don't report service group connection events as errors in dbdriver

During the upgrade of the API surface with running computes we're
going to see disconnects and reconnects for the service group API (as
conductor is gone). This is not an ERROR, but a normally expected
thing.

Change the connect to an INFO

Change the disconnect to a WARNING (if it happens a lot someone should
look into it).

In both cases try to be a lot more specific, because 'model server' is
really vague and not a term we use in ops facing documentation.

Change-Id: I55417a5b91282c69432bb2ab64441c5cea474d31

1 files changed, 10 insertions, 5 deletions

diff --git a/nova/servicegroup/drivers/db.py b/nova/servicegroup/drivers/db.py
index b204b40f9b..7e65c6c2dd 100644
--- a/nova/servicegroup/drivers/db.py
+++ b/nova/servicegroup/drivers/db.py
@@ -15,10 +15,11 @@
 
 from oslo_config import cfg
 from oslo_log import log as logging
+import oslo_messaging as messaging
 from oslo_utils import timeutils
 import six
 
-from nova.i18n import _, _LE
+from nova.i18n import _, _LI, _LW
 from nova.servicegroup import api
 from nova.servicegroup.drivers import base
 
@@ -85,10 +86,14 @@ class DbDriver(base.Driver):
             # TODO(termie): make this pattern be more elegant.
             if getattr(service, 'model_disconnected', False):
                 service.model_disconnected = False
-                LOG.error(_LE('Recovered model server connection!'))
+                LOG.info(
+                    _LI('Recovered connection to nova-conductor '
+                        'for reporting service status.'))
 
-        # TODO(vish): this should probably only catch connection errors
-        except Exception:
+        # because we are communicating over conductor, a failure to
+        # connect is going to be a messaging failure, not a db error.
+        except messaging.MessagingTimeout:
             if not getattr(service, 'model_disconnected', False):
                 service.model_disconnected = True
-                LOG.exception(_LE('model server went away'))
+                LOG.warn(_LW('Lost connection to nova-conductor '
+                             'for reporting service status.'))