ALwrity/docs/Billing_Subscription/RENEWAL_HISTORY_RETENTION_IMPLEMENTATION.md

Renewal History Retention Policy Implementation

Overview

Implemented tiered retention policy for subscription renewal history records. This ensures efficient storage while preserving critical payment and subscription data for tax/audit compliance.

Retention Policy

Tiered Retention Strategy

┌─────────────────────────────────────────────────────────────┐
│ Retention Policy: Subscription Renewal History             │
├─────────────────────────────────────────────────────────────┤
│                                                              │
│ 0-12 months:   Full records with usage snapshots            │
│                - Complete usage_before_renewal JSON         │
│                - All subscription and payment data          │
│                                                              │
│ 12-24 months:  Compressed records                           │
│                - Compressed usage snapshot (key metrics)    │
│                - All subscription and payment data          │
│                                                              │
│ 24-84 months:  Summary records                              │
│                - No usage snapshots                         │
│                - All subscription and payment data          │
│                                                              │
│ 84+ months:    Archive-ready records                        │
│                - No usage snapshots                         │
│                - Payment data preserved (tax/audit)        │
│                                                              │
│ Payment Data:  Preserved indefinitely (compliance)        │
└─────────────────────────────────────────────────────────────┘

Implementation Details

New Service

File: backend/services/subscription/renewal_history_retention.py

Class: RenewalHistoryRetentionService

Key Methods

1. check_and_apply_retention(user_id: str)

Main method that applies retention policies automatically.

Process:

1. Identifies records in each retention tier
2. Compresses usage snapshots for 12-24 month old records
3. Removes usage snapshots for 24-84 month old records
4. Ensures 84+ month old records have no snapshots
5. Returns statistics about processed records

Returns:

{
    'retention_applied': True,
    'total_records': 150,
    'compressed_count': 10,
    'summarized_count': 5,
    'archived_count': 2,
    'total_processed': 17,
    'message': 'Processed 17 records: 10 compressed, 5 summarized, 2 archived'
}

2. _compress_usage_snapshots(records)

Compresses detailed usage snapshots to key metrics only.

Before Compression:

{
    "total_calls": 1500,
    "total_tokens": 500000,
    "total_cost": 45.50,
    "provider_breakdown": {...},
    "detailed_metrics": {...},
    "trends": {...}
}

After Compression:

{
    "total_calls": 1500,
    "total_tokens": 500000,
    "total_cost": 45.50,
    "compressed_at": "2025-01-15T10:30:00",
    "note": "Usage snapshot compressed after 12 months"
}

3. _create_summary_records(records)

Removes usage snapshots entirely, keeping only subscription and payment data.

4. _mark_for_archive(records)

Ensures very old records have no snapshots (should already be done by previous stages).

5. get_retention_stats(user_id: str)

Returns statistics about records in each retention tier.

Returns:

{
    'total_records': 150,
    'recent_records': 120,  # 0-12 months
    'records_to_compress': 15,  # 12-24 months
    'records_to_summarize': 10,  # 24-84 months
    'records_to_archive': 5,  # 84+ months
    'retention_policy': {
        'compress_after_days': 365,
        'summarize_after_days': 730,
        'archive_after_days': 2555
    }
}

Integration

Automatic Application

Retention is automatically applied when fetching renewal history:

# In backend/api/subscription/routes/subscriptions.py
@router.get("/renewal-history/{user_id}")
async def get_renewal_history(...):
    # Apply retention before fetching
    retention_service = RenewalHistoryRetentionService(db)
    retention_service.check_and_apply_retention(user_id)
    # ... fetch and return records

New Endpoint

Added endpoint to get retention statistics:

GET /api/subscription/renewal-history/{user_id}/retention-stats

Returns breakdown of records by retention tier.

Configuration

Retention Periods

Currently set to:

• Compress after: 365 days (12 months)
• Summarize after: 730 days (24 months)
• Archive after: 2555 days (84 months / 7 years)

To change:

# In RenewalHistoryRetentionService class
COMPRESS_SNAPSHOT_DAYS = 365  # Change this value
SUMMARY_RECORDS_DAYS = 730    # Change this value
ARCHIVE_DAYS = 2555           # Change this value

Data Preservation

What's Preserved

✅ Always Preserved:

• Payment amount
• Payment status
• Payment date
• Stripe invoice ID
• Plan name and tier
• Billing cycle
• Period start/end dates
• Renewal type and count

✅ Preserved for 12-24 months:

• Compressed usage snapshot (key metrics only)

❌ Removed after 12 months:

• Detailed usage breakdowns
• Provider-specific metrics
• Trend data
• Detailed usage snapshots

Compliance

• Payment Data: Preserved indefinitely for tax/audit compliance
• Subscription Data: Preserved indefinitely for billing history
• Usage Snapshots: Removed after 12 months (not required for compliance)

Benefits

1. Storage Efficiency: Reduces database size by removing large JSON snapshots
2. Compliance: Preserves all payment data for tax/audit requirements
3. Performance: Smaller records = faster queries
4. Automatic: No manual intervention required
5. Gradual: Applies retention in stages, not all at once

Example Scenarios

Scenario 1: New User (0-12 months)

• 5 renewal records, all recent
• Result: All records kept with full usage snapshots

Scenario 2: Active User (12-24 months)

• 20 renewal records
• 3 records are 13 months old
• Result: 3 records get compressed snapshots, 17 remain full

Scenario 3: Long-term User (24+ months)

• 50 renewal records
• 10 records are 25 months old
• Result: 10 records have snapshots removed, payment data preserved

Scenario 4: Very Old Records (84+ months)

• 100 renewal records
• 5 records are 7+ years old
• Result: 5 records have no snapshots, ready for archive

Testing

Manual Testing

1. Create test records with old timestamps:

   UPDATE subscription_renewal_history 
   SET created_at = datetime('now', '-400 days')
   WHERE user_id = 'test_user' AND id IN (SELECT id FROM subscription_renewal_history LIMIT 5);
   

2. Trigger retention by calling /api/subscription/renewal-history/{user_id}

3. Verify:

   • Records 12-24 months old have compressed snapshots
   • Records 24+ months old have no snapshots
   • Payment data is preserved in all records

Expected Behavior

• Records are processed automatically on history queries
• Usage snapshots are compressed/removed based on age
• Payment data is never removed
• All subscription data is preserved

Monitoring

The service logs detailed information:

[RenewalRetention] Applied retention for user {user_id}: 10 compressed, 5 summarized, 2 archived

Future Enhancements

1. Archive Table: Move very old records to separate archive table
2. Scheduled Jobs: Run retention on a schedule instead of on-demand
3. Configurable Periods: Make retention periods configurable via environment variables
4. Metrics Dashboard: Show retention statistics in admin dashboard
5. Export Functionality: Allow export of old records before archive

Backward Compatibility

✅ Fully backward compatible:

• Existing records are processed automatically
• No breaking changes to API responses
• Old records without snapshots are handled correctly
• Payment data is always preserved

Related Files

• backend/services/subscription/renewal_history_retention.py - Main implementation
• backend/api/subscription/routes/subscriptions.py - API endpoint integration
• frontend/src/components/billing/SubscriptionRenewalHistory.tsx - Frontend display
• docs/Billing_Subscription/LOG_STORAGE_AND_RETENTION_REVIEW.md - Review document