21 Distributed Computing Interview Questions and Answers (2024)

Blog / 21 Distributed Computing Interview Questions and Answers (2024)
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Distributed computing is a fundamental paradigm all devs should know.

Distributed computing relates to implementing systems where computation is spread across multiple machines or nodes.

This field has exponentially grown in popularity due to the rise of large volume of traffic and data companies are expected to be able to handle.

This blog will help you understand the key concepts within distributed computing and make sure you're prepared for whatever the interviewer asks you.

Q1.

What is distributed computing, and why is it important?

Junior
  • Distributed computing is a field of computer science that deals with designing and implementing systems where computation is spread across multiple machines or nodes.
  • It's important because it allows for improved scalability, fault tolerance, and performance in large-scale applications.
Q2.

Explain the CAP theorem and its implications for distributed systems.

Junior
  • The CAP theorem states that a distributed system can only guarantee two out of these three properties at any given time:
    • Consistency: All nodes see the same data at the same time.
    • Availability: Every request receives a response without guaranteeing it contains the most recent version of the data.
    • Partition tolerance: The system continues to operate despite network partitions). In distributed systems, you must make trade-offs among these properties.
Q3.

What is the difference between synchronous and asynchronous communication in distributed systems?

Junior
  • Synchronous communication requires all parties to be active and available at the same time, while asynchronous communication allows messages to be sent and received independently of each other.
  • Asynchronous communication is often preferred in distributed systems because it provides better scalability and fault tolerance.
Q4.

What is the purpose of a distributed database?

Junior
  • The purpose of a distributed database is to store data across multiple physical locations, often spread over various networked computers or nodes, to improve data access, reliability, scalability, and potentially performance. It aims to make the distribution transparent to the user, offering a single-system view.
Q5.

Explain the concept of sharding in distributed databases.

Junior
  • Sharding in distributed databases is a technique where a large database is divided into smaller, more manageable segments called "shards." Each shard is hosted on a separate database server, allowing the database to spread its load and store more data than a single server could handle.
  • Key points:
    • Data Distribution: Data is divided based on specific criteria like range, hash, or list values.
    • Independence: Each shard functions independently, enabling parallel processing and reducing server load.
    • Scalability: Sharding allows databases to scale horizontally by adding more shards on new servers as data grows.
    • Performance Enhancement: Distributing data across multiple servers can improve read and write operation speeds.
    • Challenges: Sharding increases complexity in data management and consistency, and in performing operations across shards.
    • Use Cases: Ideal for large datasets and high transaction volumes in applications like cloud computing and big data.

Don't Let One Question Ruin Your Interview...

Q6.

What is MapReduce, and how does it work in the context of distributed computing?

Mid
  • MapReduce is a model in distributed computing for processing large datasets. It consists of two phases:
    • Map Phase: Divides the input into smaller chunks, processes each chunk, and produces intermediate key-value pairs.
    • Reduce Phase: Aggregates these intermediate outputs by key to generate the final result.
  • This model allows for efficient, parallel processing across multiple nodes, making it suitable for tasks like data filtering and aggregation in big data applications.
  • MapReduce handles data distribution, parallelization, and fault tolerance, enabling scalability and robustness in distributed environments.
Q7.

Explain the concept of distributed caching and its benefits in distributed systems.

Mid
  • Distributed caching is a method where data is stored across multiple servers in a distributed system, allowing for efficient access to frequently used information. It reduces the load on the primary data store and speeds up data retrieval by keeping data closer to the application in use.
  • Benefits include improved performance, reduced latency, and enhanced scalability.
Q8.

What are microservices, and how do they differ from monolithic architectures in distributed systems?

Mid
  • Microservices are a distributed systems architecture where applications are divided into small, independent services, each performing a specific function.
  • They differ from monolithic architectures, where all functions are integrated into a single, indivisible unit.
  • Microservices offer easier scalability, flexibility, and faster deployment, while monolithic architectures are simpler to develop and deploy initially but can become complex and unwieldy as they grow.
Q9.

Explain the concept of eventual consistency in distributed databases.

Mid
  • Eventual consistency is a consistency model in which a distributed system guarantees that, if no new updates are made to a given data item, eventually all accesses to that item will return the same value.
  • It allows for performance and availability in distributed systems but may result in temporary inconsistencies.
Q10.

What is a distributed lock, and why is it important in distributed systems?

Mid
  • A distributed lock is a synchronization mechanism that allows multiple processes or nodes in a distributed system to coordinate access to shared resources.
  • It's important for preventing race conditions, ensuring data consistency, and maintaining correctness in distributed systems.
  • A real-world example of a distributed lock is in an online banking system. Suppose two people are trying to transfer money from a joint account at the same time. The system uses a distributed lock to ensure that only one transfer processes at a time.
Q11.

Explain the concept of distributed consensus and the role of algorithms like Paxos and Raft.

Mid
  • Distributed consensus in computing is about ensuring multiple nodes in a distributed system agree on a single data value or event sequence, crucial for consistency and coordination.
  • Algorithms:
    • Paxos, known for its reliability but complex implementation, involves multiple rounds of communication to achieve consensus.
    • Raft, aimed at simplicity and easier implementation, breaks down the consensus process into leader election, log replication, and safety.
    • Both are essential for data replication, database consistency, and state management in distributed systems, especially in environments with potential node failures or unreliable communications.
Q12.

Explain the concept of leader election in distributed systems and its role in fault tolerance.

Mid
  • Leader election in distributed systems is a process where nodes elect a 'leader' to coordinate actions and decisions. This mechanism is crucial for fault tolerance as it provides a single point of coordination, ensuring system consistency and reliability.
  • In case of a leader node's failure, a new election ensures minimal disruption and continuous operation. Leader election also aids in load balancing and recovery, enhancing the system's resilience and stability.
Q13.

Explain the concept of the Two-Phase Commit (2PC) protocol and its use in distributed transaction management.

Mid
  • The Two-Phase Commit protocol is used to achieve distributed transaction consistency in a distributed database. It works by coordinating a commit decision across multiple participating nodes or databases.
    • In the first phase, all nodes vote on whether to commit or abort.
    • In the second phase, they carry out the decided action.
  • 2PC ensures that either all nodes commit or all abort, preventing partial commits.
Q14.

Explain the concept of distributed tracing and its importance in monitoring and debugging microservices architectures.

Mid
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Q15.

Explain the concept of data locality in distributed computing.

Mid
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Q16.

Explain the concept of distributed scheduling.

Senior
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Q17.

What is the purpose of a distributed lock manager (DLM) in distributed systems?

Senior
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Q18.

What is the purpose of a distributed task queue in distributed systems?

Senior
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Q19.

What is the role of ZooKeeper in distributed systems?

Senior
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Q20.

Explain the concept of distributed pub-sub (publish-subscribe) messaging systems and their use in event-driven architectures.

Senior
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Q21.

Explain the concept of vector clocks in distributed systems and how they help in determining causality among events.

Senior
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