Time
|
Action
|
T+0
|
Both interfaces are running with IF1 in the primary role.
|
T+2.1
|
IF2 reads the ActiveID and IF1’s heartbeat. Both are good, so IF2 discards data older than time 0.1.
|
T+2.9
|
Event A, IF1’s stops for any reason just before updating its heartbeat.
|
T+3.1
|
Event B, IF2 notices that IF1’s heartbeat has not updated. IF2 will discard data older than Time 1.1.
|
T+4.1
|
IF2 notices that IF1 still has not updated its heartbeat. IF2 stops discarding old queued data.
|
T+5.1
|
IF2 notices that IF1 still has not updated its heartbeat.
|
T+6.1
|
Event C, IF1 still has not updated its heartbeat so IF2 transitions to Primary sending all data received from Time 1.1 and sets the ActiveID to 2.
|
The time it takes for the failover to occur is slightly more than three seconds and the amount of overlapping data is almost two seconds from time 1.1 to time 2.9.
|
