Spend less on AWS Neptune by cleaning up idle instances

16 hours
_– the length of one day on the planet Neptune
_

On Neptune, the old adage “The days are long, but the years are short” is reversed. A day, or one rotation of the planet, takes just 16 hours, while a year – the time it takes to orbit around the sun – amounts to 165 Earth years. Neptunians, if they were out there, wouldn’t get to celebrate many birthdays. 

The Neptunians of Futurama

They would, however, have to make the most of their 16-hour days. I like to think that Neptunians would be particularly partial to streamlining and automating processes. With so few hours in a day, why waste them on mundane tasks? In that spirit, let’s look at another way to optimize your AWS environment and reduce AWS costs: removing idle Amazon Neptune clusters. 

Table of contents#

1. Why you’re probably paying too much for Amazon Neptune
2. How to identify idle Neptune clusters
3. How to remove idle Neptune clusters
4. Optimize Amazon Neptune easily and automatically with CloudFix

1. Why you’re probably paying too much for Amazon Neptune#

Amazon Neptune is a graph database. Graph databases have a different data model than either a standard relational database (table) or document databases (JSON objects). In a graph database, the fundamental structure is objects and the relationships between them. Both these objects and their relationships have properties attached to them.

Neptune’s default configuration is in a cluster, although a serverless offering was announced in October 2022 at AWS re:Invent. In the non-serverless version, Neptune can run as either a single instance or as a cluster of multiple instances. The strongly recommended configuration is to have at least two instances, split into different availability zones within the same region. For the sake of this conversation, we’ll refer to either situation as a “Neptune cluster.” 

The pricing for Neptune is based on a combination of compute, storage, and data transfer. Here’s what it costs in us-east-1 as of June 2023:

Clusters that are actively being used will rack up charges in all of these categories. But here’s the catch: you pay for compute and storage regardless of how busy, or not busy, the cluster is. That means that clusters that aren’t being actively used – idle clusters – still incur these costs. Accumulate enough unused clusters, and suddenly you’re spending a significant amount of money on idling infrastructure.

How much money? A db.t4g.medium instance costs $0.093 per hour. If you’re experimenting with a cluster, you will have two of them. $0.093 * 24 hours * 30 days * 2 instances = $134 per month, just for the instances! Larger clusters with larger instances can increase costs much faster. From pricing example 2 on the AWS Neptune pricing page, a cluster of 4 db.r5d.2xlarge would cost $5,529.60 per month, calculated as $1.92 per instance * 4 instances * 24 hours/day * 30 days/month. Ouch.

Regular Fixer blog readers know what’s coming next: to stop wasting money on idle Neptune clusters, we need to find them and delete them. Let’s tackle this (ice) giant.

2. How to identify idle Neptune clusters#

An idle Neptune cluster is one that nobody is querying anymore. It still has running instances and stored data, so it keeps billing for compute and storage, but no application is sending it requests. These clusters pile up for all the usual reasons: a proof of concept that never went further, a test environment nobody tore down, or a project that moved on to a different data store.

Finding them by hand is tedious. Neptune bills by instance, but the thing you want to clean up is the cluster, and a large organization can have clusters spread across many accounts and regions. CloudFix does this for you: it uses your cost and usage data to find every Neptune cluster across your organization, and Neptune’s own utilization metrics in CloudWatch to spot the ones that have gone unused for an extended period. Finding is read-only, so nothing in your environment changes. (If you want to learn more about CloudWatch, check out our Foundation blog on getting started with CloudWatch.)

3. How to remove idle Neptune clusters#

Alright: we’ve figured out which Neptune clusters are just sitting around, costing us money. Time to get rid of them.

Removing an idle cluster means deleting its instances and then the cluster itself. Before anything is deleted, take a final snapshot of the cluster and keep a record of its configuration. That way, if anyone ever needs the cluster again, it can be restored from the snapshot.

That’s it! Congratulations on fine-(Nep)tuning your graph database and paying less for AWS.

4. Optimize Amazon Neptune easily and automatically with CloudFix#

Like many of our fixes, implementing the process described above isn’t hard. But it’s also not one of your core business objectives, especially given the relatively modest amount of savings and the value of your engineering team’s time. That’s where CloudFix comes in. 

With CloudFix, idle Neptune clusters show up in your Recommendations, and nothing happens until you approve. When you do, the fixer runs as an AWS Systems Manager Automation runbook in your own AWS account: it snapshots the cluster, saves its configuration, and then deletes the idle cluster. Every execution is logged. Like all of our fixes, this automation has been tried, tested, and proven to save thousands of dollars for our customers. And if you ever need the cluster back, it can be restored from the snapshot with its saved configuration.

That’s a wrap on our guide to cleaning up idle Amazon Neptune clusters. No matter how you go about it, we hope your AWS savings are simply astronomical.

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