Databases on AWS

Question 1

Relational databases on AW

Answer 1

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

Question 2

RDS key feature

Answer 2

Multi-AZ for DR

Read Replicas for Performance

Question 3

What is data warehouseing?

Answer 3

Used for business intelligence

Used to pull in very large and complex data sets

Question 4

OLTP

Answer 4

Online Transaction Processing

RDS

Question 5

OLAP

Answer 5

Online Analytics Processing

Datawarehousing
RedShift

Question 6

OLTP vs OLAP

Answer 6

OLTP -

OLAP - Complicated queries for inferring info from data

Question 7

ElastiCache

Answer 7

web service that makes it easy to deploy, operate, and scale an in-memory cache in the cloud.

Used to speed up performance of existing databases by caching frequent identical queries

Flavors:
- memcached
- redis
Helps when DBs get overloaded

Question 8

RDS

Answer 8

Relational database

Question 9

Red Shift

Answer 9

Amazon’s OLAP / Datawarehousing solution

Question 10

Amazon’s NoSQL solution

Answer 10

DynamoDB

Question 11

RDS backup types

Answer 11

Automated backups

Database snapshots

Question 12

Automated Backups of RDS

Answer 12

• allow you to recover your db to any point in time within a retention period.
• backups take a full daily snapshot and store transaction logs thru the day
• During a recovery, AWS will choose the most recent snapshot and then apply the relevant transactions
• Enabled by default
• backup data stored in S3

Question 13

Automated backup retention period

Answer 13

1 - 35 days

Question 14

Database snapshots

Answer 14

done manually

stored even after RDS instance is deleted

Question 15

Restoring backups

Answer 15

restored version will be a new RDS instance w/ a new DNS endpoint

Question 16

DB encryption at rest

Answer 16

Done using the KMS service

encrypts backups, read replicas, and snapshots

Question 17

Multi-AZ

Answer 17

• designed for DR
• creating a copy of the DB in a different AZ
• standby DB synced automatically
• If primary AZ goes down -> update DNS to point to backup in secondary AZ
• supports all but Aurora
  
  • Aurora is fault-tolerant on its own

Question 18

Read replica

Answer 18

Production db asynchronously writing new data to secondary DBs.
If there is too much load on the prod db,
Could also point individual EC2 instances to specific DBs
Used for read-heavy DB workloads
Available for all DBs
Used for scaling
must have automatic backups on
up to 5 read replica copies of any DB
Each have it’s own DNS endpoint
Can have multi-AZ
can be in a separate region from primary db

Question 19

Redshift key management

Answer 19

By default, redshift takes care of key management

You can also manage your own keys through HSM or AWS KMS

Question 20

Redshift Mult-AZ

Answer 20

Only available in 1 AZ - no multi-az

Can restore snapshots to a new AZ in event of outage

Question 21

Redshift backup retention

Answer 21

enabled by default for 1 day retention period

max retention period = 35days

Question 22

Redshift number of data copies

Answer 22

Tries to maintain 3 copies:
original
replica on compute nodes
backup in S3

Question 23

Aurora compatible SQL languages

Answer 23

MySQL

PostgreSQL

Question 24

Aurora relational vs noSQL

Answer 24

Aurora is a relational database

Question 25

Aurora performance vs MySQL and PostgreSQL

Answer 25

5x better than MySQL | 3x better than PostgreSQL

Question 26

Aurora storage scaling

Answer 26

10GB - 64TB

Question 27

Aurora DR

Answer 27

designed to handle loss of up to two copies of data w/out affecting db write availability and up to three copies w/out affected read availability self-healing: data blocks and disks scanned for errors and repaired automatically

Question 28

Aurora replica types

Answer 28

Aurora replicas (15) MySQL read replicas (5) PosgreSQL (1)

Question 29

Aurora read replication

Answer 29

asynchronous in milliseconds In-region (no cross-region) Automated failover

Question 30

Aurora Serverless

Answer 30

on-demand autoscaling | good for infrequent, intermittent, or unpredictable workloads

Question 31

Aurora copies

Answer 31

6 copies; 2 copies stored in each availability zone, w/ a minimum of 3 AZs

Question 32

Aurora Snapshot sharing

Answer 32

can be shared w/ other AWS accounts

Question 33

memcached vs redis

Answer 33

memcached - simple - multithreaded redis - multi-az - advanced data types - backup/restore

Question 34

DMS - acronym

Answer 34

Database migration service

Question 35

DMS - definition

Answer 35

service to make migrating easy for relational databases, data warehouses, nosql, and other types of data stores. You can migrate into the cloud, between on-prem instances, or any combo of the two

Question 36

Caching services

Answer 36

CloudFront API Gateway ElastiCache (Memcached, Redis) DAX

Question 37

EMR - definition

Answer 37

big data platform for processing large amounts of data

Question 38

EMR - acronym

Answer 38

Elastic map reduce

Question 39

EMR cluster

Answer 39

cluster - collection of EC2 instances node - EC2 instance in the cluster node type - node's role within the cluster

Question 40

EMR node types

Answer 40

Master - manages the cluster Core - runs tasks and stores data (in HDFS) Task - runs tasks. does NOT store data

Question 41

EMR backup

Answer 41

Configure an archive of log files from master node to S3 Can only be configured when creating the cluster archive done in 5 min intervals

Question 42

Amazon Athena

Answer 42

query services that makes it easy to analyze data in S3 using SQL commands

Question 43

Athena supported data formats

Answer 43

JSON, Parquet, ORC