Multi-Tenant Architecture

1. Introduction

Multi-Tenant Architecture is a software architecture pattern where a single instance of a software application serves multiple tenants. A tenant represents a group of users who share common access with specific privileges to the software instance.

2. Key Concepts

• **Tenant**: A group of users sharing common access and privileges.
• **Isolation**: Mechanism to separate tenant data and resources.
• **Scalability**: Ability to efficiently support a growing number of tenants.
• **Resource Allocation**: Strategy to allocate resources among tenants based on their needs.

3. Types of Multi-Tenant Architectures

1. **Database-per-tenant**: Each tenant has its own database.
2. **Schema-per-tenant**: All tenants share the same database but have separate schemas.
3. **Table-per-tenant**: All tenants share the same database and schema, but their data is stored in separate tables.
4. **Shared Database**: All tenants share the same database and schema with shared tables, using a tenant identifier for data differentiation.

4. Design Principles

• **Data Isolation**: Ensure that data from different tenants is isolated to prevent unauthorized access.
• **Performance Optimization**: Design for performance and resource optimization across tenants.
• **Customizability**: Allow tenants to customize their experience without affecting others.
• **Monitoring and Logging**: Implement robust monitoring for performance and security across different tenant operations.

5. Best Practices

• **Use a Strong Authentication Mechanism**: Implement strong authentication methods to safeguard tenant data.
• **Implement Rate Limiting**: Protect against abuse by implementing rate limits per tenant.
• **Data Encryption**: Use encryption for both data at rest and data in transit.
• **Regular Audits**: Conduct regular security audits and compliance checks to ensure the architecture remains secure.

6. Code Example

Here’s a simple example of how to implement a basic multi-tenant architecture in Node.js using Express and a shared database approach.

const express = require('express');
const app = express();
const mongoose = require('mongoose');

mongoose.connect('mongodb://localhost:27017/myapp', { useNewUrlParser: true, useUnifiedTopology: true });

const tenantSchema = new mongoose.Schema({
    name: String,
    data: Object,
    tenantId: String
});

const Tenant = mongoose.model('Tenant', tenantSchema);

app.get('/tenant/:tenantId/data', async (req, res) => {
    const { tenantId } = req.params;
    const tenantData = await Tenant.find({ tenantId });
    res.json(tenantData);
});

app.listen(3000, () => {
    console.log('Server running on port 3000');
});
            

7. FAQ