Distributed file systems in HLD - Practice Problems & Coding Challenges

Challenge - 5 Problems

❓ Architecture

intermediate

Identify the main components in a distributed file system architecture

Which of the following options correctly lists the essential components of a typical distributed file system?

A Client nodes, Metadata server, Storage nodes, Network communication layer

B Client nodes, Single storage server, Local disk, Network switch

C User interface, Database server, Cache server, Load balancer

D Web server, Application server, Database server, Firewall

💡 Hint

Think about components that handle file metadata, actual file storage, and client access.

A distributed file system typically includes client nodes that request files, metadata servers that manage file information, storage nodes that hold the actual data, and a network layer to connect them all.

❓ scaling

intermediate

Scaling storage capacity in distributed file systems

You want to increase the storage capacity of a distributed file system without downtime. Which approach is most suitable?

A Increase client cache size to reduce storage needs

B Replace existing storage nodes with larger disks one by one, shutting down the system temporarily

C Compress all files to save space without adding hardware

D Add more storage nodes and update metadata servers to include them

💡 Hint

Consider how to add capacity while keeping the system available.

Adding storage nodes and updating metadata allows the system to grow without downtime. Replacing disks or compressing files may cause downtime or performance issues.

❓ tradeoff

advanced

Tradeoff between consistency and availability in distributed file systems

In a distributed file system, choosing strong consistency over availability means:

A The system always responds to requests, even if data might be outdated

B The system may reject some requests during network partitions to ensure data correctness

C The system duplicates data to multiple nodes without synchronization

D The system uses client-side caching exclusively to improve performance

💡 Hint

Think about what happens when parts of the system cannot communicate.

Strong consistency requires all nodes to agree on data before responding, so during network issues, some requests may be rejected to avoid stale data, sacrificing availability.

🧠 Conceptual

advanced

Understanding data replication strategies in distributed file systems

Which replication strategy ensures high availability and fault tolerance by storing multiple copies of data across different nodes?

A Single-node storage

B No replication

C Synchronous replication

D Local caching only

💡 Hint

Consider how data copies are kept consistent and available.

Synchronous replication stores multiple copies on different nodes and updates them simultaneously, ensuring availability and fault tolerance.

❓ estimation

expert

Estimating metadata server capacity for a large distributed file system

A distributed file system stores 1 billion files. Each file's metadata requires 1 KB of memory. If the metadata server has 256 GB of RAM, approximately how many metadata servers are needed to hold all metadata in memory?

A At least 4 metadata servers

B At least 256 metadata servers

C At least 1 metadata server

D At least 16 metadata servers

💡 Hint

Calculate total metadata size and divide by server RAM.

Total metadata size = 1 billion files * 1 KB = 1 TB. Each server has 256 GB RAM, so 1 TB / 256 GB = 4 servers needed.