Resource Based & Round Robin Load Balancing

Introduction

The Load Balancer is designed to balance RDS and VDI Hosts connections made from Parallels Remote Application Server Clients. There are 2 types of load balancing methods available:

• Resource Based
• Round Robin

Resource Based load balancing distributes sessions to servers depending on how busy the servers are. Therefore a new incoming session is always redirected to the least busy server.

Round robin load balancing redirects sessions in sequential order. For example the first session is redirected to server 1, the second session is redirected to server 2 and the third session is redirected to server 1 again when there are two terminal servers in the farm.

Both methods are explained in this chapter. The load balancing options can be configured from the Load Balancing category in the navigation bar.

Enabling Resource Based Load Balancing

Load balancing is enabled by default when more than one server is available in the site. The resource based load balancing is the default method.

To switch back to resource based from round robin load balancing, select Resource Based from the Method drop down menu.

Configuring Resource Counters

Resource based load balancing uses the below list of counters to determine if a server is busier than the other/s and vice versa:

• User sessions: redirect users to a server with the least number of sessions
• Memory: redirect users to the server with the best free/used RAM ratio
• CPU: redirect users to the server with the best free/used CPU time ratio

When all the counters are enabled, the 2X LoadBalancer adds the counter ratios together and redirects the session to the server with the most favourable combined ratio.

To remove a counter from the equation, untick the checkbox next to the counter name in the Counters section. To add it back to the equation, tick back the check box.

Round Robin Load Balancing

Round robin load balancing redirects sessions in sequential order. For example with 2 RDS servers in the farm, the first session is redirected to server 1, the second session is redirected to server 2 and the third session is redirected to server 1 again.

Enabling Round Robin Load Balancing

To enable round robin load balancing select Round Robin from the Method drop down menu in the Load Balancing section.

Advanced Load Balancing Settings

Session Management

Reconnect Disconnected Sessions

Enable the option Reconnect to disconnected sessions in the Load Balancing tab to redirect incoming user sessions to a previously disconnected session owned by the same user.

Reconnect sessions using client’s IP address only

When reconnecting to a disconnected session the Parallels 2X Remote Application Server will match the username requesting to reconnect with the username of the disconnected session to match the sessions. With this option enabled, the Parallels 2X Remote Application Server will determine to which disconnected session to reconnect the session by matching the source IP.

Limit Number of Sessions for Users

Enable this option to ensure that the same user does not open multiple sessions.