Disabling a Connection Server in VMware Horizon is a straightforward administrative task performed within the Horizon Console, often used for maintenance, upgrades, or troubleshooting purposes.
Steps to Disable a Horizon Connection Server
To temporarily take a Connection Server instance out of service and prevent it from brokering new user connections, follow these steps in the Horizon Console:
- Access Horizon Console: Log in to your Horizon environment's administrative interface, known as the Horizon Console. You typically access this via a web browser.
- Navigate to Server Settings: In the Horizon Console, locate and select Settings from the main navigation menu, then choose Servers.
- Select Connection Servers Tab: Within the Servers section, click on the Connection Servers tab to view a list of all deployed Connection Server instances in your environment.
- Identify and Select Instance: From the displayed list, carefully select the specific Connection Server instance that you intend to disable.
- Click Disable: Once the desired Connection Server is selected, click the Disable button.
This action will immediately prevent the selected Connection Server from accepting any new incoming user connection requests.
Re-enabling a Connection Server
Should you need to bring the server back into active service, you can easily do so. Simply select the previously disabled Connection Server instance on the same Connection Servers tab and click the Enable button. This will allow the server to resume brokering new connections.
Understanding Connection Server States
The following table summarizes the operational states of a Horizon Connection Server and their implications:
| State | New User Connections | Existing User Connections | Primary Use Case |
|---|---|---|---|
| Enabled | Allowed | Maintained | Normal operation, active load balancing |
| Disabled | Blocked | Maintained | Planned maintenance, troubleshooting, upgrades |
Why Disable a Connection Server?
Administrators typically disable Connection Servers for various strategic and operational reasons in a virtual desktop infrastructure (VDI) environment:
- Routine Maintenance: Applying operating system patches, firmware updates, or performing hardware maintenance on the server.
- Horizon Upgrades: Preparing for or executing an upgrade of the Horizon Connection Server software or other associated components.
- Troubleshooting and Diagnosis: Isolating a potentially problematic server to diagnose issues without impacting the entire user base. This helps in pinpointing performance bottlenecks or configuration errors.
- Decommissioning: Removing an older or redundant Connection Server from the Horizon pod as part of infrastructure optimization.
- Load Balancing Adjustments: Temporarily removing a server from the connection pool to manage user distribution or rebalance load across other active servers.
Impact of Disabling a Connection Server
When a Connection Server is disabled, it behaves as follows:
- New Connections Blocked: The server will no longer accept new login requests from users or redirect them to virtual desktops or published applications.
- Existing Sessions Unaffected: Active user sessions that were established before the server was disabled will typically remain connected and operational, assuming the underlying server hardware and software remain stable. Users will not be disconnected mid-session solely because the server's state changed to disabled.
- High Availability Maintained: Other active Connection Servers in the same Horizon pod will continue to handle new connection requests, ensuring that the overall service availability for users is maintained. This highlights the importance of having multiple Connection Servers for redundancy.
Best Practices for Managing Connection Servers
To ensure a stable and performant VMware Horizon environment, consider these best practices:
- Maintain Redundancy: Always deploy at least two Connection Servers per pod for high availability and load balancing. This allows for one server to be disabled for maintenance without service interruption. For more details on Horizon architecture, refer to the VMware Horizon documentation.
- Plan Maintenance Windows: Schedule server disabling and maintenance during off-peak hours to minimize potential user impact, even if existing sessions are not affected.
- Monitor System Health: Continuously monitor your Horizon environment, including Connection Server health, resource utilization, and user experience, before and after any administrative changes.
- Communicate Changes: Inform end-users about planned maintenance or potential service impacts, especially if multiple servers need to be taken offline sequentially.
- Verify After Changes: Always test and verify the functionality of the Connection Server after re-enabling it to ensure it is properly integrating with the Horizon pod and brokering connections as expected.
