Powershell Novice - Get all httpd processes and loop through them - powershell

Question

How do I get all processes in power-shell and loop through them and restart them if their memory has reached a X threshold?
For example, I know of this command
PS C:\Users\me> gwmi -ComputerName "localhost" -Class Win32_PerfFormattedData_PerfProc_Process -Filte
r "name like 'httpd%'"
This will give me all httpd processes (httpd, httpd#1, ...).
I would like to loop through these and check if they memory consumption threshold has been reached and if so, restart that process.
My question is primarily how to write the loop, not about how to stop and restart the service. Please explain as I never wrote a power-shell script before.
UPDATE:
I added more information to better explain what my issue is. Below code has comments showing where is see problems (PROBLEM 1 and PROBLEM 2):
$ServiceExe="httpd#1"
$ServiceEXE2="httpd"
# Service to restart ('short' service name from Service's property)
$Service="httpd.exe"
# Working set threshold of 0.2 GB
$Threshold = 200000000
# Get service processes 'httpd' and 'httpd#1'
$Process = Get-WmiObject -ComputerName "localhost" -Class Win32_PerfFormattedData_PerfProc_Process -Filter "Name='$ServiceExe'"
$Process2 = Get-WmiObject -ComputerName "localhost" -Class Win32_PerfFormattedData_PerfProc_Process -Filter "Name='$ServiceExe2'"
# Get working set memory usage for both processes and convert to GB
$wsm = $Process.WorkingSet /1024/1024/1024;
$wsm2 = $Process2.WorkingSet /1024/1024/1024;
$thgb = $Threshold/1024/1024/1024
# Format to 3 dec places
$Fwsm = $("{0:0.000}" -f $wsm);
$Fthgb =$("{0:0.000}" -f $thgb);
echo $("WorkingSet : "+ $Fwsm + " GB / Threshold : " + $Fthgb + " GB.") >> C:\temp\pslog.txt;
if($Process.workingset -gt $Threshold)
{
#PROBLEM 1: THIS WILL ONLY EXECUTE ONCE PROCESS CAPS MAX MEMORY (2GB)
stop-process -name $Service -force
stop-Service apache2.2;
start-Service apache2.2;
echo "Restarted" >> C:\temp\pslog.txt;
}
else
{
#PROBLEM 2: THIS WILL NEVER EXECUTE FOR SOME REASON
$delta = $("{0:0.000}" -f ($thgb - $wsm));
echo $("No Restarting as " + $delta + " GB remains.");
}
I was thinking to replace variables holding process 'httpd' and 'httpd#1' with a single set that I could loop through but realized that Apache may have more than 2 'httpd' processes (i.e. 'httpd', 'httpd#1', 'httpd#2', 'httpd#3', 'httpd#4', ... ). Plus, I discovered that I have the 2 problems marked in the code in update above.
Any idea what I am doing wrong in the code above and how to rewrite it to use a loop to loop through all apache processes that might be initiated, not just 2 like in example above.
UPDATE 2:
So, I rewrote my ps script and I got most of it working but I am running into an issue, hopefully last one.
In my power-shell script, I have defined variable that has my service name like this:
$ServiceName = "APACHESRV[DBx14]";
APACHESRV[DBx14] service exists in my Windows->Services.
Then in my power-shell script, I use stop-service, start-service to start the service:
echo $("Stopping: " + $ServiceName) >> C:\temp\pslog.txt;
stop-Service $ServiceName;
echo $("Starting: " + $ServiceName) >> C:\temp\pslog.txt;
start-Service $ServiceName;
$stamp = Get-Date
echo $($stamp + " Started: " + $ServiceName) >> C:\temp\pslog.txt;
This echoes everything properly and power-shell shows no errors (red-lines), however my service is not started.
Much appreciated

Answer 1

At this point, I think you are just missing your loop. You are retrieving the two process objects, but you are only working on the first one. I took the liberty of restructuring it to work on all http processes. Try this:
# Working set threshold of 0.2 GB
$Threshold = 200000000
$thgb = $Threshold/1024/1024/1024
$Fthgb =$("{0:0.000}" -f $thgb)
# Get service processes 'httpd' and 'httpd#1' Get-WmiObject -ComputerName "localhost" -Class Win32_PerfFormattedData_PerfProc_Process | where { $_.Name -like "httpd*" } | foreach {
$procobj = $_
# Get working set memory usage for both processes and convert to GB
$wsm = $procobj.WorkingSet /1024/1024/1024;
# Format to 3 dec places
$Fwsm = $("{0:0.000}" -f $wsm)
echo $("WorkingSet : "+ $Fwsm + " GB / Threshold : " + $Fthgb + " GB.") >> C:\temp\pslog.txt;
if($procobj.workingset -gt $Threshold)
{
stop-process -name $procobj.Name -force #check this, probably wrong name
stop-Service apache2.2;
start-Service apache2.2;
echo "Restarted" >> C:\temp\pslog.txt;
}
else
{
$delta = $("{0:0.000}" -f ($thgb - $wsm));
echo $("No Restarting as " + $delta + " GB remains.");
}
}

Answer 2

This should do it...
ps | where { $_.name -like "httpd*" } | foreach {
# interrogate the System.Diagnostics.Process object in $_ and do stuff with it
$_
}

Answer 3

Get all the httpd processes with the Get-Process cmdlet, loop through them with the ForEach-Object cmdlet:
# Set a threshold, eg. 120MB
$Threshold = 120 * 1024 * 1024
# Loop through the processes
Get-Process httpd* | ForEach-Object {
if($_.WS -gt $Threshold){
# Working set exceeded threshold, restart relevant service
}
}