Python爬虫监控程序设计思路
最近因为爬虫程序太多,想要为Python爬虫设计一个监控程序,主要功能包括一下几种:
1、监控爬虫的运行状态(是否在运行、运行时间等)
2、监控爬虫的性能(如请求频率、响应时间、错误率等)
3、资源使用情况(CPU、内存、网络等)
4、异常捕获与告警(当爬虫出现异常时能够及时通知)
要为Python爬虫创建一个监控程序,根据上面思路我们可以按照以下步骤实现,涵盖运行状态、性能指标、异常告警和可视化:
核心监控功能设计
-
运行状态监控
- 心跳检测:定期记录爬虫存活状态
- 进程检查:验证爬虫进程是否运行中
-
性能指标监控
- 请求统计:成功/失败请求计数
- 数据处理:已抓取/解析的项目数
- 资源使用:CPU/内存占用
- 时效指标:请求响应时间、运行时长
-
异常告警
- 错误捕获:网络异常、解析失败等
- 阈值告警:连续失败/资源超限
- 通知渠道:邮件/Slack/钉钉
-
数据持久化
- 存储日志:运行日志和错误日志
- 记录指标:时间序列数据库存储
实现方案代码示例
1. 基础监控类 (monitor.py)
import time
import logging
import psutil
from prometheus_client import start_http_server, Counter, Gauge, Histogramclass SpiderMonitor:def __init__(self, spider_name):self.spider_name = spider_nameself.start_time = time.time()# 初始化监控指标self.requests_total = Counter(f'{spider_name}_requests_total', 'Total requests')self.requests_failed = Counter(f'{spider_name}_requests_failed', 'Failed requests')self.items_scraped = Counter(f'{spider_name}_items_scraped', 'Items scraped')self.memory_usage = Gauge(f'{spider_name}_memory_usage', 'Memory usage (MB)')self.request_latency = Histogram(f'{spider_name}_request_latency', 'Request latency (seconds)')# 启动指标服务器start_http_server(8000)logging.basicConfig(filename=f'{spider_name}.log', level=logging.INFO)def record_request(self, success=True, latency=0):self.requests_total.inc()if not success:self.requests_failed.inc()if latency > 0:self.request_latency.observe(latency)def record_item(self, count=1):self.items_scraped.inc(count)def update_resources(self):process = psutil.Process()self.memory_usage.set(process.memory_info().rss / 1024 / 1024) # MBdef log_error(self, error):logging.error(f"[{time.ctime()}] ERROR: {error}")def uptime(self):return time.time() - self.start_time
2. 爬虫集成示例 (my_spider.py)
import requests
from monitor import SpiderMonitorclass MySpider:def __init__(self):self.monitor = SpiderMonitor("my_spider")self.session = requests.Session()def crawl(self, url):start = time.time()try:response = self.session.get(url, timeout=10)response.raise_for_status()# 处理数据items = self.parse(response)self.monitor.record_item(len(items))self.monitor.record_request(success=True, latency=time.time()-start)return itemsexcept Exception as e:self.monitor.record_request(success=False)self.monitor.log_error(f"URL: {url} - Error: {str(e)}")return []def parse(self, response):# 解析逻辑return [{"data": "sample"}]def run(self):while True:self.crawl("https://example.com/data")self.monitor.update_resources()time.sleep(5)if __name__ == "__main__":spider = MySpider()spider.run()
3. 独立监控进程 (monitor_daemon.py)
import time
import subprocess
import smtplib
from email.mime.text import MIMETextdef check_heartbeat(spider_name):"""检查最近15分钟是否有活动日志"""try:with open(f"{spider_name}.log") as f:logs = f.readlines()[-100:]return any(time.time() - get_log_time(line) < 900 for line in logs)except FileNotFoundError:return Falsedef get_log_time(log_line):# 从日志行提取时间戳timestamp_str = log_line.split("]")[0][1:]return time.mktime(time.strptime(timestamp_str))def send_alert(subject, message):"""发送邮件告警"""msg = MIMEText(message)msg['Subject'] = f"[SPIDER ALERT] {subject}"msg['From'] = 'monitor@example.com'msg['To'] = 'admin@example.com'with smtplib.SMTP('smtp.example.com') as server:server.send_message(msg)def monitor_daemon():spider_name = "my_spider"consecutive_failures = 0while True:if not check_heartbeat(spider_name):consecutive_failures += 1if consecutive_failures >= 3:send_alert("Spider Down", f"{spider_name} has been inactive for 45+ minutes")else:consecutive_failures = 0time.sleep(300) # 每5分钟检查一次if __name__ == "__main__":monitor_daemon()
监控系统部署方案
-
指标可视化
- 使用Prometheus收集指标(默认端口8000)
- 配置Grafana仪表盘展示:
- 请求成功率 = (1 - requests_failed/requests_total) * 100
- 内存使用趋势图
- 最近1小时错误日志
-
告警配置
# Prometheus alert.rules groups: - name: spider_alertsrules:- alert: HighFailureRateexpr: rate(my_spider_requests_failed[5m]) / rate(my_spider_requests_total[5m]) > 0.1for: 10mlabels:severity: criticalannotations:description: "超过10%的请求失败"
-
进程管理
- 使用Supervisor管理进程:
[program:my_spider] command=python /path/to/my_spider.py autostart=true autorestart=true stderr_logfile=/var/log/spider.err.log
高级功能扩展
-
分布式监控
- 使用Redis共享监控数据:
import redis r = redis.Redis() r.incr('global_requests_count')
-
网页状态面板
# 添加Flask状态页 from flask import Flask app = Flask(__name__ @app.route('/status') def status():return {"uptime": monitor.uptime(),"items": monitor.items_scraped._value.get()}
-
云服务集成
- 错误跟踪:Sentry
- 日志管理:ELK Stack
- 云监控:Datadog/Prometheus Cloud
监控仪表盘示例 (Grafana)
-
核心面板
- 请求成功率 (百分比)
- 每分钟请求量
- 内存/CPU使用曲线
- 最近错误列表
-
报警阈值
- 成功率 < 95% (警告)
- 内存 > 500MB (警告)
- 1小时无活动 (严重)
这种监控方案提供实时性能跟踪、自动告警和可视化展示,能有效提升爬虫的稳定性和可维护性。最终我们可根据实际需求调整监控粒度和告警阈值。如有任何疑问可以留言讨论。