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Blackboard Help

Set Up the Hardware Load Balancer

The hardware load balancer should be set up according to the instructions included with the load balancer.

When setting up a hardware load balancer, it is important that each application server maintains user session affinity for the entire of the session. Session affinity must be based on the user's cookie. In other words, after a user logs in and a session is created on a particular application server, that server must handle all requests associated with that session until it is closed.

Test the System

Test the system by going to a workstation other than any of the Blackboard servers. Open a Web browser and go the URL of the shared hostname configured during load balancing setup.

Configure Client IP Address Forwarding

The Client IP Address must be forwarded to ensure logs reflect the client IP Address rather than the load balancer IP Address. Otherwise, log monitoring and forensic capabilities will be limited. Implement this configuration on the load balancer. The load balancer will insert the original client IP Address in an X-Forwarded-For HTTP header.

Update Web Server Logs


Update Apache web server logs to extract the X-Forwarded-For HTTP header by updating the file and then run PushConfigUpdates. To learn more, see PushConfigUpdates.

Inserting the following value into the LogFormat directive, which inserts the X-Forwarded-For header value into the logs: "%{X-Forwarded-For}i"


LogFormat "%h %{X-Forwarded-For}i %l %u %t \"%r\" %>s %b \"%{Referer}i\" \"%{User-Agent}i\"" combined


IIS can extract the X-Forwarded-For HTTP header by using an ISAPI Log Filter. See your load balancer's guide for more information.