feat: add TTL index to MongoDB store for automatic expiration #155

strawgate · 2025-10-28T17:16:59Z

Adds a TTL index on the expires_at field in MongoDB collections to enable automatic cleanup of expired entries. MongoDB will delete expired documents approximately every 60 seconds using its built-in background process.

This brings MongoDB's TTL handling in line with other stores like DynamoDB (which has native TTL) and Elasticsearch (which has manual cleanup).

Benefits

Automatic cleanup of expired entries without manual intervention
Reduced storage usage for expired data
Leverages MongoDB's native TTL index feature

Implementation

The TTL index is created during collection setup with expireAfterSeconds=0, meaning documents will be deleted when the current time reaches the value in the expires_at field.

Related to #148

🤖 Generated with Claude Code

Summary by CodeRabbit

New Features
- Automatic entry expiration: Key-value entries now automatically expire and are removed from the database when their expiration time is reached, improving data freshness and reducing manual cleanup requirements
- Enhanced database performance: Optimized indexing strategies significantly improve the efficiency and speed of key lookup operations in the database

Adds a TTL index on the `expires_at` field in MongoDB collections to enable automatic cleanup of expired entries. MongoDB will delete expired documents approximately every 60 seconds using its built-in background process. This brings MongoDB's TTL handling in line with other stores like DynamoDB (which has native TTL) and Elasticsearch (which has manual cleanup). Benefits: - Automatic cleanup of expired entries without manual intervention - Reduced storage usage for expired data - Leverages MongoDB's native TTL index feature Related to #148 🤖 Generated with [Claude Code](https://claude.ai/code) Co-authored-by: William Easton <[email protected]>

coderabbitai · 2025-10-28T17:17:19Z

📝 Walkthrough

Walkthrough

Two MongoDB store implementations (async and sync variants) now create indexes during collection setup: a standard index on the "key" field for lookups and a TTL index on "expires_at" with expireAfterSeconds set to 0 for automatic document expiration. No control flow modifications.

Changes

Cohort / File(s)	Summary
MongoDB Collection Indexing `key-value/key-value-aio/src/key_value/aio/stores/mongodb/store.py`, `key-value/key-value-sync/src/key_value/sync/code_gen/stores/mongodb/store.py`	Added two indexes during collection setup: a standard index on "key" field for efficient key lookups, and a TTL index on "expires_at" field with expireAfterSeconds=0 to automatically expire documents when expiration time is reached

Pre-merge checks and finishing touches

❌ Failed checks (1 warning)

Check name	Status	Explanation	Resolution
Docstring Coverage	⚠️ Warning	Docstring coverage is 0.00% which is insufficient. The required threshold is 80.00%.	You can run `@coderabbitai generate docstrings` to improve docstring coverage.

✅ Passed checks (2 passed)

Check name	Status	Explanation
Description Check	✅ Passed	Check skipped - CodeRabbit’s high-level summary is enabled.
Title Check	✅ Passed	The PR title "feat: add TTL index to MongoDB store for automatic expiration" clearly and accurately summarizes the main change in the pull request. The title specifically identifies the feature being added (TTL index), the component affected (MongoDB store), and the intended benefit (automatic expiration). It is concise, specific, and non-generic—a developer scanning the commit history would understand that this PR introduces MongoDB TTL indexing functionality to enable automatic document expiration. The title correctly prioritizes the primary objective over secondary implementation details like maintaining the existing key field index.

✨ Finishing touches

📝 Generate docstrings

🧪 Generate unit tests (beta)

Create PR with unit tests
Post copyable unit tests in a comment
Commit unit tests in branch claude/issue-148-20251027-1750

📜 Recent review details

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📥 Commits

Reviewing files that changed from the base of the PR and between e2d9143 and 320f575.

📒 Files selected for processing (2)

key-value/key-value-aio/src/key_value/aio/stores/mongodb/store.py (1 hunks)
key-value/key-value-sync/src/key_value/sync/code_gen/stores/mongodb/store.py (1 hunks)

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📓 Path-based instructions (6)

**/*.py