Cloud Application and Load Balancing

Question 1

Describe the client-server paradigm: Robust.

Answer 1

Robust:

• -errors do not propagate
• -the clients and the servers are independent modules and may fail separately

Question 2

Describe the client-server paradigm: Efficient.

Answer 2

Efficient:

• -Front end server dispatches jobs to multiple back-end server
• -Exploit elasticity of cloud computing

Question 3

Describe the client-server paradigm: Support for thin clients.

Answer 3

Support for thin clients:

–Heavy computation can be offloaded to servers, allowing clients to be as lightweight as possible.

Question 4

What are the three tier architecture that the backend uses (when dealing with how to architect a cloud application)?

Answer 4

Load balancing tier: Spreading out incoming requests on to application servers
Application tier: Processing and responding to incoming requests
Data tier: Caching and handling database requests

Question 5

What is load balancing?

Answer 5

Load balancing is simply the capability to balance trafic load across a group of devices. Maximises server/network throughput, minimises response time and avoids overload

Question 6

What is a load balancer?

Answer 6

Conceptually, server load balancers (SLBs) are the bridge between the servers and the network. They understand many higher-layer protocols and network protocols. check notes for diagram

Question 7

State and explain two load distribution methods.

Answer 7

Stateless load balancing: The load balancer uses some algorithms to distribute all the incoming traffic to available dervers but does not keep track of any individual session.

Stateful load balancing: The load balancer keeps track of state information for every session and makes load-balancing decisions for each session.

Question 8

What is vertical scaling?

Answer 8

Scale by adding more computation resources (e.g. more power CPU, RAM)

Question 9

What is horizontal scaling?

Answer 9

Scale by adding more machines (similar configuration)