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2024년 SAA-C03 자격증 준비하면서 필요한 노트 정리했습니다
강의는 유데미 "Ultimate AWS Certified Solutions Architect Associate SAA-C03" 통해 공부했습니다
https://www.udemy.com/course/aws-certified-solutions-architect-associate-saa-c03
같이 공부해서 합격해보자구요 !
Section 11 : Classic Solutions Architecture Discussions
122. MyClothes.com
- Stateful web app
- requirements
- allows people to buy clothes onlin e
- there's a shopping cart
- hundreds of users simultaneously
- scale, maintain horizontal scalability and keep web applicaiton as stateless as possible
- users should not lose their shopping cart
- users should have their details in a db
1st step
- multi az elb -> auto scaling group with 3 different az
- used route 53 with alias group
Pros :
- all the pros from previous architecture is maintained
Cons :
- if user is connected to another instance by elb, shopping cart history is lost..
- users says what's wrong with the site, shopping cart function does not work >:O
2st step (session stickiness)
- Adding stickiness (session affinity) - an elb feature
Pros :
- stickiness allows users to maintain their shopping cart record
Cons :
- but if one instance goes down, it affects customers cart history no matter what
3rd step (cookie)
- Instead of ec2 storing data, user will be resposible for shopping cart data by using user cookies
Pros :
- user can connect to any instances and still will be allowed to keep shopping cart records
- ec2 instances are stateless, server does not need to know the current status
Cons :
- http requests are a bit heavier than before
- security risks, cookies should and must be validated at server side before actually handling the data
- must be less than 4kb
4th step (Server session)
- User will send session_id in web cookies
- Server will use session_id to store and retrieve data from ElastiCache
- alternative data can be stored inside dynamodb
Pros :
- Very secure, since all data is handled and stored inside the db itself
- multi az, stateless solution
Cons :
- traffic starts to increase as more sells occurs
5th step (scaling reads)
- Diffrientiating between write requests and read requests from api, handled by different db
- rds master & rds read replicas
Pros :
- Less traffic to rds, hence less latency
Cons :
- let's think of how to survive disasters
6th step (multi az)
- User elasticcache multi az & rds multi az as well to prevent from diaster failure
Pros :
- if one az goes down, other az is up and there will be no down time
Cons :
- let's think of security groups
7th step (security groups)
- open all http/https requests to elb
- restric traffic to ec2, only allow security group from the elb
- restric traffic to elastic cache + rds, only allow traffic from ec2
Pros :
- added security groups
Cons :
To summarize
- elb sticky sessions
- web clients storing cookies and making web app stateless
- ElastiCache
- RDS
- Tight security groups
같이 파이팅해서 합격해봅시당 ㅎㅎ
저는 24년 10월 중순에 시험 볼 예정입니다 ! (후기 남기도록 하겠습니다 후후)
토니이츠얼랏 : 네이버 블로그
너무너무너무 많이 먹는 토니입니당 :)
blog.naver.com
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