You are deploying a web application hosted on Compute Engine.

To fulfill the requirements of preserving logs for 12 years and ensuring data residency within European boundaries, the best approach is to use Google Cloud's operations suite (formerly Stackdriver) with a custom log bucket configured in the desired region.

Configure Cloud Logging Agent:

Install and configure the Cloud Logging agent on your Compute Engine instances. This agent collects logs from your application and system and sends them to Google Cloud's operations suite.

Create a Custom Log Bucket:

In the Cloud Logging interface, create a custom log bucket in the EUROPE-WEST1 region. This bucket will store your logs and can be configured with a custom retention period.

Set Custom Retention Policy:

Configure the retention policy for the custom log bucket to 12 years. This ensures that all logs are preserved for the required duration.

Ship Logs to the Custom Log Bucket:

Modify the logging configuration to direct logs from the Cloud Logging agent to the custom log bucket. This can be done through the logging configuration settings in the Cloud Console or by updating the agent configuration files.

This solution minimizes overhead by using managed services and ensures cost-effectiveness by leveraging Cloud Logging's built-in capabilities for log storage and retention management.

References

Cloud Logging Documentation

Creating and Managing Logs Buckets