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)?
Click on the arrows to vote for the correct answer
A. B. C. D. E.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-performanceSure, I'll be happy to explain the answer in detail.
First, let's review some basics about ElastiCache and automated backups. Amazon ElastiCache is a managed in-memory caching service that enables you to deploy and operate cache clusters in the cloud. Automated backups are enabled by default for every cache cluster, and these backups are stored in Amazon S3. When an automated backup is taken, ElastiCache takes a snapshot of the entire cache cluster and stores it in S3. During the backup process, some ElastiCache operations, such as cache evictions, are blocked to ensure data consistency.
Now, let's look at the two actions that the database specialist can perform to improve backup performance:
A. Schedule automated backup window to occur at midnight: By default, the automated backup window is set to occur during a 4-hour window that is randomly assigned by ElastiCache. If the performance issues are occurring during the backup window, one option is to schedule the backup window to occur at a different time. The database specialist could schedule the backup window to occur at midnight (or some other time when there is less traffic on the system) to minimize the impact on application performance.
B. Set the reserved-memory-percent parameter: This parameter determines the percentage of memory that is reserved by ElastiCache for its internal processes. By default, this parameter is set to 25%. If the performance issues are related to memory usage during the backup window, the database specialist could increase the reserved-memory-percent parameter to give ElastiCache more memory to work with. This would help ensure that there is enough memory available for ElastiCache to perform its backup operations without impacting application performance.
C. Create backups from a read replica: This answer is not correct because creating backups from a read replica is not directly related to improving backup performance during the automated backup window. However, creating backups from a read replica is a good practice for reducing the impact of backups on application performance in general. When you create a backup from a read replica, you can do so without impacting the performance of the primary cache cluster.
D. Increase the number of shards: This answer is not correct because increasing the number of shards is not directly related to improving backup performance during the automated backup window. Sharding is a way to partition data across multiple nodes in a cache cluster to improve performance and scalability. However, it does not directly impact backup performance.
E. Perform a resharding operation: This answer is not correct because resharding is not directly related to improving backup performance during the automated backup window. Resharding is a way to adjust the number of shards in a cache cluster to better match the workload. However, it does not directly impact backup performance.
In summary, the two actions that the database specialist can perform to improve backup performance during the automated backup window are to schedule the backup window to occur at midnight (or some other time when there is less traffic on the system) and to increase the reserved-memory-percent parameter to give ElastiCache more memory to work with.