execirse-carparkinglot

An execirse for finding nearest available car park locations

Coding approach

There are 2 approaches

- Query/Write in same database
    Pros 
        Easy to implement
    Cons
        Limitted in number of databases that support geospatial query
        Bottleneck in DB when high volume of query

- CQRS pattern, Write in DB and Query in other place
    Pros
        Optimize for query
        Flexible in choosing database
    Cons
        More efforts to implement

Decision:

Follow the Clean Architecture guideline

Apply CQRS pattern

• Postgresql for Command
• Redis for Query

All data will be stored in Postgresql, whenever a task to get car parks availability is done, populate data to Redis for querying

• Pros

  • High throughput
  • Redis could be leveraged to cache other data

• Cons

  • Resource for Redis server
  • Data in cache have to be populated periodically

Local setup

Java 17 , Maven 3.9.2

How to run

1. Clean and package project (make sure carparking-0.0.1-SNAPSHOT.jar exists in target folder)
2. Navigate to docker folder
3. Run command 'docker-compose up --build'

APIs

• Find nearest available car parks
  http://localhost:8080/carparks/nearest?latitude=1.3271974323385998&longitude=103.72106615550845&page=1&per_page=3
• Sync car parks availability info http://localhost:8080/carparks/availability-sync

Testing

Conducted manual test by myself

Does not have enough time to write unit test (spend too much time on design and clean code)