How to control Processor usage
This
document explains the setting of SNMP thresholds on processor usage
on Windows 2000 / XP operating system. It also explains how to
configure and display line graph of this usage. We will define eventsfor
this thresholds
Warning: The SNMP objects used in this how to
come from our Windows perfmib.mib file. Our examples will not work
with any other mib available on the Internet. The configuration
and installation of this MIB is explained in the How
to add SNMP performance monitoring to WIndows 2000 / XP
You should download the set of file including the perfmib.mib file
with the link on the page. We do have a working perfmib.mib before
continuing.
Processor performance object description
The setting for
this counters in LoriotPro use the following Mib entries: In
the ms-proc-processentry 
In the ms-system
The thresholds
and indicators recommended to supervise are provided below:
| Processor\% Processor
Time
ms-percentprocessortime |
85% |
Find the process that
is using a high percentage of processor time. Upgrade to a
faster processor or install an additional processor. |
|
Processor\Interrupts/sec
ms-procsr-interruptspersec |
Depends on processor;
1000 interrupts per second is a good starting point |
A dramatic increase
in this counter value without a corresponding increase in
system activity indicates a hardware problem. Identify the
network adapter causing the interrupts. You might need to
install an additional adapter or controller card. |
|
System Call/sec
ms-sys-ms-systemcallspersec |
Could be used to compare
with number of interrupt |
Should be higher than
the number of Interrupts/sec else one hardware device is
generating too much interrupts |
|
System\Processor Queue
Length
ms-sys-processorqueuelength |
2 |
This is an instantaneous
counter; observe its value over several intervals. |
The configuration in the Bulk Threshold Plug-in is done
below. 
If the threshold
is reached the event is generated in the Event Manager
Graphing the processor statistics
The first graph collect
the % of utilization from the ms-proc-PercentProcessorTime
% Processor Time is the percentage of elapsed time that all of
the threads of this process used the processor to execute instructions.
An instruction is the basic unit of execution in a computer, a thread
is the object that executes instructions, and a process is the object
created when a program is run. Code executed to handle some hardware
interrupts and trap conditions are included in this count. On Multi-processor
machines the maximum value of the counter is 100 % times the number
of processors. 
Next counters
than we can graph on the same graphic are :
ms-proc-PercentUserTime
ms-proc-PercentPrivilegedTime
% User Time is the percentage of non-idle processor time spent
in user mode. (User mode is a restricted processing mode designed
for applications, environment subsystems, and integral subsystems.
This counter displays the average busy time as a percentage of the
sample time.
% Privileged Time is the percentage of non-idle processor time spent
in privileged mode. (Privileged mode is a processing mode designed
for operating system components and hardware-manipulating drivers.
It allows direct access to hardware and all memory. The operating
system switches application threads to privileged mode to access
operating system services). % Privileged Time includes time servicing
interrupts and deferred procedure calls - DPCs. This counter displays
the average busy time as a percentage of the sample time.
A high rate
of privileged time might be attributable to a large number of
interrupts generated by a failing device.
Comparing the number of system
calls and interrupts We use the the Line Graph
plug-in and enter both OID to graph.
ms-procsr-interruptspersec
: Interrupts/sec
is the average number of hardware interrupts the processor is receiving
and servicing in each second. It does not include DPCs, which are
counted separately. This value is an indirect indicator of the activity
of devices that generate interrupts, such as the ms-system clock,
the mouse, disk drivers, data communication lines, network interface
cards and other peripheral devices. These devices normally interrupt
the processor when they have completed a task or require attention.
Normal thread execution is suspended during interrupts. Most ms-system
clocks interrupt the processor every 10 milliseconds, creating a
background of interrupt activity. This counter displays the difference
between the values observed in the last two samples, divided by
the duration of the sample interval.
ms-sys-ms-systemcallspersec : ms-systems Calls/sec is the combined rate of calls
to Windows NT ms-system service routines by all processes running
on the computer. These routines perform all of the basic scheduling
and synchronization of activities on the computer, and provide access
to non-graphic devices, memory management, and name space management.
This counter displays the difference between the values observed
in the last two samples, divided by the duration of the sample interval.
ms-sys-ms-systemcallspersec should be higher than ms-procsr-interruptspersec
else one hardware device is generating too much interrupts
We set both counters on the same graph, it will be easier to compare
them.
The green is ms-sys-ms-systemcallspersec and the red
is ms-procsr-interruptspersec.
If the red
line goes over the green line it is time to check what device interface
generates so much interrupts.
Supervising the Processor Queue
The Processor Queue Length
is the number of threads in the processor queue. There is a single
queue for processor time even on computers with multiple processors.
Unlike the disk counters, this counter counts ready threads only,
not threads that are running. A sustained processor queue of greater
than two threads generally indicates processor congestion.
This counter displays the last observed value only; it is not an
average.
Example of graph on the ms-sys-processorqueuelength
End of Document |
