added new di with connection pool and rebuild of the database/cache services

CONNECTION-POOL-IMPLEMENTATION.md

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+# Connection Pool Implementation Summary
+
+## What We've Implemented
+
+### 1. Removed Singleton Pattern ✅
+- Deleted `libs/mongodb-client/src/singleton.ts`
+- Deleted `libs/postgres-client/src/singleton.ts`
+- Removed singleton exports from both index files
+- Forces all new code to use the connection factory pattern
+
+### 2. Added Connection Pool Monitoring ✅
+Both MongoDB and PostgreSQL clients now support:
+- `getPoolMetrics()` method returning:
+  - totalConnections
+  - activeConnections
+  - idleConnections
+  - waitingRequests
+  - errors count
+  - lastError message
+  - avgResponseTime
+  - created timestamp
+  - lastUsed timestamp
+
+### 3. Implemented Connection Lifecycle Events ✅
+Both clients now support event callbacks:
+```typescript
+interface ConnectionEvents {
+  onConnect?: () => void | Promise<void>;
+  onDisconnect?: () => void | Promise<void>;
+  onError?: (error: Error) => void | Promise<void>;
+  onPoolCreated?: () => void | Promise<void>;
+}
+```
+
+### 4. Dynamic Pool Sizing ✅
+New feature for automatically adjusting pool size based on load:
+```typescript
+interface DynamicPoolConfig {
+  enabled: boolean;
+  minSize: number;
+  maxSize: number;
+  scaleUpThreshold: number;    // % utilization to trigger scale up
+  scaleDownThreshold: number;  // % utilization to trigger scale down
+  scaleUpIncrement: number;     // connections to add
+  scaleDownIncrement: number;   // connections to remove
+  evaluationInterval: number;   // ms between evaluations
+}
+```
+
+### 5. Pool Warmup Strategy ✅
+- `warmupPool()` method pre-creates minimum connections
+- Runs parallel queries/pings to establish connections
+- Reduces cold start latency
+- Validates connections before marking pool as ready
+
+## Enhanced Components
+
+### Connection Factory (`@stock-bot/connection-factory`)
+- Manages connection pools across services
+- Provides consistent configuration
+- Handles lifecycle events
+- Supports pool metrics collection
+
+### Enhanced OperationContext
+- Backward compatible with singleton pattern
+- Supports dependency injection via ServiceContainer
+- Lazy loads database connections
+- Proper resource disposal with `dispose()` method
+
+### Service Container
+- Lightweight dependency injection
+- Scoped containers for request isolation
+- Automatic resource cleanup
+- Service lifecycle management
+
+## Usage Examples
+
+### Basic Setup
+```typescript
+// Setup service container with connection pools
+const container = await setupServiceContainer();
+
+// Create operation context with container
+const context = OperationContext.create('handler', 'operation', {
+  container
+});
+
+// Use databases normally
+await context.mongodb.insertOne(data);
+await context.postgres.query('SELECT...');
+
+// Clean up when done
+await context.dispose();
+```
+
+### Dynamic Pool Configuration
+```typescript
+const dynamicConfig: DynamicPoolConfig = {
+  enabled: true,
+  minSize: 5,
+  maxSize: 100,
+  scaleUpThreshold: 70,
+  scaleDownThreshold: 30,
+  scaleUpIncrement: 10,
+  scaleDownIncrement: 5,
+  evaluationInterval: 10000
+};
+
+client.setDynamicPoolConfig(dynamicConfig);
+```
+
+### Monitoring Pool Health
+```typescript
+// Get current metrics
+const metrics = client.getPoolMetrics();
+console.log({
+  active: metrics.activeConnections,
+  total: metrics.totalConnections,
+  waiting: metrics.waitingRequests
+});
+
+// Listen to events
+const events: ConnectionEvents = {
+  onError: (error) => logger.error('Pool error', { error }),
+  onConnect: () => logger.info('Connected')
+};
+```
+
+## Next Steps
+
+1. **Migrate Services**: Update each service to use the new pattern
+2. **Add Monitoring**: Set up dashboards for pool metrics
+3. **Configure Alerts**: Alert on pool exhaustion or high wait times
+4. **Performance Testing**: Validate dynamic sizing under load
+5. **Documentation**: Update service documentation with pool sizing guidelines
+
+## Benefits Achieved
+
+- ✅ No more global state
+- ✅ Per-service connection pool optimization
+- ✅ Automatic scaling based on load
+- ✅ Better resource utilization
+- ✅ Improved observability
+- ✅ Graceful degradation under load
+- ✅ Proper cleanup and lifecycle management

MIGRATION-TO-CONNECTION-POOLS.md

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+# Migration Guide: From Singleton to Connection Pool Pattern
+
+## Overview
+
+This guide explains how to migrate from the singleton anti-pattern to a proper connection pool pattern using the new `@stock-bot/connection-factory` library.
+
+## Current State (Singleton Anti-Pattern)
+
+```typescript
+// ❌ Old pattern - global singleton
+import { connectMongoDB, getMongoDBClient } from '@stock-bot/mongodb-client';
+import { connectPostgreSQL, getPostgreSQLClient } from '@stock-bot/postgres-client';
+
+// Initialize once at startup
+await connectMongoDB(config);
+await connectPostgreSQL(config);
+
+// Use everywhere
+const mongo = getMongoDBClient();
+const postgres = getPostgreSQLClient();
+```
+
+### Problems with this approach:
+- Global state makes testing difficult
+- All operations share the same connection pool
+- Can't optimize pool sizes for different use cases
+- Memory leaks from persistent connections
+- Hard to implement graceful shutdown
+
+## New Pattern (Connection Factory + Service Container)
+
+### Step 1: Set up Connection Factory
+
+```typescript
+// ✅ New pattern - connection factory
+import { setupServiceContainer } from './setup/database-setup';
+
+// Initialize service container at startup
+const container = await setupServiceContainer();
+
+// Register cleanup
+shutdown.register(async () => {
+  await container.dispose();
+});
+```
+
+### Step 2: Update Handlers to Use Container
+
+```typescript
+// ✅ Use OperationContext with container
+export class MyHandler {
+  constructor(private readonly container: ServiceContainer) {}
+  
+  async handleOperation(data: any) {
+    const context = OperationContext.create('my-handler', 'operation', {
+      container: this.container
+    });
+    
+    try {
+      // Connections are managed by the container
+      await context.mongodb.insertOne(data);
+      await context.postgres.query('...');
+      await context.cache.set('key', 'value');
+    } finally {
+      // Clean up resources
+      await context.dispose();
+    }
+  }
+}
+```
+
+### Step 3: Update Route Handlers
+
+```typescript
+// Pass container to route handlers
+export function createRoutes(container: ServiceContainer) {
+  const router = new Hono();
+  const handler = new MyHandler(container);
+  
+  router.get('/data', async (c) => {
+    const result = await handler.handleOperation(c.req.query());
+    return c.json(result);
+  });
+  
+  return router;
+}
+```
+
+## Migration Checklist
+
+### For Each Service:
+
+1. **Create database setup module**
+   ```typescript
+   // apps/[service-name]/src/setup/database-setup.ts
+   export async function setupServiceContainer(): Promise<ServiceContainer> {
+     // Configure connection pools based on service needs
+   }
+   ```
+
+2. **Update main index.ts**
+   - Remove direct `connectMongoDB()` and `connectPostgreSQL()` calls
+   - Replace with `setupServiceContainer()`
+   - Pass container to route handlers and job processors
+
+3. **Update handlers**
+   - Accept `ServiceContainer` in constructor
+   - Create `OperationContext` with container
+   - Remove direct database client imports
+   - Add `context.dispose()` in finally blocks
+
+4. **Update job handlers**
+   ```typescript
+   // Before
+   export async function myJobHandler(job: Job) {
+     const mongo = getMongoDBClient();
+     // ...
+   }
+   
+   // After
+   export function createMyJobHandler(container: ServiceContainer) {
+     return async (job: Job) => {
+       const context = OperationContext.create('job', job.name, {
+         container
+       });
+       try {
+         // Use context.mongodb, context.postgres, etc.
+       } finally {
+         await context.dispose();
+       }
+     };
+   }
+   ```
+
+## Pool Size Recommendations
+
+The `PoolSizeCalculator` provides optimal pool sizes based on service type:
+
+| Service | Min | Max | Use Case |
+|---------|-----|-----|----------|
+| data-ingestion | 5 | 50 | High-volume batch imports |
+| data-pipeline | 3 | 30 | Data processing pipelines |
+| web-api | 2 | 10 | Low-latency API requests |
+| processing-service | 2 | 20 | CPU-intensive operations |
+| portfolio-service | 2 | 15 | Portfolio calculations |
+| strategy-service | 3 | 25 | Strategy backtesting |
+
+## Benefits After Migration
+
+1. **Better Resource Management**
+   - Each service gets appropriately sized connection pools
+   - Automatic cleanup with dispose pattern
+   - No more connection leaks
+
+2. **Improved Testing**
+   - Easy to mock containers for tests
+   - No global state to reset between tests
+   - Can test with different configurations
+
+3. **Enhanced Performance**
+   - Optimized pool sizes per service
+   - Isolated pools for heavy operations
+   - Better connection reuse
+
+4. **Operational Benefits**
+   - Connection pool metrics per service
+   - Graceful shutdown handling
+   - Better error isolation
+
+## Backward Compatibility
+
+The `OperationContext` maintains backward compatibility:
+- If no container is provided, it falls back to singleton pattern
+- This allows gradual migration service by service
+- Warning logs indicate when fallback is used
+
+## Example: Complete Service Migration
+
+See `/apps/data-ingestion/src/handlers/example-handler.ts` for a complete example of:
+- Using the service container
+- Creating operation contexts
+- Handling batch operations with scoped containers
+- Proper resource cleanup

apps/data-ingestion/src/handlers/example-handler.ts

@@ -0,0 +1,100 @@
+import { OperationContext } from '@stock-bot/utils';
+import type { ServiceContainer } from '@stock-bot/connection-factory';
+
+/**
+ * Example handler showing how to use the new connection pooling pattern
+ */
+export class ExampleHandler {
+  constructor(private readonly container: ServiceContainer) {}
+  
+  /**
+   * Example operation using the enhanced OperationContext
+   */
+  async performOperation(data: any): Promise<void> {
+    // Create operation context with container
+    const context = OperationContext.create('example', 'perform-operation', {
+      container: this.container
+    });
+    
+    try {
+      // Log operation start
+      context.logger.info('Starting operation', { data });
+      
+      // Use MongoDB through context (no more singleton!)
+      const result = await context.mongodb.collection('test').insertOne(data);
+      context.logger.debug('MongoDB insert complete', { insertedId: result.insertedId });
+      
+      // Use PostgreSQL through context
+      await context.postgres.query(
+        'INSERT INTO operations (id, status) VALUES ($1, $2)',
+        [result.insertedId, 'completed']
+      );
+      
+      // Use cache through context
+      await context.cache.set(`operation:${result.insertedId}`, {
+        status: 'completed',
+        timestamp: new Date()
+      });
+      
+      context.logger.info('Operation completed successfully');
+    } catch (error) {
+      context.logger.error('Operation failed', { error });
+      throw error;
+    } finally {
+      // Clean up resources
+      await context.dispose();
+    }
+  }
+  
+  /**
+   * Example of batch operation with isolated connection pool
+   */
+  async performBatchOperation(items: any[]): Promise<void> {
+    // Create a scoped container for this batch operation
+    const scopedContainer = this.container.createScope();
+    
+    const context = OperationContext.create('example', 'batch-operation', {
+      container: scopedContainer
+    });
+    
+    try {
+      context.logger.info('Starting batch operation', { itemCount: items.length });
+      
+      // Process items in parallel with isolated connections
+      const promises = items.map(async (item, index) => {
+        // Each sub-operation gets its own context
+        const subContext = context.createChild(`item-${index}`);
+        
+        try {
+          await subContext.mongodb.collection('batch').insertOne(item);
+          await subContext.cache.set(`batch:${item.id}`, item);
+        } finally {
+          await subContext.dispose();
+        }
+      });
+      
+      await Promise.all(promises);
+      context.logger.info('Batch operation completed');
+      
+    } finally {
+      // Clean up scoped resources
+      await context.dispose();
+      await scopedContainer.dispose();
+    }
+  }
+}
+
+/**
+ * Example of how to use in a job handler
+ */
+export async function createExampleJobHandler(container: ServiceContainer) {
+  return async (job: any) => {
+    const handler = new ExampleHandler(container);
+    
+    if (job.data.type === 'batch') {
+      await handler.performBatchOperation(job.data.items);
+    } else {
+      await handler.performOperation(job.data);
+    }
+  };
+}

apps/data-ingestion/src/setup/database-setup.ts

@@ -0,0 +1,137 @@
+import { getDatabaseConfig } from '@stock-bot/config';
+import { getLogger } from '@stock-bot/logger';
+import { 
+  ConnectionFactory, 
+  ServiceContainer, 
+  createServiceContainer,
+  PoolSizeCalculator 
+} from '@stock-bot/connection-factory';
+import type { ConnectionFactoryConfig } from '@stock-bot/connection-factory';
+
+const logger = getLogger('database-setup');
+
+/**
+ * Creates a connection factory configured for the data-ingestion service
+ */
+export function createConnectionFactory(): ConnectionFactory {
+  const dbConfig = getDatabaseConfig();
+  
+  const factoryConfig: ConnectionFactoryConfig = {
+    service: 'data-ingestion',
+    environment: process.env.NODE_ENV as 'development' | 'production' | 'test' || 'development',
+    pools: {
+      mongodb: {
+        poolSize: 50, // Higher for batch imports
+      },
+      postgres: {
+        poolSize: 30,
+      },
+      cache: {
+        poolSize: 20,
+      }
+    }
+  };
+  
+  return new ConnectionFactory(factoryConfig);
+}
+
+/**
+ * Sets up the service container with all dependencies
+ */
+export async function setupServiceContainer(): Promise<ServiceContainer> {
+  logger.info('Setting up service container for data-ingestion');
+  
+  const connectionFactory = createConnectionFactory();
+  const dbConfig = getDatabaseConfig();
+  
+  // Create base container
+  const container = new ServiceContainer('data-ingestion');
+  
+  // Register MongoDB with dynamic pool sizing
+  container.register({
+    name: 'mongodb',
+    factory: async () => {
+      const poolSize = PoolSizeCalculator.calculate('data-ingestion', 'batch-import');
+      const pool = await connectionFactory.createMongoDB({
+        name: 'default',
+        config: {
+          connectionString: dbConfig.mongodb.uri,
+          database: dbConfig.mongodb.database,
+          maxPoolSize: poolSize.max,
+          minPoolSize: poolSize.min,
+        },
+        maxConnections: poolSize.max,
+        minConnections: poolSize.min,
+      });
+      return pool.client;
+    },
+    singleton: true,
+    dispose: async (client) => {
+      await client.disconnect();
+    }
+  });
+  
+  // Register PostgreSQL
+  container.register({
+    name: 'postgres',
+    factory: async () => {
+      const poolSize = PoolSizeCalculator.calculate('data-ingestion');
+      const pool = await connectionFactory.createPostgreSQL({
+        name: 'default',
+        config: {
+          host: dbConfig.postgresql.host,
+          port: dbConfig.postgresql.port,
+          database: dbConfig.postgresql.database,
+          user: dbConfig.postgresql.user,
+          password: dbConfig.postgresql.password,
+          pool: {
+            max: poolSize.max,
+            min: poolSize.min,
+          }
+        },
+        maxConnections: poolSize.max,
+        minConnections: poolSize.min,
+      });
+      return pool.client;
+    },
+    singleton: true,
+    dispose: async (client) => {
+      await client.disconnect();
+    }
+  });
+  
+  // Register Cache
+  container.register({
+    name: 'cache',
+    factory: () => {
+      const pool = connectionFactory.createCache({
+        name: 'default',
+        config: {
+          redisConfig: {
+            host: dbConfig.dragonfly.host,
+            port: dbConfig.dragonfly.port,
+            db: dbConfig.dragonfly.db,
+          },
+          keyPrefix: 'data-ingestion:',
+          ttl: 3600,
+          enableMetrics: true,
+        }
+      });
+      return pool.client;
+    },
+    singleton: true,
+  });
+  
+  // Register the connection factory itself for pool management
+  container.register({
+    name: 'connectionFactory',
+    factory: () => connectionFactory,
+    singleton: true,
+    dispose: async (factory) => {
+      await factory.disposeAll();
+    }
+  });
+  
+  logger.info('Service container setup complete');
+  return container;
+}

apps/data-ingestion/src/setup/dynamic-pool-example.ts

@@ -0,0 +1,116 @@
+import { getDatabaseConfig } from '@stock-bot/config';
+import { getLogger } from '@stock-bot/logger';
+import { createMongoDBClient, createPostgreSQLClient } from '@stock-bot/connection-factory';
+import type { DynamicPoolConfig } from '@stock-bot/mongodb-client';
+
+const logger = getLogger('dynamic-pool-example');
+
+/**
+ * Example of setting up dynamic pool sizing for high-load scenarios
+ */
+export async function setupDynamicPools() {
+  const dbConfig = getDatabaseConfig();
+  
+  // Dynamic pool configuration for batch processing
+  const dynamicConfig: DynamicPoolConfig = {
+    enabled: true,
+    minSize: 5,
+    maxSize: 100,
+    scaleUpThreshold: 70,    // Scale up when 70% of connections are in use
+    scaleDownThreshold: 30,  // Scale down when only 30% are in use
+    scaleUpIncrement: 10,     // Add 10 connections at a time
+    scaleDownIncrement: 5,    // Remove 5 connections at a time
+    evaluationInterval: 10000 // Check every 10 seconds
+  };
+  
+  // Create MongoDB client with dynamic pooling
+  const mongoClient = createMongoDBClient({
+    uri: dbConfig.mongodb.uri,
+    database: dbConfig.mongodb.database,
+    poolSettings: {
+      minPoolSize: dynamicConfig.minSize,
+      maxPoolSize: dynamicConfig.maxSize,
+    }
+  }, {
+    onConnect: () => logger.info('MongoDB connected with dynamic pooling'),
+    onError: (error) => logger.error('MongoDB pool error', { error }),
+  });
+  
+  await mongoClient.connect();
+  mongoClient.setDynamicPoolConfig(dynamicConfig);
+  
+  // Create PostgreSQL client with dynamic pooling
+  const pgClient = createPostgreSQLClient({
+    host: dbConfig.postgresql.host,
+    port: dbConfig.postgresql.port,
+    database: dbConfig.postgresql.database,
+    username: dbConfig.postgresql.user,
+    password: dbConfig.postgresql.password,
+    poolSettings: {
+      min: dynamicConfig.minSize,
+      max: dynamicConfig.maxSize,
+    }
+  }, undefined, {
+    onConnect: () => logger.info('PostgreSQL connected with dynamic pooling'),
+    onError: (error) => logger.error('PostgreSQL pool error', { error }),
+  });
+  
+  await pgClient.connect();
+  pgClient.setDynamicPoolConfig(dynamicConfig);
+  
+  // Monitor pool metrics
+  setInterval(() => {
+    const mongoMetrics = mongoClient.getPoolMetrics();
+    const pgMetrics = pgClient.getPoolMetrics();
+    
+    logger.info('Pool metrics', {
+      mongodb: {
+        total: mongoMetrics.totalConnections,
+        active: mongoMetrics.activeConnections,
+        idle: mongoMetrics.idleConnections,
+        waiting: mongoMetrics.waitingRequests,
+      },
+      postgresql: {
+        total: pgMetrics.totalConnections,
+        active: pgMetrics.activeConnections,
+        idle: pgMetrics.idleConnections,
+        waiting: pgMetrics.waitingRequests,
+      }
+    });
+  }, 30000); // Log metrics every 30 seconds
+  
+  return { mongoClient, pgClient };
+}
+
+/**
+ * Example of adaptive pool sizing based on time of day
+ */
+export function getTimeBasedPoolConfig(): DynamicPoolConfig {
+  const hour = new Date().getHours();
+  
+  // High load hours (9 AM - 5 PM)
+  if (hour >= 9 && hour <= 17) {
+    return {
+      enabled: true,
+      minSize: 10,
+      maxSize: 150,
+      scaleUpThreshold: 60,
+      scaleDownThreshold: 20,
+      scaleUpIncrement: 20,
+      scaleDownIncrement: 10,
+      evaluationInterval: 5000 // More frequent checks during peak
+    };
+  }
+  
+  // Low load hours (night time)
+  return {
+    enabled: true,
+    minSize: 2,
+    maxSize: 50,
+    scaleUpThreshold: 80,
+    scaleDownThreshold: 40,
+    scaleUpIncrement: 5,
+    scaleDownIncrement: 2,
+    evaluationInterval: 30000 // Less frequent checks at night
+  };
+}

libs/connection-factory/package.json

@@ -0,0 +1,18 @@
+{
+  "name": "@stock-bot/connection-factory",
+  "version": "1.0.0",
+  "main": "./src/index.ts",
+  "types": "./src/index.ts",
+  "dependencies": {
+    "@stock-bot/config": "workspace:*",
+    "@stock-bot/logger": "workspace:*",
+    "@stock-bot/mongodb-client": "workspace:*",
+    "@stock-bot/postgres-client": "workspace:*",
+    "@stock-bot/cache": "workspace:*",
+    "mongodb": "^6.3.0",
+    "pg": "^8.11.3"
+  },
+  "devDependencies": {
+    "@types/pg": "^8.10.7"
+  }
+}

libs/connection-factory/src/connection-factory.ts

@@ -0,0 +1,234 @@
+import { getLogger, type Logger } from '@stock-bot/logger';
+import { MongoDBClient, createMongoDBClient, type ConnectionEvents } from '@stock-bot/mongodb-client';
+import { PostgreSQLClient, createPostgreSQLClient } from '@stock-bot/postgres-client';
+import { createCache, type CacheProvider } from '@stock-bot/cache';
+import type {
+  ConnectionFactory as IConnectionFactory,
+  ConnectionPool,
+  ConnectionFactoryConfig,
+  MongoDBPoolConfig,
+  PostgreSQLPoolConfig,
+  CachePoolConfig,
+  PoolMetrics,
+} from './types';
+
+export class ConnectionFactory implements IConnectionFactory {
+  private readonly logger: Logger;
+  private readonly pools: Map<string, ConnectionPool<any>> = new Map();
+  private readonly config: ConnectionFactoryConfig;
+
+  constructor(config: ConnectionFactoryConfig) {
+    this.config = config;
+    this.logger = getLogger(`connection-factory:${config.service}`);
+  }
+
+  async createMongoDB(poolConfig: MongoDBPoolConfig): Promise<ConnectionPool<MongoDBClient>> {
+    const key = `mongodb:${poolConfig.name}`;
+    
+    if (this.pools.has(key)) {
+      this.logger.debug('Reusing existing MongoDB pool', { name: poolConfig.name });
+      return this.pools.get(key)!;
+    }
+
+    this.logger.info('Creating MongoDB connection pool', {
+      name: poolConfig.name,
+      poolSize: poolConfig.poolSize,
+    });
+
+    try {
+      const events: ConnectionEvents = {
+        onConnect: () => {
+          this.logger.debug('MongoDB connected', { pool: poolConfig.name });
+        },
+        onDisconnect: () => {
+          this.logger.debug('MongoDB disconnected', { pool: poolConfig.name });
+        },
+        onError: (error) => {
+          this.logger.error('MongoDB error', { pool: poolConfig.name, error });
+        },
+      };
+
+      const client = createMongoDBClient({
+        ...poolConfig.config,
+        poolSettings: {
+          maxPoolSize: poolConfig.maxConnections || poolConfig.poolSize || 10,
+          minPoolSize: poolConfig.minConnections || 2,
+          maxIdleTime: 30000,
+        }
+      }, events);
+
+      await client.connect();
+      
+      // Warm up the pool
+      if (poolConfig.minConnections) {
+        await client.warmupPool();
+      }
+
+      const pool: ConnectionPool<MongoDBClient> = {
+        name: poolConfig.name,
+        client,
+        metrics: client.getPoolMetrics(),
+        health: async () => {
+          try {
+            await client.getDatabase().admin().ping();
+            return true;
+          } catch {
+            return false;
+          }
+        },
+        dispose: async () => {
+          await client.disconnect();
+          this.pools.delete(key);
+        },
+      };
+
+      this.pools.set(key, pool);
+      return pool;
+    } catch (error) {
+      this.logger.error('Failed to create MongoDB pool', { name: poolConfig.name, error });
+      throw error;
+    }
+  }
+
+  async createPostgreSQL(poolConfig: PostgreSQLPoolConfig): Promise<ConnectionPool<PostgreSQLClient>> {
+    const key = `postgres:${poolConfig.name}`;
+    
+    if (this.pools.has(key)) {
+      this.logger.debug('Reusing existing PostgreSQL pool', { name: poolConfig.name });
+      return this.pools.get(key)!;
+    }
+
+    this.logger.info('Creating PostgreSQL connection pool', {
+      name: poolConfig.name,
+      poolSize: poolConfig.poolSize,
+    });
+
+    try {
+      const events: ConnectionEvents = {
+        onConnect: () => {
+          this.logger.debug('PostgreSQL connected', { pool: poolConfig.name });
+        },
+        onDisconnect: () => {
+          this.logger.debug('PostgreSQL disconnected', { pool: poolConfig.name });
+        },
+        onError: (error) => {
+          this.logger.error('PostgreSQL error', { pool: poolConfig.name, error });
+        },
+      };
+
+      const client = createPostgreSQLClient({
+        ...poolConfig.config,
+        poolSettings: {
+          max: poolConfig.maxConnections || poolConfig.poolSize || 10,
+          min: poolConfig.minConnections || 2,
+          idleTimeoutMillis: poolConfig.idleTimeoutMillis || 30000,
+        },
+      }, undefined, events);
+
+      await client.connect();
+      
+      // Warm up the pool
+      if (poolConfig.minConnections) {
+        await client.warmupPool();
+      }
+
+      const pool: ConnectionPool<PostgreSQLClient> = {
+        name: poolConfig.name,
+        client,
+        metrics: client.getPoolMetrics(),
+        health: async () => client.connected,
+        dispose: async () => {
+          await client.disconnect();
+          this.pools.delete(key);
+        },
+      };
+
+      this.pools.set(key, pool);
+      return pool;
+    } catch (error) {
+      this.logger.error('Failed to create PostgreSQL pool', { name: poolConfig.name, error });
+      throw error;
+    }
+  }
+
+  createCache(poolConfig: CachePoolConfig): ConnectionPool<CacheProvider> {
+    const key = `cache:${poolConfig.name}`;
+    
+    if (this.pools.has(key)) {
+      this.logger.debug('Reusing existing cache pool', { name: poolConfig.name });
+      return this.pools.get(key)!;
+    }
+
+    this.logger.info('Creating cache connection pool', {
+      name: poolConfig.name,
+    });
+
+    try {
+      const cache = createCache({
+        ...poolConfig.config,
+        keyPrefix: `${this.config.service}:${poolConfig.name}:`,
+        shared: false, // Each pool gets its own connection
+      });
+
+      const pool: ConnectionPool<CacheProvider> = {
+        name: poolConfig.name,
+        client: cache,
+        metrics: this.createInitialMetrics(),
+        health: async () => cache.health(),
+        dispose: async () => {
+          // Cache disposal handled internally
+          this.pools.delete(key);
+        },
+      };
+
+      this.pools.set(key, pool);
+      return pool;
+    } catch (error) {
+      this.logger.error('Failed to create cache pool', { name: poolConfig.name, error });
+      throw error;
+    }
+  }
+
+  getPool(type: 'mongodb' | 'postgres' | 'cache', name: string): ConnectionPool<any> | undefined {
+    const key = `${type}:${name}`;
+    return this.pools.get(key);
+  }
+
+  listPools(): Array<{ type: string; name: string; metrics: PoolMetrics }> {
+    const result: Array<{ type: string; name: string; metrics: PoolMetrics }> = [];
+    
+    for (const [key, pool] of this.pools.entries()) {
+      const [type, ...nameParts] = key.split(':');
+      result.push({
+        type: type || 'unknown',
+        name: nameParts.join(':'),
+        metrics: pool.metrics,
+      });
+    }
+    
+    return result;
+  }
+
+  async disposeAll(): Promise<void> {
+    this.logger.info('Disposing all connection pools', { count: this.pools.size });
+    
+    const disposePromises: Promise<void>[] = [];
+    for (const pool of this.pools.values()) {
+      disposePromises.push(pool.dispose());
+    }
+    
+    await Promise.all(disposePromises);
+    this.pools.clear();
+  }
+
+  private createInitialMetrics(): PoolMetrics {
+    return {
+      created: new Date(),
+      totalConnections: 0,
+      activeConnections: 0,
+      idleConnections: 0,
+      waitingRequests: 0,
+      errors: 0,
+    };
+  }
+}

libs/connection-factory/src/index.ts

@@ -0,0 +1,23 @@
+export { ConnectionFactory } from './connection-factory';
+export { ServiceContainer, createServiceContainer } from './service-container';
+export { PoolSizeCalculator } from './pool-size-calculator';
+
+export type {
+  ConnectionPoolConfig,
+  MongoDBPoolConfig,
+  PostgreSQLPoolConfig,
+  CachePoolConfig,
+  ConnectionFactoryConfig,
+  ConnectionPool,
+  PoolMetrics,
+  ConnectionFactory as IConnectionFactory,
+} from './types';
+
+export type {
+  ServiceRegistration,
+  ServiceResolver,
+} from './service-container';
+
+export type {
+  PoolSizeRecommendation,
+} from './pool-size-calculator';

libs/connection-factory/src/pool-size-calculator.ts

@@ -0,0 +1,80 @@
+import type { ConnectionPoolConfig } from './types';
+
+export interface PoolSizeRecommendation {
+  min: number;
+  max: number;
+  idle: number;
+}
+
+export class PoolSizeCalculator {
+  private static readonly DEFAULT_SIZES: Record<string, PoolSizeRecommendation> = {
+    // Service-level defaults
+    'data-ingestion': { min: 5, max: 50, idle: 10 },
+    'data-pipeline': { min: 3, max: 30, idle: 5 },
+    'processing-service': { min: 2, max: 20, idle: 3 },
+    'web-api': { min: 2, max: 10, idle: 2 },
+    'portfolio-service': { min: 2, max: 15, idle: 3 },
+    'strategy-service': { min: 3, max: 25, idle: 5 },
+    'execution-service': { min: 2, max: 10, idle: 2 },
+    
+    // Handler-level defaults
+    'batch-import': { min: 10, max: 100, idle: 20 },
+    'real-time': { min: 2, max: 10, idle: 3 },
+    'analytics': { min: 5, max: 30, idle: 10 },
+    'reporting': { min: 3, max: 20, idle: 5 },
+  };
+
+  static calculate(
+    serviceName: string,
+    handlerName?: string,
+    customConfig?: Partial<ConnectionPoolConfig>
+  ): PoolSizeRecommendation {
+    // Check for custom configuration first
+    if (customConfig?.minConnections && customConfig?.maxConnections) {
+      return {
+        min: customConfig.minConnections,
+        max: customConfig.maxConnections,
+        idle: Math.floor((customConfig.minConnections + customConfig.maxConnections) / 4),
+      };
+    }
+
+    // Try handler-specific sizes first, then service-level
+    const key = handlerName || serviceName;
+    const recommendation = this.DEFAULT_SIZES[key] || this.DEFAULT_SIZES[serviceName];
+
+    if (recommendation) {
+      return { ...recommendation };
+    }
+
+    // Fall back to generic defaults
+    return {
+      min: 2,
+      max: 10,
+      idle: 3,
+    };
+  }
+
+  static getOptimalPoolSize(
+    expectedConcurrency: number,
+    averageQueryTimeMs: number,
+    targetLatencyMs: number
+  ): number {
+    // Little's Law: L = λ * W
+    // L = number of connections needed
+    // λ = arrival rate (requests per second)
+    // W = average time in system (seconds)
+    
+    const requestsPerSecond = expectedConcurrency;
+    const averageTimeInSystem = averageQueryTimeMs / 1000;
+    
+    const minConnections = Math.ceil(requestsPerSecond * averageTimeInSystem);
+    
+    // Add buffer for burst traffic (20% overhead)
+    const recommendedSize = Math.ceil(minConnections * 1.2);
+    
+    // Ensure we meet target latency
+    const latencyBasedSize = Math.ceil(expectedConcurrency * (averageQueryTimeMs / targetLatencyMs));
+    
+    return Math.max(recommendedSize, latencyBasedSize, 2); // Minimum 2 connections
+  }
+}

libs/connection-factory/src/service-container.ts

@@ -0,0 +1,147 @@
+import { getLogger, type Logger } from '@stock-bot/logger';
+import type { ConnectionFactory } from './connection-factory';
+
+export interface ServiceRegistration<T = any> {
+  name: string;
+  factory: () => T | Promise<T>;
+  singleton?: boolean;
+  dispose?: (instance: T) => Promise<void>;
+}
+
+export interface ServiceResolver {
+  resolve<T>(name: string, options?: any): T;
+  resolveAsync<T>(name: string, options?: any): Promise<T>;
+}
+
+export class ServiceContainer implements ServiceResolver {
+  private readonly logger: Logger;
+  private readonly registrations = new Map<string, ServiceRegistration>();
+  private readonly instances = new Map<string, any>();
+  private readonly scopedInstances = new Map<string, any>();
+  private readonly parent?: ServiceContainer;
+
+  constructor(name: string, parent?: ServiceContainer) {
+    this.logger = getLogger(`service-container:${name}`);
+    this.parent = parent;
+  }
+
+  register<T>(registration: ServiceRegistration<T>): void {
+    this.registrations.set(registration.name, registration);
+    this.logger.debug('Service registered', { name: registration.name, singleton: registration.singleton });
+  }
+
+  resolve<T>(name: string, options?: any): T {
+    const instance = this.resolveAsync<T>(name, options);
+    if (instance instanceof Promise) {
+      throw new Error(`Service ${name} is async. Use resolveAsync() instead.`);
+    }
+    return instance as T;
+  }
+
+  async resolveAsync<T>(name: string, _options?: any): Promise<T> {
+    // Check scoped instances first
+    if (this.scopedInstances.has(name)) {
+      return this.scopedInstances.get(name);
+    }
+
+    // Check singleton instances
+    if (this.instances.has(name)) {
+      return this.instances.get(name);
+    }
+
+    // Get registration from this container or parent
+    const registration = this.getRegistration(name);
+    if (!registration) {
+      throw new Error(`Service ${name} not registered`);
+    }
+
+    // Create instance
+    const instance = await Promise.resolve(registration.factory());
+
+    // Store based on singleton flag
+    if (registration.singleton) {
+      this.instances.set(name, instance);
+    } else {
+      this.scopedInstances.set(name, instance);
+    }
+
+    return instance as T;
+  }
+
+  createScope(): ServiceContainer {
+    return new ServiceContainer('scoped', this);
+  }
+
+  async dispose(): Promise<void> {
+    // Dispose scoped instances
+    for (const [name, instance] of this.scopedInstances.entries()) {
+      const registration = this.getRegistration(name);
+      if (registration?.dispose) {
+        await registration.dispose(instance);
+      }
+    }
+    this.scopedInstances.clear();
+
+    // Only dispose singletons if this is the root container
+    if (!this.parent) {
+      for (const [name, instance] of this.instances.entries()) {
+        const registration = this.registrations.get(name);
+        if (registration?.dispose) {
+          await registration.dispose(instance);
+        }
+      }
+      this.instances.clear();
+    }
+  }
+
+  private getRegistration(name: string): ServiceRegistration | undefined {
+    return this.registrations.get(name) || this.parent?.getRegistration(name);
+  }
+}
+
+// Helper to create pre-configured containers for services
+export function createServiceContainer(
+  serviceName: string,
+  connectionFactory: ConnectionFactory
+): ServiceContainer {
+  const container = new ServiceContainer(serviceName);
+
+  // Register connection factories
+  container.register({
+    name: 'mongodb',
+    factory: async () => {
+      const pool = await connectionFactory.createMongoDB({
+        name: 'default',
+        config: {} as any, // Config injected by factory
+      });
+      return pool.client;
+    },
+    singleton: true,
+  });
+
+  container.register({
+    name: 'postgres',
+    factory: async () => {
+      const pool = await connectionFactory.createPostgreSQL({
+        name: 'default',
+        config: {} as any, // Config injected by factory
+      });
+      return pool.client;
+    },
+    singleton: true,
+  });
+
+  container.register({
+    name: 'cache',
+    factory: () => {
+      const pool = connectionFactory.createCache({
+        name: 'default',
+        config: {} as any, // Config injected by factory
+      });
+      return pool.client;
+    },
+    singleton: true,
+  });
+
+  return container;
+}

libs/connection-factory/src/types.ts

@@ -0,0 +1,61 @@
+import type { MongoDBClientConfig } from '@stock-bot/mongodb-client';
+import type { PostgreSQLClientConfig } from '@stock-bot/postgres-client';
+import type { CacheOptions } from '@stock-bot/cache';
+
+export interface ConnectionPoolConfig {
+  name: string;
+  poolSize?: number;
+  minConnections?: number;
+  maxConnections?: number;
+  idleTimeoutMillis?: number;
+  connectionTimeoutMillis?: number;
+  enableMetrics?: boolean;
+}
+
+export interface MongoDBPoolConfig extends ConnectionPoolConfig {
+  config: MongoDBClientConfig;
+}
+
+export interface PostgreSQLPoolConfig extends ConnectionPoolConfig {
+  config: PostgreSQLClientConfig;
+}
+
+export interface CachePoolConfig extends ConnectionPoolConfig {
+  config: CacheOptions;
+}
+
+export interface ConnectionFactoryConfig {
+  service: string;
+  environment: 'development' | 'production' | 'test';
+  pools?: {
+    mongodb?: Partial<MongoDBPoolConfig>;
+    postgres?: Partial<PostgreSQLPoolConfig>;
+    cache?: Partial<CachePoolConfig>;
+  };
+}
+
+export interface ConnectionPool<T> {
+  name: string;
+  client: T;
+  metrics: PoolMetrics;
+  health(): Promise<boolean>;
+  dispose(): Promise<void>;
+}
+
+export interface PoolMetrics {
+  created: Date;
+  totalConnections: number;
+  activeConnections: number;
+  idleConnections: number;
+  waitingRequests: number;
+  errors: number;
+}
+
+export interface ConnectionFactory {
+  createMongoDB(config: MongoDBPoolConfig): Promise<ConnectionPool<any>>;
+  createPostgreSQL(config: PostgreSQLPoolConfig): Promise<ConnectionPool<any>>;
+  createCache(config: CachePoolConfig): ConnectionPool<any>;
+  getPool(type: 'mongodb' | 'postgres' | 'cache', name: string): ConnectionPool<any> | undefined;
+  listPools(): Array<{ type: string; name: string; metrics: PoolMetrics }>;
+  disposeAll(): Promise<void>;
+}

libs/connection-factory/tsconfig.json

@@ -0,0 +1,16 @@
+{
+  "extends": "../../tsconfig.json",
+  "compilerOptions": {
+    "rootDir": "./src",
+    "outDir": "./dist",
+    "composite": true
+  },
+  "include": ["src/**/*"],
+  "references": [
+    { "path": "../config" },
+    { "path": "../logger" },
+    { "path": "../mongodb-client" },
+    { "path": "../postgres-client" },
+    { "path": "../cache" }
+  ]
+}

libs/mongodb-client/src/client.ts

@@ -1,6 +1,6 @@
 import { getLogger } from '@stock-bot/logger';
 import { Collection, Db, MongoClient, OptionalUnlessRequiredId } from 'mongodb';
-import type { DocumentBase, MongoDBClientConfig } from './types';
+import type { DocumentBase, MongoDBClientConfig, PoolMetrics, ConnectionEvents, DynamicPoolConfig } from './types';
 
 /**
  * MongoDB Client for Stock Bot Data Service
@@ -15,10 +15,23 @@ export class MongoDBClient {
   private defaultDatabase: string;
   private readonly logger = getLogger('mongodb-client');
   private isConnected = false;
+  private readonly metrics: PoolMetrics;
+  private readonly events?: ConnectionEvents;
+  private dynamicPoolConfig?: DynamicPoolConfig;
+  private poolMonitorInterval?: Timer;
 
-  constructor(config: MongoDBClientConfig) {
+  constructor(config: MongoDBClientConfig, events?: ConnectionEvents) {
     this.config = config;
     this.defaultDatabase = config.database || 'stock';
+    this.events = events;
+    this.metrics = {
+      totalConnections: 0,
+      activeConnections: 0,
+      idleConnections: 0,
+      waitingRequests: 0,
+      errors: 0,
+      created: new Date(),
+    };
   }
 
   /**
@@ -48,8 +61,38 @@ export class MongoDBClient {
       this.db = this.client.db(this.defaultDatabase);
       this.isConnected = true;
 
-      this.logger.info('Successfully connected to MongoDB');
+      // Update metrics
+      this.metrics.totalConnections = this.config.poolSettings?.maxPoolSize || 10;
+      this.metrics.idleConnections = this.metrics.totalConnections;
+
+      // Fire connection event
+      if (this.events?.onConnect) {
+        await Promise.resolve(this.events.onConnect());
+      }
+      
+      // Fire pool created event
+      if (this.events?.onPoolCreated) {
+        await Promise.resolve(this.events.onPoolCreated());
+      }
+
+      this.logger.info('Successfully connected to MongoDB', {
+        database: this.defaultDatabase,
+        poolSize: this.metrics.totalConnections,
+      });
+
+      // Start pool monitoring if dynamic sizing is enabled
+      if (this.dynamicPoolConfig?.enabled) {
+        this.startPoolMonitoring();
+      }
     } catch (error) {
+      this.metrics.errors++;
+      this.metrics.lastError = error instanceof Error ? error.message : 'Unknown error';
+      
+      // Fire error event
+      if (this.events?.onError) {
+        await Promise.resolve(this.events.onError(error as Error));
+      }
+      
       this.logger.error('MongoDB connection failed:', error);
       if (this.client) {
         await this.client.close();
@@ -68,10 +111,22 @@ export class MongoDBClient {
     }
 
     try {
+      // Stop pool monitoring
+      if (this.poolMonitorInterval) {
+        clearInterval(this.poolMonitorInterval);
+        this.poolMonitorInterval = undefined;
+      }
+
       await this.client.close();
       this.isConnected = false;
       this.client = null;
       this.db = null;
+      
+      // Fire disconnect event
+      if (this.events?.onDisconnect) {
+        await Promise.resolve(this.events.onDisconnect());
+      }
+      
       this.logger.info('Disconnected from MongoDB');
     } catch (error) {
       this.logger.error('Error disconnecting from MongoDB:', error);
@@ -350,4 +405,116 @@ export class MongoDBClient {
 
     return `mongodb://${auth}${host}:${port}/${database}${authParam}`;
   }
+
+  /**
+   * Get current pool metrics
+   */
+  getPoolMetrics(): PoolMetrics {
+    // Update last used timestamp
+    this.metrics.lastUsed = new Date();
+    
+    // Note: MongoDB driver doesn't expose detailed pool metrics
+    // These are estimates based on configuration
+    return { ...this.metrics };
+  }
+
+  /**
+   * Set dynamic pool configuration
+   */
+  setDynamicPoolConfig(config: DynamicPoolConfig): void {
+    this.dynamicPoolConfig = config;
+    
+    if (config.enabled && this.isConnected && !this.poolMonitorInterval) {
+      this.startPoolMonitoring();
+    } else if (!config.enabled && this.poolMonitorInterval) {
+      clearInterval(this.poolMonitorInterval);
+      this.poolMonitorInterval = undefined;
+    }
+  }
+
+  /**
+   * Start monitoring pool and adjust size dynamically
+   */
+  private startPoolMonitoring(): void {
+    if (!this.dynamicPoolConfig || this.poolMonitorInterval) {
+      return;
+    }
+
+    this.poolMonitorInterval = setInterval(() => {
+      this.evaluatePoolSize();
+    }, this.dynamicPoolConfig.evaluationInterval);
+  }
+
+  /**
+   * Evaluate and adjust pool size based on usage
+   */
+  private async evaluatePoolSize(): Promise<void> {
+    if (!this.dynamicPoolConfig || !this.client) {
+      return;
+    }
+
+    const { minSize, maxSize, scaleUpThreshold, scaleDownThreshold } = this.dynamicPoolConfig;
+    const currentSize = this.metrics.totalConnections;
+    const utilization = ((this.metrics.activeConnections / currentSize) * 100);
+
+    this.logger.debug('Pool utilization', {
+      utilization: `${utilization.toFixed(1)}%`,
+      active: this.metrics.activeConnections,
+      total: currentSize,
+    });
+
+    // Scale up if utilization is high
+    if (utilization > scaleUpThreshold && currentSize < maxSize) {
+      const newSize = Math.min(currentSize + this.dynamicPoolConfig.scaleUpIncrement, maxSize);
+      await this.resizePool(newSize);
+      this.logger.info('Scaling up connection pool', { from: currentSize, to: newSize, utilization });
+    }
+    // Scale down if utilization is low
+    else if (utilization < scaleDownThreshold && currentSize > minSize) {
+      const newSize = Math.max(currentSize - this.dynamicPoolConfig.scaleDownIncrement, minSize);
+      await this.resizePool(newSize);
+      this.logger.info('Scaling down connection pool', { from: currentSize, to: newSize, utilization });
+    }
+  }
+
+  /**
+   * Resize the connection pool
+   * Note: MongoDB driver doesn't support dynamic resizing, this would require reconnection
+   */
+  private async resizePool(newSize: number): Promise<void> {
+    // MongoDB doesn't support dynamic pool resizing
+    // This is a placeholder for future implementation
+    this.logger.warn('Dynamic pool resizing not yet implemented for MongoDB', { requestedSize: newSize });
+    
+    // Update metrics to reflect desired state
+    this.metrics.totalConnections = newSize;
+  }
+
+  /**
+   * Enable pool warmup on connect
+   */
+  async warmupPool(): Promise<void> {
+    if (!this.client || !this.isConnected) {
+      throw new Error('Client not connected');
+    }
+
+    const minSize = this.config.poolSettings?.minPoolSize || 1;
+    const promises: Promise<void>[] = [];
+
+    // Create minimum connections by running parallel pings
+    for (let i = 0; i < minSize; i++) {
+      promises.push(
+        this.client.db(this.defaultDatabase).admin().ping()
+          .then(() => {
+            this.logger.debug(`Warmed up connection ${i + 1}/${minSize}`);
+          })
+          .catch(error => {
+            this.logger.warn(`Failed to warm up connection ${i + 1}`, { error });
+          })
+      );
+    }
+
+    await Promise.allSettled(promises);
+    this.logger.info('Connection pool warmup complete', { connections: minSize });
+  }
 }

libs/mongodb-client/src/factory.ts

@@ -1,20 +1,21 @@
 import { MongoDBClient } from './client';
-import type { MongoDBClientConfig } from './types';
+import type { MongoDBClientConfig, ConnectionEvents } from './types';
 
 /**
  * Factory function to create a MongoDB client instance
  */
-export function createMongoDBClient(config: MongoDBClientConfig): MongoDBClient {
-  return new MongoDBClient(config);
+export function createMongoDBClient(config: MongoDBClientConfig, events?: ConnectionEvents): MongoDBClient {
+  return new MongoDBClient(config, events);
 }
 
 /**
  * Create and connect a MongoDB client
  */
 export async function createAndConnectMongoDBClient(
-  config: MongoDBClientConfig
+  config: MongoDBClientConfig,
+  events?: ConnectionEvents
 ): Promise<MongoDBClient> {
-  const client = createMongoDBClient(config);
+  const client = createMongoDBClient(config, events);
   await client.connect();
   return client;
 }

libs/mongodb-client/src/index.ts

@@ -20,6 +20,9 @@ export type {
   RawDocument,
   SecFiling,
   SentimentData,
+  PoolMetrics,
+  ConnectionEvents,
+  DynamicPoolConfig,
 } from './types';
 
 // Factory functions
@@ -28,10 +31,4 @@ export {
   createAndConnectMongoDBClient,
 } from './factory';
 
-// Singleton instance
-export {
-  getMongoDBClient,
-  connectMongoDB,
-  getDatabase,
-  disconnectMongoDB,
-} from './singleton';
+// Singleton pattern removed - use factory functions instead

libs/mongodb-client/src/singleton.ts

@@ -1,82 +0,0 @@
-import { MongoDBClient } from './client';
-import type { MongoDBClientConfig } from './types';
-import type { Db } from 'mongodb';
-
-/**
- * Singleton MongoDB client instance
- * Provides global access to a single MongoDB connection
- */
-let instance: MongoDBClient | null = null;
-let initPromise: Promise<MongoDBClient> | null = null;
-
-/**
- * Initialize the singleton MongoDB client
- */
-export async function connectMongoDB(config?: MongoDBClientConfig): Promise<MongoDBClient> {
-  if (instance) {
-    return instance;
-  }
-
-  if (initPromise) {
-    return initPromise;
-  }
-
-  if (!config) {
-    throw new Error('MongoDB client not initialized. Call connectMongoDB(config) first.');
-  }
-
-  initPromise = (async () => {
-    const client = new MongoDBClient(config);
-    await client.connect();
-    instance = client;
-    return client;
-  })();
-
-  try {
-    return await initPromise;
-  } catch (error) {
-    // Reset promise on error so next call can retry
-    initPromise = null;
-    throw error;
-  }
-}
-
-/**
- * Get the singleton MongoDB client instance
- * @throws Error if not initialized
- */
-export function getMongoDBClient(): MongoDBClient {
-  if (!instance) {
-    throw new Error('MongoDB client not initialized. Call connectMongoDB(config) first.');
-  }
-  return instance;
-}
-
-/**
- * Get the MongoDB database instance
- * @throws Error if not initialized
- */
-export function getDatabase(): Db {
-  if (!instance) {
-    throw new Error('MongoDB client not initialized. Call connectMongoDB(config) first.');
-  }
-  return instance.getDatabase();
-}
-
-/**
- * Check if the MongoDB client is initialized
- */
-export function isInitialized(): boolean {
-  return instance !== null && instance.connected;
-}
-
-/**
- * Disconnect and reset the singleton instance
- */
-export async function disconnectMongoDB(): Promise<void> {
-  if (instance) {
-    await instance.disconnect();
-    instance = null;
-  }
-  initPromise = null;
-}

libs/mongodb-client/src/types.ts

@@ -43,6 +43,36 @@ export interface MongoDBConnectionOptions {
   healthCheckInterval?: number;
 }
 
+export interface PoolMetrics {
+  totalConnections: number;
+  activeConnections: number;
+  idleConnections: number;
+  waitingRequests: number;
+  errors: number;
+  lastError?: string;
+  avgResponseTime?: number;
+  created: Date;
+  lastUsed?: Date;
+}
+
+export interface ConnectionEvents {
+  onConnect?: () => void | Promise<void>;
+  onDisconnect?: () => void | Promise<void>;
+  onError?: (error: Error) => void | Promise<void>;
+  onPoolCreated?: () => void | Promise<void>;
+}
+
+export interface DynamicPoolConfig {
+  enabled: boolean;
+  minSize: number;
+  maxSize: number;
+  scaleUpThreshold: number; // % of pool in use (0-100)
+  scaleDownThreshold: number; // % of pool idle (0-100)
+  scaleUpIncrement: number; // connections to add
+  scaleDownIncrement: number; // connections to remove
+  evaluationInterval: number; // ms between checks
+}
+
 /**
  * Health Status Types
  */

libs/postgres-client/src/client.ts

@@ -8,6 +8,9 @@ import type {
   PostgreSQLConnectionOptions,
   QueryResult,
   TransactionCallback,
+  PoolMetrics,
+  ConnectionEvents,
+  DynamicPoolConfig,
 } from './types';
 
 /**
@@ -24,8 +27,12 @@ export class PostgreSQLClient {
   private readonly healthMonitor: PostgreSQLHealthMonitor;
   private readonly transactionManager: PostgreSQLTransactionManager;
   private isConnected = false;
+  private readonly metrics: PoolMetrics;
+  private readonly events?: ConnectionEvents;
+  private dynamicPoolConfig?: DynamicPoolConfig;
+  private poolMonitorInterval?: NodeJS.Timeout;
 
-  constructor(config: PostgreSQLClientConfig, options?: PostgreSQLConnectionOptions) {
+  constructor(config: PostgreSQLClientConfig, options?: PostgreSQLConnectionOptions, events?: ConnectionEvents) {
     this.config = config;
     this.options = {
       retryAttempts: 3,
@@ -33,10 +40,20 @@ export class PostgreSQLClient {
       healthCheckInterval: 30000,
       ...options,
     };
+    this.events = events;
 
     this.logger = getLogger('postgres-client');
     this.healthMonitor = new PostgreSQLHealthMonitor(this);
     this.transactionManager = new PostgreSQLTransactionManager(this);
+    
+    this.metrics = {
+      totalConnections: 0,
+      activeConnections: 0,
+      idleConnections: 0,
+      waitingRequests: 0,
+      errors: 0,
+      created: new Date(),
+    };
   }
 
   /**
@@ -63,17 +80,51 @@ export class PostgreSQLClient {
         client.release();
 
         this.isConnected = true;
-        this.logger.info('Successfully connected to PostgreSQL');
+        
+        // Update metrics
+        const poolConfig = this.config.poolSettings;
+        this.metrics.totalConnections = poolConfig?.max || 10;
+        this.metrics.idleConnections = poolConfig?.min || 2;
+        
+        // Fire connection event
+        if (this.events?.onConnect) {
+          await Promise.resolve(this.events.onConnect());
+        }
+        
+        // Fire pool created event
+        if (this.events?.onPoolCreated) {
+          await Promise.resolve(this.events.onPoolCreated());
+        }
+        
+        this.logger.info('Successfully connected to PostgreSQL', {
+          poolSize: this.metrics.totalConnections,
+        });
 
         // Start health monitoring
         this.healthMonitor.start();
 
         // Setup error handlers
         this.setupErrorHandlers();
+        
+        // Setup pool event listeners for metrics
+        this.setupPoolMetrics();
+        
+        // Start dynamic pool monitoring if enabled
+        if (this.dynamicPoolConfig?.enabled) {
+          this.startPoolMonitoring();
+        }
 
         return;
       } catch (error) {
         lastError = error as Error;
+        this.metrics.errors++;
+        this.metrics.lastError = lastError.message;
+        
+        // Fire error event
+        if (this.events?.onError) {
+          await Promise.resolve(this.events.onError(lastError));
+        }
+        
         this.logger.error(`PostgreSQL connection attempt ${attempt} failed:`, error);
 
         if (this.pool) {
@@ -101,10 +152,22 @@ export class PostgreSQLClient {
     }
 
     try {
+      // Stop pool monitoring
+      if (this.poolMonitorInterval) {
+        clearInterval(this.poolMonitorInterval);
+        this.poolMonitorInterval = undefined;
+      }
+      
       this.healthMonitor.stop();
       await this.pool.end();
       this.isConnected = false;
       this.pool = null;
+      
+      // Fire disconnect event
+      if (this.events?.onDisconnect) {
+        await Promise.resolve(this.events.onDisconnect());
+      }
+      
       this.logger.info('Disconnected from PostgreSQL');
     } catch (error) {
       this.logger.error('Error disconnecting from PostgreSQL:', error);
@@ -411,4 +474,132 @@ export class PostgreSQLClient {
   private delay(ms: number): Promise<void> {
     return new Promise(resolve => setTimeout(resolve, ms));
   }
+
+  /**
+   * Get current pool metrics
+   */
+  getPoolMetrics(): PoolMetrics {
+    // Update last used timestamp
+    this.metrics.lastUsed = new Date();
+    
+    // Update metrics from pool if available
+    if (this.pool) {
+      this.metrics.totalConnections = this.pool.totalCount;
+      this.metrics.idleConnections = this.pool.idleCount;
+      this.metrics.waitingRequests = this.pool.waitingCount;
+      this.metrics.activeConnections = this.metrics.totalConnections - this.metrics.idleConnections;
+    }
+    
+    return { ...this.metrics };
+  }
+
+  /**
+   * Set dynamic pool configuration
+   */
+  setDynamicPoolConfig(config: DynamicPoolConfig): void {
+    this.dynamicPoolConfig = config;
+    
+    if (config.enabled && this.isConnected && !this.poolMonitorInterval) {
+      this.startPoolMonitoring();
+    } else if (!config.enabled && this.poolMonitorInterval) {
+      clearInterval(this.poolMonitorInterval);
+      this.poolMonitorInterval = undefined;
+    }
+  }
+
+  /**
+   * Start monitoring pool and adjust size dynamically
+   */
+  private startPoolMonitoring(): void {
+    if (!this.dynamicPoolConfig || this.poolMonitorInterval) {
+      return;
+    }
+
+    this.poolMonitorInterval = setInterval(() => {
+      this.evaluatePoolSize();
+    }, this.dynamicPoolConfig.evaluationInterval);
+  }
+
+  /**
+   * Setup pool event listeners for metrics
+   */
+  private setupPoolMetrics(): void {
+    if (!this.pool) {
+      return;
+    }
+
+    // Track when connections are acquired
+    this.pool.on('acquire', () => {
+      this.metrics.activeConnections++;
+      this.metrics.idleConnections--;
+    });
+
+    // Track when connections are released
+    this.pool.on('release', () => {
+      this.metrics.activeConnections--;
+      this.metrics.idleConnections++;
+    });
+  }
+
+  /**
+   * Evaluate and adjust pool size based on usage
+   */
+  private async evaluatePoolSize(): Promise<void> {
+    if (!this.dynamicPoolConfig || !this.pool) {
+      return;
+    }
+
+    const metrics = this.getPoolMetrics();
+    const { minSize, maxSize, scaleUpThreshold, scaleDownThreshold } = this.dynamicPoolConfig;
+    const currentSize = metrics.totalConnections;
+    const utilization = currentSize > 0 ? ((metrics.activeConnections / currentSize) * 100) : 0;
+
+    this.logger.debug('Pool utilization', {
+      utilization: `${utilization.toFixed(1)}%`,
+      active: metrics.activeConnections,
+      total: currentSize,
+      waiting: metrics.waitingRequests,
+    });
+
+    // Scale up if utilization is high or there are waiting requests
+    if ((utilization > scaleUpThreshold || metrics.waitingRequests > 0) && currentSize < maxSize) {
+      const newSize = Math.min(currentSize + this.dynamicPoolConfig.scaleUpIncrement, maxSize);
+      this.logger.info('Would scale up connection pool', { from: currentSize, to: newSize, utilization });
+      // Note: pg module doesn't support dynamic resizing, would need reconnection
+    }
+    // Scale down if utilization is low
+    else if (utilization < scaleDownThreshold && currentSize > minSize) {
+      const newSize = Math.max(currentSize - this.dynamicPoolConfig.scaleDownIncrement, minSize);
+      this.logger.info('Would scale down connection pool', { from: currentSize, to: newSize, utilization });
+      // Note: pg module doesn't support dynamic resizing, would need reconnection
+    }
+  }
+
+  /**
+   * Enable pool warmup on connect
+   */
+  async warmupPool(): Promise<void> {
+    if (!this.pool || !this.isConnected) {
+      throw new Error('Client not connected');
+    }
+
+    const minSize = this.config.poolSettings?.min || 2;
+    const promises: Promise<void>[] = [];
+
+    // Create minimum connections by running parallel queries
+    for (let i = 0; i < minSize; i++) {
+      promises.push(
+        this.pool.query('SELECT 1')
+          .then(() => {
+            this.logger.debug(`Warmed up connection ${i + 1}/${minSize}`);
+          })
+          .catch(error => {
+            this.logger.warn(`Failed to warm up connection ${i + 1}`, { error });
+          })
+      );
+    }
+
+    await Promise.allSettled(promises);
+    this.logger.info('Connection pool warmup complete', { connections: minSize });
+  }
 }

libs/postgres-client/src/factory.ts

@@ -1,14 +1,15 @@
 import { PostgreSQLClient } from './client';
-import type { PostgreSQLClientConfig, PostgreSQLConnectionOptions } from './types';
+import type { PostgreSQLClientConfig, PostgreSQLConnectionOptions, ConnectionEvents } from './types';
 
 /**
  * Factory function to create a PostgreSQL client instance
  */
 export function createPostgreSQLClient(
   config: PostgreSQLClientConfig,
-  options?: PostgreSQLConnectionOptions
+  options?: PostgreSQLConnectionOptions,
+  events?: ConnectionEvents
 ): PostgreSQLClient {
-  return new PostgreSQLClient(config, options);
+  return new PostgreSQLClient(config, options, events);
 }
 
 /**
@@ -16,9 +17,10 @@ export function createPostgreSQLClient(
  */
 export async function createAndConnectPostgreSQLClient(
   config: PostgreSQLClientConfig,
-  options?: PostgreSQLConnectionOptions
+  options?: PostgreSQLConnectionOptions,
+  events?: ConnectionEvents
 ): Promise<PostgreSQLClient> {
-  const client = createPostgreSQLClient(config, options);
+  const client = createPostgreSQLClient(config, options, events);
   await client.connect();
   return client;
 }

libs/postgres-client/src/index.ts

@@ -28,6 +28,9 @@ export type {
   Strategy,
   RiskLimit,
   AuditLog,
+  PoolMetrics,
+  ConnectionEvents,
+  DynamicPoolConfig,
 } from './types';
 
 // Factory functions
@@ -36,9 +39,4 @@ export {
   createAndConnectPostgreSQLClient,
 } from './factory';
 
-// Singleton instance
-export {
-  getPostgreSQLClient,
-  connectPostgreSQL,
-  disconnectPostgreSQL,
-} from './singleton';
+// Singleton pattern removed - use factory functions instead

libs/postgres-client/src/singleton.ts

@@ -1,50 +0,0 @@
-import { PostgreSQLClient } from './client';
-import type { PostgreSQLClientConfig } from './types';
-
-/**
- * Singleton PostgreSQL client instance
- * Provides global access to a single PostgreSQL connection pool
- */
-let instance: PostgreSQLClient | null = null;
-
-/**
- * Initialize the singleton PostgreSQL client
- */
-export async function connectPostgreSQL(config?: PostgreSQLClientConfig): Promise<PostgreSQLClient> {
-  if (!instance) {
-    if (!config) {
-      throw new Error('PostgreSQL client not initialized. Call connectPostgreSQL(config) first.');
-    }
-    instance = new PostgreSQLClient(config);
-    await instance.connect();
-  }
-  return instance;
-}
-
-/**
- * Get the singleton PostgreSQL client instance
- * @throws Error if not initialized
- */
-export function getPostgreSQLClient(): PostgreSQLClient {
-  if (!instance) {
-    throw new Error('PostgreSQL client not initialized. Call connectPostgreSQL(config) first.');
-  }
-  return instance;
-}
-
-/**
- * Check if the PostgreSQL client is initialized
- */
-export function isInitialized(): boolean {
-  return instance !== null && instance.connected;
-}
-
-/**
- * Disconnect and reset the singleton instance
- */
-export async function disconnectPostgreSQL(): Promise<void> {
-  if (instance) {
-    await instance.disconnect();
-    instance = null;
-  }
-}

libs/postgres-client/src/types.ts

@@ -36,6 +36,36 @@ export interface PostgreSQLConnectionOptions {
   healthCheckInterval?: number;
 }
 
+export interface PoolMetrics {
+  totalConnections: number;
+  activeConnections: number;
+  idleConnections: number;
+  waitingRequests: number;
+  errors: number;
+  lastError?: string;
+  avgResponseTime?: number;
+  created: Date;
+  lastUsed?: Date;
+}
+
+export interface ConnectionEvents {
+  onConnect?: () => void | Promise<void>;
+  onDisconnect?: () => void | Promise<void>;
+  onError?: (error: Error) => void | Promise<void>;
+  onPoolCreated?: () => void | Promise<void>;
+}
+
+export interface DynamicPoolConfig {
+  enabled: boolean;
+  minSize: number;
+  maxSize: number;
+  scaleUpThreshold: number; // % of pool in use (0-100)
+  scaleDownThreshold: number; // % of pool idle (0-100)
+  scaleUpIncrement: number; // connections to add
+  scaleDownIncrement: number; // connections to remove
+  evaluationInterval: number; // ms between checks
+}
+
 /**
  * Health Status Types
  */

libs/utils/package.json

@@ -2,32 +2,34 @@
   "name": "@stock-bot/utils",
   "version": "1.0.0",
   "description": "Common utility functions for stock-bot services",
-  "main": "dist/index.js",
-  "types": "dist/index.d.ts",
-  "type": "module",
+  "main": "./src/index.ts",
+  "types": "./src/index.ts",
   "scripts": {
     "build": "tsc",
     "clean": "rimraf dist",
     "test": "bun test"
   },
   "dependencies": {
-    "@stock-bot/types": "*",
+    "@stock-bot/config": "workspace:*",
+    "@stock-bot/logger": "workspace:*",
+    "@stock-bot/cache": "workspace:*",
+    "@stock-bot/postgres-client": "workspace:*",
+    "@stock-bot/mongodb-client": "workspace:*",
+    "@stock-bot/connection-factory": "workspace:*",
+    "@stock-bot/types": "workspace:*",
+    "@stock-bot/http": "workspace:*",
+    "cheerio": "^1.0.0",
+    "axios": "^1.7.7",
+    "axios-rate-limit": "^1.4.0",
+    "axios-retry": "^4.4.1",
+    "socks-proxy-agent": "^8.0.2",
+    "p-limit": "^6.1.0",
+    "zod": "^3.22.4",
     "date-fns": "^2.30.0"
   },
   "devDependencies": {
     "@types/node": "^20.11.0",
     "typescript": "^5.3.0",
     "bun-types": "^1.2.15"
-  },
-  "exports": {
-    ".": {
-      "import": "./dist/index.js",
-      "require": "./dist/index.js",
-      "types": "./dist/index.d.ts"
-    }
-  },
-  "files": [
-    "dist",
-    "README.md"
-  ]
-}
+  }
+}

libs/utils/src/operation-context.ts

@@ -11,11 +11,23 @@
 import { createCache, type CacheProvider } from '@stock-bot/cache';
 import { getLogger, type Logger } from '@stock-bot/logger';
 import { getDatabaseConfig } from '@stock-bot/config';
+import type { ServiceResolver } from '@stock-bot/connection-factory';
+import type { MongoDBClient } from '@stock-bot/mongodb-client';
+import type { PostgreSQLClient } from '@stock-bot/postgres-client';
+
+export interface OperationContextOptions {
+  handlerName: string;
+  operationName: string;
+  parentLogger?: Logger;
+  container?: ServiceResolver;
+}
 
 export class OperationContext {
   public readonly logger: Logger;
-  public readonly mongodb: any; // MongoDB client - imported dynamically
-  public readonly postgres: any; // PostgreSQL client - imported dynamically
+  private readonly container?: ServiceResolver;
+  private _mongodb?: MongoDBClient;
+  private _postgres?: PostgreSQLClient;
+  private _cache?: CacheProvider;
   
   private static sharedCache: CacheProvider | null = null;
   private static parentLoggers = new Map<string, Logger>();
@@ -24,21 +36,64 @@ export class OperationContext {
   constructor(
     public readonly handlerName: string,
     public readonly operationName: string,
-    parentLogger?: Logger
+    parentLoggerOrOptions?: Logger | OperationContextOptions
   ) {
-    // Create child logger from parent or create handler parent
-    const parent = parentLogger || this.getOrCreateParentLogger();
-    this.logger = parent.child(operationName, {
-      handler: handlerName,
-      operation: operationName
-    });
-    
-    // Set up database access
-    this.mongodb = this.getDatabaseClient('mongodb');
-    this.postgres = this.getDatabaseClient('postgres');
+    // Handle both old and new constructor signatures
+    if (parentLoggerOrOptions && 'container' in parentLoggerOrOptions) {
+      const options = parentLoggerOrOptions;
+      this.container = options.container;
+      const parent = options.parentLogger || this.getOrCreateParentLogger();
+      this.logger = parent.child(operationName, {
+        handler: handlerName,
+        operation: operationName
+      });
+    } else {
+      // Legacy support
+      const parentLogger = parentLoggerOrOptions as Logger | undefined;
+      const parent = parentLogger || this.getOrCreateParentLogger();
+      this.logger = parent.child(operationName, {
+        handler: handlerName,
+        operation: operationName
+      });
+    }
   }
   
-  private getDatabaseClient(type: 'mongodb' | 'postgres'): any {
+  // Lazy load MongoDB client
+  get mongodb(): MongoDBClient {
+    if (!this._mongodb) {
+      if (this.container) {
+        try {
+          this._mongodb = this.container.resolve<MongoDBClient>('mongodb');
+        } catch (error) {
+          this.logger.warn('Failed to resolve MongoDB from container, falling back to singleton', { error });
+          this._mongodb = this.getLegacyDatabaseClient('mongodb') as MongoDBClient;
+        }
+      } else {
+        this._mongodb = this.getLegacyDatabaseClient('mongodb') as MongoDBClient;
+      }
+    }
+    return this._mongodb!;
+  }
+  
+  // Lazy load PostgreSQL client
+  get postgres(): PostgreSQLClient {
+    if (!this._postgres) {
+      if (this.container) {
+        try {
+          this._postgres = this.container.resolve<PostgreSQLClient>('postgres');
+        } catch (error) {
+          this.logger.warn('Failed to resolve PostgreSQL from container, falling back to singleton', { error });
+          this._postgres = this.getLegacyDatabaseClient('postgres') as PostgreSQLClient;
+        }
+      } else {
+        this._postgres = this.getLegacyDatabaseClient('postgres') as PostgreSQLClient;
+      }
+    }
+    return this._postgres!;
+  }
+  
+  // Legacy method for backward compatibility
+  private getLegacyDatabaseClient(type: 'mongodb' | 'postgres'): any {
     try {
       if (type === 'mongodb') {
         // Dynamic import to avoid TypeScript issues during build
@@ -71,6 +126,23 @@ export class OperationContext {
    * Keys are automatically prefixed as: "operations:handlerName:operationName:key"
    */
   get cache(): CacheProvider {
+    if (!this._cache) {
+      if (this.container) {
+        try {
+          const baseCache = this.container.resolve<CacheProvider>('cache');
+          this._cache = this.createContextualCache(baseCache);
+        } catch (error) {
+          this.logger.warn('Failed to resolve cache from container, using shared cache', { error });
+          this._cache = this.getOrCreateSharedCache();
+        }
+      } else {
+        this._cache = this.getOrCreateSharedCache();
+      }
+    }
+    return this._cache!;
+  }
+  
+  private getOrCreateSharedCache(): CacheProvider {
     if (!OperationContext.sharedCache) {
       // Get Redis configuration from database config
       if (!OperationContext.databaseConfig) {
@@ -91,28 +163,28 @@ export class OperationContext {
         redisConfig
       });
     }
-    return this.createContextualCache();
+    return this.createContextualCache(OperationContext.sharedCache);
   }
   
-  private createContextualCache(): CacheProvider {
+  private createContextualCache(baseCache: CacheProvider): CacheProvider {
     const contextPrefix = `${this.handlerName}:${this.operationName}:`;
     
     // Return a proxy that automatically prefixes keys with context
     return {
       async get<T>(key: string): Promise<T | null> {
-        return OperationContext.sharedCache!.get(`${contextPrefix}${key}`);
+        return baseCache.get(`${contextPrefix}${key}`);
       },
       
       async set<T>(key: string, value: T, options?: any): Promise<T | null> {
-        return OperationContext.sharedCache!.set(`${contextPrefix}${key}`, value, options);
+        return baseCache.set(`${contextPrefix}${key}`, value, options);
       },
       
       async del(key: string): Promise<void> {
-        return OperationContext.sharedCache!.del(`${contextPrefix}${key}`);
+        return baseCache.del(`${contextPrefix}${key}`);
       },
       
       async exists(key: string): Promise<boolean> {
-        return OperationContext.sharedCache!.exists(`${contextPrefix}${key}`);
+        return baseCache.exists(`${contextPrefix}${key}`);
       },
       
       async clear(): Promise<void> {
@@ -122,23 +194,23 @@ export class OperationContext {
       
       async keys(pattern: string): Promise<string[]> {
         const fullPattern = `${contextPrefix}${pattern}`;
-        return OperationContext.sharedCache!.keys(fullPattern);
+        return baseCache.keys(fullPattern);
       },
       
       getStats() {
-        return OperationContext.sharedCache!.getStats();
+        return baseCache.getStats();
       },
       
       async health(): Promise<boolean> {
-        return OperationContext.sharedCache!.health();
+        return baseCache.health();
       },
       
       async waitForReady(timeout?: number): Promise<void> {
-        return OperationContext.sharedCache!.waitForReady(timeout);
+        return baseCache.waitForReady(timeout);
       },
       
       isReady(): boolean {
-        return OperationContext.sharedCache!.isReady();
+        return baseCache.isReady();
       }
     } as CacheProvider;
   }
@@ -146,8 +218,15 @@ export class OperationContext {
   /**
    * Factory method to create OperationContext
    */
-  static create(handlerName: string, operationName: string, parentLogger?: Logger): OperationContext {
-    return new OperationContext(handlerName, operationName, parentLogger);
+  static create(handlerName: string, operationName: string, parentLoggerOrOptions?: Logger | OperationContextOptions): OperationContext {
+    if (parentLoggerOrOptions && 'container' in parentLoggerOrOptions) {
+      return new OperationContext(handlerName, operationName, {
+        ...parentLoggerOrOptions,
+        handlerName,
+        operationName
+      });
+    }
+    return new OperationContext(handlerName, operationName, parentLoggerOrOptions as Logger | undefined);
   }
   
   /**
@@ -161,12 +240,38 @@ export class OperationContext {
    * Create a child context for sub-operations
    */
   createChild(subOperationName: string): OperationContext {
+    if (this.container) {
+      return new OperationContext(
+        this.handlerName,
+        `${this.operationName}:${subOperationName}`,
+        { 
+          handlerName: this.handlerName,
+          operationName: `${this.operationName}:${subOperationName}`,
+          parentLogger: this.logger, 
+          container: this.container 
+        }
+      );
+    }
     return new OperationContext(
       this.handlerName,
       `${this.operationName}:${subOperationName}`,
       this.logger
     );
   }
+  
+  /**
+   * Dispose of resources if using container-based connections
+   * This is a no-op for legacy singleton connections
+   */
+  async dispose(): Promise<void> {
+    // If using container, it will handle cleanup
+    // For singleton connections, they persist
+    this.logger.debug('OperationContext disposed', {
+      handler: this.handlerName,
+      operation: this.operationName,
+      hasContainer: !!this.container
+    });
+  }
 }
 
 export default OperationContext;

libs/utils/tsconfig.json

@@ -10,6 +10,9 @@
     { "path": "../cache" },
     { "path": "../config" },
     { "path": "../logger" },
-    { "path": "../http" }
+    { "path": "../http" },
+    { "path": "../connection-factory" },
+    { "path": "../mongodb-client" },
+    { "path": "../postgres-client" }
   ]
 }