stock-bot/libs/data/postgres/src/health.ts
2025-06-21 18:27:00 -04:00

145 lines
3.9 KiB
TypeScript

import { getLogger } from '@stock-bot/logger';
import type { PostgreSQLClient } from './client';
import type { PostgreSQLHealthCheck, PostgreSQLHealthStatus, PostgreSQLMetrics } from './types';
/**
* PostgreSQL Health Monitor
*
* Monitors PostgreSQL connection health and provides metrics
*/
export class PostgreSQLHealthMonitor {
private readonly client: PostgreSQLClient;
private readonly logger: ReturnType<typeof getLogger>;
private healthCheckInterval: NodeJS.Timeout | null = null;
private metrics: PostgreSQLMetrics;
private lastHealthCheck: PostgreSQLHealthCheck | null = null;
constructor(client: PostgreSQLClient) {
this.client = client;
this.logger = getLogger('postgres-health-monitor');
this.metrics = {
queriesPerSecond: 0,
averageQueryTime: 0,
errorRate: 0,
connectionPoolUtilization: 0,
slowQueries: 0,
};
}
/**
* Start health monitoring
*/
start(intervalMs: number = 30000): void {
if (this.healthCheckInterval) {
this.stop();
}
this.logger.info(`Starting PostgreSQL health monitoring (interval: ${intervalMs}ms)`);
this.healthCheckInterval = setInterval(async () => {
try {
await this.performHealthCheck();
} catch (error) {
this.logger.error('Health check failed:', error);
}
}, intervalMs);
// Perform initial health check
this.performHealthCheck().catch(error => {
this.logger.error('Initial health check failed:', error);
});
}
/**
* Stop health monitoring
*/
stop(): void {
if (this.healthCheckInterval) {
clearInterval(this.healthCheckInterval);
this.healthCheckInterval = null;
this.logger.info('Stopped PostgreSQL health monitoring');
}
}
/**
* Get current health status
*/
async getHealth(): Promise<PostgreSQLHealthCheck> {
if (!this.lastHealthCheck) {
await this.performHealthCheck();
}
if (!this.lastHealthCheck) {
throw new Error('Health check failed to produce results');
}
return this.lastHealthCheck;
}
/**
* Get current metrics
*/
getMetrics(): PostgreSQLMetrics {
return { ...this.metrics };
}
/**
* Perform a health check
*/
private async performHealthCheck(): Promise<void> {
const startTime = Date.now();
const errors: string[] = [];
let status: PostgreSQLHealthStatus = 'healthy';
try {
if (!this.client.connected) {
errors.push('PostgreSQL client not connected');
status = 'unhealthy';
} else {
// Test basic connectivity
await this.client.query('SELECT 1');
// Get connection stats
const stats = await this.client.getStats();
// Check connection pool utilization
const utilization = parseInt(stats.active_connections) / parseInt(stats.max_connections);
if (utilization > 0.8) {
errors.push('High connection pool utilization');
status = status === 'healthy' ? 'degraded' : status;
}
// Check for high latency
const latency = Date.now() - startTime;
if (latency > 1000) {
errors.push(`High latency: ${latency}ms`);
status = status === 'healthy' ? 'degraded' : status;
}
this.metrics.connectionPoolUtilization = utilization;
}
} catch (error) {
errors.push(`Health check failed: ${(error as Error).message}`);
status = 'unhealthy';
}
const latency = Date.now() - startTime;
this.lastHealthCheck = {
status,
timestamp: new Date(),
latency,
connections: {
active: 1,
idle: 9,
total: 10,
},
errors: errors.length > 0 ? errors : undefined,
};
// Log health status changes
if (status !== 'healthy') {
this.logger.warn(`PostgreSQL health status: ${status}`, { errors, latency });
} else {
this.logger.debug(`PostgreSQL health check passed (${latency}ms)`);
}
}
}