Julia's coding blog - Practice makes perfect

From January 2015, she started to practice leetcode questions; she trains herself to stay focus, develops "muscle" memory when she practices those questions one by one. 2015年初, Julia开始参与做Leetcode, 开通自己第一个博客. 刷Leet code的题目, 她看了很多的代码, 每个人那学一点, 也开通Github, 发表自己的代码, 尝试写自己的一些体会. She learns from her favorite sports – tennis, 10,000 serves practice builds up good memory for a great serve. Just keep going. Hard work beats talent when talent fails to work hard.

Wednesday, April 28, 2021

System design: What is Amazon VPC?

What is Amazon VPC?

Amazon Virtual Private Cloud (Amazon VPC) enables you to launch AWS resources into a virtual network that you've defined. This virtual network closely resembles a traditional network that you'd operate in your own data center, with the benefits of using the scalable infrastructure of AWS.

Amazon VPC concepts

Amazon VPC is the networking layer for Amazon EC2. If you're new to Amazon EC2, see What is Amazon EC2? in the Amazon EC2 User Guide for Linux Instances to get a brief overview.

The following are the key concepts for VPCs:

Virtual private cloud (VPC) — A virtual network dedicated to your AWS account.
Subnet — A range of IP addresses in your VPC.
Route table — A set of rules, called routes, that are used to determine where network traffic is directed.
Internet gateway — A gateway that you attach to your VPC to enable communication between resources in your VPC and the internet.
VPC endpoint — Enables you to privately connect your VPC to supported AWS services and VPC endpoint services powered by PrivateLink without requiring an internet gateway, NAT device, VPN connection, or AWS Direct Connect connection. Instances in your VPC do not require public IP addresses to communicate with resources in the service. Traffic between your VPC and the other service does not leave the Amazon network. For more information, see AWS PrivateLink and VPC endpoints.
CIDR block —Classless Inter-Domain Routing. An internet protocol address allocation and route aggregation methodology. For more information, see Classless Inter-Domain Routing in Wikipedia.

Accessing Amazon VPC

You can create, access, and manage your VPCs using any of the following interfaces:

AWS Management Console — Provides a web interface that you can use to access your VPCs.
AWS Command Line Interface (AWS CLI) — Provides commands for a broad set of AWS services, including Amazon VPC, and is supported on Windows, Mac, and Linux. For more information, see AWS Command Line Interface.
AWS SDKs — Provides language-specific APIs and takes care of many of the connection details, such as calculating signatures, handling request retries, and error handling. For more information, see AWS SDKs.
Query API — Provides low-level API actions that you call using HTTPS requests. Using the Query API is the most direct way to access Amazon VPC, but it requires that your application handle low-level details such as generating the hash to sign the request, and error handling. For more information, see the Amazon EC2 API Reference.