Gyanrush
Start freeOpen Gyanrush
Start freeOpen Gyanrush
  1. LPU MCA Semester 1
  2. CAP470
  3. Unit 2

CAP470 · Unit 2: Cloud computing architecture

Cloud infrastructure performance, networking and resource management

10 practice questions · in the MTE and ETE syllabus

Practise this topicPractise this topic

Key points

  • Latency is delay, bandwidth is capacity
  • 99.9 percent availability allows about 43 minutes a month
  • Load balancers and auto-scaling manage demand
  • CDNs reduce latency by caching near users

Key performance measures are latency (delay before a response begins, in milliseconds), bandwidth (maximum data rate of a link), throughput (data actually delivered per second) and availability (percentage of time a service is up).

An SLA (service level agreement) states promised targets and remedies, such as service credits. Downtime allowed per 30-day month (43,200 minutes): 99 percent about 7.2 hours, 99.9 percent about 43 minutes, 99.99 percent about 4.3 minutes.

Resource management techniques:

  • Load balancing spreads requests across servers.
  • Auto-scaling adds and removes capacity with demand.
  • Provisioning can be static (fixed) or dynamic (on demand).
  • CDNs cache content at edge locations near users to cut latency.
  • Over-provisioning wastes money, while under-provisioning hurts performance.

Networking in clouds relies on virtual networks, subnets and software-defined networking (SDN).

Exam trap: high bandwidth does not guarantee low latency, because distance and routing add delay.

Try two questions

Question 1 · Tier 2, Understand

What is an SLA in cloud computing?

  1. A software license activation key tied to one single machine only
  2. A contract stating promised performance and uptime
  3. A storage layer allocation table for the disk blocks of a volume
  4. A secure login assertion used for signing on to a remote account
Show the answer

B. An SLA states measurable service targets such as uptime and the remedies if they are missed.

Why not A: An SLA is a contract about service, not a license key.

Why not C: That is a storage concept, not an SLA.

Why not D: That is an authentication mechanism, not an SLA.

Question 2 · Tier 4, Analyse

Why is resource over-provisioning a problem in the cloud?

  1. It makes the provider remove all of the customer's data
  2. It wastes money on capacity that is not used
  3. It stops virtual machines from ever starting
  4. It increases network latency to the nearest router
Show the answer

B. Provisioning more than needed means paying for idle resources.

Why not A: Over-provisioning does not cause data removal.

Why not C: Over-provisioned machines still start.

Why not D: Idle capacity does not change latency.