Catalog Service Architecture

+-------------------------------------------------------------------+
|                       Catalog Service                              |
|                                                                    |
|  +------------------+  +------------------+  +-----------------+   |
|  | CatalogController|  | DataSourceCtrl   |  | DiscoveryCtrl   |   |
|  | /api/v1/catalog  |  | /api/v1/         |  | /api/v1/catalog |   |
|  |                  |  | datasources      |  | /discovery      |   |
|  +--------+---------+  +--------+---------+  +--------+--------+   |
|           |                      |                     |           |
|  +--------v----------------------v---------------------v--------+  |
|  |                    CatalogService                            |  |
|  |  - Database browsing    - Table management                   |  |
|  |  - Tag operations       - Statistics                         |  |
|  +----------------------------+---------------------------------+  |
|                               |                                    |
|  +----------------------------v---------------------------------+  |
|  |               Supporting Services                            |  |
|  |                                                              |  |
|  |  CatalogSearchService    MetadataIngestionService            |  |
|  |  ClassificationService   LineageService                      |  |
|  |  DataGlossaryService     GovernancePolicyService             |  |
|  +------+----------+----------+-----------+---------------------+  |
|         |          |          |           |                        |
|  +------v---+ +----v----+ +--v-------+ +-v-----------+            |
|  |PostgreSQL| |Elastic  | |OpenMeta  | |Kafka        |            |
|  |          | |Search   | |data      | |Events       |            |
|  +----------+ +---------+ +----------+ +-------------+            |
+-------------------------------------------------------------------+

// CatalogDatabase - Represents a database in a data source
@Entity
public class CatalogDatabase {
    private UUID id;
    private UUID tenantId;
    private String name;
    private String fullyQualifiedName;
    private String description;
    private int tableCount;
    private UUID dataSourceId;
}
 
// CatalogTable - Represents a table with schema information
@Entity
public class CatalogTable {
    private UUID id;
    private UUID tenantId;
    private String name;
    private String fullyQualifiedName;
    private String schemaName;
    private String catalogName;
    private TableType tableType;
    private String description;
    private int columnCount;
    private List<String> tags;
}
 
// CatalogDataSource - Registered data source
@Entity
public class CatalogDataSource {
    private UUID id;
    private UUID tenantId;
    private String name;
    private String type;       // postgresql, mysql, snowflake, etc.
    private String connectionConfig;
    private boolean active;
}
 
// CatalogTag - Tag for asset organization
@Entity
public class CatalogTag {
    private UUID id;
    private UUID tenantId;
    private String name;
    private TagCategory category;  // BUSINESS, TECHNICAL, CLASSIFICATION, CUSTOM
}
 
// CatalogLineage - Lineage relationship between entities
@Entity
public class CatalogLineage {
    private UUID id;
    private UUID tenantId;
    private UUID sourceEntityId;
    private UUID targetEntityId;
    private String lineageType;
}

# application.yml
server:
  port: 8086
 
spring:
  datasource:
    url: jdbc:postgresql://${DB_HOST}:5432/${DB_NAME}
    username: ${DB_USER}
    password: ${DB_PASSWORD}
  elasticsearch:
    uris: ${ELASTICSEARCH_URL:http://elasticsearch:9200}
  kafka:
    bootstrap-servers: ${KAFKA_BOOTSTRAP_SERVERS}
    producer:
      key-serializer: org.apache.kafka.common.serialization.StringSerializer
      value-serializer: org.springframework.kafka.support.serializer.JsonSerializer
 
openmetadata:
  url: ${OPENMETADATA_URL:http://openmetadata:8585}
  auth-token: ${OPENMETADATA_TOKEN}

@GetMapping("/databases")
public ResponseEntity<Page<CatalogDatabase>> listDatabases(
        @RequestHeader("X-Tenant-ID") UUID tenantId,
        @RequestParam(defaultValue = "0") int page,
        @RequestParam(defaultValue = "20") int size) {
    Pageable pageable = PageRequest.of(page, size);
    Page<CatalogDatabase> databases = catalogService.listDatabases(tenantId, pageable);
    return ResponseEntity.ok(databases);
}