Q: What is Revenera's (FNP) Official recommendation for latency among different nodes in a triad setup?

Answer:

As per the triad configuration, we do not have any explicit acceptable latency between three servers. Each server by default will wait for 20s before it has not received any heartbeat from other server and shutting itself down. We can set this waiting period though HEARTBEAT_INTERVAL parameter. Detailed information about this parameter is as mentioned below.

 
What is HEARTBEAT_INTERVAL ?

• This option is used with three server redundancy setup. This parameter is optional and is placed on the first SERVER line in the license file. It takes the value in seconds. 

What is the purpose of HEARTBEAT_INTERVAL?

• This value is used to set to indicate how long a license server waits to receive a heartbeat from another license server in the triad before shutting itself down.

How is the timeout value calculated?

• The seconds value is used in the following equation to calculate the timeout:
  • timeout = (3 x seconds) + (seconds - 1)
  Valid timeout value is 0-120. If not specified, the default value for seconds is 20, equating to an actual timeout value of 79 seconds. Valid values for the seconds value are 0–30.

The maximum value that can be set using HEARTBEAT_INTERVAL is 30s. 
 
Poor network communication causes system performance to slow. Slow network communication can also cause a delay in the transmission of heartbeats between license servers.
 
Also if there is heavy traffic, license servers may miss heartbeats which will shutdown the vendor daemon. Hence to avoid this we would recommend to set HEARTBEAT_INTERVAL value to maximum.