Problem:

Versa Director HA failover formula

Solution:

During a failover scenario in Versa Director, three attempts are made to establish the Master-Slave switch-over. Follow this sequence of events to understand how the timeout is calculated: 

• For the slave to become the master,

Time required to START Auto fail-over or to start promoting Standby to Active node:

Auto fail-over time-out set example as  180 seconds

Split-time = 

180 (auto fail-over time-out)  / 3 = 60 seconds

Reduce- time = 

If Split-time time is > 10 seconds then (Split-time – 10) = 50 seconds, 

If Split-time time is < 10 seconds then no deduction of 10 seconds

              3 times retry x 50 seconds (Reduce- time) = 150 seconds

So, time required to START = 150 seconds = 2 minute 30 seconds

Time required to COMPLETE Auto fail-over = (Time required to START) + (Actual time taken to complete auto fail-over)

                                                                                        = 150 seconds + (Variable time (no fixed time to complete auto fail-over))