BlockingIOError - Resource temporarily unavailable

[iomn]

Files are sometimes not served completely which results in incomplete map images for instance. Corresponding error looks like the following:

gunicorn[12218]: [XXXX-XX-XX XX:XX:XX +0200] [12245] [ERROR] Socket error processing request.
gunicorn[12218]: Traceback (most recent call last):
gunicorn[12218]:   File "/path/to/backend/env/lib/python3.6/site-packages/gunicorn/workers/base_async.py", line 66, in handle
gunicorn[12218]:     six.reraise(*sys.exc_info())
gunicorn[12218]:   File "/path/to/backend/env/lib/python3.6/site-packages/gunicorn/six.py", line 625, in reraise
gunicorn[12218]:     raise value
gunicorn[12218]:   File "/path/to/backend/env/lib/python3.6/site-packages/gunicorn/workers/base_async.py", line 56, in handle
gunicorn[12218]:     self.handle_request(listener_name, req, client, addr)
gunicorn[12218]:   File "/path/to/backend/env/lib/python3.6/site-packages/gunicorn/workers/base_async.py", line 129, in handle_request
gunicorn[12218]:     six.reraise(*sys.exc_info())
gunicorn[12218]:   File "/path/to/backend/env/lib/python3.6/site-packages/gunicorn/six.py", line 625, in reraise
gunicorn[12218]:     raise value
gunicorn[12218]:   File "/path/to/backend/env/lib/python3.6/site-packages/gunicorn/workers/base_async.py", line 112, in handle_request
gunicorn[12218]:     resp.write_file(respiter)
gunicorn[12218]:   File "/path/to/backend/env/lib/python3.6/site-packages/gunicorn/http/wsgi.py", line 403, in write_file
gunicorn[12218]:     if not self.sendfile(respiter):
gunicorn[12218]:   File "/path/to/backend/env/lib/python3.6/site-packages/gunicorn/http/wsgi.py", line 393, in sendfile
gunicorn[12218]:     sent += sendfile(sockno, fileno, offset + sent, count)
gunicorn[12218]: BlockingIOError: [Errno 11] Resource temporarily unavailable