26. Design Ecommerce Product Listing

Chapter 1: Introduction to Ecommerce Product Listing Page

• Objective: Design a simple ecommerce product listing page for a small shop owner with up to 100 items.

• System Design Motive: Understand the structured approach to system design by taking small steps rather than massive leaps.

• Expected Features:

  • Owner can add, update, or delete products.

  • Customers can access the product catalog (payment features are excluded).

• Storage Requirements:

  • Total data is manageable since there are only 100 items.

  • Estimated payload for each item: 1 kilobyte, totaling up to 100 kilobytes of data.

  • Suitable to fit into a single database server.

• Database Choice:

  • Given the small size, a SQL database is recommended because of the structured nature of the data (title, description, etc.).

Chapter 2: Front End and Back End Separation

• HTTP Based Server: Expose APIs for data access.

• Load Balancer:

  • Multiple API servers are needed to handle potential high traffic, placed behind a load balancer (e.g., api.mystore.com).

  • Forms part of a classic 3-tier architecture: users, compute, and storage.

• Front End Development:

  • Essential for customer interface; uses standard front-end approaches for rendering catalog.

• Admin Interface:

  • Create a separate Admin UI for shop owners to manage inventory.

  • Separation prevents entanglement of user and admin interfaces to reduce bugs and enhance security.

Chapter 3: Facing Front End Service

• Admin UI Security: Separate admin interface is crucial as admin users have elevated privileges.

• Access Control: Ensure proper checks on API calls to verify admin privileges.

• Architecture Overview:

  • Front end interacts with back end, which communicates with the database.

  • A distinction is made for user-facing front end and admin functionalities to streamline operations and increase security.

Chapter 4: Handling High Read Load

• Backend Scaling:

  • Due to high read requests from numerous users, the backend must scale accordingly.

  • Load balancer in front of backend servers allows for additional instances during high traffic periods.

• Catalog Database Management:

  • Given read-heavy traffic, scalability is crucial.

  • A read replica setup manages excessive read requests:

    • Write requests handled by the master database.

    • Read requests can be distributed across master and replicas.

• Myth Buster: The master database can handle both reads and writes depending on frequency and load distribution.

Chapter 5: Managing Writes and Reads

• Write Operations: Admin UI writes occur less frequently (e.g., adding products).

• Connection Management:

  • Each API server connects to both the master and replica databases simultaneously.

  • Alternating read requests between master and replica to balance load effectively.

• Caching Considerations:

  • While caching can optimize reads, potential issues with cache invalidation can complicate the architecture.

  • Read replicas being easier to manage than caches here due to the simplicity of propagation of updates.

Chapter 6: Conclusion and Further Tasks

• Exercise:

  • DB Design: Create a database structure for the product catalog.

  • API Development: Build a simple backend with appropriate data handling.

  • Read Replication Setup: Implement two database connections and randomize read request distribution.

• Understanding Cache: Explore caching as an alternative while recognizing the complexities related to cache management.

• Reflection on Design Choices: The exercise encourages awareness of practical system design decisions and their implications on performance and reliability.

• This supports the understanding of structured system design in creating scalable, maintainable architectures suitable for small-scale ecommerce applications.