Data Model

CityData Entity

Đây là entity chính để lưu trữ dữ liệu IoT trong hệ thống.

Java Class

@Data
@Document(collection = "city_data")
public class CityData {
    @Id
    private String id;
    
    private String timestamp;
    private String sensorId;
    private String metricType;  // temperature, humidity, co2
    private Double value;
    private DataType dataType;  // HOT, WARM, COLD
    
    @Indexed
    private String createdAt;
}

MongoDB Document

{
  "_id": ObjectId("675fb09c1a2b3c4d5e6f7890"),
  "timestamp": "2025-12-04T22:57:00Z",
  "sensorId": "SENSOR_0042",
  "metricType": "temperature",
  "value": 45.5,
  "dataType": "HOT",
  "createdAt": "2025-12-04T22:57:01Z"
}

Field Descriptions

Field	Type	Indexed	Description
_id	ObjectId	Primary Key	MongoDB auto-generated ID
timestamp	String (ISO 8601)	Yes	Thời điểm đo của sensor
sensorId	String	Yes	ID của sensor (SENSOR_XXXX)
metricType	String	Yes	Loại metric: temperature, humidity, co2
value	Double	No	Giá trị đo được
dataType	Enum	Yes	Classification: HOT, WARM, COLD
createdAt	String (ISO 8601)	TTL Index	Thời điểm lưu vào database

---

DataType Enum

public enum DataType {
    HOT,    // Anomaly data - stored in Redis + MongoDB
    WARM,   // Important recent data - stored in MongoDB warm_db
    COLD    // Normal data - stored in MongoDB cold_db
}

---

Redis Data Structure (HOT Tier)

Key Pattern

hot:sensor:{sensorId}:{timestamp}

Example

Key: hot:sensor:SENSOR_0042:2025-12-04T22:57:00Z

Value (Hash):
  sensorId: "SENSOR_0042"
  metricType: "temperature"
  value: "45.5"
  timestamp: "2025-12-04T22:57:00Z"
  dataType: "HOT"

TTL: 3600 seconds (1 hour)

Redis Commands

# Get single HOT record
HGETALL hot:sensor:SENSOR_0042:2025-12-04T22:57:00Z

# Get all HOT keys
KEYS hot:sensor:*

# Count HOT records
DBSIZE

# Check TTL
TTL hot:sensor:SENSOR_0042:2025-12-04T22:57:00Z

---

MongoDB Collections

WARM Tier (warm_db.city_data)

Collection: city_data
Database: warm_db

Indexes:

db.city_data.createIndex({ "timestamp": 1 })
db.city_data.createIndex({ "sensorId": 1 })
db.city_data.createIndex({ "metricType": 1 })
db.city_data.createIndex({ "dataType": 1 })
db.city_data.createIndex({ "createdAt": 1 }, { expireAfterSeconds: 2592000 }) // 30 days

Document Count:

db.getSiblingDB('warm_db').city_data.countDocuments()

COLD Tier (cold_db.city_data)

Collection: city_data
Database: cold_db

Indexes: Same as WARM tier (except no TTL index)

Document Count:

db.getSiblingDB('cold_db').city_data.countDocuments()

---

EdgeNodeConfig Model

@Data
public class EdgeNodeConfig {
    private String host;
    private int port;
    private String username;
    private String password;
    private String status;  // online, offline
    private String lastPing;
}

---

SystemStats DTO

@Data
public class SystemStatsDTO {
    private long hotCount;
    private long warmCount;
    private long coldCount;
    private double incomingRate;
    private double processedRate;
    private String lastUpdate;
}

---

ML Prediction Request

{
  "source": "SENSOR_0042",
  "metric_type": "temperature",
  "value": 45.5
}

ML Prediction Response

{
  "label": "HOT",
  "uri": "https://schema.org/Warning",
  "desc": "Temperature Anomaly Detected"
}

---

Database Schema Diagram