My Tech Blog (AWS)

1. Sticky Sessions (Session Affinity)고정 세션 또는 세션 밀접성It is possible to implement stickiness so that the same client is alwyas redirected to the same instance behind a load balancerThis works for Classic Load Balancers & Application Load BalancersThe "cookie" used for stickiness has an expiration date you control Use case: make sure the user doesn't lose his session dataEnabling stickiness may bri..

1. Gateway Load Balancer■ deploy, scale, and manage a fleet of 3rd party network virtual appliances in AWS배포 및 확장과 AWS의 타사 네트워크의 가상 어플라이언스 플릿 관리에 사용된다.■ Example: Firewalls, Intrusion Detection and Prevention Systems, Deep Packet Inspection Systems, payload manipulationGWLB의 역할은 트래픽을 방화벽이나 침입 탐지 시스템(어플라이언스)로 전달하는 것이다.■ Operates at Layer 3 (Network Layer) - IP Packets 모든 로드 밸런서보다 낮은 수준에서 실행된다. - I..

1. Network Load Balancer (v2)Network load balancers (Layer 4) allow to:- Forward TCP & UDP traffic to your instances  - Handle millions of request per seconds- Less latency ~100 ms (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 trafficNot included in the AWS free tier시험문제에 고성..

1. 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)(동일 EC2 인스턴스 상의 여러 애플리케이션에 부하를 분산한다)Support for HTTP/2 and WebSocketSupport redirects  (from HTTP to HTTPS for exampleALB are a great fit for micro services & container-..

1. Scalability & High AvailabilityScalability(확장성) means that an application / system can handle greater loads by adapting.There are two kinds of scalability  - Vertical Scalability - Horizontal Scalability (=elasticity) 탄력성, 수평 확장성Scalability is linked but different to High Availability ( 확장성 != 고가용성)2. Vertical Scalability - 수직 확장성Vertically scalability means increasing the size of the instanc..

⚠️ 문제default security groups 만 남기고 보안 그룹을 제거하려고 하는데, 아래와 같은 메세지가 뜨며 삭제가 안 되는 현상 Some security groups can't be deleted.The following security groups can't be deleted. They are either default security groups, referenced by other security groups, or they are associated with instances or network interfaces. 여기서 좋은 점은 각 보안그룹 아이디별로 Reason 란에 삭제되지 않는 구체적인 이유가 나온다는 것이다.인스턴스와 연결된 경우, 네트워크 인터페이스랑 연결된 경우..

1. The most likely reason your team member is unable to attach the EBS volume to an EC2 instance `in us-east-1b` is that EBS volumes are tied to a specific Availability Zone (AZ) upon creation. Since the volume was originally attached to an EC2 instance in us-east-1a, it is restricted to that AZ and cannot be directly attached to an instance `in us-east-1b`. us-east-1a에서의 EC2 인스턴스를 종료하여, 이 인스턴스에..

EBS vs EFS1. EBS(Elastic Block Storage)▶EBS volumesOne instance (except multi-attach io1 / io2) - 한 번에 하나의 인스턴스만 연결are locked at the Availability Zone (AZ) levelgp2: IO increases if the disk size increasesgp3 & io 1: can increase IO independently▶To migrate an EBS volume across AZTake a snapshotRestore the snapshot to another AZEBS backups use IO and you shouldn't run them while your application..