity, and many other user
characteristics and usage data.
The system analyst can use the data on system resource usage and contention to monitor the performance of his system. He can thus be
aware of heavy load conditions or low performance situations that may require the use of more sophisticated data collection, reduction, and
analysis techniques for resolution.
The VM/370 scheduler maintains smoothed values of processor usage and main storage contention. Specifically, every 30 seconds, the scheduler
calculates the total wait time for the last interval and factors it into
a smoothed wait value in the following way:
(3 X old smoothed wait
value + current interval wait)
New smoothed wait value = --------------------------------
4
Thus, only 1/4 of the most recent interval wait is factored into the new
smoothed wait which makes it predominantly the old smoothed wait value.
The remaining INDICATE components are sampled prior to a user being
dropped from a queue. Because of the frequency of this event, the
remaining components are subject to a heavier smoothing than the wait time. A general expression for the smoothing follows:
(15 X old smoothed value + last
interval value)
New smoothed value = ---------------------------------
16 Other operands of the command allow users to obtain other performance
information that enables them to understand the reasons for the observed
conditions.
THE CLASS G INDICATE COMMAND The format of the class G INDICATE command is:
INDicate
r , ILOAQI IUSERI L J INDICATE LOAD -Produces the following response, where n is a decimal number: CPU-nnn% APU-nnn% Q1-nn Q2-nn STORAGE-nnn% RATIO-nnn The CPU figure indicates the percentage of time that the main processor is running and is derived from the smoothed wait
value maintained by the scheduler.

The APU figure is the percentage of time the attached
processor is running.
The contention for the processor is represented
values of the numbers of users in queue1
maintained by the scheduler.
by smoothed
and queue2,
The next field, STORAGE, is a measure of the usage of real
storage. It is a smoothed ratio of the sum of the estimated
working sets of the users in queue1 and queue2, to the number
of pageable pages in the system, expressed as a percentage.
Due to the algorithm used by the scheduler in
entry to the active queues, the value of STORAGE 100%. determining
can exceed
The scheduler contention ratio, RATIO, is a smoothed measure
of the contention for real storage, and is defined as: E+M RATIO = M is the number of users in queue1 and queue2
E is the number of users waiting to be allocated real
storage by the scheduler and, therefore, temporarily
resident in the scheduler's eligible lists.
Thus, RATIO is the ratio of active users to users being
serviced, and is 1.0 for optimum response. Optimum response
occurs when enough real storage is available to accommodate
all active users, assuming the processor can process their
commands. If E and M are both zero, the value of RATIO is set
to 1.0. Given the value of RATIO and ft, (Q1.Q2) the number of users in
the eligible list can be computed as:
E = M (RATIO-1) INDICATE USER allows a user to determine the resources used and occupied by
his virtual machine, and the I/O events that have taken place.
The following two line response is returned: PAGES: RES-nnnn is-nnnn READS=nnnnnn WRITES=nnnnnn DISK-nnnn DRUM-nnnn YTIME=nnn:nn TTIME=nnn:nn SIO=nnnnnn RDR-nnnnnn PRT-nnnnnn PCB-nnnnnn
The first line of the response displays the data from the user's VMBLeK that ls relevant to his virtual machine's paging activity and resource occupancy. RES is the current number of the user's virtual storage pages
resident in real storage at the time the command is issued. is is the most recent system estimate of the user's working
set size. Part 2. Control Program (CP) 105