Powershell for Performance counters

APM tools and perfmon are great tools to monitor the system resources utilization. We can also use simple PowerShell scripts to monitor resources utilization and much more. Needless to say all the windows server products comes with inbuilt PowerShell.

Below is the simple PowerShell script which can be used to monitor CPU and memory utilization by a particular process

1:  $loop_count = 3   
2:  $cpu_threshold = 85   
3:  $memory_threshold = 90   
4:  $sleep_interval = 5   
5:  $hitcpu = 0   
6:  $hitmemory = 0   
7:  $target="firefox"   
8:  foreach($turn in 1..$loop_count)   
9:  {   
10:   $cpu = (gwmi -class Win32_Processor).LoadPercentage   
11:   $process = Get-Process | Where-Object {$_.ProcessName -eq $target}   
12:   $memory=[Math]::Round($process.privatememorysize/1mb, 2)    
13:   Add-content c:\users\amah11\Desktop\logs.txt "CPU utilization is Currently at $cpu%'"   
14:   Add-content c:\users\amah11\Desktop\logs.txt "Memory utilized by $target is $memory"   
15:   If($cpu -ge $cpu_threshold )   
16:   {   
17:      $hitcpu = $hitcpu+1   
18:   }   
19:   If($memory -ge $memory_threshold )   
20:   {   
21:      $hitmemory = $hitmemory + 1   
22:   }   
23:   start-sleep $sleep_interval    
24:   if($hit -eq 3)    
25:   {   
26:   Write-Host "CPU utilization above $cpu_threshold" -foregroundcolor red -backgroundcolor yellow   
27:   }   
28:   if($hitmemory -eq 3)    
29:   {   
30:   Write-Host "Memory utilization above $memory_threshold" -foregroundcolor red -backgroundcolor yellow   
31:   }   
32:  }   

In this script we are storing the result in a log file and checking if any counter is going above the threshold value. Based on occurrence of threshold violation we are echoing a warning message.

Through PowerShell we have to all the performance counters available. Also, for capturing memory utilization for a process which is not running before start of test we would have to capture all instances of process and then filter out result which can be avoided in case we use ps script.