Manual failover
- Last UpdatedSep 30, 2022
- 1 minute read
To initiate manual failover, IF-Node2 must be in an equal or better state than IF-Node1. For example, failover will not trigger when IF-Node1 has a connection to Data Archive and IF-Node2 does not. IF-Node2 knows the state of IF-Node1 by reading the value of the heartbeat point for IF-Node1.
Manual failover results in overlapping data for two failover update intervals.
You trigger manual failover by changing the value of the active ID point from the failover ID for IF-Node1 to the failover ID for IF-Node2.
Changing the active ID point value on Data Archive causes the interfaces to perform the following operations:
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IF-Node2 reads the active ID value from both the shared file and the point.
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IF-Node2 recognizes that the values are not the same and waits two failover update intervals to determine which value is correct.
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When IF-Node1 does not update the active ID point, IF-Node2 updates the active ID value in the shared file and assumes primary role.
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IF-Node1 reads the new active ID value in the shared file and immediately assumes backup role.