Serverless Computing

Definition

Serverless computing is a cloud computing execution model where the cloud provider dynamically manages the allocation and provisioning of servers. Developers write and deploy code without worrying about the underlying infrastructure, which is automatically scaled by the provider.

Key Characteristics

1. No Server Management: Developers don't need to provision or maintain servers

2. Event-Driven: Functions are executed in response to events or triggers

3. Automatic Scaling: Resources scale up or down automatically with demand

4. Pay per use Billing: Customers pay only for the compute time consumed

5. Stateless: Functions are typically stateless (though some providers offer stateful options)

How It Works

1. Developer writes function code

2. Code is uploaded to a serverless platform

3. Platform provider handles:

• Infrastructure provisioning

• Operating system maintenance

• Capacity planning

• Scaling

• Logging and monitoring

4. Function executes when triggered by an event

5. Resources are automatically deallocated when not in use

Common Use Cases

• Web Applications: Backend APIs and microservices

• Data Processing: Real time file/stream processing

• IoT Applications: Handling device events and data

• Chatbots: Processing natural language requests

• Scheduled Tasks: Cron like jobs

• Automation: Business process automation

Benefits

1. Reduced Operational Complexity: No server management required

2. Cost Efficiency: Pay only for actual usage rather than pre provisioned capacity

3. Improved Scalability: Automatic scaling to handle variable workloads

4. Faster Time to Market: Developers can focus on code rather than infrastructure

5. High Availability: Built in fault tolerance and availability

Limitations

1. Cold Start Latency: Initial invocation may have delay

2. Execution Time Limits: Functions typically have maximum runtime limits

3. Vendor Lock in: Tight integration with provider's ecosystem

4. Debugging Challenges: Distributed nature makes debugging complex

5. Limited Control: Less control over runtime environment

Major Serverless Providers

1. AWS Lambda (Amazon Web Services)

2. Azure Functions (Microsoft Azure)

3. Google Cloud Functions (Google Cloud Platform)

4. IBM Cloud Functions (IBM Cloud)

5. Alibaba Cloud Function Compute (Alibaba Cloud)

6. Cloudflare Workers (Cloudflare)

Serverless Architecture Patterns

1. Function as a Service (FaaS): Core serverless pattern

2. Backend as a Service (BaaS): Cloud hosted backend services

3. Event Processing: Real time stream processing

4. Microservices: Decomposing applications into small functions

5. API Gateway Integration: Exposing functions via HTTP endpoints

Pricing Models

Serverless computing typically follows these pricing dimensions:

• Number of requests/executions

• Execution duration (rounded to nearest ms or 100ms)

• Allocated memory

• Optional features like provisioned concurrency