Cutting Costs on EKS: Shifting Stateful Workloads to Managed Databases (RDS & Aurora)

Running stateful applications on EKS can sometimes feel like burning cash when you don’t need to. Managing storage, backups, and recovery setups for these applications on Kubernetes clusters isn’t just complicated… it’s also expensive. That’s where shifting to managed databases like RDS (Relational Database Service) or Aurora can save you big time—both in dollars and hours of your team’s precious bandwidth.

In this post, we’ll break down how you can save money, cut down on management time, and boost performance by shifting your stateful workloads to RDS and Aurora. Oh, and we’ll throw in some real-world numbers so you know how much you’re actually saving.

Why Move Stateful Workloads Off EKS?

When you run stateful applications on EKS, you’re essentially paying for two things:

Compute resources: The EC2 instances running your Kubernetes nodes.
Storage: Think Persistent Volumes (PVs), storage classes, and all the data replication you need for durability and backup.

On top of that, managing stateful apps in EKS means handling a lot of the complexity yourself—like ensuring storage is always available, managing failovers, and dealing with backups. It’s time-consuming, it’s tedious, and it’s expensive.

By shifting stateful data management to RDS or Aurora, you’re passing a lot of that headache to AWS, which has finely-tuned these services to be cost-efficient and high-performance.

Show Me the Money: Cost Breakdown

Let’s get into some rough numbers to illustrate the savings.

EKS with Stateful Workloads

Imagine you’re running a PostgreSQL database in EKS with 3 EC2 instances acting as your Kubernetes worker nodes. For high availability (HA), you’re probably running replicas and have Persistent Volumes set up for storage, so that’s additional costs for storage (EBS) and backup management.

3 m5.large EC2 instances for your EKS nodes: ~$90/month per instance = $270/month.
Provisioned IOPS SSD (io1) EBS storage (500 GB): $250/month.
S3 storage for backups: $30/month.
Management time: Let’s say your team spends around 10 hours/month dealing with the database replication, backups, and recovery setups. With a skilled Kubernetes DevOps engineer making around $75/hour, that’s another $750/month.

Total: $1,300/month.

Moving to RDS (Regular with Multi-AZ)

Now, say you move that PostgreSQL database to RDS. AWS handles backups, failovers, patching, and replication for you. If you opt for multi-AZ, you’ll pay a bit more, but it comes with automatic failover, so there’s no downtime if something goes wrong.

RDS PostgreSQL (db.m5.large): $225/month or $550/month with multi-AZ.
Storage (500 GB SSD, automated backups included): $100/month.
Multi-AZ option: Adds around $110/month.
Management time: With AWS taking care of backups and failovers, you’re saving about 7 hours/month, leaving you with only 3 hours of minor maintenance. That’s $225/month for engineer time.

Total: $660/month Or $785/month with multi-AZ —still a significant drop from managing it all yourself.

Moving to Aurora

Aurora is AWS’s more scalable database option, especially for production-grade applications. It’s often more performant than RDS for high-traffic apps and scales compute and memory as well as storage automatically.

Aurora PostgreSQL (db.r5.large): $280/month.
Storage (automatically scalable): ~$120/month for comparable usage.
Management time: AWS’s managed scaling and automatic failover features bring this down to just 2 hours/month, which costs $150/month.

Total: $550/month—still less than half of running it on EKS, with minimal oversight needed.

Human Costs: Time Is Money

The real killer cost in managing EKS for stateful workloads is the human factor. If you’ve ever spent a weekend troubleshooting a Kubernetes volume that went into “Pending” or restoring a database from backup, you know it’s not just a financial drain—it’s mentally exhausting for your team.

By shifting to RDS or Aurora, your team saves time on database maintenance, failover configurations, and the intricate task of scaling storage manually. Managed services do the heavy lifting for you, so your devOps team can focus on things that actually move the business forward.

Here’s the real-world impact:

EKS: 10 hours/month = $750 in devOps time.
RDS: 3 hours/month = $225 in devOps time.
Aurora: 2 hours/month = $150 in devOps time.

Bottom Line: By shifting to managed databases, you’re not just saving infrastructure costs but potentially cutting your team’s management time by up to 80%.

Performance and Reliability Perks

Moving to RDS or Aurora doesn’t just save you money and time—it often improves performance. Aurora, for example, is built to be faster and more scalable than standard RDS, thanks to its architecture. It can auto-scale, and its read replicas are way more cost-efficient. Plus, you get multi-AZ deployments and automated failover out of the box.

If you’ve got a production application with serious traffic, this stuff matters. Performance hits on EKS because of misconfigured storage could hurt your bottom line, and frankly, managed databases are just better at handling failovers and replication.

Is It Worth It?

For most businesses, yes. Shifting stateful workloads off EKS to RDS or Aurora can:

Cut your infrastructure costs by 40-60%.
Reduce devOps time spent on managing stateful services by up to 80%.
Improve the reliability and performance of your databases.

The numbers don’t lie, and the simplicity you gain with managed services is worth its weight in gold.

Final Thoughts

Sure, running everything in EKS sounds cool and gives you more control, but is it worth the cost? Managed services like RDS and Aurora give you the best of both worlds—solid performance, lower costs, and less management overhead. So why make your devOps team sweat the small stuff when AWS can do it for you?

Spread the savings