Question 1

You are configuring the HCAs in your InfiniBand environment to maximize performance for a high-throughput, low-latency application. Which tuning parameter should you adjust on the HCA to reduce latency without causing packet loss?

Options :

A : Increase the MTU (Maximum Transmission Unit) to its highest supported value.

B : Decrease the MTU (Maximum Transmission Unit) to minimize the time it takes for small packets to be transmitted.

C : Adjust the Receive Queue Depth (RQD) to increase the ability to handle incoming traffic bursts.

D : Tune the SL (Service Level) to prioritize the application traffic over other traffic.

Answer: C

Question 2

Which of the following best describes how load balancing is achieved in an InfiniBand fabric using switches?

Options :

A : Load balancing is achieved by dynamically reassigning Local Identifiers (LIDs) to redistribute traffic across available ports.

B : Switches in an InfiniBand fabric use static routes for each connection, making load balancing impossible without manual reconfiguration.

C : InfiniBand switches use Adaptive Routing to dynamically select alternative paths based on real-time congestion information.

D : Load balancing is managed by the Host Channel Adapters (HCAs), and switches play no role in traffic distribution.

Answer: C

Question 3

You are configuring an InfiniBand fabric to optimize high-throughput, low-latency communication for a large-scale HPC cluster. Which advanced InfiniBand feature allows you to ensure traffic prioritization and reduce congestion for critical workloads?

Options :

A : Multipathing (MPIO)

B : Adaptive Routing (AR)

C : Credit-Based Flow Control

D : Service Level (SL) to Virtual Lane (VL) Mapping

Answer: D

Question 4

In an InfiniBand fabric, you are tasked with designing a QoS policy using Virtual Lanes (VLs) to segregate traffic types. Which of the following best describes how VLs should be configured for optimal traffic management?

Options :

A : Use only two Virtual Lanes: one for high-priority traffic and one for low-priority traffic, as InfiniBand guarantees low latency for all traffic.

B : Assign a separate VL for each traffic type, ensuring that critical traffic such as management traffic is isolated from application data traffic.

C : Use a single Virtual Lane (VL) for all traffic types to reduce configuration overhead and complexity.

D : Assign bandwidth-heavy traffic and latency-sensitive traffic to the same VL to maximize network resource utilization.

Answer: B

Question 5

You are configuring an InfiniBand-based high-performance computing (HPC) cluster for a scientific simulation workload that requires low latency and high throughput communication between nodes. The application is designed to leverage RDMA (Remote Direct Memory Access) to bypass the CPU and improve data transfer efficiency. You notice that while the latency is low, the throughput is not meeting expected levels. Which of the following is the most effective method to optimize RDMA performance for this application?

Options :

A : Enable CPU coalescing to allow RDMA to use more CPU resources

B : Ensure proper alignment of memory buffers to cache lines.

C : Increase MTU size on InfiniBand network interfaces

D : Disable flow control mechanisms for RDMA transfers

Answer: B