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Difficulty: Very hardHigh-Performing and Elastic Compute Solutions

A financial analytics firm is deploying a high-frequency risk assessment platform on AWS. The application uses a distributed, memory-intensive computing grid on Amazon EC2 instances to process real-time market feeds. The compute nodes must exchange state data with node-to-node network latency of less than 10 microseconds. The platform receives incoming market data streams via UDP on port 9999. A Network Load Balancer (NLB) is used to distribute the incoming UDP traffic across the EC2 instances. To monitor the health of the risk assessment application, a management service runs on TCP port 8080 on each instance. The instance fleet must scale dynamically based on CPU utilization.

Which combination of placement strategy and load balancer configuration should a Solutions Architect recommend to satisfy these requirements?

  1. A
    Launch the EC2 instances in a spread placement group. Configure the NLB target group to use the UDP protocol on port 9999, and configure the target group health checks to use the default traffic port.
  2. B
    Launch the EC2 instances in a cluster placement group within a single Availability Zone. Configure the NLB target group to use the UDP protocol on port 9999, and configure the target group health checks to use the default traffic port.
  3. Launch the EC2 instances in a cluster placement group within a single Availability Zone. Configure the NLB target group to use the UDP protocol on port 9999, and override the health check configuration to use the TCP protocol on port 8080.Answer
  4. D
    Launch the EC2 instances in a partition placement group across multiple Availability Zones. Configure the NLB target group to use the TCP protocol on port 9999, and override the health check configuration to use the TCP protocol on port 8080.

Answer

The correct configuration is to launch the EC2 instances in a cluster placement group within a single Availability Zone, configure the NLB target group to use the UDP protocol on port 9999, and override the health check configuration to use the TCP protocol on port 8080.
The correct solution involves launching the EC2 instances in a cluster placement group within a single Availability Zone, configuring the NLB target group to use the UDP protocol on port 9999, and overriding the health check configuration to use the TCP protocol on port 8080. A cluster placement group enables the low-latency, high-throughput node-to-node networking required by the distributed memory-intensive computing grid. Furthermore, because the health monitoring agent runs on a different port (TCP 8080) than the application data stream (UDP 9999), overriding the target group health check settings ensures that the NLB correctly monitors the nodes' actual health status without generating false negatives.

Step-by-Step Solution

1
Analyze the network latency requirement.
Since the distributed computing grid requires sub-10 microsecond node-to-node latency, a cluster placement group must be used to pack the instances close together on the physical hardware within a single Availability Zone.
Other placement strategies (spread, partition) are optimized for high availability and fault isolation, not low-latency node-to-node communication.
2
Identify the protocol and port for client traffic routing.
The platform receives market data streams via UDP on port 9999, which requires configuring the Network Load Balancer target group with the UDP protocol on port 9999.
Selecting the incorrect protocol (such as TCP) will prevent the NLB from properly routing the incoming UDP market data streams.
3
Determine the correct health check configuration for the target group.
Because the health monitoring daemon runs on TCP port 8080, the health check configuration must be overridden to TCP port 8080.
Leaving the health check on the default traffic port would cause the NLB to attempt to query UDP port 9999, which does not run the health service and would cause the NLB to mark all healthy instances as unhealthy.

Key Concept

High-performance EC2 networking using cluster placement groups combined with Network Load Balancer target group health check port overrides for non-standard port applications.
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High-Performing and Elastic Compute Solutions

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