RDS + Aurora + Elasticache

Question 1

RDS

Answer 1

Relational Database Service

Managed DB Service that uses SQL as a query language

Question 2

RDS Storage AUto Scaling

Answer 2

Detects when you run out of free database storage, scales automatically

You have to set Maximum Storage Threshold

Useful for applications with unpredictable workloads.

Question 3

RDS Read Replicas

Answer 3

Application performs reads and writes to replicas Database instance, which sends read data to application.

Up to 15 read replicas

within AZ, cross AZ or cross Region.

Replication is asynchronous so reads are eventually consistent.

Replicas can be promoted to their own DB

Application must update the connection string to leverage read replicas.

Use Case: you have production database taking on normal load, but you want to run a reporting application. you create read replica to run the new workload there.

Question 4

RDS Read Replicas- Network Cost

Answer 4

RDS read replicas within same region, you don’t pay that replication fee.

Question 5

RDS

Question 6

Multi AZ

Answer 6

For disaster recovery

Sync Replication

One DNS name- automatic app failover to standby

Increases availability

Failover in case of loss of AZ, loss of network, instance or storage failure.

Not used for scaling.

Read replicas can be setup as Multi AZ for disaster recovery.

Question 7

RDS from single-az to multi-az

Answer 7

zero downtime operation ( no need to stop DB)

just click on “modify” for the database and enable multi-AZ.