Tuesday, December 15, 2015

Improved Remote Desktop Connection Broker Performance with Windows Server 2016 and Windows Server 2012 R2 Hotfix (KB3091411)

Microsoft recently released a new hotfix for the RD Connection Broker role in Server 2012 R2 that significantly increases performance when brokering connections. It changes some of the algorithms that the Connection Broker role uses to process redirection requests, as well as modifies how the broker talks to the SQL database in an HA mode deployment.

At the recommendation of one of Microsoft's Premier Field Engineers, I installed this hotfix in my test RDS environment a few days ago, and have not run into any issues so far.

From the article for KB3091411:

This hotfix contains the following improvements:
  • Improves the number of successful user connections when many user connections are coming in (especially in peak logon periods).
  • Decreases CPU usage on SQL Server that's used in a High Availability-based Connection Broker deployment.
  • Optimizes the number of SQL calls that are invoked by Connection Broker when it processes RD user connections.
This hotfix improves the overall performance of the Connection Broker by being able to scale more user connections that typically occur during peak logon periods. 
This hotfix applies to both RD Session Host and Virtual Desktop Infrastructure (VDI)-based deployments.

The announcement on MSDN includes some additional metrics to help quantify some of the performance improvements:

Logon Storm
100% connection success with initial burst of 100 connections at a rate of 2 connections per second
0.2 second average connection time through RD Connection Broker, down from over a minute 
RDSH Add/Restart
100% success adding/restarting servers at rate of 1 server per second with 5 sessions per server
2 second average add/restart time, down from over thirty minutes 
MSTSC End to End
100% connection success at a rate of 100 connections per minute
25 second average connection time, down from over seven minutes
Link to the MSDN announcement - http://blogs.msdn.com/b/rds/archive/2015/12/15/improved-remote-desktop-connection-broker-performance-with-windows-server-2016-and-windows-server-2012-r2-hotfix-kb3091411.aspx

Link to KB3091411 for Windows Server 2012 R2 - https://support.microsoft.com/en-us/kb/3091411