COA Performance Optimization 2

Question 1

Which Nova scheduler filter ensures instances are placed on hosts with sufficient free RAM before considering CPU and disk resources?

Accepted Answer

RamFilter

Answer

RamFilter is applied first in the default scheduler filter chain to ensure hosts meet the instance's RAM requirements.

Question 2

What is the recommended Ceph client-side caching mode for OpenStack Cinder volumes to maximize write performance while maintaining data integrity?

Accepted Answer

writeback

Answer

Writeback mode caches writes locally before flushing to Ceph, providing the best write performance while the OSDs still ensure durability.

Question 3

Which parameter in nova.conf controls the maximum number of simultaneous live migrations per compute host?

Accepted Answer

max_concurrent_live_migrations

Answer

max_concurrent_live_migrations limits parallel live migrations per compute node to prevent network and CPU saturation.

Question 4

An OpenStack environment shows high latency on Neutron API calls. Which component should be scaled horizontally first to address this?

Accepted Answer

neutron-server

Answer

neutron-server handles all API requests and is the primary bottleneck for API latency; scaling it horizontally behind a load balancer reduces response times.

Question 5

Which Oslo messaging transport protocol offers the lowest latency for RPC calls between OpenStack services?

Accepted Answer

ZeroMQ

Answer

ZeroMQ (zmq) eliminates the broker entirely, resulting in the lowest RPC latency for direct service-to-service communication.

(COA) Certified OpenStack Administrator Exam Practice Test

(COA) Certified OpenStack Administrator Exam Practice Test

COA Performance Optimization 2