Integration Patterns Documentation¶

Overview¶

This document defines the integration patterns used in the Dispatch Center Application, providing detailed implementation guidance, technology mapping, and system-specific applications for each pattern.

Table of Contents¶

Integration Patterns Overview
Pattern 1: Request/Response - RESTful API
Pattern 2: Event-Driven Messaging
Pattern 3: Batch Processing
Pattern 4: Webhook Notifications
Pattern 5: Hybrid Integration
Pattern Selection Matrix
Implementation Guidelines
Best Practices

Integration Patterns Overview¶

Request/Response¶

flowchart TB
    client["Client"]
    server["Server"]
    client <--> server

Event-Driven Messaging¶

flowchart TB
    publisher["Publisher"]
    message_bus["Message Bus"]
    subscriber["Subscriber"]
    publisher --> message_bus
    message_bus --> subscriber

Batch Processing¶

flowchart TB
    scheduler["Scheduler"]
    etl["ETL Process"]
    data_store["Data Store"]
    scheduler --> etl
    etl --> data_store

Webhook Notifications¶

flowchart TB
    external_system["External System"]
    our_endpoint["Our Endpoint"]
    external_system --> our_endpoint

Pattern 1: Request/Response - RESTful API¶

Pattern Description¶

Synchronous communication pattern where the client sends a request and waits for an immediate response. Ideal for real-time operations requiring immediate feedback.

Technical Implementation¶

restful_api_pattern:
  protocol: "HTTPS"
  data_format: "JSON"
  authentication: "OAuth 2.0 / JWT / API Keys"
  error_handling: "HTTP status codes with detailed error responses"
  timeout: "30 seconds default"
  retry_logic: "Exponential backoff for transient failures"

Use Cases¶

Real-time data queries and updates
User-initiated actions requiring immediate response
Data validation and verification
Status checks and health monitoring

Implementation Architecture¶

[ApiController]
[Route("api/[controller]")]
public class IntegrationController : ControllerBase
{
    private readonly IExternalSystemService _externalSystemService;

    [HttpGet("customer/{id}")]
    public async Task<ActionResult<CustomerDto>> GetCustomer(string id)
    {
        try
        {
            var customer = await _externalSystemService.GetCustomerAsync(id);
            return Ok(customer);
        }
        catch (ExternalSystemException ex)
        {
            return StatusCode(502, new { Error = "External system unavailable", Details = ex.Message });
        }
    }
}

System Integration Table - Request/Response Pattern¶

System	Implementation	Endpoints	Authentication	Data Format	Use Cases
Reach	Azure API Management → Reach REST API	`/api/servicerequests` `/api/technicians` `/api/customers`	OAuth 2.0	JSON	• Service request status updates • Technician availability queries • Customer information retrieval
Maddenco	Direct REST API integration	`/api/equipment` `/api/maintenance` `/api/inventory`	API Key	JSON	• Equipment status queries • Maintenance schedule retrieval • Parts availability checks
Dayforce	Dayforce REST API	`/api/employees` `/api/schedules` `/api/timetracking`	OAuth 2.0	JSON	• Employee information queries • Schedule modifications • Real-time availability checks
GeoTab	MyGeotab API	`/api/vehicles` `/api/trips` `/api/devices`	OAuth 2.0	JSON	• Real-time vehicle location • Route optimization queries • Vehicle diagnostics
Merchant Partners	Payment Gateway API	`/api/payments` `/api/transactions` `/api/refunds`	OAuth 2.0 + TLS Client Cert	JSON	• Payment authorization • Transaction status queries • Refund processing
Treadnet	Network Management API	`/api/network/status` `/api/outages` `/api/topology`	Certificate-based	JSON	• Network status queries • Outage information retrieval • Impact assessment

Pattern 2: Event-Driven Messaging¶

Pattern Description¶

Asynchronous communication pattern using publish-subscribe messaging for loose coupling between systems. Ideal for notifications, workflow automation, and handling high-volume events.

Technical Implementation¶

event_driven_pattern:
  message_broker: "Azure Service Bus"
  pattern_type: "Publisher/Subscriber"
  message_format: "JSON with envelope"
  delivery_guarantee: "At-least-once"
  error_handling: "Dead letter queues"
  retry_policy: "Exponential backoff with circuit breaker"

Use Cases¶

Real-time notifications and alerts
Workflow automation and orchestration
Event sourcing and audit trails
System decoupling and scalability

Implementation Architecture¶

public class ServiceRequestEventPublisher
{
    private readonly ServiceBusClient _serviceBusClient;

    public async Task PublishServiceRequestCreatedAsync(ServiceRequestCreatedEvent eventData)
    {
        var message = new ServiceBusMessage(JsonSerializer.Serialize(eventData))
        {
            Subject = "ServiceRequestCreated",
            MessageId = Guid.NewGuid().ToString(),
            TimeToLive = TimeSpan.FromHours(24)
        };

        await _serviceBusClient.CreateSender("servicerequest-events").SendMessageAsync(message);
    }
}

public class ServiceRequestEventSubscriber
{
    [ServiceBusProcessor("servicerequest-events", "dispatch-subscription")]
    public async Task ProcessServiceRequestCreatedAsync(ServiceBusReceivedMessage message)
    {
        var eventData = JsonSerializer.Deserialize<ServiceRequestCreatedEvent>(message.Body);
        await _dispatchService.AssignTechnicianAsync(eventData.ServiceRequestId);
    }
}

System Integration Table - Event-Driven Messaging Pattern¶

System	Implementation	Topics/Queues	Message Types	Triggers	Processing
Reach	Service Bus → Reach webhook	`reach-events` `reach-updates`	• ServiceRequestStatusChanged • TechnicianAvailabilityUpdated • CustomerCommunicationLogged	• Status changes in Reach • Schedule modifications • Customer interactions	• Update local status • Trigger notifications • Sync customer data
Treadnet	SNMP traps → Service Bus	`network-events` `network-alerts`	• NetworkOutageDetected • ServiceImpactAlert • NetworkRestored	• Network outages • Service degradation • Infrastructure changes	• Correlate with service requests • Notify dispatch team • Update service status
GeoTab	GeoTab webhooks → Service Bus	`vehicle-events` `geofence-events`	• VehicleLocationUpdated • GeofenceEntered • GeofenceExited • VehicleStatusChanged	• GPS location changes • Geofence boundaries • Vehicle diagnostics	• Update technician location • Calculate ETAs • Trigger arrival notifications
Dayforce	Dayforce webhooks → Service Bus	`hr-events` `schedule-events`	• EmployeeScheduleChanged • TimeOffRequested • SkillCertificationUpdated	• Schedule changes • Employee status updates • Certification renewals	• Update technician availability • Adjust dispatch assignments • Validate certifications
Merchant Partners	Payment webhooks → Service Bus	`payment-events` `financial-events`	• PaymentCompleted • PaymentFailed • ChargebackReceived • RefundProcessed	• Payment confirmations • Transaction failures • Financial disputes	• Update invoice status • Trigger collections process • Generate financial reports
Maddenco	Equipment status → Service Bus	`equipment-events` `maintenance-events`	• EquipmentStatusChanged • MaintenanceScheduled • PartOrderRequired	• Equipment failures • Maintenance schedules • Inventory levels	• Update equipment status • Schedule maintenance • Order replacement parts

Pattern 3: Batch Processing¶

Pattern Description¶

Scheduled bulk data processing pattern for handling large volumes of data, data synchronization, and long-running operations that don't require real-time processing.

Technical Implementation¶

batch_processing_pattern:
  orchestration: "Azure Data Factory"
  scheduling: "Time-based triggers and dependency-based"
  processing: "Azure Functions + SQL stored procedures"
  monitoring: "Application Insights + Data Factory monitoring"
  error_handling: "Pipeline retry with notification"
  data_format: "CSV, JSON, XML, Database extracts"

Use Cases¶

Data synchronization between systems
Historical data migration
Report generation and data aggregation
Data warehouse ETL operations

Implementation Architecture¶

{
  "batch_pipeline": {
    "name": "DailyDataSynchronization",
    "schedule": "0 2 * * *",
    "activities": [
      {
        "name": "ExtractCustomerData",
        "type": "Copy",
        "source": "ExternalSystemAPI",
        "sink": "StagingDatabase"
      },
      {
        "name": "TransformData",
        "type": "DataFlow",
        "transformations": ["DataCleansing", "Deduplication", "Validation"]
      },
      {
        "name": "LoadToTargetSystem",
        "type": "Copy", 
        "source": "StagingDatabase",
        "sink": "ProductionDatabase"
      }
    ]
  }
}

System Integration Table - Batch Processing Pattern¶

System	Implementation	Schedule	Data Volume	Processing Type	Output
Reach	ADF pipeline → Reach database export	Daily 2:00 AM Historical migration (one-time)	• 10,000 service requests/month • 2TB historical data • 50,000 customer records	• Incremental sync • Data deduplication • Schema transformation	• Updated service requests • Customer master data • Historical analytics data
Dayforce	ADF pipeline → Dayforce API	Daily 1:00 AM Weekly full sync (Sunday)	• 200 employee records • 1,000 schedule entries/week • Certification data	• Employee data sync • Schedule consolidation • Skills matrix update	• Employee master data • Updated schedules • Certification status
Maddenco	ADF pipeline → Maddenco database	Daily 3:00 AM Real-time for critical alerts	• 5,000 equipment records • 500 maintenance records/day • Parts inventory	• Equipment status sync • Maintenance history • Inventory reconciliation	• Equipment master data • Maintenance schedules • Inventory levels
GeoTab	ADF pipeline → GeoTab API	Hourly for reports Daily for historical data	• 50 vehicles • 100MB GPS data/day • Trip history	• GPS data aggregation • Trip report generation • Vehicle utilization analysis	• Route analytics • Vehicle performance reports • Utilization metrics
Merchant Partners	ADF pipeline → Payment gateway	Daily settlement processing Monthly reconciliation	• 1,000 transactions/month • Settlement reports • Chargeback data	• Transaction reconciliation • Settlement processing • Financial reporting	• Reconciled transactions • Settlement reports • Financial analytics
Treadnet	ADF pipeline → Network monitoring	Weekly network reports Monthly capacity planning	• 500 network events/day • Historical outage data • Performance metrics	• Event correlation • Trend analysis • Capacity planning	• Network health reports • Outage analytics • Capacity forecasts

Pattern 4: Webhook Notifications¶

Pattern Description¶

Reverse API pattern where external systems make HTTP callbacks to notify our system of events. Provides real-time notifications without polling.

Technical Implementation¶

webhook_pattern:
  protocol: "HTTPS POST"
  security: "Signature verification + IP whitelisting"
  payload_format: "JSON"
  response_requirement: "HTTP 200-299 for acknowledgment"
  retry_behavior: "External system responsibility"
  timeout: "30 seconds"

Use Cases¶

Real-time event notifications
Payment confirmations
Status change notifications
Third-party system integration

Implementation Architecture¶

[ApiController]
[Route("api/webhooks")]
public class WebhookController : ControllerBase
{
    [HttpPost("geotab/vehicle-status")]
    [ValidateWebhookSignature("GeoTab")]
    public async Task<IActionResult> HandleGeoTabVehicleStatus([FromBody] VehicleStatusWebhook payload)
    {
        try
        {
            await _vehicleService.UpdateVehicleStatusAsync(payload);
            return Ok(new { Status = "Processed", MessageId = payload.Id });
        }
        catch (Exception ex)
        {
            _logger.LogError(ex, "Failed to process GeoTab webhook");
            return StatusCode(500, new { Error = "Processing failed" });
        }
    }
}

System Integration Table - Webhook Notifications Pattern¶

System	Implementation	Webhook Endpoints	Security	Event Types	Response Handling
GeoTab	GeoTab → Our API endpoints	`/api/webhooks/geotab/vehicle-location` `/api/webhooks/geotab/geofence` `/api/webhooks/geotab/diagnostics`	HMAC-SHA256 signature IP whitelisting	• Vehicle location updates • Geofence entry/exit • Vehicle diagnostics • Driver status changes	• Immediate acknowledgment • Async processing via Service Bus • Retry handling for failures
Merchant Partners	Payment processor → Our endpoints	`/api/webhooks/payments/confirmation` `/api/webhooks/payments/failure` `/api/webhooks/payments/chargeback`	TLS client certificates Signature verification	• Payment confirmations • Transaction failures • Chargeback notifications • Refund completions	• Immediate HTTP 200 response • Update payment status • Trigger business workflows
Maddenco	Maddenco → Our API endpoints	`/api/webhooks/maddenco/equipment-status` `/api/webhooks/maddenco/maintenance-alert` `/api/webhooks/maddenco/inventory`	API key authentication IP whitelisting	• Equipment status changes • Maintenance alerts • Inventory updates • Service notifications	• Status acknowledgment • Update equipment records • Trigger maintenance workflows
Dayforce	Dayforce → Our API endpoints	`/api/webhooks/dayforce/schedule-change` `/api/webhooks/dayforce/employee-update` `/api/webhooks/dayforce/timeoff`	OAuth 2.0 tokens Signature verification	• Schedule modifications • Employee status updates • Time-off requests • Certification updates	• Immediate acknowledgment • Update employee schedules • Adjust dispatch assignments

Pattern 5: Hybrid Integration¶

Pattern Description¶

Combination of multiple integration patterns to optimize for different types of operations within the same system integration.

Technical Implementation¶

hybrid_pattern:
  components:
    - "Real-time API for critical operations"
    - "Event-driven messaging for notifications"
    - "Batch processing for bulk operations"
    - "Webhooks for external notifications"
  orchestration: "Logic Apps + Service Bus"
  data_consistency: "Eventually consistent with reconciliation"

Use Cases¶

Complex systems requiring multiple integration types
Legacy system modernization
High-volume systems with mixed requirements

System Integration Table - Hybrid Pattern¶

System	Real-time API	Event Messaging	Batch Processing	Webhooks	Orchestration
Reach	• Service request queries • Status updates • Customer lookups	• Status change notifications • Assignment updates • Communication logs	• Historical data migration • Daily data synchronization • Report generation	• Service completion notifications • Emergency alerts • Schedule changes	Logic Apps coordinate data flow Service Bus for event routing

Pattern Selection Matrix¶

Decision Criteria Table¶

Criteria	Request/Response	Event-Driven	Batch Processing	Webhooks	Hybrid
Latency Requirements	Low (< 2 sec)	Medium (< 30 sec)	High (hours/days)	Low (< 5 sec)	Mixed
Data Volume	Low-Medium	Medium	High	Low	Mixed
Coupling	Tight	Loose	Loose	Medium	Mixed
Reliability	Medium	High	High	Medium	High
Complexity	Low	Medium	High	Low	High
Cost	Low	Medium	High	Low	High
Scalability	Medium	High	High	Medium	High

Pattern Selection Guidelines¶

selection_criteria:
  use_request_response_when:
    - "Immediate response required"
    - "User-initiated actions"
    - "Data validation needed"
    - "Low data volume"

  use_event_driven_when:
    - "Loose coupling desired"
    - "High scalability required"
    - "Async processing acceptable"
    - "Multiple consumers needed"

  use_batch_processing_when:
    - "Large data volumes"
    - "Non-time-critical operations"
    - "Scheduled operations"
    - "Data transformation required"

  use_webhooks_when:
    - "External system controls timing"
    - "Real-time notifications needed"
    - "Reverse integration required"
    - "Event-driven external triggers"

  use_hybrid_when:
    - "Complex integration requirements"
    - "Mixed latency requirements"
    - "Legacy system constraints"
    - "Gradual migration approach"

Implementation Guidelines¶

Technology Stack Mapping¶

technology_implementation:
  api_management: "Azure API Management"
  messaging: "Azure Service Bus"
  batch_processing: "Azure Data Factory + Azure Functions"
  webhook_hosting: "Azure App Service"
  orchestration: "Logic Apps"
  monitoring: "Application Insights + Azure Monitor"
  security: "Azure Key Vault + Managed Identity"

Error Handling Strategy¶

error_handling:
  request_response:
    - "HTTP status codes"
    - "Detailed error messages"
    - "Client-side retry logic"

  event_driven:
    - "Dead letter queues"
    - "Retry policies"
    - "Circuit breakers"

  batch_processing:
    - "Pipeline retry mechanisms"
    - "Error notification"
    - "Data quality validation"

  webhooks:
    - "Acknowledgment responses"
    - "Idempotency handling"
    - "Duplicate detection"

Performance Optimization¶

performance_guidelines:
  caching_strategy:
    - "Redis cache for frequently accessed data"
    - "API response caching"
    - "Database query optimization"

  throttling_and_rate_limiting:
    - "API rate limits per system"
    - "Message processing limits"
    - "Batch job resource allocation"

  monitoring_and_alerting:
    - "Response time thresholds"
    - "Error rate monitoring"
    - "Resource utilization tracking"

Best Practices¶

Security Best Practices¶

security_practices:
  authentication:
    - "OAuth 2.0 for modern APIs"
    - "API keys for simple integrations"
    - "Certificate-based for high security"

  data_protection:
    - "TLS 1.3 for all communications"
    - "Data encryption at rest"
    - "PII data minimization"

  access_control:
    - "Principle of least privilege"
    - "Regular access reviews"
    - "API gateway security policies"

Operational Best Practices¶

operational_practices:
  monitoring:
    - "End-to-end tracing"
    - "Business metric tracking"
    - "SLA monitoring"

  testing:
    - "Contract testing for APIs"
    - "Load testing for scalability"
    - "Chaos engineering for resilience"

  deployment:
    - "Blue-green deployments"
    - "Canary releases"
    - "Automated rollback procedures"

Documentation Standards¶

documentation_requirements:
  api_documentation:
    - "OpenAPI/Swagger specifications"
    - "Authentication examples"
    - "Error code references"

  integration_guides:
    - "Step-by-step setup instructions"
    - "Configuration examples"
    - "Troubleshooting guides"

  operational_runbooks:
    - "Incident response procedures"
    - "Performance tuning guides"
    - "Disaster recovery plans"

Document Version: 1.0
Last Updated: January 2026
Next Review: April 2026