why do i have error "Address already in use"?

python sockets nginx flask uwsgi

17,899

Solution 1

i have same issue, but the problem was in sqlalchemy, try to add this:

@app.teardown_request
def shutdown_session(exception=None):
    from extension import db
    db.session.remove()

Solution 2

This error means that port 9002 is already in use by another process. As per your logs that process is uwsgi probably another instance of uWSGI is running on the same address (127.0.0.1:9002). May be the port was not released while you stop flask app and your wsgi server is restarted while you run touch touch_reload. You may try the following command to release the port.

sudo fuser -k 9002/tcp

If that is a tcp process and restart your wsgi server again to see if the port is already in use.

Solution 3

maybe you stop uwsgi by crtl + z:

find the pid of process which take 8000

$ lsof -i:8000

result maybe is:

COMMAND  PID       USER   FD   TYPE ...
uwsgi   9196       xxx    4u  xxx   ...

then

$ kill 9196

Solution 4

FWIW, I had a similar issue and discovered that I was running uwsgi --http when I should have been running uwsgi --socket.

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17,899

Author by

comalex3

Python/java developer

Updated on July 22, 2022

Comments

comalex3 almost 2 years

i run my flask app, and it works good, but by the time the app is stopped and in my uwsgi log

probably another instance of uWSGI is running on the same address (127.0.0.1:9002).
    bind(): Address already in use [core/socket.c line 764]

when i run touch touch_reload, app is working again. I run anything else on the server which may take the socket.

my conf:

nginx
server {
    listen 80;
    ....
    location / {
       include uwsgi_params;
       uwsgi_pass 127.0.0.1:9001;
    }
    ....
}
server {
    listen 80;
    ....
    location / {
       include uwsgi_params;
       uwsgi_pass 127.0.0.1:9003;
    }
    ....
}

uwsgi:
chdir = /var/www/../
module = wsgihandler
socket = 127.0.0.1:9003
wsgi-file = app/__init__.py
callable = app
master = true
chmod-socket = 664
uid = root
gid = root
processes = 4
socket-timeout = 180
post-buffering = 8192
max-requests = 1000
buffer-size = 32768
logto = /var/www/.../log/uwsgi.log
touch-reload = /var/www/.../touch_reload

Havenard almost 9 years

It means port 9002 is already in use.
John La Rooy almost 9 years

How are you stopping the process?
therealprashant almost 9 years

You probably must be using ctrl+z to stop the process but that is actually just hiding it. use ctrl+c to entirely stop
therealprashant almost 9 years

additionally you can use ps aux | grep 9002 to see what are using 9002 for
comalex3 almost 9 years

I did not stop the server, it is production