Exchange 2010 LoadGen doesn’t work with a CAS Array

While attempting to use the 64-bit version of LoadGen for some Exchange 2010 testing, I found the tests were failing, and in the LoadGenSim logs were lots of errors like this one:

Microsoft.Mapi.MapiExceptionNetworkError: MapiExceptionNetworkError: Unable to make connection to the server. (hr=0x80040115, ec=-2147221227)

I then noticed that, just above these errors, I had a line which started as follows:

Outlook2003Online Error: 0 : 10/21/2010 15:20:53 -- Diagnostic context (user: 'DOMAIN\CED40A97-LGU000001'):
distinguishedName 'CN=CHGVA-EXM11 CED40A97-LGU000001,OU=DBTest2010,OU=2010SERVER,OU=Users,OU=LoadGen Objects,DC=mydomain,DC=com', exchServerDn '/o=Organisation/ou=Exchange Administrative Group (FYDIBOHF23SPDLT)/cn=Configuration/cn=Servers/

The interesting thing was that the specified exchServerDn does not actually exist. The name was one I had registered in the DNS for the CAS NLB cluster, and there is definitely no server object of that name under the Configuration branch.

As well as creating the NLB cluster I had also defined a CAS Array, and the mail databases had been created after that, meaning they had the array configured in their RpcClientAccessServer setting. Before I could get LoadGen to work I had to reset this setting on my test databases so they specified one particular CAS server, rather than the array.

set-mailboxdatabase DBTest2010 -RpcClientAccessServer

A couple of other observations..

  • Despite lots of errors in the logs about public folders and free-busy (even if you don’t select “Initialize Public Folder Database”) it seems to work fine without a PF DB on 2010 (and it won’t use one on 2007).
  • The “Initialize mailboxes” step takes ages to get going. Let it run.
  • I installed it on a regular Windows 2008R2 server – not an Exchange server.
  • I don’t know if I’m doing something wrong, but I seem to have let each new test create its own accounts. If I try and use the accounts from a previous test it tells me I didn’t select any mailusers.

3 Replies to “Exchange 2010 LoadGen doesn’t work with a CAS Array”

  1. This is not correct. Loadgen works just fine with CAS arrays. By default Loadgen searches for all the CAS servers in the environment and places them in the configuration file. If you have a CAS array you will need to configure the Loadgen configuration file by hand (see below).

    Configuration file: casarray

  2. Thanks Erin – this is great info! Do you have a reference for this? I did download the Loadgen doc and did some searches on CAS array (and variations) but I admit I didn’t read the whole doc in detail.

Comments are closed.