Script Search - divide 1000 computers into 9 groups based on attribute value

We don't have enough information about your problem to provide any guidance.

Can you use a Switch() to populate Groups in series and avoid a Nested Loop?

Can you post your existing code?

No matter how start writing this response, it quickly devolves into convolutions.

I have a collection of objects returned from - $ALLServer = (get-qadcomputer -searchroot 'top OU for wintel servers' -includedproperties customAttribute8 -sizelimit 0 )

I filter $ALLServers again into two collections of objects based on AD Site value (family of geographically similar AD sites lumped together.
So, I threw this against the wall, and found that you can chunk out a collection of objects with PowerShell - two ways. (that know of)

using Select ... wih 'first' and 'skip'
$ALLServers | select -first 90 | to something
$ALLServers | select -skip 90 -first 90 | do something
$ALLServers | select -skip 180 -first 90 | do something
... until you have all 9 chunks

For this example $Chunk_split value would be 100 if the $ALLServers.count was 900.

Using 'ranges' ... i.e. 0..9
$ALLServers[(($Chunk_split * 0) + 0)..($Chunk_split * 1)] | do something
$ALLServers[(($Chunk_split * 1) + 1)..($Chunk_split * 2)] | do something
$ALLServers[(($Chunk_split * 2) + 1)..($Chunk_split * 3)] | do something
... until you have processed all 9 chunks



Either method above gives me a subset of the whole "foreach" chunk of objects which I pipe tot he following.

| %{add-QADGroupMember -identity "CN of Group" -add-QADGroupMember -Member $_.dn -control @{OperationReason="MyReasonForDoingThis"} -proxy}

so, I have a foreach, increment the value of $i++ - essentially sliding the window that I focus on - adding those servers to a group, then slide the window to the next chunk of servers in $ALLServers and add them to the list.

I can do this with repetition of the same lines with incremented numbers ... I was hoping to automate.

If that's still clear a mud, I can sanitize the script-in-progress and share so you can see for yourself how little I know of what I'm talking about.

switch() time to google.

A sanitized script or pseudo-code would be extremely useful.

The bit that I am scratching my head about is the groupings of the servers - is it random / arbitrary or is there some correlation with the site side of things?

If it doesn't matter which server goes in which group then I believe you could accomplish fairly easily with a single loop that iterates the list of servers and sequentially pops them into one of your 9 groups until you are done.

It appears that you have 6 sites. Yet you have 9 groups. Why not have 6 groups? Or 12 groups?

The site affinity *seems* like a logical way to carve up the servers?

So why not have your groups setup thus:

ADSITE1_1 Servers
ADSITE1_2 Servers
ADSITE2_1 Servers
ADSITE2_2 Servers
ADSITE3_1 Servers
ADSITE3_2 Servers

...and so on?

Maybe there's some reason not to do it this way?

(I clearly struggle with the notion of randomly distributing the servers among various groups)

Yep - all randomly distributed between two sets of 9 groups for like-ad-sites. This is to distribute the load on the brain-dead application the customer will be using to collect eventlogs for/from.

Here's a Switch based approach:

$Servers = Get-QADComputer -SearchRoot "OU=SomeOU,DC=MyDomain,DC=Local" | select distinguishedname

Foreach ($ServersItem In $Servers)

{

# Increment the server counter

$ServerNumber += 1

# Figure out which group server 'x' should go into

　

Switch ($ServerNumber)

{ # Beginning of server group selection Switch

{($ServerNumber -le 111)} { $ServerGroup="FirstServerGroup" }

{(($ServerNumber -ge 112) -and ($ServerNumber -le 222))} { $ServerGroup="SecondServerGroup" }

{(($ServerNumber -ge 223) -and ($ServerNumber -le 333))} { $ServerGroup="ThirdServerGroup" }

# ...and so on for as many groups as you want

} # End of server group selection Switch

　

Add-QADGroupMember -Identity $ServerGroup -Member $($ServersItem.distinguishedname)

　

} # End of Servers loop

This is excellent, but I would suggest a modification to the sorting logic.

Using the modulus operator, if you iterate the collection, you will only ever receive a value of 0, 1 , 2 , 3 , 4, 5, 6 , 7 or 8. Use these as your switch cases, and there is your sort.

The pseudo-code would look like this:

$Servers = Get-QADComputer -SearchRoot "OU=SomeOU,DC=MyDomain,DC=Local" | select distinguishedname

Foreach ($ServersItem In $Servers)

{

# Increment the server counter

$ServerNumber += 1

# Figure out which group server 'x' should go into


Switch ($ServerNumber % 9)

{ # Beginning of server group selection Switch

0{ $ServerGroup="FirstServerGroup" }
1{ $ServerGroup="SecondServerGroup" }
2{ $ServerGroup="ThirdServerGroup" }
3{ $ServerGroup="FourthServerGroup" }
4{ $ServerGroup="FifthServerGroup" }
5{ $ServerGroup="SixthServerGroup" }
6{ $ServerGroup="SeventhServerGroup" }
7{ $ServerGroup="EighthServerGroup" }
8{ $ServerGroup="NinthServerGroup" }


} # End of server group selection Switch

Add-QADGroupMember -Identity $ServerGroup -Member $($ServersItem.distinguishedname)

} # End of Servers loop