Re-use existing ProcessLauncher from wsgi in RPC workers

If both are run under the same process, and api_workers >= 2, the server
process will instantiate two oslo_service.ProcessLauncher instances

This should be avoided [0], and indeed causes issues on subprocess and
signal handling: killed RPC workers not respawning, SIGHUP on master
process leading to unresponsive server, signal not properly sent to all
child processes, ...

To avoid this, use the wsgi ProcessLauncher instance if it exists

[0] https://docs.openstack.org/oslo.service/latest/user/usage.html#launchers

Change-Id: Ic821f8ca84add9c8137ef712031afb43e491591c
Closes-Bug: #1780139
This commit is contained in:
Bernard Cafarelli 2020-02-07 14:21:09 +01:00
parent f73f39f2cf
commit 13aa00026f
No known key found for this signature in database
GPG Key ID: 9531F08245465A52
3 changed files with 18 additions and 7 deletions

View File

@ -27,7 +27,7 @@ def eventlet_wsgi_server():
def start_api_and_rpc_workers(neutron_api): def start_api_and_rpc_workers(neutron_api):
try: try:
worker_launcher = service.start_all_workers() worker_launcher = service.start_all_workers(neutron_api)
pool = eventlet.GreenPool() pool = eventlet.GreenPool()
api_thread = pool.spawn(neutron_api.wait) api_thread = pool.spawn(neutron_api.wait)

View File

@ -243,7 +243,7 @@ class AllServicesNeutronWorker(neutron_worker.NeutronBaseWorker):
self._launcher.restart() self._launcher.restart()
def _start_workers(workers): def _start_workers(workers, neutron_api=None):
process_workers = [ process_workers = [
plugin_worker for plugin_worker in workers plugin_worker for plugin_worker in workers
if plugin_worker.worker_process_count > 0 if plugin_worker.worker_process_count > 0
@ -251,9 +251,14 @@ def _start_workers(workers):
try: try:
if process_workers: if process_workers:
worker_launcher = common_service.ProcessLauncher( # Get eventual already existing instance from WSGI app
cfg.CONF, wait_interval=1.0, restart_method='mutate' worker_launcher = None
) if neutron_api:
worker_launcher = neutron_api.wsgi_app.process_launcher
if worker_launcher is None:
worker_launcher = common_service.ProcessLauncher(
cfg.CONF, wait_interval=1.0, restart_method='mutate'
)
# add extra process worker and spawn there all workers with # add extra process worker and spawn there all workers with
# worker_process_count == 0 # worker_process_count == 0
@ -285,9 +290,9 @@ def _start_workers(workers):
'details.') 'details.')
def start_all_workers(): def start_all_workers(neutron_api=None):
workers = _get_rpc_workers() + _get_plugins_workers() workers = _get_rpc_workers() + _get_plugins_workers()
launcher = _start_workers(workers) launcher = _start_workers(workers, neutron_api)
registry.publish(resources.PROCESS, events.AFTER_SPAWN, None) registry.publish(resources.PROCESS, events.AFTER_SPAWN, None)
return launcher return launcher

View File

@ -226,6 +226,12 @@ class Server(object):
log_format=CONF.wsgi_log_format, log_format=CONF.wsgi_log_format,
socket_timeout=self.client_socket_timeout) socket_timeout=self.client_socket_timeout)
@property
def process_launcher(self):
if isinstance(self._server, common_service.ProcessLauncher):
return self._server
return None
class Request(wsgi.Request): class Request(wsgi.Request):