Characterisation of Distributed Systems (Revision)

Question 1

What is a Distributed System?

Answer 1

A Distributed System is a system where HW/SW components located in networked computers coordinate and communicate their actions via message passing.

Question 2

What are the 3 Inherent Characteristics of a Distributed System?

Answer 2

-Concurrency
-No global clock
-Independent Failures

Question 3

Why do we need Distributed Systems?

Answer 3

-To share resources
-To have redundancy
-To parallelize computation

Question 4

What are the Current Trends in DS?

Answer 4

-Cloud computing
-Fog computing
-Edge computing
-IoT networking
-BigData
-Decentralized networks

Question 5

What are the 7 Challenges in DS?

Answer 5

1. Heterogeneity: might have different OS, programming languages, and HW/SW components. Middleware is a software layer that provides abstraction as well as masking heterogeneity of the underlying components.
2. Openness: An open system can be extended and reimplemented in various ways.
3. Transparency: Hide the complexity of components from the user.
4. QoS: Needs to ensure system is able to meet requirements/deadlines.
5. Failure Handling: Detect Failures, Mask Failures, Tolerate Failures, Recover from failure.
6. Scalability: A system is scalable if it can remain effective while the number of resources or users goes up.
7. Concurrency: Serialize access or allow for concurrent accesses .