15. Amazon RDS for MySQL: Create, Connect, Back Up and Keep It Private
15.1 What RDS Is and Why Companies Use It
In short: RDS (Relational Database Service) is a managed database: you choose the engine (MySQL, MariaDB, PostgreSQL and others), size and storage, and AWS runs the server for you.
RDS (Relational Database Service) is a managed database: you choose the engine (MySQL, MariaDB, PostgreSQL and others), size and storage, and AWS runs the server for you. You still connect with the normal mysql client and write the same SQL you learnt in Part 5.
| Task | MySQL on your own EC2 | Amazon RDS MySQL |
|---|---|---|
| Install and OS patching | You | AWS |
| MySQL minor upgrades | You | AWS (maintenance window you choose) |
| Backups | You write mysqldump + cron |
Automated daily backups + transaction logs |
| High availability | You build replication | Tick Multi-AZ |
| SSH to the database server | Yes | No – only the MySQL port |
| Root/SUPER privilege | Yes | No – you get a "master user" with most privileges |
| Schema, users, queries, security groups | You | Still you |
Internet
│ 443/80
┌─────▼──────┐ 3306 (only from app SG) ┌──────────────────┐
│ EC2 web/app│ ───────────────────────────►│ RDS MySQL │
│ public sub.│ │ private subnets │
└────────────┘ │ Public access:NO│
└──────────────────┘
Why this matters for security
"Managed" does not mean "secure by default for your data". AWS secures the infrastructure; you secure who can connect, which users exist, what they can do and whether the app is vulnerable to SQL injection. This split is called the shared responsibility model (सामायिक जबाबदारी मॉडेल) and interviewers love asking about it.
Ravindra Bagale's Tip
Many students think that once they use RDS, they don't need to worry about SQL injection – AWS will handle it! No, friends. RDS patches the server, not your PHP code. Prepared statements, a least-privilege user and a private network are your own responsibility.
Ravindra Bagale's Tip – मराठी
बऱ्याच students ना वाटतं RDS घेतला म्हणजे SQL injection ची काळजी नाही – AWS बघेल! नाही मित्रांनो. RDS server patch करतो, तुमचा PHP code नाही. Prepared statements, least-privilege user आणि private network – ही तुमचीच जबाबदारी आहे.
Ravindra Bagale's Tip – हिंदी
बहुत से students सोचते हैं कि RDS ले लिया तो SQL injection की चिंता नहीं – AWS देख लेगा! नहीं दोस्तों. RDS server patch करता है, तुम्हारा PHP code नहीं. Prepared statements, least-privilege user और private network – यह तुम्हारी अपनी ज़िम्मेदारी है.
Practice task
From the table above, list four jobs that move to AWS with RDS and four jobs that stay with you. Explain the shared responsibility model in two sentences.