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Option to spew subprocess streams during tests...
Option to spew subprocess streams during tests This supersedes PR #4268. Run the tests with '--subproc-streams show' to show output from subprocesses (kernels, IPython.parallel components) in the terminal, or with '--subproc-streams discard' to send it to /dev/null. By default (or with '--subproc-streams capture') the output is piped, captured and displayed only when tests fail. But in some situations, a test fails because of an error which actually occurred earlier, so you have to see all the output.

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iopubwatcher.py
83 lines | 2.8 KiB | text/x-python | PythonLexer
"""A script for watching all traffic on the IOPub channel (stdout/stderr/pyerr) of engines.
This connects to the default cluster, or you can pass the path to your ipcontroller-client.json
Try running this script, and then running a few jobs that print (and call sys.stdout.flush),
and you will see the print statements as they arrive, notably not waiting for the results
to finish.
You can use the zeromq SUBSCRIBE mechanism to only receive information from specific engines,
and easily filter by message type.
Authors
-------
* MinRK
"""
import os
import sys
import json
import zmq
from IPython.kernel.zmq.session import Session
from IPython.parallel.util import disambiguate_url
from IPython.utils.py3compat import str_to_bytes
from IPython.utils.path import get_security_file
def main(connection_file):
"""watch iopub channel, and print messages"""
ctx = zmq.Context.instance()
with open(connection_file) as f:
cfg = json.loads(f.read())
location = cfg['location']
reg_url = cfg['url']
session = Session(key=str_to_bytes(cfg['exec_key']))
query = ctx.socket(zmq.DEALER)
query.connect(disambiguate_url(cfg['url'], location))
session.send(query, "connection_request")
idents,msg = session.recv(query, mode=0)
c = msg['content']
iopub_url = disambiguate_url(c['iopub'], location)
sub = ctx.socket(zmq.SUB)
# This will subscribe to all messages:
sub.setsockopt(zmq.SUBSCRIBE, b'')
# replace with b'' with b'engine.1.stdout' to subscribe only to engine 1's stdout
# 0MQ subscriptions are simple 'foo*' matches, so 'engine.1.' subscribes
# to everything from engine 1, but there is no way to subscribe to
# just stdout from everyone.
# multiple calls to subscribe will add subscriptions, e.g. to subscribe to
# engine 1's stderr and engine 2's stdout:
# sub.setsockopt(zmq.SUBSCRIBE, b'engine.1.stderr')
# sub.setsockopt(zmq.SUBSCRIBE, b'engine.2.stdout')
sub.connect(iopub_url)
while True:
try:
idents,msg = session.recv(sub, mode=0)
except KeyboardInterrupt:
return
# ident always length 1 here
topic = idents[0]
if msg['msg_type'] == 'stream':
# stdout/stderr
# stream names are in msg['content']['name'], if you want to handle
# them differently
print("%s: %s" % (topic, msg['content']['data']))
elif msg['msg_type'] == 'pyerr':
# Python traceback
c = msg['content']
print(topic + ':')
for line in c['traceback']:
# indent lines
print(' ' + line)
if __name__ == '__main__':
if len(sys.argv) > 1:
cf = sys.argv[1]
else:
# This gets the security file for the default profile:
cf = get_security_file('ipcontroller-client.json')
main(cf)