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Difficulty: HardHigh-Performing and Elastic Compute Solutions

A materials science laboratory is deploying a distributed crystalline structure simulation on Amazon EC2 instances. The simulation nodes run a specialized Message Passing Interface (MPI) application that requires sub-10 microsecond network latency. The coordination service runs on port 90959095. A Network Load Balancer (NLB) is configured to route traffic to the instances, but all instances are currently marked as unhealthy in the target group, and latency between the nodes is suboptimal. Which combination of actions will resolve the latency issues and fix the health check failures?

  1. Deploy the EC2 instances in a cluster placement group within a single Availability Zone, and update the Network Load Balancer target group health check port to 9095.Answer
  2. B
    Deploy the EC2 instances in a spread placement group within a single Availability Zone, and configure the Network Load Balancer target group health check to use the default port 80.
  3. C
    Deploy the EC2 instances in a partition placement group across multiple Availability Zones, and configure the Network Load Balancer target group health check port to 9095.
  4. D
    Deploy the EC2 instances in a cluster placement group spanning multiple Availability Zones, and update the Network Load Balancer target group health check port to 9095.

Answer

Deploy the EC2 instances in a cluster placement group within a single Availability Zone, and update the Network Load Balancer target group health check port to 9095.
Deploying the instances in a cluster placement group within a single Availability Zone ensures the lowest possible latency and highest network performance, which is required for tightly coupled MPI applications. Updating the target group health check port to 9095 aligns the Network Load Balancer's health checks with the custom port where the simulation's coordination service is listening, resolving the health check failures.

Step-by-Step Solution

1
Analyze the network latency requirement.
Tightly coupled MPI applications require sub-10 microsecond latency, which is only supported by launching instances in a cluster placement group.
A cluster placement group places instances physically close together within a single Availability Zone to achieve low-latency, high-throughput network performance.
2
Verify cluster placement group constraints.
A cluster placement group cannot span multiple Availability Zones.
Placing instances across multiple Availability Zones introduces inter-AZ network latency, which violates the cluster placement group's physical proximity design.
3
Diagnose the health check failure.
The application runs on port 9095, but the target group is using a mismatched port (e.g., port 80).
If the health check port does not match the application port, the NLB will mark the instances as unhealthy.
4
Determine the resolution steps.
Launch instances in a single-AZ cluster placement group and update the target group health check port to 9095.
This combination achieves the latency requirement and ensures the NLB correctly monitors the application's status.

Key Concept

Selecting the correct EC2 placement group for low-latency requirements and configuring matching health check ports in Elastic Load Balancing.
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High-Performing and Elastic Compute Solutions

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