VMware vSphere 7.x Advanced Design (VCAP-DCV Design 2021) — Question 11

An architect is tasked with reviewing the design of a VMware software-defined data center (SDDC) for a software development company. The platform is used to developing applications and services. It is important that the customer be able to accurately benchmark performance of developed applications.
The platform has recently commissioned new hosts to update the development cluster.
The development cluster host configuration is:
✑ 4 ESXi hosts with 2 sockets ֳ— 16 cores
✑ 512 GB RAM divided evenly between sockets
✑ There is no resource contention
The benchmarking cluster host configuration is:
✑ 8 ESXi hosts with 2 sockets ֳ— 8 cores
✑ 256 GB RAM divided evenly between sockets
✑ There is no resource contention
The customer is developing an application that includes a database virtual machine. The application developer states that the database virtual machine performs as required only when allocated 8 vCPUs 256 GB RAM. The database virtual machine performance meets the required levels when run from the development cluster. Performance benchmarking for the database virtual machine yields highly variable results when run from the benchmarking cluster. The application cannot be released without reliable performance benchmarking data.
What is a possible reason for the difference in performance test results between the development and benchmarking clusters?

Answer options

Correct answer: A

Explanation

The correct answer is A because the benchmarking cluster's configuration may cause the database virtual machine to span multiple NUMA nodes, leading to performance degradation due to increased latency in memory access. Option B is incorrect as the development cluster allows for optimal NUMA node usage. Option C does not apply as both clusters do not have resource contention. Option D is also not the main issue since the benchmarking cluster has sufficient RAM, but the NUMA architecture is impacting performance.