Cleanup WBE example to be simpler to understand

This makes the example simpler to follow and understand when
it is using threads, is in one file and just uses the simpler
in-memory kombu backend by default (it can still use the file
transport if configured to use it).

Change-Id: I7fe9758e3285e7f0a610482bf26322841fb22f39
This commit is contained in:
Joshua Harlow
2014-07-09 21:06:22 -07:00
committed by Joshua Harlow
parent 9c0329bcfa
commit 494003283f
7 changed files with 163 additions and 198 deletions

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@@ -151,3 +151,15 @@ Controlling retries using a retry controller
:language: python
:linenos:
:lines: 16-
Distributed execution (simple)
==============================
.. note::
Full source located at :example:`wbe_simple_linear`
.. literalinclude:: ../../taskflow/examples/wbe_simple_linear.py
:language: python
:linenos:
:lines: 16-

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@@ -0,0 +1,5 @@
Running 2 workers.
Executing some work.
Execution finished.
Result = {"result1": 1, "result2": 666, "x": 111, "y": 222, "z": 333}
Stopping workers.

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@@ -0,0 +1,146 @@
# -*- coding: utf-8 -*-
# Copyright (C) 2014 Yahoo! Inc. All Rights Reserved.
#
# Licensed under the Apache License, Version 2.0 (the "License"); you may
# not use this file except in compliance with the License. You may obtain
# a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
# WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
# License for the specific language governing permissions and limitations
# under the License.
import json
import logging
import os
import sys
import tempfile
import threading
top_dir = os.path.abspath(os.path.join(os.path.dirname(__file__),
os.pardir,
os.pardir))
sys.path.insert(0, top_dir)
from taskflow import engines
from taskflow.engines.worker_based import worker
from taskflow.patterns import linear_flow as lf
from taskflow.tests import utils
import example_utils # noqa
# INTRO: This example walks through a miniature workflow which shows how to
# start up a number of workers (these workers will process task execution and
# reversion requests using any provided input data) and then use an engine
# that creates a set of *capable* tasks and flows (the engine can not create
# tasks that the workers are not able to run, this will end in failure) that
# those workers will run and then executes that workflow seamlessly using the
# workers to perform the actual execution.
#
# NOTE(harlowja): this example simulates the expected larger number of workers
# by using a set of threads (which in this example simulate the remote workers
# that would typically be running on other external machines).
# A filesystem can also be used as the queue transport (useful as simple
# transport type that does not involve setting up a larger mq system). If this
# is false then the memory transport is used instead, both work in standalone
# setups.
USE_FILESYSTEM = False
BASE_SHARED_CONF = {
'exchange': 'taskflow',
}
WORKERS = 2
WORKER_CONF = {
# These are the tasks the worker can execute, they *must* be importable,
# typically this list is used to restrict what workers may execute to
# a smaller set of *allowed* tasks that are known to be safe (one would
# not want to allow all python code to be executed).
'tasks': [
'taskflow.tests.utils:TaskOneArgOneReturn',
'taskflow.tests.utils:TaskMultiArgOneReturn'
],
}
ENGINE_CONF = {
'engine': 'worker-based',
}
def run(engine_conf):
flow = lf.Flow('simple-linear').add(
utils.TaskOneArgOneReturn(provides='result1'),
utils.TaskMultiArgOneReturn(provides='result2')
)
eng = engines.load(flow,
store=dict(x=111, y=222, z=333),
engine_conf=engine_conf)
eng.run()
return eng.storage.fetch_all()
if __name__ == "__main__":
logging.basicConfig(level=logging.ERROR)
# Setup our transport configuration and merge it into the worker and
# engine configuration so that both of those use it correctly.
shared_conf = dict(BASE_SHARED_CONF)
tmp_path = None
if USE_FILESYSTEM:
tmp_path = tempfile.mkdtemp(prefix='wbe-example-')
shared_conf.update({
'transport': 'filesystem',
'transport_options': {
'data_folder_in': tmp_path,
'data_folder_out': tmp_path,
'polling_interval': 0.1,
},
})
else:
shared_conf.update({
'transport': 'memory',
'transport_options': {
'polling_interval': 0.1,
},
})
worker_conf = dict(WORKER_CONF)
worker_conf.update(shared_conf)
engine_conf = dict(ENGINE_CONF)
engine_conf.update(shared_conf)
workers = []
worker_topics = []
try:
# Create a set of workers to simulate actual remote workers.
print('Running %s workers.' % (WORKERS))
for i in range(0, WORKERS):
worker_conf['topic'] = 'worker-%s' % (i + 1)
worker_topics.append(worker_conf['topic'])
w = worker.Worker(**worker_conf)
runner = threading.Thread(target=w.run)
runner.daemon = True
runner.start()
w.wait()
workers.append((runner, w.stop))
# Now use those workers to do something.
print('Executing some work.')
engine_conf['topics'] = worker_topics
result = run(engine_conf)
print('Execution finished.')
# This is done so that the test examples can work correctly
# even when the keys change order (which will happen in various
# python versions).
print("Result = %s" % json.dumps(result, sort_keys=True))
finally:
# And cleanup.
print('Stopping workers.')
while workers:
r, stopper = workers.pop()
stopper()
r.join()
if tmp_path:
example_utils.rm_path(tmp_path)

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@@ -1,61 +0,0 @@
# -*- coding: utf-8 -*-
# Copyright (C) 2014 Yahoo! Inc. All Rights Reserved.
#
# Licensed under the Apache License, Version 2.0 (the "License"); you may
# not use this file except in compliance with the License. You may obtain
# a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
# WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
# License for the specific language governing permissions and limitations
# under the License.
import json
import logging
import sys
import taskflow.engines
from taskflow.patterns import linear_flow as lf
from taskflow.tests import utils
LOG = logging.getLogger(__name__)
if __name__ == "__main__":
logging.basicConfig(level=logging.ERROR)
engine_conf = {
'engine': 'worker-based',
'exchange': 'taskflow',
'topics': ['test-topic'],
}
# parse command line
try:
arg = sys.argv[1]
except IndexError:
pass
else:
try:
cfg = json.loads(arg)
except ValueError:
engine_conf.update(url=arg)
else:
engine_conf.update(cfg)
finally:
LOG.debug("Worker configuration: %s\n" %
json.dumps(engine_conf, sort_keys=True, indent=4))
# create and run flow
flow = lf.Flow('simple-linear').add(
utils.TaskOneArgOneReturn(provides='result1'),
utils.TaskMultiArgOneReturn(provides='result2')
)
eng = taskflow.engines.load(flow,
store=dict(x=111, y=222, z=333),
engine_conf=engine_conf)
eng.run()
print(json.dumps(eng.storage.fetch_all(), sort_keys=True))

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@@ -1,58 +0,0 @@
# -*- coding: utf-8 -*-
# Copyright (C) 2014 Yahoo! Inc. All Rights Reserved.
#
# Licensed under the Apache License, Version 2.0 (the "License"); you may
# not use this file except in compliance with the License. You may obtain
# a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
# WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
# License for the specific language governing permissions and limitations
# under the License.
import json
import logging
import sys
from taskflow.engines.worker_based import worker as w
LOG = logging.getLogger(__name__)
if __name__ == "__main__":
logging.basicConfig(level=logging.ERROR)
worker_conf = {
'exchange': 'taskflow',
'topic': 'test-topic',
'tasks': [
'taskflow.tests.utils:TaskOneArgOneReturn',
'taskflow.tests.utils:TaskMultiArgOneReturn'
]
}
# parse command line
try:
arg = sys.argv[1]
except IndexError:
pass
else:
try:
cfg = json.loads(arg)
except ValueError:
worker_conf.update(url=arg)
else:
worker_conf.update(cfg)
finally:
LOG.debug("Worker configuration: %s\n" %
json.dumps(worker_conf, sort_keys=True, indent=4))
# run worker
worker = w.Worker(**worker_conf)
try:
worker.run()
except KeyboardInterrupt:
pass

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@@ -1,6 +0,0 @@
Run worker.
Run flow.
{"result1": 1, "result2": 666, "x": 111, "y": 222, "z": 333}
Flow finished.
Stop worker.

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@@ -1,73 +0,0 @@
# -*- coding: utf-8 -*-
# Copyright (C) 2014 Yahoo! Inc. All Rights Reserved.
#
# Licensed under the Apache License, Version 2.0 (the "License"); you may
# not use this file except in compliance with the License. You may obtain
# a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
# WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
# License for the specific language governing permissions and limitations
# under the License.
import json
import os
import subprocess
import sys
import tempfile
self_dir = os.path.abspath(os.path.dirname(__file__))
sys.path.insert(0, self_dir)
import example_utils # noqa
def _path_to(name):
return os.path.abspath(os.path.join(os.path.dirname(__file__),
'worker_based', name))
def run_test(name, config):
cmd = [sys.executable, _path_to(name), config]
process = subprocess.Popen(cmd, stdin=None, stdout=subprocess.PIPE,
stderr=sys.stderr)
return process, cmd
def main():
tmp_path = None
try:
tmp_path = tempfile.mkdtemp(prefix='worker-based-example-')
config = json.dumps({
'transport': 'filesystem',
'transport_options': {
'data_folder_in': tmp_path,
'data_folder_out': tmp_path
}
})
print('Run worker.')
worker_process, _ = run_test('worker.py', config)
print('Run flow.')
flow_process, flow_cmd = run_test('flow.py', config)
stdout, _ = flow_process.communicate()
rc = flow_process.returncode
if rc != 0:
raise RuntimeError("Could not run %s [%s]" % (flow_cmd, rc))
print(stdout.decode())
print('Flow finished.')
print('Stop worker.')
worker_process.terminate()
finally:
if tmp_path is not None:
example_utils.rm_path(tmp_path)
if __name__ == '__main__':
main()