Module 5 - Storage and Databases

Question 1

What are Instance Stores?

Answer 1

Block-level storage volumes behave like physical hard drives - provide temporary block-level storage for an Amazon EC2 instance
- a disk storage that is physically attached to the host computer for an EC2 instance (when instance is terminated, you lose any data in the instance store)
- AWS recommends instance stores for use cases that involve temporary data which you do not need in the LT

Question 2

What is Amazon EBS?

Answer 2

Amazon Elastic Block Store - a service that provides block-level storage volumes that you can use with Amazon EC2 instances
- if you stop or terminate an Amazon EC2 instance, all the data on the attached EBS volume remains available (main difference from normal instance stores) - ideal for data that requires retention

Question 3

What are Amazon EBS Snapshots?

Answer 3

Allows you to take incremental backups of EBS volumes

Question 4

What is Object Storage?

Answer 4

A technology that manages data as objects - each object consists of data (image, video, text doc), metadata (means supporting data), and a key (unique identifier)

Question 5

What is Amazon S3? What are five traits?

Answer 5

A storage device.
- Store and retrieve an unlimited amount of data
- Store data as objects - store objects in buckets
- Upload a maximum object size of 5 TB
- Version objects
- Create multiple buckets

Question 6

What are the six Amazon S3 storage classes?

Answer 6

1. S3 standard
   - designed for frequently accessed data
   - 99.999999999% durability (probability of being intact after 1 year)
   - data is stored in at least three Availability Zones (facilities)
   - static website hosting (meaning a collection of each HTML file and each file is equivalent to a physical page of the actual site)
2. S3 Standard-IA
   - used for data that is accessed less frequently, but requires rapid access when needed
   - similar to S3 Standard, but has lower storage price and higher retrieval price
   - data is stored in at least three Availability Zones
   - perfect to store backups, disaster recovery files, or objects requiring LT storage
3. S3 One Zone-IA
   - stores data in a single availability zone
   - ideal: i) you want to save costs on storage, and ii) you can easily reproduce your data in the event of an Availability Zone failure
4. S3 Intelligent-Tiering
   - ideal for data with unknown or changing patterns
   - requires a small monthly monitoring and automation fee per object
5. S3 Glacier
   - “free data” (e.g., save data for auditing purposes)
   - low-cost storage designed for data archiving
   - can lock data in vaults
   - WORM - write once/read many
   - three options of retrieval (minutes to hours)
6. S3 Glacier Deep Archive
   - lowest-cost object storage class ideal for archiving
   - able to retrieve objects within 12 hours

Question 7

What is Amazon EBS? (what are the four characteristics)

Answer 7

Elastic Block Store
- Sizes up to 16 TiB (Tebibyte)
- Survive termination of their EC2 instance
- Solid state by default
- HDD options

Question 8

What is Amazon EFS?

Answer 8

Amazon Elastic File System - a scalable file system used with AWS Cloud services and on-premises resources
- unique feature: as you add and remove files, Amazon EFS grows and shrinks automatically → it can scale on demand to petabytes without disrupting applications

Question 9

What is the difference between Amazon EBS and Amazon EFS?

Answer 9

• EBS stores data in a single Availability Zone while EFS stores data across multiple Availability Zones

Question 10

Define relational databases.

Answer 10

• data is stored in a way that relates it to other pieces of data
• uses SQL (Structured Query Language) to store and query data → allows data to be stored in an easily understandable, consistent, and scalable way

Question 11

What is Amazon RDS?

Answer 11

Amazon Relational Database Service - a service that enables you to run relational databases in the AWS cloud
- automates tasks such as hardware provisioning, database setup, patching, and backups
- can integrate with other services (e.g., AWS Lambda)
- provides security options: encryption at rest (protecting data while stored) and encryption in transit (protecting data while it is being sent and received)

Question 12

What are the six types of Amazon RDS database engines?

Answer 12

1. Amazon Aurora
2. PostgreSQL
3. MySQL
4. MariaDB
5. Oracle Database
6. Microsoft SQL Server

Question 13

Define nonrelational databases.

Answer 13

Sometimes referred to as “NoSQL databases” because they use structures other than rows and columns to organise data
- basically the opposite of relational databases

Question 14

What is Amazon DynamoDB?

Answer 14

• A key-value database service which delivers single-digit millisecond performance at any scale
• Massive throughput capabilities
• Granular API access
• Serverless
• Automatic scaling → as your database shrinks or grows, DynamoDB automatically scales to adjust for changes in capacity
  
  • ideal for use cases that require high performance while scaling

Question 15

What is Amazon Redshift?

Answer 15

A data warehousing service that you can use for big data analytics - offers ability to collect data from many sources and helps you to understand relationships and trends across your data

Question 16

What is AWS DMS?

Answer 16

AWS Database Migration Services - enables you to migrate relational databases, nonrelational databases, and other types of data stores
- develop and test database migrations, database consolidation, continuous replication

Question 17

What are six additional database services? (likely not needed for exam)

Answer 17

• Amazon DocumentDB
  
  • a document database service that supports MongoDB workloads
  • ideal for content management, catalogues, user profiles
• Amazon Neptune
  
  • a graph database service
  • use to build and run applications that work with highly connected datasets, such as recommendation engines, fraud detection, and knowledge graphs
  • ideal for social networking
• Amazon QLDB
  
  • a ledger database service
  • use to review a complete history of all the changes that have been made to your application data
• Amazon Managed Blockchain
  
  • use to create and manage blockchain networks with open-source frameworks
  • Blockchain is a distributed ledger system that lets multiple parties run transactions and share data without a central authority
• Amazon ElastiCache
  
  • adds caching layers on top of your databases to help improve the read times of common requests
  • supports two types of data stores: Redis and Memcached
• Amazon DAX - DynamoDB Accelerator
  
  • in-memory cache for DynamoDB
  • helps improve response times from single-digit milliseconds to microseconds