Add a secondary Connection Broker

A secondary Connection Broker is added to a Site for redundancy. This way if the primary Connection Broker fails, the secondary Connection Broker is still available to handle the requests. Connection Brokers work in active/active manner to ensure high availability. In case of a Connection Broker failure, the next agent is always ready to handle the load. In general, the N+1 redundancy approach should be used per Site. Note that for auto-promotion you shouldn't have more than three Connection Brokers (auto-promotion is described later in this section).

When you have one more secondary Connection Brokers installed, the runtime data is replicated on each agent, so if any service fails, the downtime is reduced to a minimum. In addition, any active Connection Broker is used for authentication purposes with both the AD and any 2nd level authentication provider used.

The primary Connection Broker performs the same tasks as secondary Connection Brokers but has additional responsibilities. It manages certain processes that must be managed by a single Connection Broker. The following table lists processes managed by the primary Connection Broker and secondary Connection Brokers:

Process	Primary Connection Broker	Secondary Connection Brokers
Monitor PAs (counters)	Yes	Yes
Monitor RD Session Hosts (counters)	Yes	Yes
Monitor Providers (counters)	Yes	Yes
Monitor RDS Sessions (reconnection)	Yes	Yes
Monitor Deployed RDS applications	Yes	Yes
Monitor VDI session (reconnections)	Yes	Yes
Manage system settings	Yes	No
Send licensing information & heart beat	Yes	No
Process and send CEP information	Yes	No
Send information to reporting server	Yes	No
Manage RDS scheduler	Yes	No
Reporting engine information	Yes	Future versions
Shadowing	Yes	Future versions
Send email notifications	Yes	No

As a demonstration of how load distribution between multiple Connection Brokers works, consider the following example:

• Suppose we have two Connection Brokers: PA1 (primary) and PA2 (secondary).

• Suppose we also have 10 RD Session Hosts: RDS1, RDS2 ... RDS10

The resulting load will be distributed as follows:

• RDS1—RDS5 will use PA1 as their preferred Connection Broker.

• RDS6—RDS10 will use PA2 as their preferred Connection Broker.

Planning for secondary Connection Brokers

RAS Connection Brokers running on the same Site communicate with each other and share the load. The amount of data being transmitted from one agent to another is quite large, so a reliable high-speed communication channel must be ensured (e.g. a subnetwork can be configured for Connection Broker communications).

When adding a secondary Connection Broker to a Site, you specify an IP address for it. Make sure that the IP addresses of all agents belong to the same network segment. The port that Connection Brokers use to communicate with each other is TCP 20030.

There's no physical limit to how many Connection Brokers you can add to a Site. However, the best results are achieved with only two-three agents present. The three-agent scenario is highly recommended, especially when you have Providers and want to enable high availability for VDI. Adding more than two secondary Connection Brokers to a Site may have a reverse effect and actually degrade the system performance. Note that this does not apply to secondary Connection Brokers in standby mode, which is explained in Configuring RAS Connection Brokers.

Adding a secondary RAS Connection Broker to a Site

To add a secondary Connection Broker:

1. Navigate to Infrastructure > Connection Brokers.

2. Choose Add from the ellipsis menu (or click the plus-sign icon). The Add new wizard opens.

3. On the Host page, specify the following:

   • Host name: FDQN of the host that hosts the RAS Connection Broker. Click Resolve IP to obtain the host IP address automatically.

   • IP address: The host IP address. Click Resolve Name to obtain the host FQDN automatically.

4. On the Agent Settings page, specify the following:

   • Alternative IPs: One or more alternative IP addresses, separated by a semicolon. These addresses will be used if RAS Secure Gateways fail to connect to the RAS Connection Broker using its FQDN or the address specified on the previous page. This can happen, for example, if Gateways are connecting from a different network, which is not joined to Active Directory.

   • Description: Add an optional description.

   • Enable firewall rules: Select to automatically configure the firewall on the host.

   • Restart host if required: Automatically restart host after the installation, if it is required.

   • Install a gateway with a Connection Broker: Select this option if you also want to install a RAS Secure Gateway on the specified host. If you select this option, you may also select the Enable HTML5 Gateway option to automatically enable User Portal on the Gateway.

5. On the Summary page, review the settings and click Create.

From this point, follow the onscreen instructions and add the Connection Broker to the Farm.