Practice Test Geeks(COA) Certified OpenStack Administrator Exam Practice Test
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Performance Optimization Flashcards

7 cards from real COA practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.

Read the first 7 Performance Optimization flashcards as text

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

    Answer: RamFilter

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

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

    Answer: writeback

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

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

    Answer: max_concurrent_live_migrations

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

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

    Answer: neutron-server

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

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

    Answer: ZeroMQ

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

  6. What does enabling 'reserved_host_memory_mb' in Nova accomplish for performance optimization?

    Answer: Reserves host RAM so the hypervisor and OS retain enough memory, preventing instance scheduling on overloaded hosts

    reserved_host_memory_mb subtracts a fixed amount from the host's reported available RAM so Nova won't overcommit the hypervisor OS itself.

  7. Which Keystone token provider type has the best performance for large-scale deployments because it requires no database lookup on validation?

    Answer: fernet

    Fernet tokens are cryptographically self-contained, so Keystone can validate them without a database round-trip, dramatically reducing validation latency.