Delays in presence updates or high latency in database operations may occur when OCS 2007 R2 and OCS 2007 R2, Group Chat are running under high concurrency

In a mixed Microsoft Office Communications Server (OCS) 2007 R2 and Microsoft Office Communications Server 2007 R2 Group Chat environment that is running under high concurrency, you may find delays in user presence updates or high latency in database operations.

This issue occurs because of the high presence polling rate of OCS 2007 R2 Group Chat Client. High presence polling rate requires the OCS 2007 R2 database to process the current presence status of all the users more frequently. Therefore, the load of the system is increased.

To resolve this issue, follow these steps:

1. Install the following cumulative update for Office Communications Server 2007 R2 Group Chat Client:
   
   2032922   (http://support.microsoft.com/kb/2032922 / ) Description of the update for Office Communications Server 2007 R2 Group Chat Client: July 2010
2. Set the polling frequency for OCS 2007 R2 Group Chat Client. To do this, follow these steps:
   1. Add a PresencePollFrequencySecond DWORD registry entry to the following registry subkey:
      
      HKEY_CURRENT_USER\Software\Policies\Microsoft\GroupChatConsole\Limits
   2. Set the value for the PresencePollFrequencySecond registry entry.
      Note The default and minimum value of the polling frequency is 125 seconds. The maximum value of the polling frequency is 3600 seconds.

Microsoft has confirmed that this is a problem in the Microsoft products that are listed in the "Applies to" section.

You can monitor the following counters to determine whether the load on the Office Communications Server pool indicates performance related issues:

LC:Usrv – 00 – DBStore\USrv – 000 – Queue Latency (msec)
LC:Usrv – 00 – DBStore\USrv – 004 – Sproc Latency (msec)

Be aware that these counters may also indicate issues that can be resolved by necessary disk configuration as documented in the deployment guide.