openstack/oslo.service
Code Issues Proposed changes

Merge "restart: don't stop process on sighup when mutating"

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Zuul 2019-08-30 11:51:58 +00:00 committed by Gerrit Code Review
commit 41186e6163
2 changed files with 35 additions and 16 deletions
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13
doc/source/user/usage.rst
View File

@ -143,10 +143,15 @@ requests have been fully served.
To force instantaneous termination SIGINT signal must be sent.
On receiving SIGHUP configuration files are reloaded and a service
is being reset and started again. Then all child workers are gracefully
stopped using SIGTERM and workers with new configuration are
spawned. Thus, SIGHUP can be used for changing config options on the go.
The behavior on receiving SIGHUP varies based on how the service is configured.
If the launcher uses the ``reload`` restart_method (the default), then the
service will reload its configuration and any threads will be completely
restarted. If the ``mutate`` restart_method is used, then only the
configuration options marked as mutable will be reloaded and the service
threads will not be restarted.
See :py:class:`oslo_service.service.Launcher` for more details on the
``restart_method`` parameter.
*NOTE:* SIGHUP is not supported on Windows.
*NOTE:* Config option graceful_shutdown_timeout is not supported on Windows.

38
oslo_service/service.py
View File

@ -261,12 +261,10 @@ class Launcher(object):
"""
self.conf = conf
conf.register_opts(_options.service_opts)
self.services = Services()
self.services = Services(restart_method=restart_method)
self.backdoor_port = (
eventlet_backdoor.initialize_if_enabled(self.conf))
self.restart_method = restart_method
if restart_method not in _LAUNCHER_RESTART_METHODS:
raise ValueError(_("Invalid restart_method: %s") % restart_method)
def launch_service(self, service, workers=1):
"""Load and start the given service.
@ -309,7 +307,7 @@ class Launcher(object):
"""
if self.restart_method == 'reload':
self.conf.reload_config_files()
elif self.restart_method == 'mutate':
else: # self.restart_method == 'mutate'
self.conf.mutate_config_files()
self.services.restart()
@ -372,7 +370,7 @@ class ServiceLauncher(Launcher):
super(ServiceLauncher, self).wait()
except SignalExit as exc:
signame = self.signal_handler.signals_to_name[exc.signo]
LOG.info('Caught %s, exiting', signame)
LOG.info('Caught %s, handling', signame)
status = exc.code
signo = exc.signo
except SystemExit as exc:
@ -518,7 +516,7 @@ class ProcessLauncher(object):
launcher.wait()
except SignalExit as exc:
signame = self.signal_handler.signals_to_name[exc.signo]
LOG.info('Child caught %s, exiting', signame)
LOG.info('Child caught %s, handling', signame)
status = exc.code
signo = exc.signo
except SystemExit as exc:
@ -668,16 +666,18 @@ class ProcessLauncher(object):
if not _is_sighup_and_daemon(self.sigcaught):
break
child_signal = signal.SIGTERM
if self.restart_method == 'reload':
self.conf.reload_config_files()
elif self.restart_method == 'mutate':
self.conf.mutate_config_files()
child_signal = signal.SIGHUP
for service in set(
[wrap.service for wrap in self.children.values()]):
service.reset()
for pid in self.children:
os.kill(pid, signal.SIGTERM)
os.kill(pid, child_signal)
self.running = True
self.sigcaught = None
@ -743,7 +743,10 @@ class Service(ServiceBase):
class Services(object):
def __init__(self):
def __init__(self, restart_method='reload'):
if restart_method not in _LAUNCHER_RESTART_METHODS:
raise ValueError(_("Invalid restart_method: %s") % restart_method)
self.restart_method = restart_method
self.services = []
self.tg = threadgroup.ThreadGroup()
self.done = event.Event()
@ -776,12 +779,23 @@ class Services(object):
self.tg.wait()
def restart(self):
"""Reset services and start them in new threads."""
self.stop()
self.done = event.Event()
"""Reset services.
The behavior of this function varies depending on the value of the
restart_method member. If the restart_method is `reload`, then it
will stop the services, reset them, and start them in new threads.
If the restart_method is `mutate`, then it will just reset the
services without restarting them.
"""
if self.restart_method == 'reload':
self.stop()
self.done = event.Event()
for restart_service in self.services:
restart_service.reset()
self.tg.add_thread(self.run_service, restart_service, self.done)
if self.restart_method == 'reload':
self.tg.add_thread(self.run_service,
restart_service,
self.done)
@staticmethod
def run_service(service, done):