We were seeing high CPU usage (98-99%) for MonitoringHost.exe on many servers with managed agents in SCOM R2 across a mix of platforms (Windows 2003, 2008, virtual, physical, SQL, 32-bit, 64-bit) which would grind the server to a holt and dramatically affect multiple VMs if the affected server is a Hyper-V host. Our short term fix was to rename the C:Program FilesSystem Center Operations Manager 2007Health Service State directory and restart the ‘System Center Management’ service.
We’ve recently applied this hotfix – http://support.microsoft.com/kb/968967 – which has now permanently fixed the high CPU usage issue. Looks like the underlying cause was MSMXL 6.0 related.
I’ve recently been doing some testing with Quality of Service (QoS) at the workstation level to see if we can get improvements with audio / video quality with Office Communicator 2007 R2. After making the registry change (HKEY_LOCAL_MACHINE SoftwareMicrosoftRTCTransportQoSEnabled) and starting the QoS RSVP service I did some testing. The video and audio quality on peer to peer calls was severely degraded to the point where a conversation was not possible and the call would often disconnect after a few seconds.
In summary, don’t use Quality of Service (QoS) at the workstation level with OCS, stick to doing prioritization at the network level….