Revert "Set default of api_workers to number of CPUs"

This reverts commit c65175811b.

This is in relation to:
https://bugs.launchpad.net/neutron/+bug/1432065

Change-Id: I97562840ff57f43958c1e3e56aa41219bd01c8c5

etc/neutron.conf

@@ -201,12 +201,10 @@ lock_path = $state_path/lock
 # =========== end of items for l3 extension =======
 
 # =========== WSGI parameters related to the API server ==============
-# Number of separate worker processes to spawn.  A value of 0 runs the
+# Number of separate worker processes to spawn.  The default, 0, runs the
 # worker thread in the current process.  Greater than 0 launches that number of
-# child processes as workers.  The parent process manages them.  If not
+# child processes as workers.  The parent process manages them.
-# specified, the default value is equal to the number of CPUs available to
+# api_workers = 0
-# achieve best performance.
-# api_workers = <number of CPUs>
 
 # Number of separate RPC worker processes to spawn.  The default, 0, runs the
 # worker thread in the current process.  Greater than 0 launches that number of

neutron/service.py

@@ -18,7 +18,6 @@ import logging as std_logging
 import os
 import random
 
-from oslo_concurrency import processutils
 from oslo_config import cfg
 from oslo_log import log as logging
 from oslo_messaging import server as rpc_server
@@ -41,9 +40,8 @@ service_opts = [
                default=40,
                help=_('Seconds between running periodic tasks')),
     cfg.IntOpt('api_workers',
-               help=_('Number of separate API worker processes for service. '
+               default=0,
-                      'If not specified, the default is equal to the number '
+               help=_('Number of separate API worker processes for service')),
-                      'of CPUs available for best performance.')),
     cfg.IntOpt('rpc_workers',
                default=0,
                help=_('Number of RPC worker processes for service')),
@@ -167,13 +165,6 @@ def serve_rpc():
                               'details.'))
 
 
-def _get_api_workers():
-    workers = cfg.CONF.api_workers
-    if workers is None:
-        workers = processutils.get_worker_count()
-    return workers
-
-
 def _run_wsgi(app_name):
     app = config.load_paste_app(app_name)
     if not app:
@@ -181,7 +172,7 @@ def _run_wsgi(app_name):
         return
     server = wsgi.Server("Neutron")
     server.start(app, cfg.CONF.bind_port, cfg.CONF.bind_host,
-                 workers=_get_api_workers())
+                 workers=cfg.CONF.api_workers)
     # Dump all option values here after all options are parsed
     cfg.CONF.log_opt_values(LOG, std_logging.DEBUG)
     LOG.info(_LI("Neutron service started, listening on %(host)s:%(port)s"),

neutron/tests/functional/test_service.py

@@ -1,31 +0,0 @@
-# Copyright 2014 Red Hat, Inc.
-#
-#    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.
-
-from oslo_concurrency import processutils
-from oslo_config import cfg
-
-from neutron import service
-from neutron.tests import base
-
-
-class TestService(base.BaseTestCase):
-
-    def test_api_workers_default(self):
-        self.assertEqual(processutils.get_worker_count(),
-                         service._get_api_workers())
-
-    def test_api_workers_from_config(self):
-        cfg.CONF.set_override('api_workers', 1234)
-        self.assertEqual(1234,
-                         service._get_api_workers())