使用flask框架进行web开发的时候,默认情况是单一的进程。当出现并发请求,就会出现排队现象。
解决:
- 开发环境, threaded=True
if __name__ == '__main__': # 多进程与多线程不能同时开启 #app.run('0.0.0.0', port=5001, threaded=False, processes=3) # 适用多进程启动服务 #app.run('0.0.0.0', port=5001, threaded=True) # 适用多线程启动服务
- 生产环境,使用gunicorn部署
python常见的web部署搭配nginx+gunicorn。
一、gunicorn安装
pip install gunicorn
二、配置参数详解
参考:
1、Gunicorn配置部分的翻译
2、Gunicorn-配置详解
3、python之gunicorn的配置
4、gunicorn官方文档
具体参数如下:
[2019-07-04 19:37:21 +0800] [31677] [DEBUG] Current configuration:
config: /home/gunicorn/config.py
bind: ['172.28.171.98:8080']
backlog: 2048
workers: 1
worker_class: sync
threads: 1
worker_connections: 1000
max_requests: 0
max_requests_jitter: 0
timeout: 600
graceful_timeout: 30
keepalive: 2
limit_request_line: 4094
limit_request_fields: 100
limit_request_field_size: 8190
reload: True
reload_engine: auto
reload_extra_files: []
spew: False
check_config: False
preload_app: False
sendfile: None
reuse_port: False
chdir: /home/260190/PycharmProjects/文档内容修订检测
daemon: False
raw_env: []
pidfile: None
worker_tmp_dir: None
user: 1000
group: 1000
umask: 0
initgroups: False
tmp_upload_dir: None
secure_scheme_headers: {'X-FORWARDED-PROTOCOL': 'ssl', 'X-FORWARDED-PROTO': 'https', 'X-FORWARDED-SSL': 'on'}
forwarded_allow_ips: ['127.0.0.1']
accesslog: /home/260190/PycharmProjects/文档内容修订检测/gunicorn/access.log
disable_redirect_access_to_syslog: False
access_log_format: %(h)s %(l)s %(u)s %(t)s "%(r)s" %(s)s %(b)s "%(f)s" "%(a)s"
errorlog: /home/260190/PycharmProjects/文档内容修订检测/gunicorn/error.log
loglevel: debug
capture_output: True
logger_class: gunicorn.glogging.Logger
logconfig: None
logconfig_dict: {}
syslog_addr: udp://localhost:514
syslog: False
syslog_prefix: None
syslog_facility: user
enable_stdio_inheritance: False
statsd_host: None
statsd_prefix:
proc_name: None
default_proc_name: main:app
pythonpath: None
paste: None
on_starting: <function OnStarting.on_starting at 0x7fc33c6579d8>
on_reload: <function OnReload.on_reload at 0x7fc33c657ae8>
when_ready: <function WhenReady.when_ready at 0x7fc33c657bf8>
pre_fork: <function Prefork.pre_fork at 0x7fc33c657d08>
post_fork: <function Postfork.post_fork at 0x7fc33c657e18>
post_worker_init: <function PostWorkerInit.post_worker_init at 0x7fc33c657f28>
worker_int: <function WorkerInt.worker_int at 0x7fc33c47e0d0>
worker_abort: <function WorkerAbort.worker_abort at 0x7fc33c47e1e0>
pre_exec: <function PreExec.pre_exec at 0x7fc33c47e2f0>
pre_request: <function PreRequest.pre_request at 0x7fc33c47e400>
post_request: <function PostRequest.post_request at 0x7fc33c47e488>
child_exit: <function ChildExit.child_exit at 0x7fc33c47e598>
worker_exit: <function WorkerExit.worker_exit at 0x7fc33c47e6a8>
nworkers_changed: <function NumWorkersChanged.nworkers_changed at 0x7fc33c47e7b8>
on_exit: <function OnExit.on_exit at 0x7fc33c47e8c8>
proxy_protocol: False
proxy_allow_ips: ['127.0.0.1']
keyfile: None
certfile: None
ssl_version: 2
cert_reqs: 0
ca_certs: None
suppress_ragged_eofs: True
do_handshake_on_connect: False
ciphers: TLSv1
raw_paste_global_conf: []
[2019-07-04 19:37:21 +0800] [31677] [INFO] Starting gunicorn 19.9.0
[2019-07-04 19:37:21 +0800] [31677] [DEBUG] Arbiter booted
[2019-07-04 19:37:21 +0800] [31677] [INFO] Listening at: http://172.28.171.98:8080 (31677)
[2019-07-04 19:37:21 +0800] [31677] [INFO] Using worker: sync
[2019-07-04 19:37:21 +0800] [31680] [INFO] Booting worker with pid: 31680
[2019-07-04 19:37:21 +0800] [31677] [DEBUG] 1 workers
[2019-07-04 19:37:41 +0800] [31680] [DEBUG] worker: SIGWINCH ignored.
[2019-07-04 19:37:41 +0800] [31677] [INFO] Handling signal: winch
[2019-07-04 19:37:41 +0800] [31677] [DEBUG] SIGWINCH ignored. Not daemonized
三、项目中的配置文件config.py
:
有的也写成gunicorn.conf
,应该是一样的
import multiprocessing
bind = "127.0.0.1:5000"
# workers = multiprocessing.cpu_count() * 2 + 1
workers = 10
accesslog = '/home/gunicorn/access.log' # 访问日志目录
errorlog = '/home/gunicorn/error.log' # 错误日志目录
capture_output = True # 重定向标准输出到错误日志。默认为False。
timeout = 600 # 过期时间
loglevel = "debug" # 日志级别,这个日志级别指的是错误日志的级别,而访问日志的级别无法设置
# debug、info、warning、error、critical
reload = True # 重载 更改代码的时候重启workers, 只建议在开发过程中开启。
daemon = True # 以守护进程形式来运行Gunicorn进程。其实就是将这个服务放到后台去运行。默认为False。
启动:gunicorn -c config.py main:app
或者 gunicorn -c gunicorn.conf main:app
三、总结
命令行运行 gunicorn -c config.py main:app
,开启10进程,超时时间为10min,服务后台运行,重定向标准输出到错误日志,输出错误日志,访问日志等。解决了之前总是用nohup python main.py >out.log 2>&1 &来启动Flask后台服务的问题。