Distributed Systems

Generating unique ID seems to be a simple task, but it is not in a high-load distributed systems!

This topic consists of:

• Understanding the requirements and why it is a complicated task
• Possible solutions:
  • Multi-master replication
  • Universally unique identifier (UUID)
  • Ticket server
  • Twitter SNOWFLAKE approach (seems to be the best one!)
• Details:
  • Timestamp
  • Sequence number
• Other issues
  • Clock synchronization
  • Section length tuning
  • High availability

These items are disclosed in a very interesting Chapter 7 of the book:

Key-Value stores are the most basic but widely used data storages.

Design of key-value store consists of understanding the following topics:

• What do we want from key-value store?
• Single server key-value store
• DISTRIBUTED key-value store:
  • CAP theorem
  • Real-world trade-offs for distributed systems
• System components:
  • Data partition
  • Data replication
  • Consistency
  • Inconsistency resolution: Versioning
  • Handling all types of failures: Failure detection, Handling TEMPORARY failures, Handling PERMANENT failures, Handling data center outage
• System architecture diagram
• Write path
• Read path

These items are disclosed in a very interesting Chapter 6 of the book: