An application development team complains that they are experiencing performance issues with ElastiCache. After investigation, a database specialist determines that the performance issues occur during the automated backup window. What actions can the specialist perform to improve backup performance (select TWO)?

Answer options:

A.Schedule automated backup window to occur at midnight.
B.Set the reserved-memory-percent parameter.
C.Create backups from a read replica.
D.Increase the number of shards.
E.Perform a resharding operation.

Answer: B and C
Option A is incorrect because rescheduling the backups will not resolve performance issues.
Option B is CORRECT because the reserved-memory-percent parameter specifies the amount of memory available for non-data use. Setting or increasing this parameter value for cluster nodes can improve performance during backups since more memory will be allocated for the backup processes.
Option C is CORRECT because by performing backups from one of the read replicas, the primary node remains unaffected and can continue serving requests without any performance degradation.
Option D is incorrect because increasing the number of shards increases the number of nodes in a clustered-mode ElastiCache cluster. It would not improve backup performance.
Option E is incorrect because resharding an ElastiCache means changing the number of nodes in the cluster and performing a redistribution of key spaces. It would not improve backup performance.
Reference:
https://docs.aws.amazon.com/AmazonElastiCache/latest/red-ug/backups.html#backups-performance