Time-Turner Protocol

"I mark the hours, every one, nor have I yet outrun the Sun. My use and value, unto you, are gauged by what you have to do."

The Time-Turner enables safe reversal of changes when things go wrong.

When to Use Time-Turner

Automatic Triggers

• •Deployment health check fails
• •Error rate exceeds threshold
• •Critical test fails post-deploy
• •Security vulnerability discovered

Manual Triggers

• •Human requests rollback
• •Headmaster declares rollback
• •Slytherin veto on deployment

Rollback Readiness

Every Year 5+ Task Must Have

## Time-Turner Preparation

### Rollback Trigger Conditions
[What would cause us to rollback]

### Rollback Steps
1. [Specific step 1]
2. [Specific step 2]
3. [Verification step]

### Rollback Verification
[How to confirm rollback succeeded]

### Data Considerations
[Any data that would be lost/affected]

### Point of No Return
[When rollback becomes impossible]

Rollback Tiers

Tier 1: Code Rollback (Git)

Scope: Application code only Time: Minutes Risk: Low

# Identify the commit to revert to
git log --oneline

# Revert to previous commit
git revert HEAD

# Or reset to specific commit (if safe)
git reset --hard <commit-sha>

# Push rollback
git push origin main

Tier 2: Deployment Rollback

Scope: Running application version Time: Minutes to hours Risk: Medium

# Docker/Container rollback
docker pull <previous-image-tag>
docker-compose up -d

# Kubernetes rollback
kubectl rollout undo deployment/<name>

# Cloud platform rollback
# (Platform-specific commands)

Tier 3: Database Rollback

Scope: Schema and/or data Time: Hours Risk: High

# Run down migration
npm run migrate:down

# Or restore from backup
pg_restore -d <database> <backup-file>

Tier 4: Full System Restore

Scope: Entire system state Time: Hours to days Risk: Critical

• •Restore from system backup
• •Rebuild from infrastructure code
• •Full data restoration

Rollback Procedure

Step 1: Assess

## Rollback Assessment

**Issue**: [What went wrong]
**Severity**: [P1/P2/P3/P4]
**Affected Systems**: [List]
**User Impact**: [Description]

### Rollback Decision
**Tier Needed**: [1/2/3/4]
**Estimated Time**: [Duration]
**Data Loss Risk**: [Yes/No - Details]

Step 2: Communicate

• •Update Marauder's Map: "TIME-TURNER ACTIVE"
• •Notify all Houses
• •Alert human if Year 5+
• •Update status page if public-facing

Step 3: Execute

• •Follow pre-documented rollback steps
• •One person executes, one verifies
• •No improvisation - follow the plan

Step 4: Verify

• •Run smoke tests
• •Check error rates
• •Verify critical paths
• •Monitor for 15 minutes

Step 5: Document

• •Create Pensieve entry
• •Record what went wrong
• •Document actual rollback steps
• •Note any deviations from plan

Rollback Templates

Code Rollback Template

#!/bin/bash
# Time-Turner: Code Rollback

echo "Starting code rollback..."

# Store current state
CURRENT_COMMIT=$(git rev-parse HEAD)
echo "Current commit: $CURRENT_COMMIT"

# Rollback
git revert --no-commit HEAD
git commit -m "Time-Turner: Rollback from $CURRENT_COMMIT"

# Verify
npm run test

if [ $? -eq 0 ]; then
  echo "Rollback successful"
  git push origin main
else
  echo "Rollback verification failed!"
  git reset --hard $CURRENT_COMMIT
  exit 1
fi

Deployment Rollback Template

#!/bin/bash
# Time-Turner: Deployment Rollback

PREVIOUS_VERSION=$1

echo "Rolling back to version: $PREVIOUS_VERSION"

# Pull previous image
docker pull myapp:$PREVIOUS_VERSION

# Stop current
docker-compose down

# Update compose file
sed -i "s/myapp:latest/myapp:$PREVIOUS_VERSION/" docker-compose.yml

# Start previous version
docker-compose up -d

# Health check
sleep 10
curl -f http://localhost/health || exit 1

echo "Rollback complete"

Rollback Points

Creating Rollback Points

Before any Year 3+ change, create a rollback point:

## Rollback Point: [ID]
**Created**: [Timestamp]
**Task**: [What we're about to do]
**State Captured**:
- Git commit: [SHA]
- Database migration: [Version]
- Config version: [Version]
- Deployed version: [Tag]

**Restore Commands**:
[Exact commands to return to this state]

Rollback Point Retention

• •Keep last 5 rollback points
• •Keep all Year 7 rollback points for 30 days
• •Archive to long-term storage monthly

Post-Rollback Actions

Immediate (Within 1 hour)

• • Verify system stable
• • Update Marauder's Map
• • Notify stakeholders
• • Begin root cause analysis

Short-term (Within 24 hours)

• • Complete Pensieve entry
• • Identify fix for original issue
• • Plan re-deployment
• • Update rollback procedures if needed

Long-term (Within 1 week)

• • Post-incident review
• • Update prevention measures
• • Train team on learnings
• • Update House skills if applicable

Point Deductions

Rollback Drills

Monthly, conduct a rollback drill:

1. •Pick a random Year 3-5 change
2. •Pretend it caused an issue
3. •Execute rollback procedure
4. •Measure time to recovery
5. •Document any issues with the plan
6. •Update procedures as needed

Drill Participation: All Houses Points: +5 for successful drill completion