After reviewing performance metrics for the week, we’ve discovered an issue with the load balancer for LOUIE which would cause issues with profile creation in outlook. By nature, the load balancer will tie an entire IP C class subnet affinity to a single CAS node. Normally, this isn’t an issue, but with additions to Global Catalogs in the forest, Outlook clients would automatically try to break affinity on NSPI proxy requests. Unfortunately, this provided extra difficulty in diagnosing this issue as our staff would often be unable to replicate profile creation issues.

Starting at 11:00 PM Eastern tonight (4/29/11) we will begin to take down the current load balancer for replacement. Clients using Outlook and Active Sync will be disconnected during the replacement. Clients can utilize OWA by logging into specific CAS nodes, eg,

Maintenance is expected to last until 11:30 PM Eastern. We understand this is an extremely short notice, however, in the interest of providing solid performance by Monday we need to utilize as much time over the weekend to stress test the new load balancer. We appreciate your patience as we strive to continue bringing a solid Hosted Exchange experience.


Update 11:00 PM Eastern: We are beginning maintenance to replace the CAS load balancer for LOUIE

Update 11:54 PM Eastern: Service was restored near 11:35 PM Eastern and we’ve confirmed all services are active and online. We are going to continue to monitor the traffic and connection rates over the weekend.