Load balancing mailboxes across Exchange 2010 message stores using IDM policy rules

Credits go to Father Ron at my work.

The following may look like a lot of xml code, but after pasting it into one of your creation policy rules on the Subscriber channel it is only 2 conditions and 2 actions, this is by far the easiest quickest way to load balance the creation of exchange accounts across the different homeMDBs.

We have 16 Exchange homeMDBs and we are using the xpath operation of mod and the variable of ($time (we are using the number of milliseconds) mod 16 1). So if you had 25 MDB's then you would modify the below code to read ($time mod 25) 1. You will also need to update the exchange rule in the command policy as well.
<description>default Exchange assignment</description>
<comment>Provision Exchange mailbox</comment>
<if-global-variable mode="nocase" name="drv.exchMailboxMethod" op="equal">policy</if-global-variable>
<if-class-name op="equal">User</if-class-name>
<do-set-local-variable name="time" scope="policy">
<token-time format="!JTIME" tz="UTC"/>
<do-set-dest-attr-value name="homeMDB">
<arg-value type="string">
<token-text xml:space="preserve">CN=DB</token-text>
<token-xpath expression="$time mod 16 1"/>
<token-text xml:space="preserve">,CN=Databases,CN=Exchange Administrative Group (FYDIBOHF23SPDLT),CN=Administrative Groups,CN=EXCHANGE,CN=Microsoft Exchange,CN=Services,CN=Configuration,DC=ad,DC=georgiahealth,DC=edu</token-text>


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Comment List
  • Thanks! This is a great tip on how to specify the target mail store. It is also possible to query the target mail stores and select a target mail store based on utilization or anti-affinity rules to distribute mail accounts evenly across multiple mail stores, and prevent all the members of a department from being allocated to the same store. We do this in our TriVir Exchange 2007/2010 driver (www.trivir.com/.../powershell). Once you get into the Powershell layer, you can create linked mailboxes, manage distribution lists and completely manage all aspects of Exchange configuration and data from IDM. -- bkynaston@trivir.com