Databases - Backups + Multi-AZ + Read Replicas Flashcards

1
Q

Types of Backups

A

Automated Backups, Database Snapshots

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Automated Backups

A

allow you to recover your DB to any point in time within a retention period. they will take a full daily snapshot and will store transaction logs throughout the day

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Retention period range

A

1-35 days, 7 days by default

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Recover an automated backup

A

AWS will choose the most recent daily backup, and then apply transaction logs relevant to that day

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Which type of backup is enabled by default?

A

Automated

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Where is the backup data stored?

A

S3

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

How much storage will you get?

A

Free storage space = size of your database

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

When are backups taken?

A

within a defined window

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What will happen to storage I/O during the backup window?

A

may be suspended

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Are DB snapshots manual or automated?

A

Manual

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

When the RDS instance is deleted, what happens to automated backups?

A

They are deleted.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

When the RDS instance is deleted, what happens to DB snapshots?

A

They are stored

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

When the RDS instance is deleted, do you have a chance to make one final snapshot?

A

Yes.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What happens when you restore either an automated backup or a DB snapshot?

A

the restored version of the DB will be a new RDS instance with a new end point.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Encryption at rest is supported for which DBs?

A

MySQL, Oracle, SQL Server, PostgreSQL, MariaDB

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

How do you perform encryption on DBs?

17
Q

Will underlying storage, backups, read replicas, and snapshots be encrypted after the RDS instance is encrypted?

18
Q

Can you encrypt an existing DB instance?

A

No, you will need to create a new DB instance and migrate your data into it.

19
Q

to scale up RDS

A

take a snapshot, restore snapshot to larger instance size

20
Q

Multi-AZ is good for

A

failover/disaster recovery only.

21
Q

If you use Multi-AZ, will AWS handle the replication?

22
Q

Is Multi-AZ good for improving performance?

A

No. You need Read Replicas.

23
Q

Use case for Read Replicas

A

If DB has a lot of reads performed to it, you can change the connection of the EC2 instances to read from read replicas instead of the main DB

24
Q

Multi-AZ db options

A

All except Aurora, which has it by default.

25
Read replica db options
MySQL Server, PostgreSQL, MariaDB
26
Read replicas are used for
scaling, not DR
27
In order to deploy a read replica
you must have automatic backups turned on
28
How many read replicas can you have for one database?
5
29
Can you have read replicas of read replicas?
Yes, but watch out for latency
30
Is read replica asynchronous or synchronous?
asynchronous
31
Is Multi AZ asynchronous or synchronous?
synchronous
32
Will each read replica have a DNS endpoint?
Yes
33
Can you have read replicas that have multi-AZ turned on?
No. You can create read replicas of Multi-AZ source dbs though.
34
Can read replicas be promoted to their own databases?
Yes, but this breaks replication
35
Can you change the instance size of a read replica?
Yes
36
DynamoDB vs RDS
DynamoDB offers push button scaling, so you can scale your DB on the fly, w/o any down time. RDS is not so easy and you usually have to use a bigger instance size or add a read replica