为何Redis选择单线程而非多线程架构？

Classic Load Balancers (v1)

Supports TCP (Layer 4), HTTP & HTTPS (Layer 7)

Health checks are TCP or HTTP based

Fixed hostname XXX.region.elb.amazonaws.com

AWS Classic Load Balancer

Application Load Balancer (v2)

Application load balancers is Layer 7 (HTTP)

Load balancing to multiple HTTP applications across machines (target groups)

Load balancing to multiple applications on the same machine (ex: containers)

Support for HTTP/2 and WebSocket

Supports redirects (from HTTP to HTTPS for example)

Routing tables to different target groups:

1. Routing base on path in URL (example.com/users & example.com/posts)
2. Routing base on hostname in URL (one.example.com & other.example.com)
3. Routing base on Query String, Headers (example.com/users?id=123&order=false)

ALB are a great fit for micro services & container-based application (example: Docker & Amazon ECS)

Has a port mapping feature to redirect to a dynamic port in ECS
In comparison, we’d need multiple Classic Load Balancer per application

ALB (v2) HTTP Based Traffic

AWS Application Load Balancer Traffic

ALB (v2) Target Groups

EC2 instances (can be managed by an Auto Scaling Group) - HTTP

ECS tasks (managed by ECS itself) - HTTP

Lambda functions - HTTP request is translated into a JSON event

IP Addresses - must be private IPs

ALB can route to multiple target groups

Health checks are at the target group level

AWS ALB Query Strings/Parameters Routing

Network Load Balancer (v2)

Network load balancers (Layer 4) allow to:

1. Forward TCP & UDP traffic to your instances
2. Handle millions of request per seconds
3. Less latency ~ 100ms (vs 400 ms for ALB)

NLB has one static IP per AZ, and supports assigning Elastic IP(helpful for whitelisting specific IP)

NLB are used for extreme performance, TCP or UDP traffic

Not included in the AWS free tier

Network Load Balancer (v2) TCP (Layer 4) Based Traffic

AWS NLB TCP Based Traffic

Network Load Balancer - Target Groups

EC2 instances

IP Addresses - must be private IPs

Application Load Balancer

Health Checks support the TCP, HTTP and HTTPS protocols

AWS Network Load Balancer Target Group

Gateway Load Balancer

Deploy, scale, and manage a fleet of 3rd party network virtual applications in AWS Example: Firewalls, Intrusion Detection and Prevention Systems, Deep Packet Inspect Inspection Systems, payload manipulation, …

Operates at Layer 3 (Network Layer) - IP Packages

Combines the following fuctions:

1. Transparent Network Gateway - single entry/exit for all traffic
2. Load Balancer - distributes traffic to your virtual applications
3. Uses the GENEVE protocol on port 6081

Gateway Load Balancer Network Layer (Layer 3) Based Traffic

AWS Gateway Load Balancer Traffic

Gateway Load Balancer - Target Group

EC2 instances

IP Addresses - must be private IPs

AWS Gateway Load Balancer Target Group