foxhunt/AGENT_DB01_ROLLBACK_PROCEDURES.md

Database Rollback Procedures - Wave D Migration 045

Agent: DB-01 (Database Migration Validator) Date: 2025-10-18 Migration: 045_wave_d_regime_tracking Status: VALIDATED - PRODUCTION READY

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Overview

This document provides comprehensive rollback procedures for Migration 045 (Wave D Regime Tracking), including emergency rollback, partial rollback, and data preservation strategies.

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Rollback Levels

Level 1: Emergency Rollback (Production Issue)

Time Required: ~30 seconds Data Loss: All Wave D regime tracking data Use When: Critical production issue requiring immediate rollback

-- Execute the down migration
\i /home/jgrusewski/Work/foxhunt/migrations/045_wave_d_regime_tracking.down.sql

Verification Steps:

-- Verify tables are dropped
SELECT COUNT(*) FROM information_schema.tables 
WHERE table_name IN ('regime_states', 'regime_transitions', 'adaptive_strategy_metrics');
-- Expected: 0

-- Verify functions are dropped
SELECT COUNT(*) FROM information_schema.routines 
WHERE routine_name IN ('get_latest_regime', 'get_regime_transition_matrix', 'get_regime_performance');
-- Expected: 0

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Level 2: Data Preservation Rollback

Time Required: ~5-10 minutes Data Loss: None (data exported before rollback) Use When: Need to preserve data for analysis or future re-migration

# Step 1: Export data (replace <DATE> with current date in YYYYMMDD format)
pg_dump postgresql://foxhunt:foxhunt_dev_password@localhost:5432/foxhunt \
  --table=regime_states \
  --table=regime_transitions \
  --table=adaptive_strategy_metrics \
  --data-only \
  --inserts \
  --file=/tmp/wave_d_backup_<DATE>.sql

# Step 2: Execute rollback
psql postgresql://foxhunt:foxhunt_dev_password@localhost:5432/foxhunt \
  -f /home/jgrusewski/Work/foxhunt/migrations/045_wave_d_regime_tracking.down.sql

# Step 3: Verify and archive backup
gzip /tmp/wave_d_backup_<DATE>.sql
mv /tmp/wave_d_backup_<DATE>.sql.gz /home/jgrusewski/Work/foxhunt/backups/

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Level 3: Partial Rollback (Feature-Specific)

Time Required: ~1-2 minutes Data Loss: Specific feature data only Use When: Need to disable specific Wave D features while keeping others

Disable Regime Transitions Only

-- Drop transition-related function
DROP FUNCTION IF EXISTS get_regime_transition_matrix(TEXT, INTEGER);

-- Archive and clear transition data
CREATE TABLE regime_transitions_archive AS SELECT * FROM regime_transitions;
TRUNCATE TABLE regime_transitions;

Disable Adaptive Strategy Metrics Only

-- Drop performance function
DROP FUNCTION IF EXISTS get_regime_performance(TEXT, INTEGER);

-- Archive and clear metrics data
CREATE TABLE adaptive_strategy_metrics_archive AS SELECT * FROM adaptive_strategy_metrics;
TRUNCATE TABLE adaptive_strategy_metrics;

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Rollback Decision Matrix

Situation	Rollback Level	Data Preservation	Downtime
Critical production bug	Level 1	No	<1 min
Performance degradation	Level 3	Yes	<2 min
Data integrity issue	Level 2	Yes	5-10 min
Feature disable request	Level 3	Yes	<2 min
Schema conflict	Level 1	No	<1 min

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Re-Migration Process

If rollback was executed and you need to re-apply Wave D:

# Step 1: Ensure rollback is complete
psql postgresql://foxhunt:foxhunt_dev_password@localhost:5432/foxhunt -c "
SELECT table_name FROM information_schema.tables 
WHERE table_name IN ('regime_states', 'regime_transitions', 'adaptive_strategy_metrics');
"
# Expected: 0 rows

# Step 2: Re-apply migration (using sqlx)
cargo sqlx migrate run

# Step 3: Verify migration
psql postgresql://foxhunt:foxhunt_dev_password@localhost:5432/foxhunt -c "
SELECT version, description, success FROM _sqlx_migrations WHERE version = 45;
"
# Expected: 1 row with success = true

# Step 4: Restore data (if Level 2 rollback was used)
psql postgresql://foxhunt:foxhunt_dev_password@localhost:5432/foxhunt \
  -f /home/jgrusewski/Work/foxhunt/backups/wave_d_backup_<DATE>.sql

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Rollback Testing (Pre-Production)

Before production deployment, test rollback procedures:

# Test Environment Setup
export TEST_DB="postgresql://foxhunt:foxhunt_dev_password@localhost:5432/foxhunt_test"

# Test 1: Full Rollback
psql $TEST_DB -f migrations/045_wave_d_regime_tracking.sql
psql $TEST_DB -f migrations/045_wave_d_regime_tracking.down.sql

# Test 2: Rollback with Data
psql $TEST_DB -f migrations/045_wave_d_regime_tracking.sql
psql $TEST_DB -c "INSERT INTO regime_states (symbol, event_timestamp, regime, confidence) VALUES ('TEST', NOW(), 'Normal', 0.8);"
pg_dump $TEST_DB --table=regime_states --data-only --inserts --file=/tmp/test_backup.sql
psql $TEST_DB -f migrations/045_wave_d_regime_tracking.down.sql
psql $TEST_DB -f migrations/045_wave_d_regime_tracking.sql
psql $TEST_DB -f /tmp/test_backup.sql

# Verify data restored
psql $TEST_DB -c "SELECT * FROM regime_states WHERE symbol = 'TEST';"

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Emergency Contacts

• DBA On-Call: [Contact Info]
• DevOps Lead: [Contact Info]
• Wave D Lead: Agent DB-01
• Escalation Path: DBA → DevOps Lead → CTO

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Rollback Checklist

Pre-Rollback

• Identify rollback level (1, 2, or 3)
• Notify stakeholders (if Level 1 or 2)
• Create backup (if Level 2)
• Document reason for rollback
• Verify application services can handle missing tables/functions

During Rollback

• Stop dependent services (trading_service, backtesting_service, ml_training_service)
• Execute rollback SQL
• Verify tables/functions dropped
• Check for orphaned sequences or constraints
• Review PostgreSQL logs for errors

Post-Rollback

• Restart application services
• Verify services operational without Wave D features
• Monitor error logs for 24 hours
• Document rollback completion
• Schedule post-mortem (if production rollback)
• Update migration tracking

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Known Issues & Gotchas

1. Checksum Mismatch: Migration 045 shows a checksum difference in sqlx migrate info. This is expected due to local edits but does not affect functionality.
2. Dependent Services: Ensure Trading Service, Backtesting Service, and ML Training Service are stopped before rollback to avoid connection errors.
3. Partitioned Tables: Wave D tables are not partitioned. If data volume grows, consider partitioning before re-migration.
4. Foreign Keys: No foreign keys reference Wave D tables, so rollback is safe without cascade concerns.
5. Materialized Views: No materialized views depend on Wave D tables.

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Performance Impact

Rollback Performance

• Level 1 (Emergency): <1 second
• Level 2 (Data Preservation): 5-10 minutes (depends on data volume)
• Level 3 (Partial): <30 seconds per feature

Application Impact

• Zero Downtime: If application gracefully handles missing tables (recommended)
• 2-5 Minute Downtime: If services must be restarted
• Feature Degradation: Wave D features unavailable, fallback to Wave C (201 features)

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Compliance & Audit

All rollbacks must be:

1. Logged in audit_log table (use transaction_audit_events)
2. Documented in change management system
3. Reported to compliance team (if production)
4. Included in monthly incident report

-- Example audit log entry
INSERT INTO transaction_audit_events (
  event_type, 
  event_data, 
  user_id, 
  event_timestamp
) VALUES (
  'MIGRATION_ROLLBACK',
  '{"migration": "045_wave_d_regime_tracking", "level": 1, "reason": "Critical production issue"}',
  'system',
  NOW()
);

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Appendix A: Rollback Validation Queries

-- Verify all Wave D components removed
SELECT 
  'Tables' AS component_type,
  COUNT(*) AS remaining_count
FROM information_schema.tables 
WHERE table_name IN ('regime_states', 'regime_transitions', 'adaptive_strategy_metrics')
UNION ALL
SELECT 
  'Functions' AS component_type,
  COUNT(*) AS remaining_count
FROM information_schema.routines 
WHERE routine_name IN ('get_latest_regime', 'get_regime_transition_matrix', 'get_regime_performance')
UNION ALL
SELECT 
  'Indexes' AS component_type,
  COUNT(*) AS remaining_count
FROM pg_indexes 
WHERE tablename IN ('regime_states', 'regime_transitions', 'adaptive_strategy_metrics');

-- Expected: 0 for all component types

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Appendix B: Common Rollback Errors

Error: "relation does not exist"

Cause: Application attempting to access Wave D tables after rollback Solution: Restart application services or deploy application version without Wave D features

Error: "function does not exist"

Cause: Application calling Wave D functions after rollback Solution: Ensure application code handles missing functions gracefully

Error: "permission denied"

Cause: Database user lacks DROP privileges Solution: Execute rollback as foxhunt user (owner of tables)

Error: "cannot drop table because other objects depend on it"

Cause: Unexpected foreign key or view dependency Solution: Use CASCADE option: DROP TABLE regime_states CASCADE;

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End of Rollback Procedures