COPY: Distributed Systems (3rd Edition) - Chapter 01: Introduction (Selected Slides)

Podcast

Play an AI-generated podcast conversation about this lesson

Questions and Answers

What is the primary characteristic of a distributed system according to the text?

A collection of centralized computing elements

A collection of nodes with a static set of neighbors

A single coherent system with a global clock

A collection of autonomous computing elements (correct)

What is the implication of each node having its own notion of time in a distributed system?

It requires a global clock to be implemented across the system

It leads to fundamental synchronization and coordination problems (correct)

It leads to improved synchronization and coordination between nodes

It is not a problem as long as the nodes communicate regularly

How do nodes in a distributed system typically communicate with each other?

Through a central server that manages all communications

By broadcasting messages to all other nodes in the system

By using a fully connected topology where each node can talk to any other node

By communicating only with their known neighbors (correct)

What is the relationship between the nodes in a distributed system?

The nodes are interdependent and must collaborate to appear as a single system Signup and view all the answers

What is the purpose of the 'overlay network' mentioned in the text?

To manage the dynamic set of neighbors that each node can communicate with Signup and view all the answers

What is the key challenge mentioned in the text regarding the collection of autonomous nodes in a distributed system?

Managing group membership and node authorization Signup and view all the answers

What is the main problem with applying replication according to the text?

Inconsistencies due to modifying one copy Signup and view all the answers

Why does always keeping copies consistent require global synchronization?

To ensure data integrity Signup and view all the answers

What does global synchronization on each modification preclude according to the text?

Large-scale solutions Signup and view all the answers

How can the need for global synchronization be reduced?

By tolerating inconsistencies Signup and view all the answers

What is highlighted as being application dependent in the text?

Tolerating inconsistencies Signup and view all the answers

Why does having multiple copies lead to inconsistencies?

"Always keeping copies consistent" Signup and view all the answers

What is the key characteristic of a distributed system that emphasizes the system operating the same way regardless of user interaction?

Distribution transparency Signup and view all the answers

Which of the following is NOT a well-known example of an overlay network?

Cloud computing platforms Signup and view all the answers

What is the primary role of middleware in distributed systems?

To provide a common interface for applications across different computers Signup and view all the answers

Which of the following is a key challenge in hiding partial failures in a distributed system?

The inevitability of some nodes failing at any given time Signup and view all the answers

Which of the following is NOT a characteristic of a structured overlay network?

Nodes have references to randomly selected other nodes Signup and view all the answers

What is the primary design goal of middleware in distributed systems?

To provide a common set of components and functions for applications Signup and view all the answers

Which of the following is NOT considered a component of scalability in distributed systems?

Processing power of individual nodes Signup and view all the answers

What is the main challenge that modern distributed systems still face today, according to the text?

Geographical and administrative scalability Signup and view all the answers

What is the typical solution used to address size scalability in distributed systems?

Deploying multiple powerful servers operating independently in parallel Signup and view all the answers

Which of the following is NOT a key component of scalability in distributed systems?

Reliability of individual nodes Signup and view all the answers

Why do many developers of modern distributed systems use the term scalable without clearly explaining why their system actually scales?

They have only accounted for size scalability, not geographical or administrative scalability Signup and view all the answers

What is one of the canonical examples of supporting resource sharing mentioned?

Peer-to-peer assisted multimedia streaming Signup and view all the answers

What does 'The network is the computer' refer to?

A concept by John Gage about cloud computing Signup and view all the answers

What is a type of distribution transparency discussed in the text?

Replication Signup and view all the answers

Why is full distribution transparency considered challenging according to the text?

Due to the practical impossibility of hiding network failures Signup and view all the answers

What is one of the disadvantages of full distribution transparency mentioned in the text?

Higher performance costs Signup and view all the answers

When dealing with users in different time zones, what aspect may favor exposing distribution according to the text?

Easing user understanding Signup and view all the answers

What cannot be hidden when aiming for full distribution transparency according to the text?

Communication latencies Signup and view all the answers

Why is distinguishing a slow computer from a failing one considered challenging according to the text?

'Slow' computers often mimic failure symptoms Signup and view all the answers

Study Notes

Distributed Systems

Primary characteristic: Loosely coupled, autonomous nodes that communicate and coordinate to achieve a common goal.
Implication of individual node time: Each node has its own notion of time, leading to potential inconsistencies and difficulties with synchronizing events across the system.
Node communication: Nodes typically communicate with each other through message passing over a network.
Node relationship: Nodes are interconnected and indirectly dependent on each other; they collectively form a single system.
Overlay Network purpose: Enhances communication and resource sharing among nodes, creating a separate virtual network structure on top of the underlying physical network.
Challenge with autonomous nodes: Ensuring consistent data and behavior across the system while maintaining independence.
Problem with replication: Maintaining consistency across all replicas of data, especially in the presence of failures or network issues.
Requirement for global synchronization: Ensuring that updates to replicated data are applied consistently across all nodes, necessitating a coordinated approach.
Preclusion of global synchronization: Precludes allowing changes to be made independently on different nodes, as it would require a global consensus to ensure consistency.
Reducing global synchronization: Employing techniques like optimistic concurrency control to manage data consistency without needing full global synchronization for every update.
Application dependency: The specific methods used for managing data consistency and handling failures are often dependent on the specific application's requirements and the nature of the distributed system.
Inconsistency due to multiple copies: Multiple copies of data can lead to inconsistencies if updates are not managed carefully, especially during failures or network partitions.
System operating independently of user interaction: A key character of a distributed system is that the system operates the same way regardless of user interaction, ensuring continuous and resilient operation.
Not a well-known example of an overlay network: Centralized social media platforms like Facebook or Twitter.
Middleware’s role: Provides abstractions and services to simplify the development and management of distributed applications.
Challenge in hiding partial failures: Determining which nodes are actually experiencing failures or network problems, as opposed to being temporarily unavailable due to network latency or other transient issues.
Not a characteristic of a structured overlay network: Decentralized and dynamic node placement, relying instead on predefined patterns or structures for node organization and communication.
Middleware’s design goal: Simplify application development and communication by handling the complexities of distributed environments.
Not a component of scalability in distributed systems: Network bandwidth.
Challenge modern systems face: Balancing scalability with consistency, availability, and fault tolerance.
Typical solution for size scalability: Scaling out by adding more nodes to the system.
Not a key component of scalability in distributed systems: Processing speed of a single node.
Use of 'scalable' without explanation: Many developers use the term without clearly explaining how their system actually handles size scalability, performance under load, or distribution of workload.
Canonical example of supporting resource sharing: File systems like Hadoop Distributed File System (HDFS) or Google File System (GFS) allow multiple nodes to access and share files.
'The network is the computer': Refers to the idea that distributed systems treat the network as a fundamental computational resource, leveraging its capabilities for data storage, processing, and communication.
Type of distribution transparency: Location transparency, where applications can access resources without knowing their physical location.
Challenge with full distribution transparency: Requires complex mechanisms to hide the complexities of the distributed system, including network communication, failure handling, and data consistency.
Disadvantage of full distribution transparency: Can lead to performance overheads and complicate debugging, as the underlying distributed nature of the system is hidden from developers and users.
Exposure of distribution when dealing with time zones: May benefit from exposing the distribution of the system, allowing users to understand the time difference when interacting with resources in different locations.
Cannot be hidden when aiming for full distribution transparency: Failures, as they are a fundamental aspect of distributed systems and cannot be completely masked from the system's operation.
Challenge in distinguishing slow computers from failing ones: Requires sophisticated mechanisms to monitor and diagnose node performance, making it difficult to determine if a slow response is due to a temporary network issue or a real node failure.

Studying That Suits You

Use AI to generate personalized quizzes and flashcards to suit your learning preferences.

Description

Test your knowledge on the introduction to distributed systems based on selected slides from the 3rd edition of the book 'Distributed Systems' by M. van Steen and A. S. Tanenbaum. Explore the definition and characteristic features of distributed systems.