AWS Well Architect

Question 1

What are the 5 pillers of a Well Architected

Answer 1

• Resilient Architectures
• Performant Architectures
• Secure Applications and Architectures
• Operationally Excellent
• Cost optimization

Question 2

EC2 Instance Store

Answer 2

Ephemeral Volumes
Only Certain EC2 instance
Fixed Capacity
Disk type and capacity depends on EC2 instance type
Application-Level durability

Question 3

Design Resilient Architectures

Answer 3

1. 1 Choose reliable/resilient storage
2. 2 Determine how to design decoupling mechanisms using AWS services
3. 3 Determine how to design a multi-tier architecture solution
4. 4 Determine how to design high availability and/or fault tolerant solutions

Question 4

Elastic Block Store

Answer 4

Different Types
Encryption
Snapshots
Provisioned capacity including sometimes IOPS
Independent Lifecycle than EC2 instance
Multiple volumes striped to create large volumes

Question 5

Amazon EFS

Answer 5

File storage in AWS Cloud
Shared Storage
Petabyte-scale file system
Elastic Capacity
Supports NFS v4.0 and v4.1 (NFSv4) protocol
Compatible with Linux-based AMIs for EC2
Not Windows compatible

Question 6

Amazon S3

Answer 6

Consistency model
Storage classes & Durability - standard, standard - IA
Encryption (data at rest) - SSE-S3, SSE-KMS, SSE-C
Encryption (data in transit) - HTTPS
Versioning

Question 7

Amazon S3 consistence Model

Answer 7

1st write is strongly consistent, updates are eventually consistent. A read right after an update may produce the previous version

Question 8

Amazon S3 encryption types

Answer 8

SSE-S3 – built in encryption key
SSE-KMS – Key management key is use
SSW-C – Customer provided key

Question 9

Glacier retrieval types

Answer 9

Expedited – more expensive, up to 5 min
Standard –
Bulk – Slowest but cheapest 12 hours

Question 10

SQS

Answer 10

Simple Queue Services

Can be used to decouple date flow

Question 11

Fault Tolerant vs High Availability

Answer 11

High available can have degradation, Fault Tolerant has a higher bar and cannot have degradation

Question 12

Thoughts on Resilent Arhitectures

Answer 12

Single AZ is never the right answer
AWS managed service is always preferred
Fault Tolerant and High Availability are not the same thing
Expect that everything will fail at some point and design accordingly

Question 13

Designing Performant Architectures

Answer 13

1) Choose performant storage and databases
2) Apply caching to improve performance
3) Design solution for elasticity and scalability

Question 14

Which EBS drive type to use

Answer 14

SSD General Purpose 10,000 IOPS, 160 MiB/s
SSD Provisioned IOPS 32,000 IOPS, 500 MiB/s
HDD ThroughPut Optimised 500 IOPS, 500 MiB/s
HDD Cold 250 IOPS, 250 MiB/s

SSD good for random read/write, HDD good for sequential read/write

Question 15

When to use RDS

Answer 15

1) Complex transactions of comple queries
2) Medium to High query/write rate
3) on more then a single worker node/shard
4) high durability

Question 16

Do no use RDS

Answer 16

1) massive read/write rates (i.e. over 150K write/sec)
2) Sharding
3) Simple Get/Put request queries
4) RDBMS customization

Question 17

Which RDS engines support read replicas

Answer 17

MySQL, MariaDB, PostrgreSQL, and Auroa

Question 18

ElastiCache type defferances

Answer 18

MemCacheD
1_ Multithreading
2_Low Maintenance
3_Easy Horizontal Scalability with Auto Discovery
Redis
1_Support for Data Strutures
2_Persistence
3_Atomic Operations
4_Pub/Sub messaging
5_Read Replicas/Failover
6_Cluster mode/shared clusters

Question 19

What is an advantage of using elasticache with dynamic content

Answer 19

Uses the AWS backbone as opposed to internet backbone

Question 20

What is needed for AutoScaling

Answer 20

Auto Scaling Launch Config
-specify Ec2 instance size and AMI name
Auto Scaling group
-reference the launch config
-specifies min, man, and desired size of the auto scale group
-may reference the elb
-health check type
Auto Scale Policy
-specifies how much to scale in or scale out
-one or more may be attached to auto scaling group

Question 21

Amazon DLM

Answer 21

Data lifecycle manager

Question 22

Can you encrypt a volume in use

Answer 22

NO, you need to create a snapshot, encrypt the snapshot, then restore to a EBS volume