The Complete 2022 Guide to AWS Relational Database Service

Welcome dear reader! With this comprehensive guide my goal is to make you a confident user of Amazon RDS capabilities.

Whether you are new to managed databases or an experienced engineer, you will find insights here to successfully leverage RDS.

Why Cloud Databases and RDS

Let‘s first understand the context around emergence of database-as-a-service offerings like RDS…

Traditionally databases were housed in on-premise data centers requiring substantial hardware and expert personnel. With cloud, the economics have shifted completely.

According to 2021 estimates, over 75% of new databases will be deployed in the cloud!

This explosive growth is driven by factors like:

✔️ Flexible consumption model

✔️ Automation reducing operational overheads

✔️ High availability across zones

✔️ Faster innovation pace

Clearly for most applications, DIY database hosting no longer makes practical sense!

Among cloud database services, AWS RDS is the undisputed leader used by over 500,000 customers!

RDS makes it simple to setup, operate, scale and monitor relational databases with minimal costs.

Let‘s look deeper into why RDS should be your preferred database deployment option…

Key Benefits of using AWS RDS

While embracing latest technology is exciting, practical business owners need concrete bottomline value.

Here is how using RDS can benefit your business:

Save on Total Cost of Ownership

By leveraging RDS managed service instead of self-managed databases, you can reduce costs by up to:

  • 76% capital expenditure savings from no infrastructure needed
  • 72% more DBA productivity translating to operational gains
  • 5X better resource utilization from auto-scaling capabilities

Clearly RDS yields substantial savings which drop straight to your bottomline!

Enhance Productivity of Development Teams

RDS makes developers love their job by:

✔️ Zero time wasted on database maintenance tasks

✔️ Quickly spin production-grade databases using Infrastructure-as-Code

✔️ Effortless replication, failover capabilities

Your developers can focus on application logic instead of operational chores.

Deliver Higher Application Reliability

Nothing hurts business reputation more than shaky application infrastructure. RDS improves reliability by:

✔️ Built-in redundancy through Multi-AZ mirroring

✔️ Instant failover mechanism to meet 99.99% uptime SLA

✔️ Point-in-time recovery in case of emergencies

RDS capabilities give your app always-on resilience!

Clearly whether from cost, productivity or reliability angle, RDS checks all the boxes!

Now that you know the landscape, let‘s get into RDS nuts and bolts…

Deep Dive into RDS Capabilities

RDS provides turnkey building blocks to assemble cloud-native database backend that scales seamlessly.

Let‘s explore what makes RDS tick under the hood.

Multi-AZ High Availability

Mission critical systems require 24×7 access without downtime. Multi-AZ feature creates a duplicate secondary instance that gets synchronous data repliation from primary node.

This mirror instance resides in another isolated availability zone to protect form zone level failures.

In case the master node becomes unavailable, RDS will automatically promote the secondary to take it‘s place without skipping a beat!

Read Replicas

Applications like content management systems see very skewed traffic with heavy read operations vs writes.

Read replicas allow creating multiple copies of primary instance strictly for handling read queries:

[Diagram showing master RDS with multiple Read replicas]

This approach partitions traffic to optimize DB performance. AWS can even scale replicas automatically based on actual load patterns.

Take advantage of read replicas to enhance scalability!

Cross Region Disaster Recovery

While multi-AZ topology safeguards from isolated zone outages, it is still 1 single region dependent.

For true disaster proofing, RDS allows cross-region replication of backups:

[Diagram showing primary db backed up to S3 which replicates cross region]

This ensures even regional failures have you covered!

Security Hardened

Being custodians of data, it is paramount your database has rock solid security foundations:

✔️ Encryption using KMS

✔️ IAM policies & roles access

✔️ VPC network isolation

✔️ Security group firewall rules

RDS has all bases covered to achieve robust security posture!

And much more we will cover…let‘s continue our RDS discovery journey!

Database Migration Strategies

For enterprises with existing database investments, seamless migration to RDS is critical.

Here are proven patterns to harness RDS with continuity:


Also called lift-and-reshape, this pattern migrates on-premise or self-hosted databases as-is. This allows leveraging RDS without product changes.

[Diagram showing migration without changes]

Recommended for apps with near end-of-life or limited engineering bandwidth.


This approach migrates core data while modernizing application tech stack itself:

[Diagram showing migration with tech stack changes]

Allows maximal business agility but requires non-trivial product engineering effort.

Retire and Rebuild

In this model, existing database is maintained while greenfield RDS instance is built from ground up:

[Diagram showing old DB running parallel to new RDS system]

This parallel track model derisks migration allowing fallback if issues. Useful when business logic strongly coupled to current DB.

Analyze above patterns against company priorities to pick the right database migration strategy tailored to your needs.

The AWS Database Migration Service (DMS) greatly simplifies actual movement of databases to RDS through incremental replication minimizing downtime.

Right Sizing Guide

A common pitfall is to use excessive instance sizes that lead to waste. Optimizing RDS costs need precise sizing aligned to application peaks.

Here is a methodical approach:

1. Baseline requirements

Begin with non-functional aspects like data retention policies, recovery time/point objectives, durability needs and failure tolerances.

This establishes the foundational must-haves.

2. Model data growth

Hard numbers on storage and IOPS needs helps pick the right disk capacity and type – standard or provisioned IOPS.

Estimate both average and peak scenarios.

3. Dimension compute

Analyze application query patterns, dimensionality and joins etc. to arrive at CPU, memory and networking limits.

Again use typical and max projections. Leave buffer for unused capacity.

Right sizing using data driven approach prevents bad case undershoot or overspend risk. Let actual usage guide decisioning.

Scaling Strategies

Even a well sized system will need capacity improvements over time. Organizations using RDS can choose from 3 scaling models:

🔼 Scale-Up

For modest growth, change the RDS instance type to next size. This increases underlying vCPU, RAM and storage specs.

Minimal effort but has hard ceiling.

🔼 Scale-Out

RDS makes horizontal scaling seamless through read replicas that can handle entire read queries.

This partitioning helps exponentially scale operational capacity.

🔼 Auto Scaling

For large installations and spiky traffic, configure dynamic scaling policies in CloudWatch.

This allows RDS to automatically spin or downsize replicas based on actual load metric – elegant!

Evaluate above models and use judiciously to build runway to absorb future capacity.

Cost Optimization Levers

While RDS ease-of-use is attractive, cost anxieties can be a barrier especially for smaller firms.

Utilize below tips to keep RDS expenses firmly under check:

Compute savings

🔹 Right size aligning to realistic peaks avoiding over-provisioning

🔹 Leverage EC2 RI pricing for lower database instance costs

🔹 Enable auto pause for dev/test environments not needing 24×7

Storage savings

🔹 Backup storage is function of retention period so optimize to SLAs

🔹 Transition aged data to Glacier for archival requirements

🔹 Leverage compression to reduce storage footprint

Domain expertise

Work with AWS database partner to optimize RDS spending using above constructs tailored to your specific use.

Using data driven rigor, you can now make RDS work at price points palatable even for smaller companies.

Wrapping Up

We have covered a ton of ground in this guide! Here are the key takeaways about AWS RDS capabilities:

✔️ Fully managed service saves time and money vs self-managed databases

✔️ Multiple database engines like MySQL, PostgreSQL supported

✔️ High availability, read scaling integrated

✔️ Security hardened out of the box

✔️ Auto scaling, point-in-time recovery features

RDS has certainly evolved as a mature database platform you can entrust critical systems to.

I hope this guide helped demystify RDS and set you up for success whether an expert or beginner.

Wishing you pleasant times ahead using the power of relational cloud databases!