定位与处理步骤
一 快速定位慢请求
tail -n 200 /var/log/yourapp.loggrep -i "slow query" /var/log/yourapp.log | grep -i "100ms"jq 'select(.duration > 100)' combined.logawk '{sum+=$2; count++; arr[NR]=$2} END {asort(arr); p95=arr[int(count*0.95)]; print "avg:", sum/count, "ms; p95:", p95, "ms"}' combined.log二 在 Node.js 中准确记录耗时
const express = require('express');
const app = express();
app.use((req, res, next) => {
const start = Date.now();
res.on('finish', () => {
const duration = Date.now() - start;
if (duration > 100) { // 阈值示例:100ms
console.log(`Slow request: ${req.method} ${req.url} - ${duration}ms`);
}
});
next();
});
app.listen(3000);
const express = require('express');
const morgan = require('morgan');
const winston = require('winston');
const logger = winston.createLogger({
level: 'info',
format: winston.format.json(),
transports: [
new winston.transports.File({ filename: 'error.log', level: 'error' }),
new winston.transports.File({ filename: 'combined.log' })
]
});
app.use(morgan('combined', { stream: { write: msg => logger.info(msg.trim()) } }));
const { Pool } = require('pg');
const pool = new Pool();
const start = Date.now();
pool.query('SELECT * FROM users WHERE id = $1', [userId], (err, res) => {
const duration = Date.now() - start;
if (err) return logger.error(`Query failed: ${err.stack}`);
logger.info(`Query ${duration}ms: SELECT * FROM users WHERE id = $1`, [userId]);
});
const start = process.hrtime();
// ... your code
const [s, ns] = process.hrtime(start);
const ms = s * 1000 + ns / 1e6;
console.log(`Execution time: ${ms.toFixed(2)} ms`);
三 数据库侧慢查询排查与优化
CREATE EXTENSION IF NOT EXISTS pg_stat_statements;
SELECT query, calls, total_time, rows,
100.0 * shared_blks_hit / nullif(shared_blks_hit + shared_blks_read, 0) AS hit_percent
FROM pg_stat_statements
ORDER BY total_time DESC
LIMIT 10;
四 监控告警与持续优化
pm2 start app.js --name my-app && pm2 monitsudo nano /etc/logrotate.d/nodejs
/path/to/your/nodejs/logs/*.log {
daily
rotate 7
missingok
notifempty
compress
delaycompress
sharedscripts
}