Retain Cloud Audit logs for 3 years across hundreds of projects cost-effectively. What should you do?

Storing Cloud Audit logs for three years across hundreds of projects cost-effectively is best achieved by exporting them to a Coldline Storage bucket. Coldline storage is designed for data accessed less than once a month, offering a low-cost solution for long-term archival with reasonable access times, making it ideal for audit logs that are infrequently accessed but legally required to be retained. Exporting to BigQuery would be significantly more expensive for long-term, infrequently accessed data, as BigQuery is optimized for analytics and querying. A custom script using the Logging API to copy logs to BigQuery would incur similar BigQuery costs and add unnecessary operational overhead for maintenance. Exporting to Cloud Pub/Sub and then to Cloud SQL via Dataflow would introduce multiple services, increasing complexity and cost, and Cloud SQL is not optimized for large-scale, long-term log storage.