Chapter 1 : Overview
Tutorial For Cloud Native Development with use case of Building SaaS Multitenant using Enterprise Microservices and Tenant Specific Customizations.
Cloud Native Development Tutorial
Tutorial Contents
Tutorial will cover below microservices development:
- Enterprise Microservices Development
- Enterprise Microservices
- Build Main Product Microservices V1
- Synchronous Communications Based Microservices
- Using REST WebClient and Helper Microservices
- Synchronous Communications Based Microservices
- SaaS Multitenant
- Extend Enterprise Microservices
- Extend Main Product Microservices V2
- with Tenant Manager Customization Services
- Extend Main Product Microservices V2
- Tenant Specific Customization Using Microservices
- Synchronous Communications Based Customization Using Microservices
- Using REST WebClient and Tenant-specific Microservices
- Event-Based Customization Using Microservices
- Using Kafka Events and Tenant-specific Microservices
- Synchronous Communications Based Customization Using Microservices
- Extend Enterprise Microservices
- BFF Backend For Frontend
Microservices Tech Stack
Tech Stack: Java 17 Spring Boot 3 Database: PostgreSQL Ver 8.2+ API Type: REST
Use Case - Ordering System - Enterprise SaaS Multitenant
Sample Tables
Enteprise microservices sample table SQLs.
- Sample Enteprise Microservices Tables SQL - For MySQL
- Sample Enteprise Microservices Tables SQL - For PostgreSQL
Tables in SQL script
- customer
- tenant
- product
- inventory
- orders
- shipping
SaaS Multitenant
Building SaaS Multitenant using Enterprise Microservices and Tenant Specific Customizations
Software Requirements Specification
User Stories
- Main Product V1 Features
| Feature | Service | Input | Output |
|---|---|---|---|
| Create Order | order-service-v1 | customerId, tenantId, productId, orderQuantity | orderId, orderStatus |
| ↓ → Call Check Inventory Quantity exists for Order fullfillment | inventory-quantity-check-service | productId, orderQuantity | quantityAvailable (true/false) |
- inventory-quantity-check-service
- If quantity available, deduct quantity from inventory and write LOG entry
- Inventory Consumption: productId: 2, orderQuantity: 10
- Main Product V2 Features Plus
- Tenant Specific Customization
| Feature | Service | Input | Output |
|---|---|---|---|
| Create Order and Handle Tenant Customizations, if any | order-service-v2 | customerId, tenantId, productId, orderQuantity | orderId, orderStatus |
| ↓ → Call Check Inventory Quantity exists for Order fullfillment | inventory-quantity-check-service | productId, orderQuantity | quantityAvailable (true/false) |
| ↓ → Call Check Tenant Specific Customizations | tenant-manager-cust-service | customerId, tenantId, productId, orderId, orderQuantity | orderId, orderStatus |
| ↓ → If Tenant 2, call - Check orderQuantity is > 5 | tenant-2-validation-service | orderQuantity | validationPass (true/false) |
| ↓ → If Tenant 3, send order event, which shipping service will consume and create shipping entry | customerId, tenantId, productId, orderQuantity | order event sent | |
| Shipping service will poll for and consume order event, then will create shipping entry | tenant-3-shipping-service | order event ( customerId, tenantId, productId, orderQuantity) | shippingId (shipping entry) |
- tenant-3-shipping-service
- Upon creating shipping entry, write LOG entry
- Order Event Consumed : customerId: 1, tenantId: 2, productId: 2, orderId: 3
- Shipping Created : shippingId: 2
Enterprise Microservices Design
Microservices for BFF Backend For Frontend
| Services | Backend Project | Port | |
|---|---|---|---|
| BFF | emapi-BFF-service | emapi-BFF | 9060 |
Microservices for Main Product and Customizations
- Architecture Model
| Product | Service | Service | |||||
|---|---|---|---|---|---|---|---|
| Main Product | [ Order Service ] | → ← | sync | → ← | [ inventory-quantity-check-service ] | ||
| ↑ ↓ sync | |||||||
| Tenant Customization | [ Tenant Manager ] [ + Customization Service ] | → ← | sync | → ← | [ tenant-2-validation-service ] | ||
| ↓ →→→ | → | event message queue | → | [ tenant-3-shipping-service ] |
- Microservices Details
| Services | Backend Project | Port | |
|---|---|---|---|
| Main Product | order-service-v1 | emapi-order-svc-v1 | 9070 |
| inventory-quantity-check-service | emapi-inv-check-svc | 9072 | |
| Tenant Customization | order-service-v2 | emapi-order-svc-v2 | 9070 |
| tenant-manager-cust-service | emapi-tenant-mgr-cust-svc | 9074 | |
| tenant-2-validation-service | emapi-tenant-2-svc | 9076 | |
| tenant-3-shipping-service | emapi-tenant-3-svc | 9078 |
Microservices Communications
Microservices Communicate With Details
| Services | Port | Communication Mode | With Service | Port | |
|---|---|---|---|---|---|
| Main Product | order-service-v1 | 9070 | synchronous-webclient | inventory-quantity-check-service | 9072 |
| Tenant Customization | order-service-v2 | 9070 | synchronous-webclient | tenant-manager-cust-service | 9074 |
| tenant-manager-cust-service | 9074 | synchronous-webclient | tenant-2-validation-service | 9076 | |
| tenant-manager-cust-service | 9074 | asynchronous-event | tenant-3-shipping-service | 9078 |
Considerations
- Enterprise Microservices can be developed with low code customizations after using EasyManage Builder and generating code.
- Security is skipped for tutorial purposes
- Frontend Flutter app can be used for providing mobile app
- BFF Backend For Frontend for mobile app is directly available after code generation.
- The code generated from EasyManage can be cleaned, leaving what is required for the microservices, as by default generated code contains lot more features and GraphQL APIs also.