eofs | EOF analysis in Python

I have no idea what VPN this is, but it looks like that it is messing with the traffic.

This behavior is for example typical when using a company VPN, which also means to use the companies filtering when accessing the internet. Often Deep Packet Inspection is implemented here to control and limit access, and this can result in deliberately breaking outgoing connections.

This problem occurs because calling close() on the content stream will try to consume the remaining content. This is currently not explicitly mentioned in the documentation (see also HTTPCORE-656), but is mentioned in the tutorials:

The difference between closing the content stream and closing the response is that the former will attempt to keep the underlying connection alive by consuming the entity content while the latter immediately shuts down and discards the connection.
[...]
There can be situations, however, when only a small portion of the entire response content needs to be retrieved and the performance penalty for consuming the remaining content and making the connection reusable is too high, in which case one can terminate the content stream by closing the response.

Therefore in your case it seems appropriate to not close the InputStream returned by getContent() but only close the HttpResponse (which you are apparently not doing yet).

In Bash, background commands in a shell script are run differently from background commands typed at the terminal. See the Bash manual on Lists of Commands, where it says:

If a command is terminated by the control operator ‘&’, the shell executes the command asynchronously in a subshell. This is known as executing the command in the background, and these are referred to as asynchronous commands. The shell does not wait for the command to finish, and the return status is 0 (true). When job control is not active (see Job Control), the standard input for asynchronous commands, in the absence of any explicit redirections, is redirected from /dev/null.

Job control is not normally active in a script.

Note that this behaviour in Bash is consistent with the requirements of the POSIX shell, as noted by Joseph Sible.

Did you:

Keepalive connections are closed immediately regardless of the worker_shutdown_timeout value, as clients are expected to re-open them as needed. The worker_shutdown_timeout applies to connections with actual requests being processed - these requests will be terminated when shutdown timeout expires.

If your clients cannot handle keepalive connection being closed by the server, probably there is room for improvement in the client code.

Have a look to this post.
You should clear the ax at the start of the animate function with ax.cla() and move the colorbar definition outside that function.

It looks like this might be a problem on the server side, not with your code. The SysCallError code you're getting is a Windows Sockets error code. Citing from the Microsoft Docs:

WSAECONNRESET 10054

Connection reset by peer.
An existing connection was forcibly closed by the remote host. This normally results if the peer application on the remote host is suddenly stopped, the host is rebooted, the host or remote network interface is disabled, or the remote host uses a hard close (see setsockopt for more information on the SO_LINGER option on the remote socket). This error may also result if a connection was broken due to keep-alive activity detecting a failure while one or more operations are in progress. Operations that were in progress fail with WSAENETRESET. Subsequent operations fail with WSAECONNRESET.

It might be that this was a temporary issue. I was able to run your script and send requests for quite a while without issues. If this keeps happening when sending requests to that server, consider catching these exceptions using something like this:

I found the solution for people who might have the same issue. You need to add encrypted=False.

Instead of