blueprint <multi-process-api-service>

Add multiprocess support for API serivces (EC2/OSAPI_Compute/OSAPI_Volume/Metadata).

2012-06-1 v7:
    * Add unittest to cover worker recovery, service termination functionality
    in wsgi.py, fix python 2.6 compatibility issue.
    * Modify generate_uid() to introduce per-process seeds in utils.py to avoid
    collisions.
    * Add worker session to nova.conf.sample.
2012-05-21 v6:
    * Fix 'test_wsgi' unittest error.
2012-04-28 v5:
    * Add SIGINT handler and fix child-parent race condition when Ctrl+C is
    pressed.
2012-03-31 v4:
    * Fixed typo, removed debug code.
2012-03-30 v3:
    * Fixed localization/pep8 error in unittest, add metadata test.
    * nova/wsgi.py:Server: use the greenthread pool created for each process.
    * nova/service.py: remove debug code
2012-03-27 v2:
    * Fixed unittest error.
    * nova/wsgi.py:Server: Use self._logger to do logging in multiprocess mode.
    * nova/wsgi.py:Server: Move self._pool creation into proper place.
    * code style fix.
2012-03-25 v1:
    * Modification to nova/service.py and nova/wsgi.py in order to support
    multiprocess (a.k.a. workers) for various API services.  If multiprocess
    mode is enabled, (i.e. flags 'APINAME_workers' set to positive numbers),
    corresponding API service will run in target number of process(es). There
    is also a master_worker process spawned for managing all workers (handling
    signal/termination).
    * Add unittest for multiprocess API service, also alter testing/runner.py
    to adopt new unittest.

Change-Id: Ia045e595543ddfd192894b2a05801cc4b7ca90cb

1 files changed, 16 insertions, 10 deletions

diff --git a/nova/service.py b/nova/service.py
index b179cda6c..136668311 100644
--- a/nova/service.py
+++ b/nova/service.py
@@ -61,12 +61,18 @@ service_opts = [
     cfg.IntOpt('ec2_listen_port',
                default=8773,
                help='port for ec2 api to listen'),
+    cfg.IntOpt('ec2_workers',
+               default=0,
+               help='Number of workers for EC2 API service'),
     cfg.StrOpt('osapi_compute_listen',
                default="0.0.0.0",
                help='IP address for OpenStack API to listen'),
     cfg.IntOpt('osapi_compute_listen_port',
                default=8774,
                help='list port for osapi compute'),
+    cfg.IntOpt('osapi_compute_workers',
+               default=0,
+               help='Number of workers for OpenStack API service'),
     cfg.StrOpt('metadata_manager',
                default='nova.api.manager.MetadataManager',
                help='OpenStack metadata service manager'),
@@ -76,12 +82,18 @@ service_opts = [
     cfg.IntOpt('metadata_listen_port',
                default=8775,
                help='port for metadata api to listen'),
+    cfg.IntOpt('metadata_workers',
+               default=0,
+               help='Number of workers for metadata service'),
     cfg.StrOpt('osapi_volume_listen',
                default="0.0.0.0",
                help='IP address for OpenStack Volume API to listen'),
     cfg.IntOpt('osapi_volume_listen_port',
                default=8776,
-               help='port for os volume api to listen')
+               help='port for os volume api to listen'),
+    cfg.IntOpt('osapi_volume_workers',
+               default=0,
+               help='Number of workers for OpenStack Volume API service')
     ]
 
 FLAGS = flags.FLAGS
@@ -135,14 +147,6 @@ class Launcher(object):
         :returns: None
 
         """
-        def sigterm(sig, frame):
-            LOG.audit(_("SIGTERM received"))
-            # NOTE(jk0): Raise a ^C which is caught by the caller and cleanly
-            # shuts down the service. This does not yet handle eventlet
-            # threads.
-            raise KeyboardInterrupt
-
-        signal.signal(signal.SIGTERM, sigterm)
 
         for service in self._services:
             try:
@@ -362,10 +366,12 @@ class WSGIService(object):
         self.app = self.loader.load_app(name)
         self.host = getattr(FLAGS, '%s_listen' % name, "0.0.0.0")
         self.port = getattr(FLAGS, '%s_listen_port' % name, 0)
+        self.workers = getattr(FLAGS, '%s_workers' % name, 0)
         self.server = wsgi.Server(name,
                                   self.app,
                                   host=self.host,
-                                  port=self.port)
+                                  port=self.port,
+                                  workers=self.workers)
 
     def _get_manager(self):
         """Initialize a Manager object appropriate for this service.