VMware Horizon provides no native method to load-balance client requests to Horizon Connection Servers. It is recommended that we implement some load-balancing solution to help balance the client connections across all the Horizon Connection Servers in our infrastructure.
There are different options to perform load traffic management for components such as Unified Access Gateway, Horizon Connection Servers, and App Volumes Managers.
AVI Networks Load balancer For VMware Horizon
VMware Horizon load balancing with Avi gives enterprises better automation and operational simplicity for VDI deployments at a lower TCO by providing a software solution for modern VDI infrastructure design.
Benefits of VMware Horizon Load Balancing with Avi
The NSX Advanced Load Balancer(AVI) platform includes the following core components:
Fast VDI Deployments | Deliver virtual desktops and apps quickly in any data center or cloud environment with the great end-user experience. |
On-demand Autoscaling | Dynamic, on-demand autoscaling seamlessly scales load balancing capacity in response to real-time traffic conditions to deliver high-performance virtual desktops and apps in any data center or cloud. |
Easy Troubleshooting | Pinpoint analytics and end-user insights simplify the troubleshooting and resolution of end-user computing (EUC) issues. |
Simplified Operations | Simplify operations with central management of all load balancers, handle moves, changes, or additions seamlessly, and get health scores on servers and network performance. |
Architecture Overview: Avi Vantage Platform – 100% software-defined, scalable, and distributed modern architecture that best matches the new generation of applications.
The Avi Vantage architecture separates the data and control planes to deliver application services beyond load balancings, such as application analytics, predictive autoscaling, micro-segmentation, and self-service for app owners in both on-premises or cloud environments.
The Avi Vantage Platform has three core components – Avi Service Engines, Avi Controller cluster, and the Avi Admin Console:
• Controller cluster
Controller is the single point of management and control. It serves as the brain of the entire Avi Vantage system, and for high availability, it is typically deployed as a three-node cluster. As its name implies, the Controller implements the control plane.
• Service Engines
Service Engines (SEs) handle all data plane operations within Avi Vantage by receiving and executing instructions from the Controller. The SEs perform load balancing and all client- and server-facing network interactions. It collects real-time application telemetry from application traffic flows
• Admin Console
Admin Console is a modern web-based user interface that provides role-based access to control, manage and monitor applications. Its capabilities are likewise available via the Avi CLI. All services provided by the platform are available as REST API calls to enable IT automation, developer self-service, and a variety of third party integrations.
NSX Advanced Load Balancer(Avi Platform) – Supports multi-cloud and application services with intelligent and automated engines.
Design Considerations for Horizon
The considerations for deploying Avi for Horizon load balancing include:
- Internal vs external clients
- The number of public IPs available
- National Institute of Standards and Technology (NIST) or Health Insurance Portability and Accountability Act (HIPAA) compliance
- Source IP address affinity requirement
- The smart card or True SSO used to authenticate
- Multi site architecture (requires GSLB)
- Sizing
The same deployment designs can be used both on premises on vCenter and on VMware Cloud.
High Availability: –
To ensure the highest level of uptime for a site, including through Avi Vantage software upgrades, careful consideration must be made to ensure the availability for both Avi Controllers and Avi Service Engines.
Refer to Overview of Avi Vantage High Availability for more information on High Availability.
Avi Controller sizing:
Avi Vantage can run with a single Avi Controller (single-node deployment) or with a 3-node Avi Controller cluster. In a deployment that uses a single Avi Controller, that Avi Controller performs all administrative functions as well as all analytics data gathering and processing.
In a production deployment, a 3-node cluster is recommended. In a 3-node Avi Controller cluster, 1 Avi Controller is the leader Avi and is used for control-plane activities and workflows. The other 2 Avi Controllers are followers. The follower Avi Controller nodes are used for analytics. The follower Avi Controller nodes also provide backup in case the leader Avi Controller fails.

Avi SE sizing
For Horizon deployments, the SE sizing depends on the number of users and the throughput per user. SE sizing also depends on the applications accessed over the VDI as higher bandwidth apps like video and 3D modeling would require higher throughput. The highest contributing factor to throughput would be the secondary protocols (Blast/PCoIP).
3 design options for load balancing Unified Access Gateway (UAG):
- Single VIP with Two Virtual Services: The Blast and PCoIP protocols flow via the Avi SEs, hence the SEs have to be sized for the Blast and PCoIP throughput.
- Single L4 Virtual Service: The Blast and PCoIP protocols flow via the Avi SEs, hence the SEs have to be sized for the Blast and PCoIP throughput.
- (n+1) VIP: Only the XML-API protocol flows via Avi SE hence the number of SEs required would be lesser.
It is recommended to have separate SEs for connection server load balancing to avoid traffic to flow back into the DMZ for internal clients.
Active/Active high availability configuration requires a minimum of two service engines.
Each site will require to be sized for its own SEs with an additional SE for GSLB requirement between sites.Active/Active high availability configuration requires a minimum of two service engines.
Depending on the use cases Avi can be used in front of UAG and Connection Servers.Reference Architecture for Horizon and UAG (AVI Networks)

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