WAR: Idle OpenSearch Domains

The AWS Well-Architected Framework emphasizes managing your cloud resources efficiently to control costs and maintain operational efficiency. Identifying and addressing idle OpenSearch domains aligns directly with the Cost Optimization Pillar (CO), specifically the principle of CO.2: Rightsizing. This principle focuses on using resources efficiently to avoid unnecessary spending for underutilized resources.

Here's a breakdown of the implications of idle OpenSearch domains and strategies for optimizing your OpenSearch resource usage:

What are Idle OpenSearch Domains?

OpenSearch is a search and analytics platform. An OpenSearch domain on Amazon OpenSearch Service (AOS) is a managed deployment that provides the infrastructure and resources to run OpenSearch clusters. An idle OpenSearch domain can be defined in a few ways:

• Low Search Activity: The domain experiences consistently low search query volume over an extended period.
• No Active Users: The domain has minimal or no active users performing searches or interacting with the data.
• Not Serving a Purpose: The domain was provisioned for a specific project or purpose that is no longer relevant, or it might be a leftover from testing or development phases.

Why are Idle OpenSearch Domains a Concern?

Even when idle, OpenSearch domains incur charges based on their configuration, including:

• Instance Type: The compute resources allocated to the cluster nodes.
• Storage Size: The amount of storage provisioned for the cluster's data.
• Elasticsearch Version: The specific OpenSearch version running in the domain (some versions might have higher costs).
• Running State (Optional): If using reserved instances, there might be ongoing charges even when the domain is stopped.

These ongoing costs can add up significantly, especially if you have a large number of idle domains in your account. Additionally, maintaining idle domains clutters your environment and makes it difficult to identify and manage actively used resources.

Identifying Idle OpenSearch Domains:

Here are some methods to identify idle OpenSearch domains in your AWS environment:

• Amazon OpenSearch Service Console: Use the AOS console to list all your domains. Look for domains with minimal search activity metrics over a desired timeframe.
• AWS CloudWatch: Utilize CloudWatch to monitor key OpenSearch metrics like search queries and indexing operations. Set up alarms to notify you when domain activity falls below a certain threshold for an extended period.
• AWS Cost Explorer: Analyze your AWS cost reports to identify domains with ongoing charges but minimal search activity patterns.

Strategies for Dealing with Idle OpenSearch Domains:

Once you've identified idle OpenSearch domains, here are some options to optimize your costs:

• Delete Idle Domains: For domains no longer required, the most cost-effective solution is to delete them entirely. This removes the domain from your account and eliminates all associated charges.
• Stop Idle Domains (if applicable): If using reserved OpenSearch instances, consider stopping idle domains (if supported by your reservation type). This reduces costs compared to a running state but keeps the domain readily available when needed.
• Rightsize Domain Configuration: Evaluate your active domains and consider downsizing instance types or storage size if they are oversized for your current search volume. This reduces costs without impacting performance for active users.

Automating Idle Domain Management:

• CloudWatch Alarms and Lambda Functions: Set up CloudWatch alarms to trigger Lambda functions when domain activity falls below a threshold. These Lambda functions can automate actions like sending notifications for review or initiating the deletion process for idle domains.

Benefits of Addressing Idle OpenSearch Domains:

By proactively identifying and addressing idle OpenSearch domains, you can achieve the following benefits:

• Reduced Costs: Eliminate unnecessary charges associated with inactive search clusters.
• Improved Resource Management: Maintain a clean and organized set of OpenSearch domains, simplifying management and resource allocation.
• Optimized Cloud Environment: Ensure your OpenSearch resources are appropriately sized and used to their full potential, aligning with cost-effective cloud practices.

Alignment with the Well-Architected Framework:

Following these strategies aligns with the Well-Architected Framework's Cost Optimization principle. By optimizing your OpenSearch domain usage, you can ensure you're only paying for the search and analytics capabilities you actively use and maintain a cost-effective and efficient cloud environment.