Data Migration Strategy

Document ID: GP-MIG-2025-001

Document Control

Revision History and Approval Log

Version	Date	Author	Description of Changes	Risk Assessment	Architect Approval	Tech Anchor Approval	Status
0.1	2025-01-10	[Author Name]	Initial draft - Basic migration strategy outline	Low	Pending (@arch_lead)	Pending (@tech_lead)	Draft
0.2	2025-01-12	[Author Name]	Added detailed component diagrams and data flow	Low	Approved (@arch_lead) 2025-01-13	Pending (@tech_lead)	In Review
0.3	2025-01-14	[Author Name]	Updated security protocols and added rollback procedures	Medium	Pending (@arch_lead)	Pending (@tech_lead)	In Review
1.0	2025-01-18	[Author Name]	Production release candidate - Complete implementation guide	Medium	Pending (@arch_lead)	Pending (@tech_lead)	Awaiting Approval

Approval Requirements

• Architect review required for: architecture design, system integration, performance considerations, scalability strategy, security architecture, risk assessment

• Tech Anchor review required for: implementation details, code standards, testing strategy, deployment procedures, monitoring setup, operational considerations

Document Information

• Classification: Confidential

• Last Updated: January 18, 2025

• Document Owner: [Author Name], Platform Migration Team

• Key Contacts:

  • Lead Architect: [Name] (@arch_lead)

  • Technical Anchor: [Name] (@tech_lead)

Overview

This document provides technical implementation details for migrating XXX from Legacy to Modern platform. The migration involves three primary synchronization strategies: One-time migration, CDC (Change Data Capture), and programmatic synchronization.

1. Prerequisites

• Access to both Legacy and Modern environments

• AWS DMS configured for data replication

• ACL service credentials

• Database access to Legacy systems

2. Infrastructure Setup

2.1 Technical Decisions Summary

Key Architectural Decisions

1. Auditing data Call Implementation

   • Must be asynchronous to prevent latency issues

   • Using temporary ACL service (temporary solution)

   • Will be decommissioned after modernization

2. Data Storage Strategy

   • All non-PII partner data will be stored in modern platform

   • Using JSONB in PostgreSQL for flexible data storage

   • Separate table structure for transactional vs. analytical data

3. Legacy System Integration

   • PAN status/expiry and token data accessed via token lookup service

   • OB indicator programmatically synced in temp and provisioning device tables

   • Duplicate provisioning risk accepted and tracked by product team

4. Event Management

   • ODIs events required for portal status history

   • WebSphere MQ integration for event publishing

   • Event flow documentation pending from technical team

2.2 Database Configuration

-- Legacy NWS Schema Update
ALTER TABLE provision_status 
ADD COLUMN sync_status VARCHAR(20),
ADD COLUMN last_sync_timestamp TIMESTAMP;

-- Modern Platform Schema - Core Tables
CREATE TABLE token_status (
    token_id VARCHAR(64) PRIMARY KEY,
    status VARCHAR(20),
    last_updated TIMESTAMP,
    sync_status VARCHAR(20)
);

2.2 Service Configuration

# app-ddx-trdc-google-hce Configuration
acl:
  sync:
    batch-size: 100
    retry-attempts: 3
    timeout: 5s
  endpoints:
    nws: ${NWS_ENDPOINT}
    ods: ${ODS_ENDPOINT}

3. Implementation Steps

3.1 Asynchronous Processing Implementation

// Async DS Call Handler
async function handleDSCall(requestData) {
    const eventId = generateEventId();
    await publishToEventQueue({
        eventId,
        type: 'DS_PROVISION_REQUEST',
        data: requestData,
        timestamp: new Date().toISOString()
    });
    
    return {
        requestId: eventId,
        status: 'ACCEPTED'
    };
}

// Partner Data Storage Handler
async function storePartnerData(partnerData) {
    const sanitizedData = removePIIData(partnerData);
    await db.query(`
        INSERT INTO partner_data (partner_id, data, metadata)
        VALUES ($1, $2, $3)
    `, [partnerData.partnerId, sanitizedData, extractMetadata(partnerData)]);
}

3.2 Event Management

3.1 Token System Integration

1. Configure Token System connection:

const tokenConfig = {
    endpoint: process.env.TOKEN_SYSTEM_ENDPOINT,
    timeout: 5000,
    retryAttempts: 3,
    batchSize: 50
};

1. Implement token status synchronization:

async function syncTokenStatus(tokenId) {
    try {
        const tokenStatus = await TokenSystem.getStatus(tokenId);
        await Promise.all([
            syncToNWS(tokenStatus),
            syncToODS(tokenStatus)
        ]);
        await updateSyncStatus(tokenId, 'COMPLETED');
    } catch (error) {
        await handleSyncError(tokenId, error);
    }
}

3.2 Provision Status Management

1. Implement status transition logic:

const VALID_TRANSITIONS = {
    'RECEIVED': ['PROCESSING', 'FAILED'],
    'PROCESSING': ['COMPLETED', 'FAILED'],
    'COMPLETED': ['VERIFIED'],
    'FAILED': ['RECEIVED'],
    'VERIFIED': ['ELIGIBLE'],
    'ELIGIBLE': []
};

function validateTransition(currentStatus, newStatus) {
    return VALID_TRANSITIONS[currentStatus]?.includes(newStatus) ?? false;
}

1. Status synchronization implementation:

async function syncProvisionStatus(provisionId) {
    const lockKey = `provision_lock_${provisionId}`;
    const lock = await acquireLock(lockKey);
    
    try {
        const status = await getProvisionStatus(provisionId);
        await syncToLegacySystem(status);
        await updateSyncMetadata(provisionId);
    } finally {
        await releaseLock(lock);
    }
}

3.3 Error Handling and Retry Logic

class SyncError extends Error {
    constructor(message, retryable = true) {
        super(message);
        this.retryable = retryable;
    }
}

async function retryWithBackoff(fn, maxAttempts = 3) {
    for (let attempt = 1; attempt <= maxAttempts; attempt++) {
        try {
            return await fn();
        } catch (error) {
            if (!error.retryable || attempt === maxAttempts) throw error;
            await sleep(Math.pow(2, attempt) * 1000);
        }
    }
}

4. Monitoring and Logging

4.1 Metrics Configuration

const metrics = {
    syncLatency: new Histogram({
        name: 'sync_latency_ms',
        help: 'Synchronization latency in milliseconds',
        buckets: [10, 50, 100, 200, 500, 1000]
    }),
    syncErrors: new Counter({
        name: 'sync_errors_total',
        help: 'Total synchronization errors'
    })
};

4.2 Logging Implementation

const logger = winston.createLogger({
    level: 'info',
    format: winston.format.json(),
    defaultMeta: { service: 'migration-service' },
    transports: [
        new winston.transports.File({ filename: 'error.log', level: 'error' }),
        new winston.transports.File({ filename: 'combined.log' })
    ]
});

5. Deployment Strategy

5.1 Ramp-Up Plan

• Start with 1% traffic to modern platform

• Monitor error rates and latency

• Increase by 5% weekly if metrics are stable

• Rollback plan if error rate exceeds 0.1%

5.2 Deployment Configuration

apiVersion: apps/v1
kind: Deployment
metadata:
  name: migration-service
spec:
  replicas: 3
  strategy:
    rollingUpdate:
      maxSurge: 1
      maxUnavailable: 0

6. Testing Requirements

6.1 Test Cases

1. Status transition validation

2. Data consistency checks

3. Latency monitoring

4. Error handling verification

5. Recovery procedures

6. Security validation

6.2 Test Data Generation

function generateTestData(count) {
    return Array.from({ length: count }, (_, i) => ({
        provisionId: `test_${i}`,
        status: 'RECEIVED',
        timestamp: new Date().toISOString()
    }));
}

7. Rollback Procedures

7.1 Emergency Rollback

async function emergencyRollback(batchId) {
    await stopIncomingTraffic();
    await revertDatabaseChanges(batchId);
    await notifyTeam();
    await switchToLegacySystem();
}

8. Security Considerations

8.1 Data Encryption

const crypto = require('crypto');

function encryptSensitiveData(data) {
    const cipher = crypto.createCipher('aes-256-gcm', process.env.ENCRYPTION_KEY);
    let encrypted = cipher.update(data, 'utf8', 'hex');
    encrypted += cipher.final('hex');
    return encrypted;
}

Contact Information

• Technical Lead: [Contact Information]

• Database Team: [Contact Information]

• Security Team: [Contact Information]

• Operations Team: [Contact Information]