In our lab tests, we are able to achieve more than 10,000 individual virtual machine (VM) run-time connections over a two-hour period. These tests show the range of scale possible with Remote Desktop Connection Broker (RD Connection Broker). Within the connection process, the overall time measured is overwhelmingly determined by the VM start and protocol connection time. RD Connection Broker does not greatly impact connection time.
RD Connection Broker is a role service within the Remote Desktop Services (RDS) workload in Windows Server 2008 R2. RD Connection Broker provides the following functionality to an RDS deployment:
While you can visit this link to learn more about RD Connection Broker, this entry will speak to the scalability experiences we have seen at Microsoft with RD Connection Broker.
We conduct multiple test scenarios within our Microsoft Labs which simulate real world scenarios. Many of these tests are outlined within our current white papers on the Scalability of RD Session Host and VDI deployments. The tests outlined in this entry will draw a particular focus on the RD Connection Broker server’s ability to handle connections.
We have run tests in our lab specifically against an RD Connection Broker server (Windows Server 2008 R2) and reached 40,000 VMs connected to stub VMs. A stub VM is a piece of code that emulates a virtual machine. This stub VM receives the API calls from Hyper-V and the RD Connection Broker server and simulates the proper return codes from those API calls. Additionally, in deployments of the full VDI system, we have seen no performance bottleneck with the RD Connection Broker server in handling connections to personal virtual desktops or virtual desktop pools.
The following configuration was used to validate the scale of our RD Connection Broker server:
Using the above configuration, the following tests were performed:
The test results from connecting to the 1000 configured personal virtual desktops and virtual desktop pools are below:
Average connection time to get the desktop
Number of simultaneous successful connection requests
Number of connection requests per minute
Status of metric (success metric – average connection time < 2 min, 50 simultaneous connection requests)
Initial connectivity to Windows 7 personal virtual desktop
Exceeds scale goals
Initial connectivity to Windows 7 virtual desktop pool
Meets scale goals
In addition to the tests above we also ran 2 test runs of 10+ hours on Windows 7 and Windows XP personal virtual desktops, totaling 10K+ connections by using a single RD Connection Broker server.
The tests and results documented in this white paper are specific to a VDI workload. However, the VDI workload on the RD Connection Broker server is more intensive than a workload for an RD Session Host server. Therefore, given the scaling when using a VDI implementation, you should expect at least as good and likely better scale when using an RD Session Host server deployment. [Added 10/22/2010]
For more information about how to scale your overall Remote Desktop Services deployment, see the following:
Can I have the configuration of server which hosts RDCB ?