RDS - Relational Database Service Flashcards
What is RDS
Relational Database Service is a managed DB service for DB that use SQL and allows you to create databases in the cloud that are managed by AWS
What are the databases managed by RDS?
- Postgres
- MySQL
- MariaDB
- Oracle
- Microsoft SQL Server
- Aurora (AWS Proprietary database)
What can’t you do on RDS that can do if you would have a DB deployed on EC2?
you can’t SSH into your instance
What you must do to have backups in RDS?
nothing, backups are automatically enabled in RDS
What does allow you to do the RDS automated backups?
to restore to any point in time from oldest backup to 5 minutes ago
How frequently does run a RDS full backup?
daily during the maintenance windows
how frequently are transaction logs backed up on RDS?
every 5 minutes
how many days are automatic logs retained by default in RDS?
7 days, can be increased to 35
what are RDS DB snapshots?
they are backups manually triggered by the user
how many days are db snapshots retained by default in RDS?
for as long as you want
What is the max number of read replicas allowed in RDS?
up to 5
Are RDS read replicas cross AZ or cross regions?
yes to all
how does happen replication on RDS?
async
If something is wrong what can you do with your RDS replica?
you can promote it to be a master DB
What needs to be done on application side to leverage RDS replicas?
applications must update the connection string
what SQL statements are allowed on RDS replicas?
just selects
What is a common use of RDS replicas?
to run a reporting application to run some analytics
What happens when data goes from 1 AZ to another?
there is a cost involved
What can you do to reduce cost of RDS replicas?
you can have them in the same AZ
What is RDS multi AZ for disaster recovery setup?
RDS uses read replicas and the replication is sync
What is provided by RDS multi-AZ for disaster recovery setup?
one DNS name and automatic failover to standby
How and when can you encrypt data at rest on RDS?
with AWS KMS - AES-256 only at launch time
how can you encrypt a read replica of a master RDS that is not encrypted?
you can’t
What RDS DBs can use TDE (Transparent Data Encryption)?
Oracle and SQL Server
What can you use to encrypt RDS data in-flight?
SSL certificates
How are RDS snapshots in terms of encryption?
snapshots preserve encryption status
What can you do when you copy a RDS snapshot?
you can encrypt it
How can you encrypt an un-encrypted RDS DB?
1-create a snapshot
2-copy and enable encryption
3-restore the DB from the encrypted snapshot
4-migrate applications to the new DB and delete the old one
What does RDS use to secure network?
leverages SGs as EC2 instances controling which IP / SG can communicate with RDS
Within what is usually RDS deployed?
within a private subnet
What does help to control who can manage RDS?
IAM policies through RDS API
How can you login into RDS DBs?
using traditional username and password
What RDS DBs allow to authenticate using IAM-based auth?
Postgre and MySQL
What you need to use IAM-based auth on RDS?
an auth token obtained through IAM and RDS API calls
What is the lifetime of RDS IAM auth tokens?
15 minutes
What are RDS parameter groups?
it allows you to manage your DB engine configuration by associating your DB instances
Is Aurora open source?
no, it is a proprietary technology from AWS
Which DBs are supported as Aurora DB?
Postgres and MySQL
How is Aurora performance compared to RDS MySQL and Posgre?
5x MySQL
3x Postgre
How does increment Aurora storage?
automatically in increments of 10GB, up to 64TB
How many replicas can you use on Aurora?
Aurora can have 15 replicas while MySQL has 5, and the replication process is faster (sub 10 ms replica lag)
What are the main features of Aurora?
- Automatic fail-over
- Backup and Recovery
- Isolation and security
- Industry compliance
- Push-button scaling
- Automated Patching with Zero Downtime
- Advanced Monitoring
- Routine Maintenance
- Backtrack: restore data at any point of time without using backups
What is provided by Aurora cluster?
A writer endpoint to master and a Reader endpoint for replicas
What is provided by Aurora cluster Reader Endpoint?
A connection load balancing
Can you scale on Aurora?
you can auto scale replicas
What is Aurora Serverless?
is an on-demand, auto-scaling configuration based on actual usage for Amazon Aurora
What is good for Aurora Serverless?
for infrequent, intermittent or unpredictable workloads
As what can you infer an Online Transactional Processing (OLTP)?
as a Relational Database
How can you set auto scaling in RDS?
you can’t auto scale RDS
What is Global Aurora?
It allows a single Aurora database to span multiple AWS regions, with fast replication to enable low-latency global reads and disaster recovery from region-wide outages
What is provided by Global Aurora?
o 1 Primary Region (read / write)
o Up to 5 secondary (read-only) regions, replication lag is less than 1 second
o Up to 16 Read Replicas per secondary region
o Helps for decreasing latency
o Promoting another region (for disaster recovery) has an RTO of < 1 minute
