Summary

This article discusses the HEARTBEAT_INTERVAL property to allow users to avoid timeouts due to network latency over large distances

Synopsis

What are the network latency constraints for running a three server configuration for FlexNet Publisher license servers?

I have read the Selecting a License Server Machine and the Network Bandwidth for License Server sections of the FlexNet Publisher License Administration Guide but am looking for more concrete information and numbers if possible.

Discussion

The HEARTBEAT_INTERVAL value is the correct method of increasing the available time to compensate for any latency between the servers.

When a license server comes up in a three server redundancy setup, it immediately tries to communicate with the other servers and will be unable to serve licenses until it has made at least one connection (referred to as a quorum). Setting the HEARTBEAT_INTERVAL on the server line of a license configures how long the server will wait to receive a response from a heartbeat.

The following information relating to the HEARTBEAT_INTERVAL is taken from the Using Other Capabilities with Three-Server Redundancy section of the FlexNet Publisher Programming Reference for License File Based Licensing:

HEARTBEAT_INTERVAL=seconds

This indicates how long the license servers wait to receive a heartbeat from another license server before shutting down the vendor daemon. This value is used in the following equation to calculate the actual timeout value:

timeout = (3 * seconds) + (seconds * 1)

Valid timeout value is 0-120. The default value is 20, which equates to an actual timeout of 79 seconds. Valid seconds values are 0 through 30. This parameter is optional and should be placed on the first SERVER line in the license file. This value can be changed after the license file has been signed. The license server must be running a version 10.8 or later vendor daemon to use this keyword.

The information above shows that while the default value is 20, this can be configured to be as high as 120 should this be required.