Exam AWS-SysOps topic 1 question 862 discussion

Ans: C & E Ref: https://docs.aws.amazon.com/AmazonElastiCache/latest/mem-ug/SelectEngine.html Ref: https://aws.amazon.com/elasticache/redis/?trk=ps_a134p000003y4xrAAA&trkCampaign=pac_RTA_Redis-Managed_2020&sc_channel=ps&sc_campaign=pac_RTA_Google_us_redis-pdp_non-brand_prosp_en_5-12-20&sc_outcome=PaaS_Digital_Marketing&sc_geo=NAMER&sc_country=US&sc_publisher=Google&sc_category=Database&sc_detail=%2Bredis&sc_content=Redis%20General_bmm&sc_matchtype=b&sc_segment=436410813560&sc_medium=PAC-PaaS-P|PS-GO|Non-Brand|Desktop|PA|Database|ElastiCache|US|EN|Text&s_kwcid=AL!4422!3!436410813560!b!!g!!%2Bredis&ef_id=EAIaIQobChMIl42G-Kni7AIVEI-GCh0GYABbEAAYASAAEgLGovD_BwE:G:s&s_kwcid=AL!4422!3!436410813560!b!!g!!%2Bredis Notes: Amazon ElastiCache for Redis supports both Redis cluster and non-cluster modes and provides high availability via support for automatic failover by detecting primary node failures and promoting a replica to be primary with minimal impact.

I saw this question verified somewhere else so.

Redis supports data partitioning, which allows you to distribute the dataset across multiple Redis shards (node groups) in a Redis cluster. Each shard can handle a subset of the data, and this enables horizontal scaling, making it suitable for handling large datasets with high read/write throughput. Redis (cluster mode enabled) supports online resharding, which means you can dynamically add or remove shards (node groups) from the cluster while it's running, without any downtime. This makes it easy to scale the Redis cluster up or down based on changing requirements, such as increasing capacity during peak auction times and reducing it during off-peak times.

https://docs.aws.amazon.com/AmazonElastiCache/latest/mem-ug/SelectEngine.html

Thank you for your work, but did you notice in your reference documents that in fact the answer is A, C and E? A..Data partitioning is the first option from the answers that shows up in the table...https://docs.amazonaws.cn/en_us/AmazonElastiCache/latest/red-ug/SelectEngine.html | Good luck to anybody facing this question...

Online resharding and MutliAz failover, aws is eminently clear : https://docs.aws.amazon.com/AmazonElastiCache/latest/mem-ug/SelectEngine.html

its CE https://docs.amazonaws.cn/en_us/AmazonElastiCache/latest/red-ug/SelectEngine.html Online Resharding is not supported on Memcached High Availabilty

I will go for D and E. I tried to create a memcached Cluster in ElastiCache Console, under Availability Zones Placement, you can select more than 1 AZ for the cluster. So option C seems not advantage for Redis over Memcached. Btw, in 2020/03, AWS announced Global datastores for Redis, https://docs.aws.amazon.com/AmazonElastiCache/latest/red-ug/Redis-Global-Datastore.html If this is a recent question in the exam, I guess it should D and E.

C. Multi-AZ with automatic failover E. Online resharding Seem correct

apologies answer is C & E: https://docs.aws.amazon.com/AmazonElastiCache/latest/mem-ug/SelectEngine.html check the table of comparisons

Notes: Multi-AZ is enabled by default on Redis (cluster mode enabled) clusters. Redis (cluster mode enabled) supports partitioning your data across up to 250 node groups. You can dynamically change the number of shards as your business needs change. One advantage of partitioning is that you spread your load over a greater number of endpoints, which reduces access bottlenecks during peak demand. Answer is A&C

CE https://jayendrapatil.com/aws-elasticache-certification/

I'll go with C,E

A&B are on both Redis & memcache Only Redis has C&E https://aws.amazon.com/elasticache/redis-vs-memcached/#:~:text=into%20your%20application.-,Data%20partitioning,more%20data%20when%20demand%20grows.

Ans is C,E

C. For high availability ---- The platform must be available at all times. E. For performance----- Online resharding

AE https://docs.amazonaws.cn/en_us/AmazonElastiCache/latest/red-ug/SelectEngine.html https://docs.aws.amazon.com/AmazonElastiCache/latest/red-ug/redis-cluster-resharding-online.html