AWS
Table of Contents
AWS stands of Amazon Web Service. It offer broad range of cloud services.
Traditional vs Serverless Web hosting⌗
| Traditional | Serverless |
|---|---|
| Provision Capacity | Runs On-Demand (unlimited capacity Only pay for Code Executions) |
| Scaling (Pay too much or server issues) | Scales Automatically (Pay What you need) |
| Update OS & Software | Runs on Managed AWS Infrastructure (up-to-date and secure environment) |
| Lots of Overhead for SPA + API Apps | Great for SPA + API Apps |
API Gateway (REST API)⌗
API Gateway is fully managed service that allows you to easily create, publish, maintain, monitor, secure API’s at any scale. An API, acts as a “front door” for applications to access data, functionality, or business logic from your backend services like servers, databases or lambda.
Things API Gateway can do:
- Create RESTful API’s and WebSockets API’s
- Integration with backend services: API Gateway can route API requests to various backend services like AWS Lambda functions, Amazon EC2 instances, or other web apps.
- Manage Traffic: API Gateway handles tasks like traffic management, throttling to limit requests, and Cross-Origin Resource Sharing (CORS) for secure communication between different domains.
- Secure API’s: API Gateway helps us to secure APIs with features like IAM authorization and access control.
- Monitor API’s: API Gateway provides metrics and logging to help you monitor the health and performance of our API’s.
Lambda (LOGIC)⌗
It’s designed to let us run our code without having to worry about provisioning or managing servers yourself.
- Serverless: We don’t need to set up or manage servers. AWS Lambda takes care of all the underlying infrastructure, so we can focus on writing code.
- Event-driven: Our code (packaged as Lambda function) executes in response to events. These events can be triggered by various AWS services like S3 file upload, API Gateway requests, or DynamoDB changes.
- Automatic Scaling: Lambda automatically scales our code up or down to handle the workload. We have to only pay for the compute time for our code.
- Cost-effective: Since we only pay for what we use, Lambda can be a cost-effective way to run code that doesn’t require constant uptime.
- Supported languages: Java, Go, Node.js, C#, Python, Ruby and PowerShell
DynamoDB (DATA)⌗
It is fully managed NoSQL database provided by AWS. It is key-value database similar to mongoDB. It does not support SQL queries. Instead, it uses a propritetary API based on JSON. This API is generally not called directly by user developers, but invoked through AWS SDKs.
DynamoDB is primarily a key-value store in the sense that its data model consists of key-value pairs in a schemaless, very large, non relational table of rows (records). It does not support RDBMS methods to join tables through foreign keys. It can also support a document store data model using JSON.
Data Structure:
- Keys :- partition key is key (eg. UserID) and we store value against that partion key. eg. { UserID : firstName }. So here UserID is partition key and firstName is attribute. Partition key should be unique.
Note: why is it call partition key? DynamoDB stores data in fleet of SSD and it try to store data effectively by partitioning it over SSDs.
Partition key + sort key Instead just using partition key as primary key dynamoDB gives option to use sort key. Using both partition and sort key we can get new primary key. So when we have same key we can use sort key (timestamp) this gives us primary key.
- Attributes :- Attributes are the values stored against the partition key(key).
- Indexes :-
- Global Secondary Indexes: Some application might need to perform many kinds of queries, using a variety of different attributes as query criteria. We can set 5 of this per table.