Replica Data After Promotion

In most cases, activity recorded on the replica instance is not written directly to the replica instance internal database. The replica instance data is first stored in a local data grid. During the replication process, the replica instance data is sent at regular intervals to the primary instance where it is stored in the primary instance internal database. At regular intervals, the primary instance pushes data updates to the replica instance, where it is stored in the replica instance internal database. The following figure shows the path of the data between the replica instance and the primary instance.

When a replica instance is promoted to the primary instance, all of the data in the replica instance internal database is preserved. However, any data in the old primary instance that was not sent to the replica instance before it is promoted is lost.

The following table lists the operations that generate the data that is recorded on the replica instance and sent to the primary instance. The table also identifies the impact of data that might be lost when a replica instance is promoted to the primary instance.

Operation

Data Changes Stored on Replica Instance

Promotion Impact if Data Is Lost

Comments

User logs on.

A user’s Last Logon date is updated each time the user logs on.

The user’s Last Logon date will be stale.

The user’s Last Logon date will be updated the next time the user logs on.

User changes PIN.

User’s new PIN is updated.

Token reverts to previous PIN. If PIN is expired, the user will be prompted to change it.

User may call for assistance.

User updates password.

User’s new password is recorded.

User password reverts to previous password. If password is expired, user will be prompted to change it.

User may call for assistance.

A user is assigned a new token.

The new token assigned to the user is recorded.

The token does not work.

If a user’s new token does not work after promoting a replica instance, the user’s existing token must be unassigned, and the user must be assigned a new token.

Replica instance IP address is changed.

Replica instance IP address in the internal database is updated.

The hosts table reverts to the previous IP address.

The IP address will update during the next restart. User may call for assistance.

New user registers (Principal Registration).

User records are created in the internal database.

New user would revert to unregistered state.

The user will be asked to register again. User may call for assistance.

Related Concepts

Replica Instance