Exam AWS-SysOps topic 1 question 595 discussion

B is correct

You can reduce the lag between updates to a source DB instance and the subsequent updates to the Read Replica by doing the following: Set the DB instance class of the Read Replica to have a storage size comparable to that of the source DB instance. Make sure that parameter settings in the DB parameter groups used by the source DB instance and the Read Replica are compatible. For more information and an example, see the discussion of the max_allowed_packet parameter in the next section. Disable the query cache. For tables that are modified often, using the query cache can increase replica lag because the cache is locked and refreshed often. If this is the case, you might see less replica lag if you disable the query cache. You can disable the query cache by setting the query_cache_type parameter to 0 in the DB parameter group for the DB instance.

When the AuroraReplicaLagMaximum metric for a replica is high, it indicates that there is a delay between the primary instance and the replica in the Aurora DB cluster. This means that changes made to the primary instance may not be immediately replicated to the replica. As a result, users may experience inconsistencies in the shopping cart information displayed by the application. It's important to note that Aurora replicas are designed to provide high availability and scalability, but there can be some replication lag due to network latency or other factors. Applications should be designed to handle such replication lag and ensure data consistency across replicas.

B is the answer

Answer is "B". As user might be connecting to the ReadReplica which is having high utilization. So, its kind of a blip and if user tries again; he would be connected to a healthy node which will resolve the problem.

B. Users intermittently notice that the cart is not updated correctly.

Agree. B is correct answer.

I'll go with B

B. Users intermittently notice that the cart is not updated correctly.

https://docs.aws.amazon.com/AmazonRDS/latest/AuroraUserGuide/CHAP_Troubleshooting.html#CHAP_Troubleshooting.MySQL.ReplicaLag

Any one can provide comment, How to fix this kind of issues in realtime ?