Best Practices for EMR Cluster Optimization
Question
A team is building an EMR Cluster in AWS.
Management has requested that costs are optimized when working with the cluster.
At the same time, you need to ensure capacity needs are met to ensure that EMR jobs are run as per demand.
Which of the following can help you accomplish this? Choose 2 answers from the options given below.
Answers
Explanations
Click on the arrows to vote for the correct answer
A. B. C. D.Answer - B and C.
The AWS Documentation mentions the following.
The instance fleets configuration for a cluster offers the widest variety of provisioning options for EC2 instances.
With instance fleets, you specify target capacities for On-Demand Instances and Spot Instances within each fleet.
When the cluster launches, Amazon EMR provisions instances until the targets are fulfilled.
You can specify up to five EC2 instance types per fleet for Amazon EMR to use when fulfilling the targets.
You can also select multiple subnets for different Availability Zones.
When Amazon EMR launches the cluster, it looks across those subnets to find the instances and purchasing options you specify.
While a cluster is running, if Amazon EC2 reclaims a Spot Instance because of a price increase, or an instance fails, Amazon EMR tries to replace the instance with any of the instance types that you specify.
This makes it easier to regain capacity during a spike in Spot pricing.
Instance fleets allow you to develop a flexible and elastic resourcing strategy for each node type.
For example, within specific fleets, you can have a core of On-Demand capacity supplemented with less-expensive Spot capacity if available, and then switch to On-Demand capacity if Spot isn't available at your price.
Option A is incorrect since using Spot Instances for the master node is not recommended.
Option D is incorrect since this would not be the most cost effective option.
For more information on Instance fleets, please refer to the below URL.
https://docs.aws.amazon.com/emr/latest/ManagementGuide/emr-instance-fleet.htmlTo optimize costs while meeting capacity needs for an EMR cluster in AWS, the following two options can be used:
Option A: Use Spot Instances for the master, core and task nodes Spot instances are unused EC2 instances that can be made available at a lower price than On-Demand instances. They can be used to optimize the cost of an EMR cluster while maintaining the required capacity. Spot instances can be used for master, core, and task nodes in an EMR cluster. The spot market price can fluctuate, so the interruption of instances is also possible when the market price is higher than the bid price. Therefore, it is essential to design the EMR job with a resilient architecture to handle any sudden failure of Spot instances. By using spot instances for the EMR cluster, significant cost savings can be achieved.
Option B: Use an Instance fleet configuration for the EMR Cluster The Instance fleet is a feature that allows configuring multiple instance types and sizes within a single EMR cluster. With Instance Fleet, it is possible to mix and match the type and size of instances based on the workload requirements. This allows an EMR cluster to optimally match capacity needs while also reducing costs. The Instance Fleet can provide flexibility in cost savings by allowing a combination of spot, reserved, and on-demand instances to be used. This ensures that EMR jobs are executed at a low cost and with sufficient capacity.
Option C: Use a combination of On-demand and Spot Instances for Core and task nodes. This option allows for a combination of both On-demand and Spot Instances to be used for core and task nodes in an EMR cluster. This option provides a balance between cost and capacity needs. It can help reduce costs while ensuring that the EMR jobs are completed within the required time frame. However, it requires careful planning to ensure that the instance configuration is optimal and the job is architected in a way that handles interruptions.
Option D: Use On-Demand Instances for the master, core, and task nodes. This option is not the best choice to optimize costs for an EMR cluster. On-Demand instances are the most expensive type of instances, and using them for an EMR cluster will increase the cost significantly. While it can ensure that the EMR jobs are run without interruptions, it does not provide cost optimization.
In conclusion, options A and B can help optimize costs while meeting capacity needs for an EMR cluster. Option C can also be used but requires careful planning, while option D is not recommended.
