gunicorn 几种 worker class 性能测试比较

Gunicorn, 一个支持WSGI协议的web服务器
Flask, 一个轻量级的python web框架
Gunicorn目前自带支持几种工作方式:

sync (默认值)
eventlet
gevent
tornado
测试环境准备
python 2.7+
redis-server 2.8.4
压力测试工具ab
代码及相关python包准备 创建虚一个新的虚拟环境并安装需要的包
$ mkvirtualenv test
$ workon test

$ cat requirements.txt
gunicorn==19.3.0
flask==0.10.1
flask-redis==0.1.0
gevent==1.0.2
tornado==4.2
eventlet==0.17.4

$ pip install -r requirements.txt
测试程序app.py

:::python
from flask import Flask
from flask_redis import FlaskRedis

REDIS_URL = "redis://:password-string@localhost:6379/0"
app = Flask(__name__)
app.config.from_object(__name__)

redis = FlaskRedis(app, True)

@app.route("/")
def index():
    redis.incr("hit", 1)
    return redis.get("hit")

if __name__ == '__main__':
    app.run()
开始测试
使用ab工具,并行500个客户端, 发送50000次请求

$ ab -c 500 -t 30 -r "http://127.0.0.1:8000/"
分别使用四种方式启动使用服务， 并开启４个worker

$ gunicorn -w 4 app:app --error-logfile - --worker-class sync
$ gunicorn -w 4 app:app --error-logfile - --worker-class gevent
$ gunicorn -w 4 app:app --error-logfile - --worker-class tornado
$ gunicorn -w 4 app:app --error-logfile - --worker-class eventlet
结果比较

Worker class	Time taken for tests	Complete requests	Failed requests	Requests per second	用户平均请求等待时间	服务器平均处理时间	最小连接时间	平均连接时间	50%的连接时间	最大连接时间
sync	37.363 s	49928	793	1336.29	374.169 ms	0.748 ms	5 ms	75 ms	17 ms	31746 ms
tornado	13.995	50000	543	3572.64	139.953 ms	0.280 ms	6 ms	110 ms	24 ms	13837 ms
eventlet	8.156	50000	0	6130.74	81.556	0.163 ms	2 ms	80 ms	62 ms	3153 ms
gevent	7.647 s	50000	0	6538.23	76.473 ms	0.153 ms	1 ms	74 ms	52 ms	1122 ms
从测试结果来看，默认自带sync效率很低，并且在测试时发现，采用sync方式在高并发时 会出现woker重启的情况, 如下:

[2015-06-25 11:31:06 +0000] [27040] [CRITICAL] WORKER TIMEOUT (pid:27064)
[2015-06-25 11:31:06 +0000] [27040] [CRITICAL] WORKER TIMEOUT (pid:27051)
[2015-06-25 11:31:06 +0000] [27040] [CRITICAL] WORKER TIMEOUT (pid:27045)
[2015-06-25 11:31:06 +0000] [27040] [CRITICAL] WORKER TIMEOUT (pid:27046)
[2015-06-25 11:31:06 +0000] [27064] [INFO] Worker exiting (pid: 27064)
[2015-06-25 11:31:06 +0000] [27051] [INFO] Worker exiting (pid: 27051)
[2015-06-25 11:31:06 +0000] [27045] [INFO] Worker exiting (pid: 27045)
[2015-06-25 11:31:06 +0000] [27046] [INFO] Worker exiting (pid: 27046)
[2015-06-25 11:31:06 +0000] [27263] [INFO] Booting worker with pid: 27263
[2015-06-25 11:31:06 +0000] [27264] [INFO] Booting worker with pid: 27264
[2015-06-25 11:31:06 +0000] [27277] [INFO] Booting worker with pid: 27277
[2015-06-25 11:31:06 +0000] [27280] [INFO] Booting worker with pid: 27280
eventlet 和gevent两种方式效果最好，数据基本差不多.

文章作者 crazygit