Python error address already in use

FIX: Python Socket Error 48: Address already in use

• Python is a very common programming language used in many of today’s programs.
• The article below will show you how to handle Python Socket Error 48.
• If you can’t handle Python, then maybe you should use a program to convert it into something you know.
• If you need more general troubleshooting guides, visit our Fix page.

You get the python socket error 48: Address already in use when a process attempts to bind itself to a busy port. Processes on the server connect to the internet via ports, and if you do not specify a port, the default port (8000) is used.

To solve this issue and clear the error, you have to bind the process to an unused port using one of the solutions in this guide.

How do I fix the python socket error 48: Address already in use?

1. Specify an unused port number for the process

1. If you were creating the process using the following command:

Add the port number after the above command, so that it becomes:

NOTE that you should change the (Port Number) in the command to the actual port number.

1. After running the above command, confirm if the python socket error 48 error is gone.

2. Free up the port

1. Locate and list the processes using the port by running the command below:

1. If successful, you will see the process codes in the argument, looking like the line below:

1. From the argument above, if multiple python processes are active, it is easy to spot the process running SimpleHTTPServer.
2. From the argument above, we can now kill the process with code 89332 to free up the port. Enter the following command to kill this process :

1. If the process is not responding, you can also kill the process using the tougher command below:

1. The above command sends a standard SIGTERM signal.
2. Finally, bind the process to the port you just freed up by running the following command:

NOTE that you should change the (Port Number) in the command to the actual port number.

After entering the last command above, the process will be created on the free port. This method has proven to repair the python socket error 48.

3. Restart Raspberry Pi

Raspberry Pi cannot kill processes automatically, and so, the processes running on the ports must be ended manually.

This solution is basically the same principle as the above method. If you get the python socket error 48: Address already in use on Raspberry Pi, restarting it can fix the error .

As mentioned at the beginning of this troubleshooting guide, the process may already be bound to port 800 (the default port) if you ran it before.

You can easily clear the python socket error 48: Address already in use by specifying an unused port or freeing up the port that the process is bound to.

If you get the error on Raspberry Pi, simply restart it to repair.

By following any of the above-written methods you should be able to fix the Python Socket Error 48.

However, we would appreciate it if you let us know which method worked best for you by leaving us a message in the comments section below.

Still having issues? Fix them with this tool:

Источник

OSError: Address «» already in use. #33

I’m running into an error when trying to run app.run_server(mode=’external’)

Even if I kill all ports, and even if I change the port to a random number (for instance: app.run_server(mode=’external’, port=2000) ), the error still persists. I don’t know how to resolve this. Help would be appreciated! Thanks!

Full error:

The text was updated successfully, but these errors were encountered:

Help needed, I got the same Error too, thanks

Unfortunately, the code always print that error regardless of the true reason of the failure. I also got that error but the true cause was that jupyter-dash was trying to test for success (access the _alive url) in a hostname that is not available in my enviroinment (#32).

You can easily fix it inside the code of your module, and that’s probably the workaround for now because the authors of this library don’t seem to be very responsive.

ccdavid, could i trouble you to detail your fix/workaround with sample code? thanks

I have the same issue. No matter what I do I get the «Address already in use» error. I am running jupyterlab on a server and am port-forwarding to local machine. More info:

Jupyterlab has been rebuilt
Running the following (in individual cells):

produces no error. Output from last two lines is

However, app.run_server() always throws «OSError: Address ‘http://0.0.0.0:xxxx’ already in use», no matter the mode or port number.

I am having the same issue. Whatever port i put, it displays the error: «OSError: Address ‘http://0.0.0.0:xxxx’ already in use»
@ccdavid could you please tell us what solution you’ve found?

@jonmmease , do you have any idea about this?

Error that we are encountering is as @ccdavid mentioned default error anytime python context cannot connect to the spawned dash server. As seen in the https://github.com/plotly/jupyter-dash/blob/master/jupyter_dash/jupyter_app.py#L306

After you call app.run_server(mode=’external’, port=8050) (or other mode, it does not matter) it should spawn dash server. You can chceck by sudo netstat -nlp | grep 8050 if the server is running you should see something like this:

Second option is to curl localhost with correct port to see if it’s accessible curl http://localhost:8050 should return dash-like response for example:

If dash server is running successfully and you are getting error mentioned above there is an issue with connecting from python to the localhost. Solution will depend on your setup. My problem was that container in which I run jupyter lab used proxy and was connecting to different localhost. Ignoring proxy for localhost solved my problem.

had the same error no matter what mode was used. The link to the address that is said to be already in use leads to an error page of the Flask server. The page displays a message that no layout was set in the app. The following snippet led to success:

Is the port already in use by another service at the OS level? See how 2000 is in use but 2194-2196 are blank?
http://www.networksorcery.com/enp/protocol/ip/ports02000.htm

For my case, whatever port i’ve used it gave me that error.

I’m running into the same issue. Its happening on Windows 10, Python 3.7 x64. Latest versions of JupyterLab Dash and JupyterDash. Once you run the cell in the notebook the dash server is started and I can navigate to it externally where everything works, but it does not show up inline and just gives the error regardless of the mode argument.

Hey folks, not sure if my solution helps because my error is «NoLayout Exception» even though I did create them, but there is the same message «OSError: Address ‘http://127.0.0.1:2000’ already in use. Try passing a different port to run_server.» at the bottom.

I am working on Google Colab. I just restarted the Colab, and things got solved.

What versions of dash and Jupyter and python are you using?

I tested the same code in Linux Virtual environment with same results on Python 3.8 and latest versions of Dash and Jupyter.

What versions of dash and Jupyter and python are you using?

I tested the same code in Linux Virtual environment with same results on Python 3.8 and latest versions of Dash and Jupyter.

I am just using the default Google Colab settings for Python and Jupyter. I think Colab is using Python 3.6.9. For Dash, I am !pip install jupyter-dash every time I reconnect to Colab so I guess it is the latest version.

so just pass different parameter port=? port number which is valid and not used I tried this it work for me
OSError: Address ‘http://127.0.0.1:8050’ already in use.
Try passing a different port to run_server.

If you go in your variable browser after executing the «faulty» code and you see your app (instance of dash.Dash), you might just type «del app» to delete this instance. Afterwards it worked for me.

So I after trying a lot of different ports I checked the rest of the code.
And I noticed that I wrote:

Now it works perfectly in mode=’inline’ and mode=’external’ with all the ports 8050, 30000, 5000, etc..

So basically because I forgot to put the external stylesheet URL in a list I had the «OSError: Address ‘http://. ‘ already in use. Try passing a different port to run_server.».

Conclusion, the error message is not necessarily due to wrong ip/port address.

The port busy error can also arise when you have two or more layout components that have the same id assigned. Usually the traceback will indicate a «DuplicateIdError» as well, but if you are importing layouts (e.g. from other python files) the only error that you might see is the «Address . already in use» error.

Hey all, I had the above error in Google Colab. Restarting the kernel worked for me.

Hope this helps you too!

I would prefer to have a python command to elegantly close the port as the code is shutdown, instead of leaving it open and giving an error the next time the program is run. However i find the following command is useful to close any blocking port (just replace 8050 with whatever port is causing a problem)

sudo lsof -t -i tcp:8050 | xargs kill -9

After spending a few days with jupyter-dash , it feels like the «port already in use» is really just the app hanging due to uncaught errors (e.g. bad stylesheet assignment) during initialization.

It’s like the webserver half of the program is waiting for the app half of the program to be ready. then either failing to release the port when the app building fails or just claiming that error because it doesn’t know what else to do. An error isn’t being caught on the app side.

# Wait for app to respond to _alive endpoint

I can rerun an app on the same port repeatedly without a problem.

Could the url be pushed to the server rather than pulled?

Источник

OSError: [Errno 98] Address already in use #296

I use SocketConnection with tcp protocol.

When I run a bunch of tests, sometimes (for me usually after between 15 000 — 30 000 test cases) I got the following error:

It happens on both Windows and WSL and different versions of Python. No other application is connecting to the target port. Any ideas?

The text was updated successfully, but these errors were encountered:

When I have both server and fuzzer on the same machine, everything works fine.

Well, after the weekend, I cannot reproduce this issue again. So I will believe that it was some environmental problem and hope that it never shows again. Closing this issue for now and when I see this behavior again, I will try to investigate it more and share with you guys what I’ve found.

I think I’ve seen that sort of thing before, but it was also transient for me. I remember something about the OS sometimes holding onto TCP connections. Could also be another program that happened to be trying to use the same port.

It also depends on your configuration — if you’re simply connecting to another TCP server, this would be rather unexpected.

Well, it happens again 😢

There is indeed a problem that TCP connections are not terminated. They are stuck in the state: TimeWait

You can see it here:

and the list continues. until all port numbers are exhausted.

Error message on WSL:

Error message on Windows:

When I run tests from the docker container (running on WSL, docker connected to Windows docker client) or from «native» Linux (on Hyper-V), the issue seems to be gone. So I assume that Windows sockets somehow do this.

@jtpereyda
maybe it can be somehow related to #281, what do you think?

Do the sockets get freed after terminating the script?

Can’t say if it’s related off hand

Unfortunately, no. Even after a longer period of time (like

20 minutes), they all are in state TimeWait . I need to restart OS to get rid of them.

@starek4 could you test if adding self._sock.shutdown(socket.SHUT_RDWR) before close() fixes the issue?

Lines 116 to 125 in e3c79dc

Unfortunately, this does not solve the issue. I added self._sock.shutdown(socket.SHUT_RDWR) between lines 122 and 123 and I can still reproduce this issue.

Research

First of all, this is a valid TCP behavior. This always happens if requests are sent so quickly, that we exhaust available socket resources. So when I create

15k requests in short period of time, this always happen. For better understanding of following text I recommend to read article about TIME_WAIT here.

How to solve it

As we are on client-side, we used ephemeral ports. So setting socket to SO_REUSEADDR or SO_EXCLUSIVEADDRUSE will not help.

The only thing we can do is to catch errno.EADDRINUSE , then try to wait for some period of time and after that, we can try it again.

But, how long to wait? Sockets usually stay in TIME_WAIT state for 2*MSL (maximum segment life). According to RFC 793, MSL should be something about 2 minutes. Microsoft reflects that, so they set up TcpTimedWaitDelay for 2 * MSL, so 4 minutes.

My suggestion is that when we get errno.EADDRINUSE error, we can repeatedly open a connection up to 4 minutes. I tested it on Windows and WLS and it works great. Is that OK with you, guys (@jtpereyda @SR4ven )?

I will create a pull request so you can see this in code.

Источник

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We will introduce when the error Address already in use occurs in Python and how to solve it with examples.

Address already in use Error in Python

This article will teach the Python stack error that occurs when running a program that uses a port. We will learn why this error occurs and how to resolve it and make your program run smoothly.

This error occurs when we are trying to access a port already in use and cannot be freed for the program we are trying to use.

Now, let’s discuss how we can resolve this error. Many methods resolve this error, but we will learn a few methods with examples.

In Python, if we create a program that runs over a server and has to perform some tasks over a server, this error can occur. Let’s discuss how to resolve this error.

As shown below, we will write the port number after the following command, which becomes available.

# python
python -m SimpleHTTPServer (443)

When we run this command and run our program again, we will use port 443 to perform some tasks. It will run smoothly without any problem because now the port is available for usage.

If this method still doesn’t help us run our program, we can use another method that can surely free up the taken port with some steps.

First, we will run the following command to locate and list the processes using the port, as shown below.

# python
ps -fA | grep python

If this command was successful, we could see the process codes in the argument. If the argument displays multiple processes running on the port, we can spot the process that is blocking the port by searching for the SimpleHTTPServer process, as shown below.

# python
443 89330 12879 0 1:53AM ttys00 0:00.15 python -m SimpleHTTPServer

We will check for the port that the process is using, and we will use it to kill the process with the code and free up the port by using the following command as shown below.

It will kill the process and free up the port. If the process is still not responding, we can use a tougher command below.

# python
sudo kill -9 89330

Once the process is killed and your port is free, we can bind up the freed port using the following command.

# python
python -m SimpleHTTPServer (443)

So following these steps, we can free up the port and get rid of the socket error Address already in use in Python.

Hi all!

I’m running into an error when trying to run app.run_server(mode='external')

Even if I kill all ports, and even if I change the port to a random number (for instance: app.run_server(mode='external', port=2000)), the error still persists. I don’t know how to resolve this. Help would be appreciated! Thanks!

Full error:

---------------------------------------------------------------------------
OSError                                   Traceback (most recent call last)
<ipython-input-5-0a3a9f2580ba> in <module>
----> 1 app.run_server(mode='external', port=2000)

/opt/anaconda3/lib/python3.7/site-packages/jupyter_dash/jupyter_app.py in run_server(self, mode, width, height, inline_exceptions, **kwargs)
    317                 )
    318 
--> 319         wait_for_app()
    320 
    321         if JupyterDash._in_colab:

/opt/anaconda3/lib/python3.7/site-packages/retrying.py in wrapped_f(*args, **kw)
     47             @six.wraps(f)
     48             def wrapped_f(*args, **kw):
---> 49                 return Retrying(*dargs, **dkw).call(f, *args, **kw)
     50 
     51             return wrapped_f

/opt/anaconda3/lib/python3.7/site-packages/retrying.py in call(self, fn, *args, **kwargs)
    210                 if not self._wrap_exception and attempt.has_exception:
    211                     # get() on an attempt with an exception should cause it to be raised, but raise just in case
--> 212                     raise attempt.get()
    213                 else:
    214                     raise RetryError(attempt)

/opt/anaconda3/lib/python3.7/site-packages/retrying.py in get(self, wrap_exception)
    245                 raise RetryError(self)
    246             else:
--> 247                 six.reraise(self.value[0], self.value[1], self.value[2])
    248         else:
    249             return self.value

/opt/anaconda3/lib/python3.7/site-packages/six.py in reraise(tp, value, tb)
    701             if value.__traceback__ is not tb:
    702                 raise value.with_traceback(tb)
--> 703             raise value
    704         finally:
    705             value = None

/opt/anaconda3/lib/python3.7/site-packages/retrying.py in call(self, fn, *args, **kwargs)
    198         while True:
    199             try:
--> 200                 attempt = Attempt(fn(*args, **kwargs), attempt_number, False)
    201             except:
    202                 tb = sys.exc_info()

/opt/anaconda3/lib/python3.7/site-packages/jupyter_dash/jupyter_app.py in wait_for_app()
    313                     "Address '{url}' already in use.n"
    314                     "    Try passing a different port to run_server.".format(
--> 315                         url=url
    316                     )
    317                 )

OSError: Address 'http://127.0.0.1:2000' already in use.
    Try passing a different port to run_server.