> For the complete documentation index, see [llms.txt](https://awsarch.adot8.com/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://awsarch.adot8.com/module-14.md).
# Module 14
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Oonuh wan fi deal wit nuh serva
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Using Microservices instead of full servers is much more efficient in regards to management and cost
Benefits:
* No server management
* Continuous scaling
* Pay-for-value services
* Built-in high availability
* Suitable for event-driven and microservice architectures
### AWS Serverless services
#### Example: Serverless Three-Tier Design
### Microservices
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Microservices are autonomous and specialized in their field
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#### Example of breaking down a big service into microservices
### Lambda
* Simply compute code for a simple task. Same thing as Azure Functions
* Can be event-driven and even layerd
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* No more than 15 minutes
* Workloads that use more than 10 GB of memory are not suitable for Lambda
* Containers can help migrate legacy applications
* The price to run a Lambda function increases with the number of invocations, duration, and memory allocated
* Containers can be continuously run at a fixed cost
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### AWS Step Functions
* Is a serverless orchestration service to manage workflows between multiple AWS services
* Has state machines (workflows) that contain a series of event-driven states (steps)
* Manages each workflow’s state, checkpoints, and restarts
* Provides error handling capability
* Can transfer data between states\\
* States can filter and manipulate data
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Just like python story games. Depending on the the action/result different functions will be executed. All start with the initial task
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Each one of these steps can be a Lambda function
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#### Use cases
### Amazon API Gateway
* Provides the ability to create, publish, and maintain REST, HTTP, and WebSocket APIs
* Configurable traffic management, authorization, and resource access control
* Provides access to AWS services and publicly accessible endpoints
* Hosts multiple versions and stages of an application’s API
* Establishes client usage plans to monetize and control APIs •Can cache common responses
#### Benefits
#### API Types
| Rest API's | HTTP API's | WebSocket API's |
| ------------------------------------------------------------------------------------------------------------------------------------ | ------------------------------------------- | ---------------------------------------------------------------------------- |
| Collection of routes and methods | Collection of routes and methods | Collection of WebSocket routes |
| For apps that require API management features, such as usage plans, payload validation, private API endpoints, and resource policies | For Microservices | For real-time applications |
| Supports cross-origin resource sharing (CORS | Suppors CORS | Establishes a session between client and backend services |
| Stateless | Lower latency and lower cost than REST APIs | API management features are validate payload schema and data transformations |
| | Stateless | Stateful |
### API Gateway Backend Integration
#### How a traditional application can be made better with Microservices and API Gateway
#### Shopping Cart
#### Payments
#### Delivery
