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Merged
Dobrunia merged 1 commit into from
Nov 7, 2025
Merged

feat: implement graceful shutdown and optimize database connection ha… #7

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33 changes: 32 additions & 1 deletion main.js
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Original file line number Diff line number Diff line change
Expand Up @@ -5,6 +5,37 @@ dotenv.config();
const host = process.env.APP_IP || '0.0.0.0';
const PORT = process.env.PORT || 3000;

app.listen(PORT, host, () => {
const server = app.listen(PORT, host, () => {
console.log(`Server running on http://${host}:${PORT}`);
});

// Graceful shutdown handlers
const shutdown = async (signal) => {
console.log(`\n${signal} получен. Начинаем graceful shutdown...`);

// Останавливаем прием новых запросов
server.close(() => {
console.log('✅ HTTP сервер закрыт');
});

// Закрываем соединения с БД
if (app.gracefulShutdown) {
await app.gracefulShutdown();
} else {
process.exit(0);
}
};

// Обработка сигналов для graceful shutdown
process.on('SIGTERM', () => shutdown('SIGTERM'));
process.on('SIGINT', () => shutdown('SIGINT'));

// Обработка необработанных ошибок
process.on('unhandledRejection', (reason, promise) => {
console.error('❌ Unhandled Rejection at:', promise, 'reason:', reason);
});

process.on('uncaughtException', (error) => {
console.error('❌ Uncaught Exception:', error);
shutdown('uncaughtException');
});
55 changes: 37 additions & 18 deletions src/app.js
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Expand Up @@ -37,21 +37,17 @@ app.use((err, req, res, next) => {
// Register routes
registerRoutes(app);

// Database connection check
function checkDatabaseConnection() {
return db
.getConnection()
.then((connection) => {
return connection.ping().then(() => {
console.log('✅ Успешное подключение к базе данных MySQL');
connection.release();
return true;
});
})
.catch((err) => {
console.error('❌ Ошибка подключения к базе данных:', err);
return false;
});
// Оптимизированная проверка подключения - использует pool.query вместо getConnection
// Это не занимает отдельное соединение
async function checkDatabaseConnection() {
try {
await db.query('SELECT 1');
console.log('✅ Успешное подключение к базе данных MySQL');
return true;
} catch (err) {
console.error('❌ Ошибка подключения к базе данных:', err.message);
return false;
}
}

// Try to connect multiple times before giving up
Expand All @@ -60,8 +56,10 @@ async function ensureDatabaseConnection(attempts = 5, delay = 5000) {
const connected = await checkDatabaseConnection();
if (connected) return true;

console.log(`Повторная попытка подключения к БД (${i + 1}/${attempts})...`);
await new Promise((resolve) => setTimeout(resolve, delay));
if (i < attempts - 1) {
console.log(`Повторная попытка подключения к БД (${i + 1}/${attempts})...`);
await new Promise((resolve) => setTimeout(resolve, delay));
}
}

console.error('❌ Не удалось подключиться к базе данных после нескольких попыток.');
Expand All @@ -75,4 +73,25 @@ ensureDatabaseConnection().then((connected) => {
}
});

module.exports = app;
// Graceful shutdown function
async function gracefulShutdown() {
console.log('🛑 Начало graceful shutdown...');
const dbModule = require('./config/db');

try {
if (dbModule.closePool) {
await dbModule.closePool();
}
console.log('✅ Graceful shutdown завершен');
process.exit(0);
} catch (err) {
console.error('❌ Ошибка при graceful shutdown:', err);
process.exit(1);
}
}

// Экспортируем app и функцию для graceful shutdown
const appWithShutdown = app;
appWithShutdown.gracefulShutdown = gracefulShutdown;

module.exports = appWithShutdown;
58 changes: 28 additions & 30 deletions src/config/db.js
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Expand Up @@ -4,12 +4,12 @@ require('dotenv').config();
const { SQL_HOST, SQL_USER, SQL_PASSWORD, SQL_DB } = process.env;

if (!SQL_HOST || !SQL_USER || !SQL_PASSWORD || !SQL_DB) {
throw new Error(
'❌ Отсутствуют переменные окружения для подключения к базе данных',
);
throw new Error('❌ Отсутствуют переменные окружения для подключения к базе данных');
}

const poolSize = 30;
// Оптимизированный pool size: после оптимизации запросов (SQL JOIN) нужно меньше соединений
// 10 соединений достаточно для большинства нагрузок
const poolSize = 10;
const pool = mysql.createPool({
host: SQL_HOST,
user: SQL_USER,
Expand All @@ -18,27 +18,13 @@ const pool = mysql.createPool({
waitForConnections: true,
connectionLimit: poolSize,
queueLimit: 0,
enableKeepAlive: true, // Enable TCP keep-alive
keepAliveInitialDelay: 10000, // Initial delay before sending keep-alive probes
connectTimeout: 30000, // Increase connection timeout to 30 seconds
enableKeepAlive: true,
keepAliveInitialDelay: 10000,
connectTimeout: 30000,
// Соединения автоматически освобождаются после запросов
// Keep-alive ping не нужен - pool сам управляет соединениями
});

// More frequent keep-alive to prevent ECONNRESET
const pingInterval = 30000; // 30 seconds
setInterval(() => {
pool
.query('SELECT 1')
.then(() => {
console.log('✅ MySQL keep-alive ping successful');
})
.catch((err) => {
console.error(
'❌ Ошибка при поддержании соединения с MySQL:',
err.message,
);
});
}, pingInterval);

// Wrapper function to retry failed queries
async function executeWithRetry(queryFn, retries = 3, delay = 500) {
let lastError;
Expand All @@ -50,13 +36,8 @@ async function executeWithRetry(queryFn, retries = 3, delay = 500) {
lastError = err;

// Only retry on connection errors
if (
err.code === 'ECONNRESET' ||
err.code === 'PROTOCOL_CONNECTION_LOST'
) {
console.log(
`Reconnecting after ${err.code}, attempt ${attempt + 1}/${retries}`,
);
if (err.code === 'ECONNRESET' || err.code === 'PROTOCOL_CONNECTION_LOST') {
console.log(`Reconnecting after ${err.code}, attempt ${attempt + 1}/${retries}`);
if (attempt < retries - 1) {
await new Promise((resolve) => setTimeout(resolve, delay));
continue;
Expand All @@ -77,4 +58,21 @@ pool.query = function (...args) {
return executeWithRetry(() => originalQuery(...args));
};

// Graceful shutdown function
async function closePool() {
return new Promise((resolve, reject) => {
pool.end((err) => {
if (err) {
console.error('❌ Ошибка при закрытии pool:', err);
reject(err);
} else {
console.log('✅ Pool закрыт успешно');
resolve();
}
});
});
}

// Экспортируем pool и функцию для graceful shutdown
module.exports = pool;
module.exports.closePool = closePool;