This is my first article where I write about Propietary Software, specifically about VMware Horizon, which is the VMware’s Virtual Desktops Infrastructure solution. I know I’ll receive some nagging from those free software supporters who read this.
Several customers and users have frequently asked about which or what load balancing scheme to use for the incoming connections, what load balancing is more compatible with VMware Horizon and so on; but VMware does not have nor offer any manufacturer preference about this infrastructure component. Any load balancing system can be useful, but depending on the environment, any scheme can be chosen.
VMware Horizon has a component called View Connection Server, whose function is the administration of the Virtual Desktop Infrastructure, managing and control of user’s sessions to their Virtual Desktop that is assigned, that is either a Floating Desktop, Full Desktop, Phisical Desktop and others. If the View Connection Server fails, the users can not login during this downtime. There is another variable if you have a large user population (above 2000 concurrent sessions), where it is necessary to install another View Connection Server to support that amount of users.
View Connection Server has the limit to support until 2000 concurrent users, and when there are environments with a bigger population, and to avoid View Connection Server as the single point of failre, a load balancer is needed.
In View Connection Server installation options, there is a Replica Mode installation, this is used to synchronize with a previously installed View Connection Server, using ADAM and JMS technologies, making the Replica of the View Connection Server an exact clone of the first one. You can even log in to the Administration Console in any of them to manage the same infrastructure. You can install more Replica Connection Servers in the same way. View Connection Server and neither its Replicas have any kind of technology to load balance the users connections, and this is the reason why to use a third party solution to accomplish this.
Below is a list of different ways to load balance the incomming connections in View Connection Servers.
vSphere HA is a technology inside the vSphere virtualization platform that provides High Availability in the Virtual Machines that hosts, and comes to action when the Virtual Machines that are selected to protect, and that are located in an ESXi node that fails, reboot in another ESXi node that is a member of the same cluster.
vSphere Fault Tolerance is a technology inside the vSphere virtualization platform that provides Fault Tolerance in Virtual Machines selected to protect, those protected Virtual Machines have a “mirror” running in another ESXi node, when the ESXi node fails, the “mirrors” of the protected Virtual Machines start to function in online mode, having the perception that there was no failure.
Microsoft Windows Network Load Balancing is a technology indise Microsoft Windows Server that provides load balancing in native form within the Operating System. This technology allows the traffic distribution between members of the NLB cluster and redirects connections in case of a cluster member fails.
vCloud Networking and Security is a component part of VMware vCloud that provides VPN, Load Balancing, NAT and DHCP services within the Virtual Infrastructure through Virtual Appliances. vShield Edge is responsable of Load Balancing service between Application Virtual Machines.
This Load Balancer is a Virtual Appliance with all features and functionality that provides a Physical Appliance, with the advantage that it uses resources from the virtual infrastructure and no physical space in the Data Center. This Load Balancer can be proprietary, obtained from a manufacturer or can be a Free or Open Source Load Balancer, there are several choices and alternatives, and a Free or Open Source alternative can be as robust and efficient as a proprietary one.
A physical Load Balancer is an appliance that is installed and connected to the Data Center network. This Load Balancer can be proprietary, obtained from a manufacturer, or can be a Free or Open Source Load Balancer, where the software is installed in an available equipment, and can be as robust and efficient as a proprietary, depending of the quality of the equipment hardware where it was installed.
Every solution described is suitable depending of the environment where VMware Horizon will be implemented, and there is no preference of which one is better than another. The DNS Round Robin alternative is not listed because actually it is not a real load balancing solution.