Configuring a failover or redundant Observer Reporting Server

If you need a high degree of availability for Observer Reporting Server, then enable the Observer Reporting Server redundancy feature. Redundancy, also known as failover, helps maintain a high “up” time for your Observer Reporting Server system and its reports.

If your primary Observer Reporting Server system becomes unavailable for any reason, then the secondary Observer Reporting Server system automatically becomes active and available for reports. By having a failover Observer Reporting Server system, you can help ensure that maximum availability is maintained for your data.

The redundant Observer Reporting Server feature relies on features within the Windows Server 2008 R2 operating system called Network Load Balancing (NLB). Although load balancing can be used for scalability in other systems, Observer Reporting Server uses the feature exclusively for failover services.

The systems in a Network Load Balancing cluster send “heartbeat” packets between each other to confirm that each system is available. Systems in a cluster are constantly exchanging heartbeat packets. A system is marked as failed if it has not responded to a heartbeat packet within five seconds. If the cluster detects that the primary Observer Reporting Server system is not responding, the secondary Observer Reporting Server system is immediately brought online, usually with users being unaware that there was a problem.

Figure 3. Example of failover operation

To learn more about the clustering and failover features in Windows Server 2008 R2, see www.networkinstruments.com/failover. Also on the page is a white paper that contains many details and is recommended reading.

Enabling and configuring Observer Reporting Server redundancy requires making changes to the Windows operating system and Observer Reporting Server program itself. The changes must be made on both the primary Observer Reporting Server system and the failover system. The operating system changes must be made, which may require system restarts, before configuring the Observer Reporting Server program.