Exchange Maximum Allowed Sessions Per User

By default Microsoft Exchange limits the number of sessions a user can have open to 32.  This can be a problem for DigiScope┬« if the Database Action Thread Settings in DigiScope exceed the server's "Maximum Allowed Sessions Per Use" settings, since each thread in DigiScope is equivalent to one (1) session.  Another issue to consider is that DigiScope uses one thread/session to establish a system connection.  Since the default "Maximum Allowed Sessions Per User" is set to 32, this means that DigiScope can only use 31 threads without encountering problems.  Therefore if you increase DigiScope's thread settings to a value more than 31, you will need to adjust the "Maximum Allowed Sessions Per User" setting on the target Exchange server by following the instructions outlined below.

ATTENTION:  When utilizing Project Based or Perpetual licensing, you can use DigiScope on multiple machines without issue.  However keep in mind that when executing actions against a Production Exchange Server, the SESSIONS/THREADS in use are cumulative. EXAMPLE: If you have two machines configured to use 32 Database Action Threads in DigiScope, you should configure your Exchange Servers Maximum Allowed Sessions Per Use to a minimum of 66, i.e. 32 threads +1 system connection = 33 x 2 DigiScope machines = 66

NOTE: Before making any changes to the Windows Registry, you should back up/export the section being modified so you can restore the settings should something go wrong.

In order increase the maximum allowed sessions per user, follow these steps:

  1. On the target Exchange server start the Registry Editor (Regedit.exe) and then navigate to the following registry key:

  2. If the Maximum Allowed Sessions Per User registry value doesn't already exist, create a new DWORD registry value and name it Maximum Allowed Sessions Per User.

  3. Now Modify the Maximum Allowed Sessions Per User registry value and set the Decimal value to 1 plus the number of threads you wish to use in DigiScope®.

  4. After setting the Maximum Allowed Sessions Per User registry value, you will need to restart the Microsoft Exchange Information Store service before the change will take affect.

NOTE: If you are utilizing Database Availability Groups or Client Access Server you will need to follow the steps above on all Mailbox servers involved.

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