RDS Flashcards
Why might you install a DB on EC2 rather than use RDS?
Full control over database, or database that AWS doesn’t offer with RDS.
Why is it generally a bad idea to install a DB on EC2 rather than use RDS?
No RDS features, single A Z, not easy to scale.
How is access to an RDS instance controlled?
Security Group
In Multi A Z, why can’t the standby instance be used for scaling?
The standby instance can only be accessed on failover.
In Multi A Z, can standby instances live in another region?
No.
In multi A Z, about how long does it take for the CNAME to start pointing to the standby instance?
1-2 minutes.
How long does it take for a manual snapshot to expire?
It doesn’t, must be manually deleted
How long is an automatic backup available for?
0-35 days.
Where are backups stored?
AWS Managed S3 buckets
How often do automated backups occur?
Every 5 minutes
When a restore is created from a backups, do you have to update applications that point to the database?
Yes, because the RDS instance will have a new address
How can you improve an application’s database reads from RDS?
Use read replicas
Why are read replicas good for disaster recovery?
Have near 0 RPO and can be promoted quickly (low RTO)
In what situation would a read replica not be good for DR?
data corruption
What is the maximum size of the database cluster used by Amazon Aurora?
128 TB
How is Aurora made to be highly available?
Its cluster is replicated across several A Z’s
What are the advantages of Aurora Serverless?
Scales easier for unpredictable or variable workloads workloads. Also removes complexity of management.
What is the main functionality given by using Aurora Global Databases?
Allow data to be replicated globally
What are two advantages given by Aurora Global Databases?
Global read scaling and cross region disaster recovery.
How can Aurora Multi Master be used to build a fault tolerant application?
Aurora Multi Master allows for multiple r/w replicas, so if one master fails another can be used immediately.
True or False: DMS can be used to migrate data between two on premises databases.
False, one database MUST be on AWS.
When is Schema Conversion Tool used in DMS?
When migrating from one instance type to another e.g. MySQL -> MSSQL
