RDS

Question 1

What does RDS stand for?

Answer 1

Relational Database Servers

Question 2

What are the 2 types of RDS backups? What is the big difference between them?

Answer 2

• Automated Backups
• Database Snapshots
• Big difference is whether they are taken automatically vs. manually

Question 3

What do RDS Automated Backups allow you to do?

Answer 3

Automated backups allow you to recover your database to any point in time within a retention period

Question 4

How long is the retention period for Automated Backups?

Answer 4

can be between 1 and 35 days

Question 5

What do RDS automated backups store?

Answer 5

• A full daily snapshot AND
• transaction logs throughout the day

Question 6

How do RDS Automated Backups do a recovery?

Answer 6

choose the most recently daily backup, and apply the transaction logs relevant to that day

Question 7

How specific can the timing of an RDS Automated Backup recovery be?

Answer 7

You can do a point in time recovery, down to a second, within the retention period

Question 8

Are RDS Automated Backups enabled by default?

Answer 8

Yes

Question 9

Where are RDS Automated Backups stored?

Answer 9

in S3.

Question 10

What is the pricing model for RDS Automated Backup storage?

Answer 10

Backups are stored in S3, and you get free storage space equal to the size of the DB

Question 11

Why might enabling RDS Automated Backups result in a elevated latencies over a brief period of time?

Answer 11

During the backup window, storage I/O may be suspended while your data is being backed up, so you may get elevated latency.

Question 12

After you delete the original RDS instance, are RDS automated backups deleted as well?

Answer 12

Yes

Question 13

After you delete the original RDS instance, are DB snapshots deleted as well?

Answer 13

No

Question 14

After restoring an RDS Automated Backup, is the restored version of the DB on the same DNS as the old DB?

Answer 14

No

Question 15

After restoring an RDS Manual Snapshot, is the restored version of the DB on the same DNS as the old DB?

Answer 15

No

Question 16

For what DB engines is RDS Encryption at Rest supported?

Answer 16

(All of them)

• MySQL
• Oracle
• SQLServer
• PostgreSQL
• MariaDB
• Aurora

Question 17

What does RDS Encryption at Rest use for encryption?

Answer 17

KMS

Question 18

Once your RDS instance is encrypted using RDS Encryption at Rest, are automated backups automatically encrypted as well?

Answer 18

Yes

Question 19

Once your RDS instance is encrypted using RDS Encryption at Rest, are read replicas automatically encrypted as well?

Answer 19

Yes

Question 20

Once your RDS instance is encrypted using RDS Encryption at Rest, are DB snapshots automatically encrypted as well?

Answer 20

Yes

Question 21

Does RDS Multi-AZ boost performance?

Answer 21

NO (that’s Read Replicas)

Question 22

What does RDS Multi-AZ do?

Answer 22

• automatic, synchronous replication of your DB in another AZ
• Automatic failover in case the primary instance goes down

Question 23

With what RDS DB engines does Multi-AZ work?

Answer 23

(All except Aurora)

• SQLServer
• Oracle
• MySQLServer
• PostgreSQL
• MariaDB

Question 24

Assuming Multi-AZ is turned on, what is a way that you can force a failover for your RDS instance?

Answer 24

Reboot your RDS instance

Question 25

What type of replication is involved with RDS Read Replicas?

Answer 25

**Asynchronous replication**

Question 26

What is the primary difference between a primary instance and its read replica?

Answer 26

The read replica is **read-only**

Question 27

With what RDS DB engines are Read Replicas compatible?

Answer 27

(all except SQLServer) * MySQLServer * PostgreSQL * MariaDB * Oracle * Aurora

Question 28

Do you need to have automatic backups turned on in order to use read replicas?

Answer 28

**Yes**

Question 29

Can you have RDS Read Replicas of RDS Read Replicas?

Answer 29

**Yes, but watch out for replication latency issues**

Question 30

Does an RDS instance and its read replica share a DNS endpoint?

Answer 30

**No**, **each read replica has its own DNS endpoint**

Question 31

Can you have Multi-AZ RDS Read Replicas?

Answer 31

**Yes**

Question 32

Can you have RDS Read Replicas of RDS DBs that are sources for Multi-AZ?

Answer 32

**Yes**

Question 33

Can you turn a read replica into a "normal" database?

Answer 33

**Yes, but this breaks replication**

Question 34

Can you have an RDS Read Replica in a region that is different from the primary instance, assuming you are using Multi-AZ?

Answer 34

**Yes**

Question 35

Can you have an RDS Read Replica of an RDS instance which is not using multi-AZ?

Answer 35

**Yes**

Question 36

What are the two best ways to improve RDS performance?

Answer 36

* Read Replicas * Elasticache

Question 37

In RDS, can you create a Read Replica in another region?

Answer 37

**Depends on the underlying database format** **(All except SQLServer are supported)**

Question 38

How do you Encrypt and unencrypted RDS instance?

Answer 38

1. Create a snapshot of the unencrypted RDS DB 2. Copy the snapshot and tick "Enable Encryption" 3. Restore the RDS DB instance from the encrypted snapshot

Question 39

What is the maximum number of Read Replicas you can have for a single RDS instance?

Answer 39

**15**

Question 40

You have an unencrypted RDS instance. How do you create an encrypted read replica?

Answer 40

You can't

Question 41

What are the 2 key features of RDS? What are they primarily for?

Answer 41

* Multi-AZ (for distaster recovery) * Read Replicas (for performance)

Question 42

Does **RDS** **Multi-AZ** require changing the connection string?

Answer 42

If you lose access to your primary database, AWS can automatically point incoming requests to your secondary database **without changing the connection string**

Question 43

How do **Read Replicas** work in RDS?

Answer 43

* There is **no automatic failover**. If your primary instance goes down, you'll need to create a new URL to connect to the secondary instance * **All writes to the primary instance are copied over to the read replica(s)**

Question 44

Suppose you want to be able to handle a surge of incoming traffic to your RDS instance and scale out your application. What key feature of RDS would you use to do this?

Answer 44

**Read Replicas**

Question 45

What is the maximum number of read replicas that can be made from a single primary RDS instance?

Answer 45

up to **5 copies**

Question 46

Does RDS run on virtual machines?

Answer 46

**Yes**

Question 47

How can you log in to the OS of an RDS instance?

Answer 47

**You can't**

Question 48

How can you patch the OS or database of an RDS instance?

Answer 48

**This is Amazon's responsibility** **(you can't**)

Question 49

Is RDS Serverless?

Answer 49

**No, (except for Aurora)** RDS runs on virtual machines