First you must determine how many similar users can be run concurrently
on a given configuration before the throughput of individual users
becomes unacceptable.
Every installation should use the automatic monitoring facilities to
simplify and automate the collection of performance data. A virtual
machine should also be set up to analyze and report the collected data.
TheVM/370 Performance/Monitor Analysis program (VMAP) does such a task.
Formore information about the capabilities of this program and for
details about ordering it, see the publicationVirtygl !gcil!iIL1IQ This program or
user-written analysis programs should be run on a daily basis to analyze
the collected data. Data reduction should preferably be run at off-peak
hours to minimize the effect on the performance of the system that is
doing data reduction. Initially, the data collected withMONITOR default options should be analyzed to establish a familiarity with the
load environment and performance profile of each virtual machinesystem and its effect on CP. Once a performance profile is established for each system and
associated virtual machines, the analyst shouldbe able to detect points
of contention between processor(s) storage,I/O, and paging subsystems. Normally the spool file monitoring options should be used. However,
if large volumes of trace data are to be collected, then monitoring to
tape should be used. Tape is also useful if benchmarking is frequently
done and all of the new monitor trace and sampled data must be archived
for possible future use. The default mode of operation of the
Performance/Montior Analysis Program is to keep the condensedACUM files
and not the raw data.
If SEEKs data is needed, a sampling technique is suggested. A simple
implementation might be to use aCMS EXEC procedure to enable SEEKs for
ten seconds every ten minutes. This would produce SEEKs data while
limiting the volume of data collected. An alternative is to create a
list of devices for which data for the SEEKs class is to be collected.CP will collect data for only those devices in the list. To create the
list, use theINCLUDE or EXCLUDE options of the MONITOR command's SEEK
operand. If data is collected for only a few devices, consider
collecting data for longer periods of time.LOAD ENVIRONMENTS OF VM/370 Two distinct uses of VM/370 can be readily identified and, consequently
some differences in criteria for acceptable performance may occur. The
system may be required to time share multiple batch-type virtual
machines with interactive machines performing minor support roles; or,
the system may be primarily required to provide good interactive
time-sharing services in the foreground, with a batch background
absorbing spare resources of real storage and processor.124 IBM iM/370 Programmer·s Guiae
on a given configuration before the throughput of individual users
becomes unacceptable.
Every installation should use the automatic monitoring facilities to
simplify and automate the collection of performance data. A virtual
machine should also be set up to analyze and report the collected data.
The
For
details about ordering it, see the publication
user-written analysis programs should be run on a daily basis to analyze
the collected data. Data reduction should preferably be run at off-peak
hours to minimize the effect on the performance of the system that is
doing data reduction. Initially, the data collected with
load environment and performance profile of each virtual machine
associated virtual machines, the analyst should
of contention between processor(s) storage,
if large volumes of trace data are to be collected, then monitoring to
tape should be used. Tape is also useful if benchmarking is frequently
done and all of the new monitor trace and sampled data must be archived
for possible future use. The default mode of operation of the
Performance/Montior Analysis Program is to keep the condensed
and not the raw data.
If SEEKs data is needed, a sampling technique is suggested. A simple
implementation might be to use a
ten seconds every ten minutes. This would produce SEEKs data while
limiting the volume of data collected. An alternative is to create a
list of devices for which data for the SEEKs class is to be collected.
list, use the
operand. If data is collected for only a few devices, consider
collecting data for longer periods of time.
some differences in criteria for acceptable performance may occur. The
system may be required to time share multiple batch-type virtual
machines with interactive machines performing minor support roles; or,
the system may be primarily required to provide good interactive
time-sharing services in the foreground, with a batch background
absorbing spare resources of real storage and processor.