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Difficulty: HardHigh-Performing and Elastic Compute Solutions

A financial services company is deploying a distributed in-memory data grid (IMDG) on Amazon EC2 instances to cache real-time trading data. The grid nodes require sub-millisecond node-to-node network latency and high throughput for clustering and state replication. Additionally, the grid must expose an administration API port (port 8443) to a Network Load Balancer (NLB) for health monitoring and external control, while the main grid communication runs on port 5701. How should a solutions architect configure the EC2 instances and the NLB target group to meet these requirements?

  1. Launch the EC2 instances in a cluster placement group. Register the instances in the NLB target group on port 5701, and configure the target group health checks to explicitly use port 8443.Answer
  2. B
    Launch the EC2 instances in a partition placement group. Register the instances in the NLB target group on port 5701, and allow the target group health checks to default to the traffic port.
  3. C
    Launch the EC2 instances in a spread placement group. Register the instances in the NLB target group on port 5701, and configure the target group health checks to explicitly use port 8443.
  4. D
    Launch the EC2 instances in a cluster placement group. Register the instances in the NLB target group on port 5701, and allow the target group health checks to default to the traffic port.

Answer

Launch the EC2 instances in a cluster placement group, register the instances in the NLB target group on port 5701, and configure the target group health checks to explicitly use port 8443.
A cluster placement group is designed for low-latency, high-throughput node-to-node communication within a single Availability Zone. Since the main grid traffic is on port 5701, the targets must be registered on that port. However, because the health status is monitored via an administration API on port 8443, the health check port must be explicitly overridden to port 8443, otherwise the load balancer will query the traffic port (5701) and fail to receive valid health responses.

Step-by-Step Solution

1
Analyze placement group requirements for the EC2 instances.
Determine that a cluster placement group is required because the distributed in-memory data grid requires sub-millisecond node-to-node latency and high throughput.
Cluster placement groups pack instances close together within an Availability Zone to enable low-latency, high-throughput network performance.
2
Configure the target group for the Network Load Balancer.
Register target instances on the grid's primary communication port (port 5701) where the application traffic runs.
Traffic routing must point to the primary port where nodes handle incoming client connections and data replication.
3
Configure the health check port override in the target group settings.
Configure the target group health check port explicitly to port 8443.
By default, the load balancer performs health checks on the registered traffic port (port 5701). Since the administration and health API runs on port 8443, the health check port must be overridden, otherwise the load balancer will query the wrong port and mark the targets as unhealthy.

Key Concept

EC2 cluster placement groups for low-latency networking combined with custom port overrides for target group health checks.
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High-Performing and Elastic Compute Solutions

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