AWS RDS MySQL - General Purpose SSD VS Magnetic

6
votes

I've created an Amazon EC2 instance to host a website. I also need a MySQL RDS to store my DB and I have to choose between General Purpose SSD and Magnetic storage. From docs I see:

General Purpose (SSD) – Amazon RDS General Purpose (SSD) storage delivers a consistent baseline of 3 IOPS per provisioned GB and provides the ability to burst up to 3,000 IOPS.

Above this section:

Magnetic storage (formerly known as RDS Standard storage) may be used for small database workloads where data is accessed less frequently.

When selecting a GP SSD I see this message:

Provisioning less than 100 GB of General Purpose (SSD) storage for high throughput workloads could result in higher latencies upon exhaustion of the initial General Purpose (SSD) IO credit balance.

At this point, I note that my DB size is about 300MB and I don't think that it would increase much more, so I would have to pay for much more size for GP SSD. In the other side, the site has around 3000 visitors per day, so I may need a better performance than magnetic ones.

Should I pay for 100GB when I'll be using only up to 500MB? Could be magnetic storage enough for this case? Is there any other consideration to take into account?

2
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2 Answers

2
votes

Recently we have migrated our complete project to Magnetic storage, and it is working perfectly fine, even with a db size of 30GB.

Go for Magnetic storage, and test your production app for sometime. https://aws.amazon.com/ebs/previous-generation/

A throughput of 40-90 MB/s is far enough for a DB size of 300MB, and 3000 users in a day.

Any day you can migrate yourself to General purpose SSD or provisioned SSD if in case required.

2
votes

The great thing about software controlled infrastructure is that it is easy to try things out and then change them

Pick the cheaper option, run it for a while. Look at the Cloudwatch stats and also your own metrics for usability. If they are acceptable then great. If not, then upgrading to a better disk type is not a difficult task