openstack/neutron-lib
Code Issues Proposed changes

Merge "Add setproctitle support to the workers module"

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This commit is contained in:
Zuul 2019-02-20 10:03:26 +00:00 committed by Gerrit Code Review
commit 66c415280a
5 changed files with 147 additions and 2 deletions
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1
lower-constraints.txt
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@ -78,6 +78,7 @@ requests==2.14.2
requestsexceptions==1.2.0
rfc3986==0.3.1
Routes==2.3.1
setproctitle==1.1.10
six==1.10.0
snowballstemmer==1.2.1
Sphinx==1.6.2

84
neutron_lib/tests/unit/test_worker.py
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@ -12,6 +12,8 @@
# License for the specific language governing permissions and limitations
# under the License.
import six
import mock
from neutron_lib.callbacks import events
@ -34,6 +36,14 @@ class _BaseWorker(worker.BaseWorker):
pass
# Same as _BaseWorker, but looks like a process launch instead of eventlet
class _ProcWorker(_BaseWorker):
def __init__(self, worker_process_count=1, set_proctitle='on'):
super(_ProcWorker, self).__init__(worker_process_count, set_proctitle)
self._my_pid = -1 # make it appear to be a separate process
class TestBaseWorker(base.BaseTestCase):
def setUp(self):
@ -51,3 +61,77 @@ class TestBaseWorker(base.BaseTestCase):
base_worker.start()
self._reg.notify.assert_called_once_with(
resources.PROCESS, events.AFTER_INIT, base_worker.start)
# Forked workers, should call setproctitle
def test_proctitle_default(self):
with mock.patch('setproctitle.setproctitle') as spt:
_ProcWorker().start()
six.assertRegex(self, spt.call_args[0][0],
'^neutron-server: _ProcWorker \(.*python.*\)$')
def test_proctitle_custom_desc(self):
with mock.patch('setproctitle.setproctitle') as spt:
_ProcWorker().start(desc="fancy title")
six.assertRegex(self, spt.call_args[0][0],
'^neutron-server: fancy title \(.*python.*\)$')
def test_proctitle_custom_name(self):
with mock.patch('setproctitle.setproctitle') as spt:
_ProcWorker().start(name="tardis")
six.assertRegex(self, spt.call_args[0][0],
'^tardis: _ProcWorker \(.*python.*\)$')
def test_proctitle_empty(self):
with mock.patch('setproctitle.setproctitle') as spt:
_ProcWorker().start(desc="")
six.assertRegex(self, spt.call_args[0][0],
'^neutron-server: _ProcWorker \(.*python.*\)$')
def test_proctitle_nonstring(self):
with mock.patch('setproctitle.setproctitle') as spt:
_ProcWorker().start(desc=2)
six.assertRegex(self, spt.call_args[0][0],
'^neutron-server: 2 \(.*python.*\)$')
def test_proctitle_both_empty(self):
with mock.patch('setproctitle.setproctitle') as spt:
_ProcWorker().start(name="", desc="")
six.assertRegex(self, spt.call_args[0][0],
'^: _ProcWorker \(.*python.*\)$')
def test_proctitle_name_none(self):
with mock.patch('setproctitle.setproctitle') as spt:
_ProcWorker().start(name=None)
six.assertRegex(self, spt.call_args[0][0],
'^None: _ProcWorker \(.*python.*\)$')
# Forked, but proctitle disabled
def test_proctitle_off(self):
with mock.patch('setproctitle.setproctitle') as spt:
_ProcWorker(set_proctitle='off').start()
self.assertIsNone(spt.call_args)
# Eventlet style worker, should never call setproctitle
def test_proctitle_same_process(self):
with mock.patch('setproctitle.setproctitle') as spt:
_BaseWorker().start()
self.assertIsNone(spt.call_args)
def test_setproctitle_on(self):
with mock.patch('setproctitle.setproctitle') as spt:
_ProcWorker(set_proctitle='on').start(name="foo", desc="bar")
six.assertRegex(self, spt.call_args[0][0],
'^foo: bar \(.*python.*\)$')
def test_setproctitle_off(self):
with mock.patch('setproctitle.setproctitle') as spt:
_ProcWorker(set_proctitle='off').start(name="foo", desc="bar")
self.assertIsNone(spt.call_args)
def test_setproctitle_brief(self):
with mock.patch('setproctitle.setproctitle') as spt:
_ProcWorker(set_proctitle='brief').start(name="foo", desc="bar")
self.assertEqual(spt.call_args[0][0], 'foo: bar')

36
neutron_lib/worker.py
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@ -12,7 +12,10 @@
# License for the specific language governing permissions and limitations
# under the License.
import os
from oslo_service import service
import setproctitle
from neutron_lib.callbacks import events
from neutron_lib.callbacks import registry
@ -45,15 +48,24 @@ class BaseWorker(service.ServiceBase):
# default class value for case when super().__init__ is not called
_default_process_count = 1
def __init__(self, worker_process_count=_default_process_count):
def __init__(self, worker_process_count=_default_process_count,
set_proctitle='on'):
"""Initialize a worker instance.
:param worker_process_count: Defines how many processes to spawn for
worker:
0 - spawn 1 new worker thread,
1..N - spawn N new worker processes
set_proctitle:
'off' - do not change process title
'on' - set process title to descriptive string and parent
'brief' - set process title to descriptive string
"""
self._worker_process_count = worker_process_count
self._my_pid = os.getpid()
self._set_proctitle = set_proctitle
if set_proctitle == 'on':
self._parent_proctitle = setproctitle.getproctitle()
@property
def worker_process_count(self):
@ -63,13 +75,33 @@ class BaseWorker(service.ServiceBase):
"""
return self._worker_process_count
def start(self):
def setproctitle(self, name="neutron-server", desc=None):
if self._set_proctitle == "off" or os.getpid() == self._my_pid:
return
if not desc:
desc = self.__class__.__name__
proctitle = "%s: %s" % (name, desc)
if self._set_proctitle == "on":
proctitle += " (%s)" % self._parent_proctitle
setproctitle.setproctitle(proctitle)
def start(self, name="neutron-server", desc=None):
"""Start the worker.
If worker_process_count is greater than 0, a callback notification
is sent. Subclasses should call this method before doing their
own start() work.
Automatically sets the process title to indicate that this is a
child worker, customizable via the name and desc arguments.
:returns: None
"""
# If we are a child process, set our proctitle to something useful
self.setproctitle(name, desc)
if self.worker_process_count > 0:
registry.notify(resources.PROCESS, events.AFTER_INIT, self.start)

27
releasenotes/notes/setproctitle_for_workers-e8805fcaf34026ab.yaml Normal file
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@ -0,0 +1,27 @@
features:
- |
``neutron_lib.worker.BaseWorker`` will now set the process title
on process start, if it is a new process. By default, the name
will be "neutron-server", and the description will be the name
of the worker class, followed by the original process title.
Both fields are customizable via the ``name`` and ``desc``
arguments to ``BaseWorker.start()``, and the change
can be disabled via the ``set_proctitle`` argument to the
``__init__`` function. ``neutron.conf`` will have a setting
for disabling this functionality for all in-tree workers, but
by default, all out of tree plugin workers will set their name
at fork time. Available settings are 'on' (described above, and
the default), 'off' (same as today), or 'brief', which settings
the process name to just name and description. 'brief' is probably
most useful/simple for deployers, but 'on' is the default in order
to prevent as many script related breakages as possible.
upgrade:
- Any plugin which forks worker processes from neutron-server will
have its proctitle set to "neutron-server" plus a classname in ps
output. Any tool used for monitoring/maintenance that watches
the process table should be modified to only look for the string
``neutron-server``. On the plus side, it will now be possible
to distinguish which process belongs to which plugin, based on
the new naming. Note that the original process string is still
in the proctitle, so as long as the scripting is not looking for
a perfect string match, it should continue to work.

1
requirements.txt
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@ -22,6 +22,7 @@ oslo.service!=1.28.1,>=1.24.0 # Apache-2.0
oslo.utils>=3.33.0 # Apache-2.0
oslo.versionedobjects>=1.31.2 # Apache-2.0
osprofiler>=1.4.0 # Apache-2.0
setproctitle>=1.1.10 # BSD
WebOb>=1.7.1 # MIT
weakrefmethod>=1.0.2;python_version=='2.7' # PSF
os-traits>=0.9.0 # Apache-2.0