Skip to content

Latest commit

 

History

History
71 lines (55 loc) · 2.96 KB

DesignResilientArchitectures.md

File metadata and controls

71 lines (55 loc) · 2.96 KB
Raw

Domain 1: Design Resilient Architectures

1.1 Choose reliable/resilient storage.

3 Options for Storage

  • EC2 Instance Store ( Ephemeral storage ) Fixed capacity, app level durability ( caching, storing data )

  • EBS Elastic Block Store

    • Connects to one EC2 Instance at a time
    • Decoupled from the EC2 Instance unlike Ephemeral storage
    • Provisioned Capacity
    • Multiple volumes
    • Raid Zero and Striping to achieve

  • 4 Types of EBS Volumes

    • General Purpose SSD (gp2)
    • Provisioned IOPS SSD (io1)
    • Throughput Optimized HDD (st1)
    • Cold HDD (sc1)

  • EFS Elastic File System

    • Petabyte scale file system
    • Linux based AMI's
    • Shared storage

  • Object Storage

    • S3 Standard, 99.99% availability, 11 9's durability
    • S3- IA ( Infrequently Accessed ) Lower fee than S3 but charged retrieval fee
    • S3 One Zone - IA , do not require multiple availability zone data resilience -
    • S3 - Intelligent Tiering - 99.9% availability ( Moves stale data to lower tiers automatically )
    • S3 Glacier - Data archive
    • S3 Glacier Deep Archive - retrieval time of 12 hrs is acceptable ( Lowest cost! )
    • S3 gives you strong consistency for new objects
    • S3 gives you eventual consistency for existing objects
    • Many storage classes and 99.999999999 Durability
    • Glacier ( bulk 12 hrs, expedited 5 minutes ) encrypts data by default , regional durability
    • EBS, S3 and EFS allow native encryption of data at rest
    • S3 bucket names are global
    • To prevent accidental data loss with S3, enable versioning and MFA Delete on bucket

  • Encryption At Rest (Server Side) is achieved by:

    • S3 Managed Keys - SSE - S3
    • AWS Key Management Service, Managed Keys - SSE-KMS ( cooperative encryption )
    • Server Side Encryption with Customer provided Keys - SSE-C

1.2 Determine how to design decoupling mechanisms using AWS services.

SQS

  • When a retention period expires, the message is deleted
  • After processing you need to delete the message on the queue
  • Use SQS to queue work asynchronously even when resources are offline
  • Use SQS with a load balancer when distributing a heavy load to instances
  • Use Elastic IP addresses to route clients to a new server identity when one goes offline

Short polling

  • Short polling occurs when the WaitTimeSeconds parameter of a ReceiveMessage request is set to 0 in one of two ways:
    • The ReceiveMessage call sets WaitTimeSeconds to 0.
    • The ReceiveMessage call doesn’t set WaitTimeSeconds, but the queue attribute ReceiveMessageWaitTimeSeconds is set to 0.

1.3 Determine how to design a multi-tier architecture solution.

  • Each tier can scale independently

1.4 Determine how to design high availability and/or fault tolerant architectures.

  • Lifecycle configuration allows lifecycle management of objects in a bucket. The configuration is a set of one or more rules, where each rule defines an action for Amazon S3 to apply to a group of objects. Bucket policies and IAM define access to objects in an S3 bucket.