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Python/Flask Unittest, suppress Broken Pipe Error 32

When running unittests I often get error: [Errno 32] Broken pipe. It seems to be a harmless error that happens during testing, but I haven't been able to prevent or otherwise suppress it.
Some things that I have tried include changing SIGPIPE handling to SIG_DFL and running the app with threaded=True. If I were to try/except I don't know which code to wrap since this is in the context of unittesting.
I don't care about catching/preventing the error as much as just suppressing its output while all the other tests finish running. What else should I try?
Edit:
Here is some example code that often, but does not always result in the error:
def test_register(self):
self.driver.get(self.get_server_url() + url_for(u'register'))
body = self.driver.find_element_by_id(u'body')
username_input = body.find_element_by_id(u'username')
username_input.send_keys(self.USER1_DISPLAY_USERNAME)
privacy_policy = body.find_element_by_id(u'privacy_policy')
privacy_policy.click()
#NOTE: not shown - more lines filling out form elements exactly like the above lines
self.driver.execute_script("window.scrollTo(0, document.body.scrollHeight);")
register_button = body.find_element_by_id(u'onclick-register')
register_button.click()
And here is an example of the error message:
----------------------------------------
Exception happened during processing of request from ('127.0.0.1', 44668)
Traceback (most recent call last):
File "/usr/lib/python2.7/SocketServer.py", line 599, in process_request_thread
self.finish_request(request, client_address)
File "/usr/lib/python2.7/SocketServer.py", line 334, in finish_request
self.RequestHandlerClass(request, client_address, self)
File "/usr/lib/python2.7/SocketServer.py", line 657, in __init__
self.finish()
File "/usr/lib/python2.7/SocketServer.py", line 716, in finish
self.wfile.close()
File "/usr/lib/python2.7/socket.py", line 283, in close
self.flush()
File "/usr/lib/python2.7/socket.py", line 307, in flush
self._sock.sendall(view[write_offset:write_offset+buffer_size])
error: [Errno 32] Broken pipe
----------------------------------------
This seems to only happen with integration tests. I'm using Selenium and a LiveServerTestCase with a LIVESERVER_PORT port set to 8943. The mention of port 44668 in the error message looks suspicious.
My problem sounds exactly like Suppress print output in unittests but none of those solutions work.

I found a solution by redirecting stderr and stdout.
In create_app() add the following:
_stderr, _stdout = sys.stderr, sys.stdout
null = open(os.devnull,'wb')
sys.stdout = sys.stderr = null

Celery upgrade (3.1->4.1) - Connection reset by peer

We are working with celery at the last year, with ~15 workers, each one defined with concurrency between 1-4.
Recently we upgraded our celery from v3.1 to v4.1
Now we are having the following errors in each one of the workers logs, any ideas what can cause to such error?
2017-08-21 18:33:19,780 94794 ERROR Control command error: error(104, 'Connection reset by peer') [file: pidbox.py, line: 46]
Traceback (most recent call last):
File "/srv/dy/venv/lib/python2.7/site-packages/celery/worker/pidbox.py", line 42, in on_message
self.node.handle_message(body, message)
File "/srv/dy/venv/lib/python2.7/site-packages/kombu/pidbox.py", line 129, in handle_message
return self.dispatch(**body)
File "/srv/dy/venv/lib/python2.7/site-packages/kombu/pidbox.py", line 112, in dispatch
ticket=ticket)
File "/srv/dy/venv/lib/python2.7/site-packages/kombu/pidbox.py", line 135, in reply
serializer=self.mailbox.serializer)
File "/srv/dy/venv/lib/python2.7/site-packages/kombu/pidbox.py", line 265, in _publish_reply
**opts
File "/srv/dy/venv/lib/python2.7/site-packages/kombu/messaging.py", line 181, in publish
exchange_name, declare,
File "/srv/dy/venv/lib/python2.7/site-packages/kombu/messaging.py", line 203, in _publish
mandatory=mandatory, immediate=immediate,
File "/srv/dy/venv/lib/python2.7/site-packages/amqp/channel.py", line 1748, in _basic_publish
(0, exchange, routing_key, mandatory, immediate), msg
File "/srv/dy/venv/lib/python2.7/site-packages/amqp/abstract_channel.py", line 64, in send_method
conn.frame_writer(1, self.channel_id, sig, args, content)
File "/srv/dy/venv/lib/python2.7/site-packages/amqp/method_framing.py", line 178, in write_frame
write(view[:offset])
File "/srv/dy/venv/lib/python2.7/site-packages/amqp/transport.py", line 272, in write
self._write(s)
File "/usr/lib64/python2.7/socket.py", line 224, in meth
return getattr(self._sock,name)(*args)
error: [Errno 104] Connection reset by peer
BTW: our tasks in the form:
#app.task(name='EXAMPLE_TASK'],
bind=True,
base=ConnectionHolderTask)
def example_task(self, arg1, arg2, **kwargs):
# task code

We are also having massive issues with celery... I spend 20% of my time just dancing around weird idle-hang/crash issues with our workers sigh
We had a similar case that was caused by a high concurrency combined with a high worker_prefetch_multiplier, as it turns out fetching thousands of tasks is a good way to frack the connection.
If that's not the case: try to disable the broker pool by setting broker_pool_limit to None.
Just some quick ideas that might (hopefully) help :-)

Flask/http- tell the client that the request needs some more time to complete

I have a web service(REST) where one request might take up to 30 sec to return an answer (lots of calculation). There is a risk, that during the calculation, the client webbrowser aborts(?) the existing connection and retries. Here is the console-output of the server-side:
Exception happened during processing of request from ('127.0.0.1', 53209)
Traceback (most recent call last):
File "C:\Users\tmx\Anaconda2\lib\SocketServer.py", line 290, in _handle_request_noblock
self.process_request(request, client_address)
File "C:\Users\tmx\Anaconda2\lib\SocketServer.py", line 318, in process_request
self.finish_request(request, client_address)
File "C:\Users\tmx\Anaconda2\lib\SocketServer.py", line 331, in finish_request
self.RequestHandlerClass(request, client_address, self)
File "C:\Users\tmx\Anaconda2\lib\SocketServer.py", line 654, in __init__
self.finish()
File "C:\Users\tmx\Anaconda2\lib\SocketServer.py", line 713, in finish
self.wfile.close()
File "C:\Users\tmx\Anaconda2\lib\socket.py", line 283, in close
self.flush()
File "C:\Users\tmx\Anaconda2\lib\socket.py", line 307, in flush
self._sock.sendall(view[write_offset:write_offset+buffer_size])
error: [Errno 10053] An established connection was aborted by the software in your host machine
One option is what I thought of is to somehow notify the client that "I'm alivem but the request is still needs some more time", or to somehow set the timeout on server side. What are the possibilities?

It's difficult to run code in Flask after you've already returned some data. Your options are to either use something like a task queue (see Celery), or to yield your response in multiple parts.
Views in Flask can return strings, but they can also return iterables that contain strings. So you could return "abc", ["abc"], or a generator that will yield "abc". If you do your processing between yields, data will get sent to the client while the request is still running.
Take a look at the following example:
def generator_that_does_the_calculation():
sleep(1)
yield "I'm alive, but I need some time\n"
sleep(1)
yield "Still alive here\n"
sleep(1)
yield "Done\n"
#app.route('/calculate')
def calculate():
return Response(generator_that_does_the_calculation())

python xmlrpc timeout error

I am using xmlrpc to contact a local server. On the client side, Sometimes the following socket timeout error and happens and its not a consistent error.
Why is it happening? What could be the reason for socket timeout?
<class 'socket.timeout'>: timed out
args = ('timed out',)
errno = None
filename = None
message = 'timed out'
strerror = None
Traceback on the server side is as follows
Exception happened during processing of request from ('127.0.0.1', 34855)
Traceback (most recent call last):
File "/usr/lib/python2.4/SocketServer.py", line 222, in handle_request
self.process_request(request, client_address)
File "/usr/lib/python2.4/SocketServer.py", line 241, in process_request
self.finish_request(request, client_address)
File "/usr/lib/python2.4/SocketServer.py", line 254, in finish_request
self.RequestHandlerClass(request, client_address, self)
File "/usr/lib/python2.4/SocketServer.py", line 521, in __init__
self.handle()
File "/usr/lib/python2.4/BaseHTTPServer.py", line 314, in handle
self.handle_one_request()
File "/usr/lib/python2.4/BaseHTTPServer.py", line 308, in handle_one_request
method()
File "/usr/lib/python2.4/SimpleXMLRPCServer.py", line 441, in do_POST
self.send_response(200)
File "/usr/lib/python2.4/BaseHTTPServer.py", line 367, in send_response
self.send_header('Server', self.version_string())
File "/usr/lib/python2.4/BaseHTTPServer.py", line 373, in send_header
self.wfile.write("%s: %s\r\n" % (keyword, value))
File "/usr/lib/python2.4/socket.py", line 256, in write
self.flush()
File "/usr/lib/python2.4/socket.py", line 243, in flush
self._sock.sendall(buffer)
error: (32, 'Broken pipe')
I killed the server and restarted it. Its working fine now.
What could be the reason?
My machine's RAM went full yesterday night by a process and came back to normal today morning.
Will this error be because of some swapping of processes?

Looks like the client socket it timing out waiting for the server to respond. Is it possible that your server might take a lot time to respond some times? Also, if the server is causing the machine to go into swap, that would slow it down making a timeout possible.
If I remember right, socket timeout is not set in xmlrpc in python. Are you doing socket.setdefaulttimeout somewhere in your code?
If it is expected that your server will take time once in a while, then you could set a higher timeout value using above.
HTH

Selenium in Python

I've been using urllib2 to access webpages, but it doesn't support javascript, so I took a look at Selenium, but I'm quite confused even having read its docs.
I downloaded Selenium IDE add-on for firefox and I tried some simple things.
from selenium import selenium
import unittest, time, re
class test(unittest.TestCase):
def setUp(self):
self.verificationErrors = []
self.selenium = selenium("localhost", 4444, "*chrome", "http://www.wikipedia.org/")
self.selenium.start()
def test_test(self):
sel = self.selenium
sel.open("/")
sel.type("searchInput", "pacific ocean")
sel.click("go")
sel.wait_for_page_to_load("30000")
def tearDown(self):
self.selenium.stop()
self.assertEqual([], self.verificationErrors)
if __name__ == "__main__":
unittest.main()
I just access wikipedia.org and type pacific ocean in the search field, but when I try to compile it, it gives me a lot of errors.

If running the script results in a [Errno 111] Connection refused error such as this:
% test.py
E
======================================================================
ERROR: test_test (__main__.test)
----------------------------------------------------------------------
Traceback (most recent call last):
File "/home/unutbu/pybin/test.py", line 11, in setUp
self.selenium.start()
File "/data1/unutbu/pybin/selenium.py", line 189, in start
result = self.get_string("getNewBrowserSession", [self.browserStartCommand, self.browserURL, self.extensionJs])
File "/data1/unutbu/pybin/selenium.py", line 219, in get_string
result = self.do_command(verb, args)
File "/data1/unutbu/pybin/selenium.py", line 207, in do_command
conn.request("POST", "/selenium-server/driver/", body, headers)
File "/usr/lib/python2.6/httplib.py", line 898, in request
self._send_request(method, url, body, headers)
File "/usr/lib/python2.6/httplib.py", line 935, in _send_request
self.endheaders()
File "/usr/lib/python2.6/httplib.py", line 892, in endheaders
self._send_output()
File "/usr/lib/python2.6/httplib.py", line 764, in _send_output
self.send(msg)
File "/usr/lib/python2.6/httplib.py", line 723, in send
self.connect()
File "/usr/lib/python2.6/httplib.py", line 704, in connect
self.timeout)
File "/usr/lib/python2.6/socket.py", line 514, in create_connection
raise error, msg
error: [Errno 111] Connection refused
----------------------------------------------------------------------
Ran 1 test in 0.063s
FAILED (errors=1)
then the solution is most likely that you need get the selenium server running first.
In the download for SeleniumRC you will find a file called selenium-server.jar (as of a few months ago, that file was located at SeleniumRC/selenium-server-1.0.3/selenium-server.jar).
On Linux, you could run the selenium server in the background with the command
java -jar /path/to/selenium-server.jar 2>/dev/null 1>&2 &
You will find more complete instructions on how to set up the server here.

I would suggest you to use a webdriver, you can find it here: http://code.google.com/p/selenium/downloads/list. If you want to write tests as a coder (and not with the use of your mouse), that thing would work better then the RC version you're trying to use, at least because it would not ask you for an SeleniumRC Jar Instance. You would simply have a binary of a browser or use those ones that are already installed on your system, for example, Firefox.

I faced with this issue in my project and found that problem was in few webdriver.get calls with very small time interval between them. My fix was not to put delay, just remove unneeded calls and error disappears.
Hope, it can helps for somebody.