Failover license servers

In the license management environment, client machines can be directed to multiple license servers to create a pseudo failover or backup environment. This allows these client machines to be redirected to a second license server with minimal downtime.

To create a failover environment, you will need two separate license manager servers, Windows, UNIX, or Linux, each with the same version of the license manager installed. On the client machines, the failover is created using either ArcGIS Administrator or by setting an environment variable.

Note:

The failover setup described here does not provide 100 percent uptime. The clients will be required to save their work, exit the application, and restart.

Following is an example to illustrate the concept:

Company X has license servers in Dallas and Redlands, both serving ArcGIS 10 licenses. The license server in Dallas has seven seats of ArcInfo. The license server in Redlands has five seats of ArcInfo and one seat of ArcPress. The goal is to have the users in Dallas failover to the Redlands license server if the license server in Dallas fails, and the Redlands users failover to Dallas if the Redlands license server fails.

The first step is to check to make sure the license servers are accessible from both end-user locations.

Once the servers are accessible, you can use the license file variable on each of the client machines to create the failover environment.

The users in Dallas will set the following in the ArcGIS Administrator in the License Manager entry:

dallas;redlands

The users in Redlands will set the following in the ArcGIS Administrator in the License Manager entry:

redlands;dallas

If setting these license servers as environment variables, use the following notation:

Name: ARCGIS_LICENSE_FILE
Value: @dallas;@redlands

Additional considerations

• Once a client application, such as ArcMap, binds itself to a particular license server, it can only use licenses from that server. In the above example, if the application is bound to the license server in Dallas, it cannot use the ArcPress extension available on the Redlands license server.
• If clients failing over to a second license server will need certain extensions available that they had on their primary license server, those extensions will need to be available on the secondary license server.
• When a license server fails, the client machines will not be automatically redirected to the secondary license server. Instead, each client will receive a message that the connection to the license server has been lost and that attempts to reestablish the connection will occur five times, at 2-minute intervals. The user then has two choices:
  • Continue working in the software and hope the license manager connection is restored. If the license manager is repaired in the 10-minute time frame, the client software will automatically reconnect.
  • Save the project and close the application. Immediately reopen the application and continue working.

    When the application is reopened, it will check for the first license server in the list, then failover to the second license server if the first is still not operational.