AWS Resiliency Flashcards
For the AWS Certified Solutions Architect—Associate exam prep. Increase understanding about AWS resiliency, including fault tolerance, scalability, availability, and loosely-coupled architectures.
What is resiliency?
The ability to recover when stressed by loads, attacks, or failure of any workload components.
What is the difference between vertical and horizontal scaling?
What is the cost optimization for each?
Vertical scaling: Increasing the size of the instances.
Horizontal scaling: Increasing the amount of instances.
Cost optimization:
What is elasticity?
Using automatic scaling alongside horizontal scaling to match capacity with demand.
What can AWS Auto scaling do? What about EC2 Auto scaling?
What are the difference EC2 Auto scaling policies?
Amazon Elastic Compute Cloud (EC2)
Elastic Container Service (ECS)
Elastic Kubernetes Service (EKS)
AWS Lambda
Relational Database Service (RDS)
DynamoDB
NoSQL, low latency at extreme scale.
Amazon Aurora
Cloud-native relational database service.
Amazon Redshift
Data warehouse.
For resiliency in RDS, when would you use read-replicas or a multi-AZ design?
Use read replicas for performance and availability benefis. (This is not a cache replacement.)
Multi-AZ design doesn’t scale your needs, allow you to access it directly, or provide added performance on the standby copy. Multi-AZ is only good for high availability.
Which services provide caching abilities?
- Amazon CloudFront
- ElastiCache
- DynamoDB Accelerator (DAX)
What is RDS Proxy?
How does it make applications more scalable, resilient, and secure?
Gives applications the ability to pull and share database connections. This improves efficiency and app scalability.
What are the AWS edge networking services?
When should you use each one?
- Amazon CloudFront
- Route 53
- AWS Global Accelerator
AWS Transfer Family
Grants the ability to create, automate, and monitor your file transfer and data processing.
Does not require your own code or infrastructure. Supports up to three AZs.
What is service-oriented architecture? What is microservices architecture?
Service-oriented architecture:Making software components reusable through service interfaces
Microservices architecture: Makes software components smaller and simpler.
What is the difference between API-driven, event-driven, and streaming data?
Amazon API Gateway
AWS Fargate
Serverless compute for containers.
What is concurrency and transactions in AWS Lambda?
Amazon Simple Queue Service (SQS)
definition…
Can deliver high throughput by scaling message producers and consumers horizontally.
What is synchronous vs asynchronous decoupling?
Synchronous decoupling requires components to always be available.
Asynchronous decoupling involves communication between components through durable components.
What is the difference between high availability and fault tolerance?
High availability is designing for minimal downtime.
Fault tolerance is designing for zero downtime and is typically more expensive.
What are ways to design an architecture for disaster recovery?
- Backups stored offsite
- Backups stored in the cloud
- Run disaster simulation tests
- Build resources needed for operational redundancy (like servers and databases)
What are legacy applications?
Answer…
Component migrations are not possible.
What are the two disaster recovery objectives and their definitions?
- Recovery Time Objective (RTO): Maximum acceptable delay between a service interruption and service restoration. What’s the maximum time the application can be unavailable?
- Recovery Point Objective (RPO): Maximum acceptable amount of time since the last data recovery point. How often does the data need to be backed up?
What are the four disaster recovery strategies?
Which are active/active and active/passive? What’s the RPO and RTO?
Active/Active
* Multi-site active-active: Zero downtime and near zero data loss. $$$$. Real-time RTO/RPO.
Active/Passive
* Warm Standby: Smaller, always-running instance, with scalability available after event. $$$. Minutes of RTO/RPO.
* Pilot Light: Data live, services idle. $$. 10s of minutes of RTO/RPO.
* Backup & Restore: Provision all AWS resources and restore backups after event. $. Hours of RTO/RPO.
How does Amazon Aurora work for cross-regional failover?
How long does it take to failover?
How does RDS multi-AZ deployment failover work?
How long is the database down?
How do DynamoDB global tables work?
What backup and recovery options does it have?
How can you improve availability and disaster recovery for legacy applications that are not cloud native?
AWS Elastic Disaster Recovery
How can it be used with on-premises and cloud-based applications?
Amazon Machine Images (AMIs)
EC2 Image Builder
How do routing tables work?
VPC Peering Connections
AWS Transit Gateway
AWS Site-to-Site VPN
AWS Direct Connect Locations
AWS Direct Connect Gateways
AWS Route 53 Resolver
Which services can automate deployment?
Which can be used for containers?
- Elastic Beanstalk
- CloudFormation
- OpsWorks
For containers:
1. ECS
2. EKS
Which services can help you find vulnerabilities in your infrastructure and code?
- Amazon Inspector
- Amazon CodeGuru
What are the various DNS routing capabilities of Route 53?
Which support global architectures?
Amazon CloudWatch
How do you initate automated actions using CloudWatch alarms?
AWS X-Ray
EventBridge
Amazon Polly
What is a use case for Polly in high availability and fault tolerance?
Large volumes of IT service requests
Which two services can be used to create a self-healing environment that can tolerate a single point of failure of a single EC2 instance, or a loss of an entire AZ?
Is it EC2 Auto Scaling and Elastic Load Balancer?
AWS Global Accelerator
What’s the difference between EC2 Auto Scaling and AWS Auto Scaling?
What’s the difference between stateful and stateless applications?
What is a sticky session, and why does it keep customers on the same instance?
