A Cantrill - RDS

Question 1

What type of database model is DynamoDB?

Answer 1

DDB is a Wide Column model of database.

Question 2

What type of database model is Redshift?

Answer 2

Column database

Question 3

What are characteristics of ACID dbs in AWS exam terms?

Answer 3

Atomic Consistent Isolated Durable.

RDS typically. Structured. Not great at scaling

Question 4

What are characteristics of BASE dbs in AWS exam terms?

Answer 4

BasicallyAvailable SoftState Eventually Consistent

DynamoDB. Highly scalable, NoSQL

Question 5

Running DBs on an EC2 is considered a bad practice, t or f?

Answer 5

Running DBs on EC2 is NOT best practice. Lots of overhead.

Use case: DB vendor specific requirements. OR need more control of DB at OS level

Question 6

Can one RDS instance have multiple databases on it?

Answer 6

Yes, multiple dbs can run on one RDS Instance.

Question 7

Are snapshots automatically deleted by AWS?
Are automated backups automatically deleted by AWS?

Answer 7

-No, Snapshots are not automatically deleted. Must be manually deleted.
-Yes, Automated backups are deleted according to the retention period.

Question 8

What happens when you restore from a snapshot in RDS?

Answer 8

A new RDS instance is created when you restore from a snapshot. You will need to update with the new instance name in your database

Question 9

In RDS, what HA setup is used for both Synchronous and Asynchronous replications?

Answer 9

In RDS the following are the setups for each type of replication:

Synchronous replication = multi AZ
Asynchronous replication = Read replicas

Question 10

If you are running a single instance RDS, how do you add a standby instance to this setup?

Answer 10

-Select your RDS database
-Modify
-Select create a standby database instance

RDS then creates the instance and DB in another AZ. Data is synchronously replicated from the primary to the new standby.

Question 11

What happens when a primary RDS instance fails in a primary/standby scenario?

Answer 11

Upon failure, the CNAME of the db will change to point at the standby db instance. Standby then becomes the primary.

Question 12

What are some use cases for Aurora Serverless?

Answer 12

Infrequently used applications, New Applications, Variable or unpredictable workloads, Test and DEV databases.

Question 13

What is RDS Proxy?

Answer 13

A fully managed, DB proxy for RDS that handles connections between application and DB. Helps with connection load stress directly on the DB.

Auto scaled and HA. Provides connection pooling. Only accessible from VPC.

Question 14

When should you use RDS proxy?

Answer 14

-When your DB is getting too many connection errors
-When using Lambda functions to your DB
-RDS can be used to reduce failover time for the DB

Question 15

What is Database Migration Service (DMS) ?

Answer 15

The Database Migration Service (DMS) is a managed service which allows for 0 data loss, low or 0 downtime migrations between 2 database endpoints.

Question 16

What are the 2 ways to use SSL to connect to your SQL Server DB instance in AWS?

Answer 16

-Force SSL for all connections
-Encrypt specific connections

Question 17

What AWS feature can be used to authenticate to your DB with an auth token and not a password?

What DB engines is it compatible with?

Answer 17

IAM DB Authentication works with MySQL and PostgreSQL to allow DB authentication using an auth token

Question 18

In order to encrypt traffic from APP to DB using specific connections, what must be done in the environment?

Answer 18

To use SSL from a specific client, you must obtain certificates for the client computer, import certificates on the client computer, and then encrypt the connections from the client computer.

-Example: Download the Root CA certificate, import the cert to your server and configure the application to use SSL to encrypt connects to your DB (RDS)

Question 19

If you have a single Aurora instance (no Aurora replica), what happens during failover for the single instance ?

Answer 19

Aurora will attempt to create a new DB Instance in the same Availability Zone as the original instance and is done on a best-effort basis.