请教使用 gunicorn 部署 flask 时遇到的 redis 连接数飙升问题

小弟写了个简单的 flask 接口，其中使用了 redis，连接 redis 的语句写在全局里了，如下：
cache = redis.StrictRedis('127.0.0.1', 6379)

然后使用 gunicorn 部署，部署命令是：
gunicorn --workers=9 --worker-class=gevent t_fl:app -b 0.0.0.0:5002

在高并发情况下（并发两千至五千）执行十万次请求，使用 info clients 命令查看 redis 的客户端连接数飙升到 3000 左右，严重拖慢了查询速度。请问有什么解决办法。

Redis

gunicorn

flask

并发

4 条回复 • 2018-06-05 15:49:56 +08:00

myyou

2018-01-08 11:58:12 +08:00

使用 Redis 连接池 ConnectionPool 设置最大连接数量

lywane

2018-01-08 12:32:03 +08:00

@myyou
如下声明之后，
rdp = redis.ConnectionPool(host='127.0.0.1', port=6379,max_connections=10)
cache = redis.StrictRedis(connection_pool=rdp)

请求过来时会报错：
[2018-01-08 12:06:10,117] ERROR in app: Exception on / [POST]
Traceback (most recent call last):
File "/usr/lib64/python2.7/site-packages/flask/app.py", line 1982, in wsgi_app
response = self.full_dispatch_request()
File "/usr/lib64/python2.7/site-packages/flask/app.py", line 1614, in full_dispatch_request
rv = self.handle_user_exception(e)
File "/usr/lib64/python2.7/site-packages/flask/app.py", line 1517, in handle_user_exception
reraise(exc_type, exc_value, tb)
File "/usr/lib64/python2.7/site-packages/flask/app.py", line 1612, in full_dispatch_request
rv = self.dispatch_request()
File "/usr/lib64/python2.7/site-packages/flask/app.py", line 1598, in dispatch_request
return self.view_functions[rule.endpoint](**req.view_args)
File "/opt/t_fl.py", line 54, in index
timeout, endtime = get_timeout_endtime(GID)
File "/opt/t_fl.py", line 20, in get_timeout_endtime
timeout_endtime = cache.get(gid)
File "/usr/lib/python2.7/site-packages/redis/client.py", line 976, in get
return self.execute_command('GET', name)
File "/usr/lib/python2.7/site-packages/redis/client.py", line 665, in execute_command
connection = pool.get_connection(command_name, **options)
File "/usr/lib/python2.7/site-packages/redis/connection.py", line 965, in get_connection
connection = self.make_connection()
File "/usr/lib/python2.7/site-packages/redis/connection.py", line 981, in make_connection
raise ConnectionError("Too many connections")

myyou

2018-01-08 14:54:08 +08:00

gunicorn 使用 gevent 时--worker-connections 默认 1000，你可以把这个值设置小一些

liuxingpu

2018-06-05 15:49:56 +08:00

我也碰到这个问题,请问楼主解决了没?