/j2ee-core-patterns

Random Java Enterprise Patterns

Step 1: Outline use cases, constraints, and assumptions

Gather requirements and scope the problem. Ask questions to clarify use cases and constraints. Discuss assumptions.

  • Who is going to use it?
  • How are they going to use it?
  • How many users are there?
  • What does the system do?
  • What are the inputs and outputs of the system?
  • How much data do we expect to handle?
  • How many requests per second do we expect?
  • What is the expected read to write ratio?

Step 2: Create a high level design

Outline a high level design with all important components.

  • Sketch the main components and connections
  • Justify your ideas

Step 3: Design core components

Dive into details for each core component.

  • Generating and storing a hash of the full url
    • [MD5] [Base62]
    • Hash collisions
    • SQL or NoSQL
    • Database schema
  • Translating a hashed url to the full url
    • Database lookup
  • API and object-oriented design

Step 4: Scale the design

Identify and address bottlenecks, given the constraints. For example, do you need the following to address scalability issues?

  • Load balancer
  • Horizontal scaling
  • Caching
  • Database sharding
  • Discuss potential solutions and trade-offs. Everything is a trade-off.