Cloud Storage Lifecycle Tiering with matchesStorageClass

What Object Lifecycle Management is:

Object Lifecycle Management is a built-in feature of Google Cloud Storage that automates the transition of objects to colder storage classes or deletes them when predefined conditions are met. Rules are assigned at the bucket level and evaluated asynchronously by Google Cloud Storage.

How it meets the requirements:

• Transition to Nearline at 30 days (✓): Rule 1 uses the SetStorageClass action set to NEARLINE, paired with the age condition of 30 days and matchesStorageClass set to STANDARD. When a Standard object reaches 30 days of age, Cloud Storage transitions it to Nearline storage without rewriting the data.
• Transition to Coldline at 90 days (✓): Rule 2 uses the SetStorageClass action set to COLDLINE, paired with the age condition of 90 days and matchesStorageClass set to NEARLINE. This ensures that objects already in Nearline transition to Coldline once their overall age reaches 90 days.
• Permanent deletion at 365 days (✓): Rule 3 uses the Delete action with an age condition of 365 days, removing objects that have reached the end of their 1-year retention lifecycle regardless of their current storage class.

Key advantages and capabilities:

• Zero-downtime tiering: Automatically cascades data through cheaper storage tiers without manual intervention or application code updates.
• No rewrite overhead: Using SetStorageClass does not rewrite the object data or incur retrieval fees or early deletion penalties during transition.
• Cumulative age evaluation: An object's age is measured from its original creation time, allowing progressive multi-stage lifecycle pipelines.
• Cost minimization: Progressively reduces the per-gigabyte at-rest storage rate while retaining access to data for analytics as it cools.

Why this is optimal:

This configuration cleanly separates the transition and deletion criteria into discrete, standard lifecycle rules using the native SetStorageClass and Delete actions. It avoids common misconfigurations by explicitly specifying both the target age and the current matchesStorageClass condition for each tier.