Troubleshooting Memory Issues with OpenTofu and Terraform

If you're experiencing high memory usage during Terraform or OpenTofu plan executions, here's how to diagnose and address the issue.

Symptoms

Common signs of memory issues include:

• Plan operations taking significantly longer than expected

• Memory usage growing continuously during plan execution

• Plan operations failing due to out-of-memory conditions

Diagnostic Steps

1. Enable debug logging by setting the environment variable TF_LOG=DEBUG in your stack's environment variables

2. For more detailed logging (use cautiously as it may contain sensitive information), you can set TF_LOG=TRACE

3. Monitor memory usage during the run to establish baseline memory requirements

4. Test the same configuration with different Terraform/OpenTofu versions to isolate version-specific issues

Version Compatibility

If you encounter memory issues, try testing your configuration with different versions of Terraform or OpenTofu. Memory behavior can vary significantly between versions. For example, if Terraform 1.12.1 works well but earlier versions or OpenTofu show memory issues, this may indicate a regression that needs to be reported.

Reporting Issues

If you identify a potential issue in OpenTofu:

1. Create an issue in the OpenTofu GitHub repository

2. Include the following information:

   • Versions tested (both working and problematic versions)

   • Basic memory usage statistics

   • Debug logs (ensure to remove any sensitive information)

   • Infrastructure scale (number of resources, state file size)