The EMR Delete Idle Clusters tool helps optimize your AWS costs by identifying and safely removing Amazon EMR clusters that have been idle for an extended period, helping to eliminate unnecessary compute expenses.

What It Does

This Finder identifies EMR clusters in your AWS environment that have been idle for an extended period (monitored over the last 30 days), creating unnecessary costs without providing business value. It recommends either enabling auto-termination for supported clusters or manual termination for clusters where auto-termination is not available.

How It Works

The EMR Delete Idle Clusters Finder:

  • Verifies that the EMR cluster exists and is operational
  • Analyzes the CloudWatch ‘IsIdle’ metric over the last 30 days to identify consistently idle clusters
  • Examines the annual cost of the cluster, extrapolated from the last 31 days of usage, to ensure it exceeds the minimum cost threshold for optimization (default $100)
  • Determines if the cluster is in a region and running an EMR version that supports auto-termination
  • Generates appropriate recommendations based on the findings

AWS Services Affected

This CloudFix feature interacts with the following AWS services:

Amazon EMR
Amazon CloudWatch
Amazon EMR Amazon CloudWatch

CloudFix analyzes CloudWatch metrics to identify EMR clusters that have been idle for an extended period and safely removes them to optimize your AWS costs.

Benefits

  1. Cost Savings: Eliminate expenses from idle EMR clusters that are not providing value to your organization
  2. Resource Optimization: Free up resources in your AWS account by removing unused clusters
  3. Improved Visibility: Gain insights into idle EMR resources that might otherwise go unnoticed
  4. Environmental Impact: Reduce unnecessary compute usage, contributing to sustainability goals
  5. Best Practice Implementation: Align with AWS best practices for cost optimization through lifecycle management

Implementation Details

CloudFix provides two approaches based on cluster compatibility:

  1. For auto-termination supported clusters:
    • Identifies clusters running EMR versions 5.30.0, 6.1.0, or later in supported regions
    • Recommends enabling auto-termination with appropriate idle timeout settings
    • Provides guided steps for implementing auto-termination through the AWS console or API
  2. For clusters not supporting auto-termination:
    • Recommends manual termination after verification that the cluster is truly idle
    • Provides guidance on data backup considerations before termination
    • Outlines steps for safely terminating the cluster via AWS console or API

Frequently Asked Questions

Is this implemented automatically?

No. Due to the potential impact on data stored within EMR clusters, CloudFix provides recommendations but does not automatically implement these changes. You maintain complete control over which clusters are modified or terminated.

What should I consider before terminating an EMR cluster?

Before terminating an EMR cluster, ensure that:

  • All necessary data has been backed up or migrated to persistent storage (e.g., Amazon S3)
  • Any required log files have been archived
  • No scheduled or upcoming workloads depend on this cluster
  • Appropriate stakeholders have been notified of the planned termination

How does CloudFix determine if a cluster is idle?

CloudFix uses the ‘IsIdle’ CloudWatch metric provided by Amazon EMR, which indicates whether a cluster is idle based on YARN application activity, HDFS utilization, and other factors. A cluster is considered idle when this metric consistently shows inactivity over the analysis period.

What versions of EMR support auto-termination?

Auto-termination is supported on EMR versions 5.30.0, 6.1.0, or later. For versions 5.34.0 and 6.4.0 or later, auto-termination includes additional idle detection criteria for Python kernels and other interactive workloads.

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