Merge lp:~rackspace-titan/nova/instance_states into lp:~hudson-openstack/nova/trunk

[Brian Lamar]

Fixed and improved the way instance "states" are set. Instead of relying on solely the power_state of a VM, there are now explicitly defined VM states and VM task states which respectively define the current state of the VM and the task which is currently being performed by the VM.

Currently instance states are not working as intended. This is remedied by using a strategy outlined in the SQLAlchemy code by Ewan which describes our transition from 2 columns (state, state_description) to three columns (power_state, vm_state, and task_state):

OLD:
state - This loosely represented the 'state' of the virtual machine
state_description - This gave slightly more information on the virtual machine state

NEW:
power_state - This corresponds to the *actual* VM state on the hypervisor
vm_state - This represents the concept of a VM -- what the VM should be doing
task_state - This represents a current task which is being worked on by the VM

To see a list of possible vm_states see nova/compute/vm_states.py
To see a list of possible task_states see nova/compute/task_states.py

While this change is rather large, it involved changing all 'state' references to 'power_state' and involved the insertion of more database updates to give an accurate reflection of an instance at any point in time.

[Brian Waldon (bcwaldon)]

This is absolutely incredible. You've done a great job, here. One general comment before the line-by-line stuff:

Can we align the states with respect to tense? I don't think all of our states need to end in ING or ED. What do you think?

16: I think you might want to expand this comment to explain yourself better better

53/54: Should this be 'stopped' and 'terminated'? According to the allowed EC2 values, these don't seem correct.

189: Can you log the output of the command you allude to?

955/990: You should probably file a bug for this, seems like a simple cleanup item

1224: Thank you for cleaning this function up.

1335/1390: I would love to expand on these module-level docstrings. I think adding a bit more context/explanation of what the task/vm_states represent would be very helpful.

1458/1471: Not sure what these comments mean...

review: Needs Fixing

[Brian Lamar (blamar)]

> This is absolutely incredible. You've done a great job, here. One general
> comment before the line-by-line stuff:
>
> Can we align the states with respect to tense? I don't think all of our states
> need to end in ING or ED. What do you think?

The original design had all vm_states and task_states in the same tenses. No INGs or EDs.

task_states.SCHEDULE just didn't have the same effect on me as task_states.SCHEDULING but really it's not a huge difference in my mind. We're just a few seds away from changing everything so it's not difficult. Some of them get more confusing IMO without ING or ED:

NETWORK vs NETWORKING
PAUSE vs PAUSED
STOP vs STOPPED

Would you recommend unification of tenses or just removal of all ING/ED/tense?

[Brian Waldon (bcwaldon)]

> > This is absolutely incredible. You've done a great job, here. One general
> > comment before the line-by-line stuff:
> >
> > Can we align the states with respect to tense? I don't think all of our
> states
> > need to end in ING or ED. What do you think?
>
> The original design had all vm_states and task_states in the same tenses. No
> INGs or EDs.
>
> task_states.SCHEDULE just didn't have the same effect on me as
> task_states.SCHEDULING but really it's not a huge difference in my mind. We're
> just a few seds away from changing everything so it's not difficult. Some of
> them get more confusing IMO without ING or ED:
>
> NETWORK vs NETWORKING
> PAUSE vs PAUSED
> STOP vs STOPPED
>
> Would you recommend unification of tenses or just removal of all ING/ED/tense?

Actually, I think it makes a lot more sense now. Tasks make sense to end in -ING and vm_states in -ED (or no suffix at all). There are a few specific states I want to point out:

task_states.SPAWN -> task_states.SPAWNING

vm_states.VERIFY_RESIZE just seems weird. How does RESIZE_VERIFICATION sound, or WAITING?

Can task_states.UNPAUSING go away in favor of RESUMING? This is more of a question than a suggestion, I can see why we might want to leave it.

What about these for images:
task_states.SNAPSHOTTING -> IMAGE_SNAPSHOT
task_states.BACKING_UP -> IMAGE_BACKUP

task_states.HARD_REBOOTING should go away until we support it. If you want to leave it, can you rename it to REBOOTING_HARD?

task_states.PASSWORD -> UPDATING_PASSWORD

task_states.STARTING -> BOOTING
'starting' can easily mean a million different things

I don't see any 'shutdown' states.

[lp:~rackspace-titan/nova/instance_states]

1491. By Brian Lamar on 2011-08-25

Review feedback.

1492. By Brian Lamar on 2011-08-25

Merged trunk.

1493. By Brian Lamar on 2011-08-25

Bumped migration number.

[Brian Lamar (blamar)]

> 16: I think you might want to expand this comment to explain yourself better
> better

Updated with link to EC2 spec, does that help?

>
> 53/54: Should this be 'stopped' and 'terminated'? According to the allowed EC2
> values, these don't seem correct.

Fixed. They weren't like that before, but you're suggestion seems logical.

>
> 189: Can you log the output of the command you allude to?

Fixed to output status.

> 955/990: You should probably file a bug for this, seems like a simple cleanup
> item

Not sure it's a 'bug', but I created a BP https://blueprints.launchpad.net/nova/+spec/remove-virt-driver-callbacks

>
> 1224: Thank you for cleaning this function up.

Thanks, I really want to highlight this because I don't want anyone surprised at the difference in functionality. All we're doing in the interval tasks right now is sync'ing power states. All actual VM state transition should be done through explicit database updates in the compute API/manager and NOT through this method.

>
> 1335/1390: I would love to expand on these module-level docstrings. I think
> adding a bit more context/explanation of what the task/vm_states represent
> would be very helpful.

Added some details. Do these help?

>
> 1458/1471: Not sure what these comments mean...

Whoops. Those methods shouldn't have still been there. Removed those.

[Brian Lamar (blamar)]

> > > This is absolutely incredible. You've done a great job, here. One general
> > > comment before the line-by-line stuff:
> > >
> > > Can we align the states with respect to tense? I don't think all of our
> > states
> > > need to end in ING or ED. What do you think?
> >
> > The original design had all vm_states and task_states in the same tenses. No
> > INGs or EDs.
> >
> > task_states.SCHEDULE just didn't have the same effect on me as
> > task_states.SCHEDULING but really it's not a huge difference in my mind.
> We're
> > just a few seds away from changing everything so it's not difficult. Some of
> > them get more confusing IMO without ING or ED:
> >
> > NETWORK vs NETWORKING
> > PAUSE vs PAUSED
> > STOP vs STOPPED
> >
> > Would you recommend unification of tenses or just removal of all
> ING/ED/tense?
>
> Actually, I think it makes a lot more sense now. Tasks make sense to end in
> -ING and vm_states in -ED (or no suffix at all). There are a few specific
> states I want to point out:
>
> task_states.SPAWN -> task_states.SPAWNING

Updated.

>
> vm_states.VERIFY_RESIZE just seems weird. How does RESIZE_VERIFICATION sound,
> or WAITING?

I actually updated that state to be a task, because it's not really a VM state. The VM is active, but the task is "waiting for input to see if I should revert or not". It's now task_states.RESIZE_VERIFY

>
> Can task_states.UNPAUSING go away in favor of RESUMING? This is more of a
> question than a suggestion, I can see why we might want to leave it.

Technically unpausing is the opposite of pausing and resuming is the opposite of suspending. It's a little silly I admit, but they have subtle differences so I'd like to keep them if that's not a deal-breaker.

>
> What about these for images:
> task_states.SNAPSHOTTING -> IMAGE_SNAPSHOT
> task_states.BACKING_UP -> IMAGE_BACKUP

Good suggestion. Updated.

>
> task_states.HARD_REBOOTING should go away until we support it. If you want to
> leave it, can you rename it to REBOOTING_HARD?

I've removed it, it's not supported at all and it seems silly to have in there.

>
> task_states.PASSWORD -> UPDATING_PASSWORD

Updated.

>
> task_states.STARTING -> BOOTING
> 'starting' can easily mean a million different things

I very much like the task pairs. STOPPING and STARTING correspond well and when thought about in a compute/instance sense I'm not sure the word is quite so ambiguous?

>
> I don't see any 'shutdown' states.

STOPPED means the VM is stopped/shutoff. STOPPING mean the VM is in the process of being shut down. I'm open to suggestions on making this clearer.

[lp:~rackspace-titan/nova/instance_states]

1494. By Brian Lamar on 2011-08-25

review feedback

1495. By Brian Lamar on 2011-08-25

Test fixup after last review feedback commit.

1496. By Brian Lamar on 2011-08-26

Merged trunk and fixed conflicts.

[Brian Waldon (bcwaldon)]

Fantastic.

review: Approve

[lp:~rackspace-titan/nova/instance_states]

1497. By Brian Lamar on 2011-08-26

Tiny tweaks to the migration script.

1498. By Brian Lamar on 2011-08-29

Merged trunk.

1499. By Brian Lamar on 2011-08-29

Increased migration number.

1500. By Brian Lamar on 2011-08-29

Merged trunk.

1501. By Brian Lamar on 2011-08-29

Merged trunk.

1502. By Brian Lamar on 2011-08-30

Fix a bad merge on my part, this fixes rebuilds\!

[Matt Dietz (cerberus)]

I like the fixes here and the new functionality!

A question for later, but have we ever swung back around to using an actual statemachine to enforce transitions? I think the code here all looks sound, but experience tells me that decisions based on state in the code can be fragile, at best. I'm asking because of things like the following:

519 + self.update(context,
520 + instance_id,
521 + vm_state=vm_states.SUSPENDED,
522 + task_state=task_states.RESUMING)

It doesn't really matter what state the instance was in before. It's suspend and about to resume, now. I know we didn't really enforce the state in all scenarios previously, so I guess I can't expect this patch to take care of all of those in one shot. I bring it up because it seems like in certain instances, you've chosen to try and enforce that the instance is in a good state,
but others aren't covered. Do we maybe we want to consider implementing a more statemachine-esque cleanup in a subsequent patch?

948 + # NOTE(blamar): None of the virt drivers use the 'callback' param

I wondered this myself. Good catch. Make a bug?

Great work on the tests!

I'll add my approve. Just want to touch base with you first and see what (if any) intent there is regarding my comments above.

[Alex Meade (alex-meade)]

1424: should this be vm_state.STOPPED?
 Also, vm_state should be vm_states? and imported?

[Vish Ishaya (vishvananda)]

> 1424: should this be vm_state.STOPPED?
> Also, vm_state should be vm_states? and imported?

Yes the imports from a few lines up is wrong, importing power_states

I can't find any other issues, good work.

review: Needs Fixing

[lp:~rackspace-titan/nova/instance_states]

1503. By Brian Lamar on 2011-08-31

Merged trunk.

1504. By Brian Lamar on 2011-08-31

Removed extraneous import and s/vm_state.STOP/vm_states.STOPPED/

[Brian Lamar (blamar)]

Great catch, that should be fixed now.

[Vish Ishaya (vishvananda)]

looks good now

review: Approve

=== modified file 'nova/api/ec2/cloud.py'
--- nova/api/ec2/cloud.py	2011-08-17 23:44:34 +0000
+++ nova/api/ec2/cloud.py	2011-08-31 14:15:31 +0000
@@ -47,6 +47,7 @@
 from nova import volume
 from nova.api.ec2 import ec2utils
 from nova.compute import instance_types
+from nova.compute import vm_states
 from nova.image import s3
 
 
@@ -78,6 +79,30 @@
     return {'private_key': private_key, 'fingerprint': fingerprint}
 
 
+# EC2 API can return the following values as documented in the EC2 API
+# http://docs.amazonwebservices.com/AWSEC2/latest/APIReference/
+#    ApiReference-ItemType-InstanceStateType.html
+# pending | running | shutting-down | terminated | stopping | stopped
+_STATE_DESCRIPTION_MAP = {
+    None: 'pending',
+    vm_states.ACTIVE: 'running',
+    vm_states.BUILDING: 'pending',
+    vm_states.REBUILDING: 'pending',
+    vm_states.DELETED: 'terminated',
+    vm_states.STOPPED: 'stopped',
+    vm_states.MIGRATING: 'migrate',
+    vm_states.RESIZING: 'resize',
+    vm_states.PAUSED: 'pause',
+    vm_states.SUSPENDED: 'suspend',
+    vm_states.RESCUED: 'rescue',
+}
+
+
+def state_description_from_vm_state(vm_state):
+    """Map the vm state to the server status string"""
+    return _STATE_DESCRIPTION_MAP.get(vm_state, vm_state)
+
+
 # TODO(yamahata): hypervisor dependent default device name
 _DEFAULT_ROOT_DEVICE_NAME = '/dev/sda1'
 _DEFAULT_MAPPINGS = {'ami': 'sda1',
@@ -1039,11 +1064,12 @@
 
         def _format_attr_instance_initiated_shutdown_behavior(instance,
                                                                result):
-            state_description = instance['state_description']
-            state_to_value = {'stopping': 'stop',
-                              'stopped': 'stop',
-                              'terminating': 'terminate'}
-            value = state_to_value.get(state_description)
+            vm_state = instance['vm_state']
+            state_to_value = {
+                vm_states.STOPPED: 'stopped',
+                vm_states.DELETED: 'terminated',
+            }
+            value = state_to_value.get(vm_state)
             if value:
                 result['instanceInitiatedShutdownBehavior'] = value
 
@@ -1198,8 +1224,8 @@
             self._format_kernel_id(instance, i, 'kernelId')
             self._format_ramdisk_id(instance, i, 'ramdiskId')
             i['instanceState'] = {
-                'code': instance['state'],
-                'name': instance['state_description']}
+                'code': instance['power_state'],
+                'name': state_description_from_vm_state(instance['vm_state'])}
             fixed_addr = None
             floating_addr = None
             if instance['fixed_ips']:
@@ -1618,22 +1644,22 @@
         # stop the instance if necessary
         restart_instance = False
         if not no_reboot:
-            state_description = instance['state_description']
+            vm_state = instance['vm_state']
 
             # if the instance is in subtle state, refuse to proceed.
-            if state_description not in ('running', 'stopping', 'stopped'):
+            if vm_state not in (vm_states.ACTIVE, vm_states.STOPPED):
                 raise exception.InstanceNotRunning(instance_id=ec2_instance_id)
 
-            if state_description == 'running':
+            if vm_state == vm_states.ACTIVE:
                 restart_instance = True
                 self.compute_api.stop(context, instance_id=instance_id)
 
             # wait instance for really stopped
             start_time = time.time()
-            while state_description != 'stopped':
+            while vm_state != vm_states.STOPPED:
                 time.sleep(1)
                 instance = self.compute_api.get(context, instance_id)
-                state_description = instance['state_description']
+                vm_state = instance['vm_state']
                 # NOTE(yamahata): timeout and error. 1 hour for now for safety.
                 #                 Is it too short/long?
                 #                 Or is there any better way?

=== modified file 'nova/api/openstack/common.py'
--- nova/api/openstack/common.py	2011-08-17 07:41:17 +0000
+++ nova/api/openstack/common.py	2011-08-31 14:15:31 +0000
@@ -27,7 +27,8 @@
 from nova import log as logging
 from nova import quota
 from nova.api.openstack import wsgi
-from nova.compute import power_state as compute_power_state
+from nova.compute import vm_states
+from nova.compute import task_states
 
 
 LOG = logging.getLogger('nova.api.openstack.common')
@@ -38,36 +39,61 @@
 XML_NS_V11 = 'http://docs.openstack.org/compute/api/v1.1'
 
 
-_STATUS_MAP = {
-    None: 'BUILD',
-    compute_power_state.NOSTATE: 'BUILD',
-    compute_power_state.RUNNING: 'ACTIVE',
-    compute_power_state.BLOCKED: 'ACTIVE',
-    compute_power_state.SUSPENDED: 'SUSPENDED',
-    compute_power_state.PAUSED: 'PAUSED',
-    compute_power_state.SHUTDOWN: 'SHUTDOWN',
-    compute_power_state.SHUTOFF: 'SHUTOFF',
-    compute_power_state.CRASHED: 'ERROR',
-    compute_power_state.FAILED: 'ERROR',
-    compute_power_state.BUILDING: 'BUILD',
+_STATE_MAP = {
+    vm_states.ACTIVE: {
+        'default': 'ACTIVE',
+        task_states.REBOOTING: 'REBOOT',
+        task_states.UPDATING_PASSWORD: 'PASSWORD',
+        task_states.RESIZE_VERIFY: 'VERIFY_RESIZE',
+    },
+    vm_states.BUILDING: {
+        'default': 'BUILD',
+    },
+    vm_states.REBUILDING: {
+        'default': 'REBUILD',
+    },
+    vm_states.STOPPED: {
+        'default': 'STOPPED',
+    },
+    vm_states.MIGRATING: {
+        'default': 'MIGRATING',
+    },
+    vm_states.RESIZING: {
+        'default': 'RESIZE',
+    },
+    vm_states.PAUSED: {
+        'default': 'PAUSED',
+    },
+    vm_states.SUSPENDED: {
+        'default': 'SUSPENDED',
+    },
+    vm_states.RESCUED: {
+        'default': 'RESCUE',
+    },
+    vm_states.ERROR: {
+        'default': 'ERROR',
+    },
+    vm_states.DELETED: {
+        'default': 'DELETED',
+    },
 }
 
 
-def status_from_power_state(power_state):
-    """Map the power state to the server status string"""
-    return _STATUS_MAP[power_state]
-
-
-def power_states_from_status(status):
-    """Map the server status string to a list of power states"""
-    power_states = []
-    for power_state, status_map in _STATUS_MAP.iteritems():
-        # Skip the 'None' state
-        if power_state is None:
-            continue
-        if status.lower() == status_map.lower():
-            power_states.append(power_state)
-    return power_states
+def status_from_state(vm_state, task_state='default'):
+    """Given vm_state and task_state, return a status string."""
+    task_map = _STATE_MAP.get(vm_state, dict(default='UNKNOWN_STATE'))
+    status = task_map.get(task_state, task_map['default'])
+    LOG.debug("Generated %(status)s from vm_state=%(vm_state)s "
+              "task_state=%(task_state)s." % locals())
+    return status
+
+
+def vm_state_from_status(status):
+    """Map the server status string to a vm state."""
+    for state, task_map in _STATE_MAP.iteritems():
+        status_string = task_map.get("default")
+        if status.lower() == status_string.lower():
+            return state
 
 
 def get_pagination_params(request):

=== modified file 'nova/api/openstack/servers.py'
--- nova/api/openstack/servers.py	2011-08-24 14:37:59 +0000
+++ nova/api/openstack/servers.py	2011-08-31 14:15:31 +0000
@@ -95,17 +95,15 @@
         search_opts['recurse_zones'] = utils.bool_from_str(
                 search_opts.get('recurse_zones', False))
 
-        # If search by 'status', we need to convert it to 'state'
-        # If the status is unknown, bail.
-        # Leave 'state' in search_opts so compute can pass it on to
-        # child zones..
+        # If search by 'status', we need to convert it to 'vm_state'
+        # to pass on to child zones.
         if 'status' in search_opts:
             status = search_opts['status']
-            search_opts['state'] = common.power_states_from_status(status)
-            if len(search_opts['state']) == 0:
+            state = common.vm_state_from_status(status)
+            if state is None:
                 reason = _('Invalid server status: %(status)s') % locals()
-                LOG.error(reason)
                 raise exception.InvalidInput(reason=reason)
+            search_opts['vm_state'] = state
 
         # By default, compute's get_all() will return deleted instances.
         # If an admin hasn't specified a 'deleted' search option, we need
@@ -608,9 +606,8 @@
 
         try:
             self.compute_api.rebuild(context, instance_id, image_id, password)
-        except exception.BuildInProgress:
-            msg = _("Instance %s is currently being rebuilt.") % instance_id
-            LOG.debug(msg)
+        except exception.RebuildRequiresActiveInstance:
+            msg = _("Instance %s must be active to rebuild.") % instance_id
             raise exc.HTTPConflict(explanation=msg)
 
         return webob.Response(status_int=202)
@@ -750,9 +747,8 @@
             self.compute_api.rebuild(context, instance_id, image_href,
                                      password, name=name, metadata=metadata,
                                      files_to_inject=personalities)
-        except exception.BuildInProgress:
-            msg = _("Instance %s is currently being rebuilt.") % instance_id
-            LOG.debug(msg)
+        except exception.RebuildRequiresActiveInstance:
+            msg = _("Instance %s must be active to rebuild.") % instance_id
             raise exc.HTTPConflict(explanation=msg)
         except exception.InstanceNotFound:
             msg = _("Instance %s could not be found") % instance_id

=== modified file 'nova/api/openstack/views/servers.py'
--- nova/api/openstack/views/servers.py	2011-08-23 04:17:57 +0000
+++ nova/api/openstack/views/servers.py	2011-08-31 14:15:31 +0000
@@ -21,13 +21,12 @@
 import os
 
 from nova import exception
-import nova.compute
-import nova.context
 from nova.api.openstack import common
 from nova.api.openstack.views import addresses as addresses_view
 from nova.api.openstack.views import flavors as flavors_view
 from nova.api.openstack.views import images as images_view
 from nova import utils
+from nova.compute import vm_states
 
 
 class ViewBuilder(object):
@@ -61,17 +60,13 @@
 
     def _build_detail(self, inst):
         """Returns a detailed model of a server."""
+        vm_state = inst.get('vm_state', vm_states.BUILDING)
+        task_state = inst.get('task_state')
 
         inst_dict = {
             'id': inst['id'],
             'name': inst['display_name'],
-            'status': common.status_from_power_state(inst.get('state'))}
-
-        ctxt = nova.context.get_admin_context()
-        compute_api = nova.compute.API()
-
-        if compute_api.has_finished_migration(ctxt, inst['uuid']):
-            inst_dict['status'] = 'RESIZE-CONFIRM'
+            'status': common.status_from_state(vm_state, task_state)}
 
         # Return the metadata as a dictionary
         metadata = {}

=== modified file 'nova/compute/api.py'
--- nova/compute/api.py	2011-08-26 20:36:45 +0000
+++ nova/compute/api.py	2011-08-31 14:15:31 +0000
@@ -37,6 +37,8 @@
 from nova import volume
 from nova.compute import instance_types
 from nova.compute import power_state
+from nova.compute import task_states
+from nova.compute import vm_states
 from nova.compute.utils import terminate_volumes
 from nova.scheduler import api as scheduler_api
 from nova.db import base
@@ -75,12 +77,18 @@
 
 
 def _is_able_to_shutdown(instance, instance_id):
-    states = {'terminating': "Instance %s is already being terminated",
-              'migrating': "Instance %s is being migrated",
-              'stopping': "Instance %s is being stopped"}
-    msg = states.get(instance['state_description'])
-    if msg:
-        LOG.warning(_(msg), instance_id)
+    vm_state = instance["vm_state"]
+    task_state = instance["task_state"]
+
+    valid_shutdown_states = [
+        vm_states.ACTIVE,
+        vm_states.REBUILDING,
+        vm_states.BUILDING,
+    ]
+
+    if vm_state not in valid_shutdown_states:
+        LOG.warn(_("Instance %(instance_id)s is not in an 'active' state. It "
+                   "is currently %(vm_state)s. Shutdown aborted.") % locals())
         return False
 
     return True
@@ -251,10 +259,10 @@
             'image_ref': image_href,
             'kernel_id': kernel_id or '',
             'ramdisk_id': ramdisk_id or '',
+            'power_state': power_state.NOSTATE,
+            'vm_state': vm_states.BUILDING,
             'config_drive_id': config_drive_id or '',
             'config_drive': config_drive or '',
-            'state': 0,
-            'state_description': 'scheduling',
             'user_id': context.user_id,
             'project_id': context.project_id,
             'launch_time': time.strftime('%Y-%m-%dT%H:%M:%SZ', time.gmtime()),
@@ -415,6 +423,8 @@
             updates['display_name'] = "Server %s" % instance_id
             instance['display_name'] = updates['display_name']
         updates['hostname'] = self.hostname_factory(instance)
+        updates['vm_state'] = vm_states.BUILDING
+        updates['task_state'] = task_states.SCHEDULING
 
         instance = self.update(context, instance_id, **updates)
         return instance
@@ -750,10 +760,8 @@
             return
 
         self.update(context,
-                    instance['id'],
-                    state_description='terminating',
-                    state=0,
-                    terminated_at=utils.utcnow())
+                    instance_id,
+                    task_state=task_states.DELETING)
 
         host = instance['host']
         if host:
@@ -773,9 +781,9 @@
             return
 
         self.update(context,
-                    instance['id'],
-                    state_description='stopping',
-                    state=power_state.NOSTATE,
+                    instance_id,
+                    vm_state=vm_states.ACTIVE,
+                    task_state=task_states.STOPPING,
                     terminated_at=utils.utcnow())
 
         host = instance['host']
@@ -787,12 +795,18 @@
         """Start an instance."""
         LOG.debug(_("Going to try to start %s"), instance_id)
         instance = self._get_instance(context, instance_id, 'starting')
-        if instance['state_description'] != 'stopped':
-            _state_description = instance['state_description']
+        vm_state = instance["vm_state"]
+
+        if vm_state != vm_states.STOPPED:
             LOG.warning(_("Instance %(instance_id)s is not "
-                          "stopped(%(_state_description)s)") % locals())
+                          "stopped. (%(vm_state)s)") % locals())
             return
 
+        self.update(context,
+                    instance_id,
+                    vm_state=vm_states.STOPPED,
+                    task_state=task_states.STARTING)
+
         # TODO(yamahata): injected_files isn't supported right now.
         #                 It is used only for osapi. not for ec2 api.
         #                 availability_zone isn't used by run_instance.
@@ -1020,6 +1034,10 @@
     @scheduler_api.reroute_compute("reboot")
     def reboot(self, context, instance_id):
         """Reboot the given instance."""
+        self.update(context,
+                    instance_id,
+                    vm_state=vm_states.ACTIVE,
+                    task_state=task_states.REBOOTING)
         self._cast_compute_message('reboot_instance', context, instance_id)
 
     @scheduler_api.reroute_compute("rebuild")
@@ -1027,21 +1045,25 @@
                 name=None, metadata=None, files_to_inject=None):
         """Rebuild the given instance with the provided metadata."""
         instance = db.api.instance_get(context, instance_id)
+        name = name or instance["display_name"]
 
-        if instance["state"] == power_state.BUILDING:
-            msg = _("Instance already building")
-            raise exception.BuildInProgress(msg)
+        if instance["vm_state"] != vm_states.ACTIVE:
+            msg = _("Instance must be active to rebuild.")
+            raise exception.RebuildRequiresActiveInstance(msg)
 
         files_to_inject = files_to_inject or []
+        metadata = metadata or {}
+
         self._check_injected_file_quota(context, files_to_inject)
+        self._check_metadata_properties_quota(context, metadata)
 
-        values = {"image_ref": image_href}
-        if metadata is not None:
-            self._check_metadata_properties_quota(context, metadata)
-            values['metadata'] = metadata
-        if name is not None:
-            values['display_name'] = name
-        self.db.instance_update(context, instance_id, values)
+        self.update(context,
+                    instance_id,
+                    metadata=metadata,
+                    display_name=name,
+                    image_ref=image_href,
+                    vm_state=vm_states.ACTIVE,
+                    task_state=task_states.REBUILDING)
 
         rebuild_params = {
             "new_pass": admin_password,
@@ -1065,6 +1087,11 @@
             raise exception.MigrationNotFoundByStatus(instance_id=instance_id,
                                                       status='finished')
 
+        self.update(context,
+                    instance_id,
+                    vm_state=vm_states.ACTIVE,
+                    task_state=None)
+
         params = {'migration_id': migration_ref['id']}
         self._cast_compute_message('revert_resize', context,
                                    instance_ref['uuid'],
@@ -1085,6 +1112,12 @@
         if not migration_ref:
             raise exception.MigrationNotFoundByStatus(instance_id=instance_id,
                                                       status='finished')
+
+        self.update(context,
+                    instance_id,
+                    vm_state=vm_states.ACTIVE,
+                    task_state=None)
+
         params = {'migration_id': migration_ref['id']}
         self._cast_compute_message('confirm_resize', context,
                                    instance_ref['uuid'],
@@ -1130,6 +1163,11 @@
         if (current_memory_mb == new_memory_mb) and flavor_id:
             raise exception.CannotResizeToSameSize()
 
+        self.update(context,
+                    instance_id,
+                    vm_state=vm_states.RESIZING,
+                    task_state=task_states.RESIZE_PREP)
+
         instance_ref = self._get_instance(context, instance_id, 'resize')
         self._cast_scheduler_message(context,
                     {"method": "prep_resize",
@@ -1163,11 +1201,19 @@
     @scheduler_api.reroute_compute("pause")
     def pause(self, context, instance_id):
         """Pause the given instance."""
+        self.update(context,
+                    instance_id,
+                    vm_state=vm_states.ACTIVE,
+                    task_state=task_states.PAUSING)
         self._cast_compute_message('pause_instance', context, instance_id)
 
     @scheduler_api.reroute_compute("unpause")
     def unpause(self, context, instance_id):
         """Unpause the given instance."""
+        self.update(context,
+                    instance_id,
+                    vm_state=vm_states.PAUSED,
+                    task_state=task_states.UNPAUSING)
         self._cast_compute_message('unpause_instance', context, instance_id)
 
     def _call_compute_message_for_host(self, action, context, host, params):
@@ -1200,21 +1246,37 @@
     @scheduler_api.reroute_compute("suspend")
     def suspend(self, context, instance_id):
         """Suspend the given instance."""
+        self.update(context,
+                    instance_id,
+                    vm_state=vm_states.ACTIVE,
+                    task_state=task_states.SUSPENDING)
         self._cast_compute_message('suspend_instance', context, instance_id)
 
     @scheduler_api.reroute_compute("resume")
     def resume(self, context, instance_id):
         """Resume the given instance."""
+        self.update(context,
+                    instance_id,
+                    vm_state=vm_states.SUSPENDED,
+                    task_state=task_states.RESUMING)
         self._cast_compute_message('resume_instance', context, instance_id)
 
     @scheduler_api.reroute_compute("rescue")
     def rescue(self, context, instance_id):
         """Rescue the given instance."""
+        self.update(context,
+                    instance_id,
+                    vm_state=vm_states.ACTIVE,
+                    task_state=task_states.RESCUING)
         self._cast_compute_message('rescue_instance', context, instance_id)
 
     @scheduler_api.reroute_compute("unrescue")
     def unrescue(self, context, instance_id):
         """Unrescue the given instance."""
+        self.update(context,
+                    instance_id,
+                    vm_state=vm_states.RESCUED,
+                    task_state=task_states.UNRESCUING)
         self._cast_compute_message('unrescue_instance', context, instance_id)
 
     @scheduler_api.reroute_compute("set_admin_password")

=== modified file 'nova/compute/manager.py'
--- nova/compute/manager.py	2011-08-26 13:54:53 +0000
+++ nova/compute/manager.py	2011-08-31 14:15:31 +0000
@@ -56,6 +56,8 @@
 from nova import utils
 from nova import volume
 from nova.compute import power_state
+from nova.compute import task_states
+from nova.compute import vm_states
 from nova.notifier import api as notifier
 from nova.compute.utils import terminate_volumes
 from nova.virt import driver
@@ -146,6 +148,10 @@
         super(ComputeManager, self).__init__(service_name="compute",
                                              *args, **kwargs)
 
+    def _instance_update(self, context, instance_id, **kwargs):
+        """Update an instance in the database using kwargs as value."""
+        return self.db.instance_update(context, instance_id, kwargs)
+
     def init_host(self):
         """Initialization for a standalone compute service."""
         self.driver.init_host(host=self.host)
@@ -153,8 +159,8 @@
         instances = self.db.instance_get_all_by_host(context, self.host)
         for instance in instances:
             inst_name = instance['name']
-            db_state = instance['state']
-            drv_state = self._update_state(context, instance['id'])
+            db_state = instance['power_state']
+            drv_state = self._get_power_state(context, instance)
 
             expect_running = db_state == power_state.RUNNING \
                              and drv_state != db_state
@@ -177,29 +183,13 @@
                     LOG.warning(_('Hypervisor driver does not '
                             'support firewall rules'))
 
-    def _update_state(self, context, instance_id, state=None):
-        """Update the state of an instance from the driver info."""
-        instance_ref = self.db.instance_get(context, instance_id)
-
-        if state is None:
-            try:
-                LOG.debug(_('Checking state of %s'), instance_ref['name'])
-                info = self.driver.get_info(instance_ref['name'])
-            except exception.NotFound:
-                info = None
-
-            if info is not None:
-                state = info['state']
-            else:
-                state = power_state.FAILED
-
-        self.db.instance_set_state(context, instance_id, state)
-        return state
-
-    def _update_launched_at(self, context, instance_id, launched_at=None):
-        """Update the launched_at parameter of the given instance."""
-        data = {'launched_at': launched_at or utils.utcnow()}
-        self.db.instance_update(context, instance_id, data)
+    def _get_power_state(self, context, instance):
+        """Retrieve the power state for the given instance."""
+        LOG.debug(_('Checking state of %s'), instance['name'])
+        try:
+            return self.driver.get_info(instance['name'])["state"]
+        except exception.NotFound:
+            return power_state.FAILED
 
     def get_console_topic(self, context, **kwargs):
         """Retrieves the console host for a project on this host.
@@ -251,11 +241,6 @@
 
     def _setup_block_device_mapping(self, context, instance_id):
         """setup volumes for block device mapping"""
-        self.db.instance_set_state(context,
-                                   instance_id,
-                                   power_state.NOSTATE,
-                                   'block_device_mapping')
-
         volume_api = volume.API()
         block_device_mapping = []
         swap = None
@@ -389,17 +374,12 @@
         updates = {}
         updates['host'] = self.host
         updates['launched_on'] = self.host
-        instance = self.db.instance_update(context,
-                                           instance_id,
-                                           updates)
+        updates['vm_state'] = vm_states.BUILDING
+        updates['task_state'] = task_states.NETWORKING
+        instance = self.db.instance_update(context, instance_id, updates)
         instance['injected_files'] = kwargs.get('injected_files', [])
         instance['admin_pass'] = kwargs.get('admin_password', None)
 
-        self.db.instance_set_state(context,
-                                   instance_id,
-                                   power_state.NOSTATE,
-                                   'networking')
-
         is_vpn = instance['image_ref'] == str(FLAGS.vpn_image_id)
         try:
             # NOTE(vish): This could be a cast because we don't do anything
@@ -418,6 +398,11 @@
                 # all vif creation and network injection, maybe this is correct
                 network_info = []
 
+            self._instance_update(context,
+                                  instance_id,
+                                  vm_state=vm_states.BUILDING,
+                                  task_state=task_states.BLOCK_DEVICE_MAPPING)
+
             (swap, ephemerals,
              block_device_mapping) = self._setup_block_device_mapping(
                 context, instance_id)
@@ -427,9 +412,12 @@
                 'ephemerals': ephemerals,
                 'block_device_mapping': block_device_mapping}
 
+            self._instance_update(context,
+                                  instance_id,
+                                  vm_state=vm_states.BUILDING,
+                                  task_state=task_states.SPAWNING)
+
             # TODO(vish) check to make sure the availability zone matches
-            self._update_state(context, instance_id, power_state.BUILDING)
-
             try:
                 self.driver.spawn(context, instance,
                                   network_info, block_device_info)
@@ -438,13 +426,21 @@
                         "virtualization enabled in the BIOS? Details: "
                         "%(ex)s") % locals()
                 LOG.exception(msg)
-
-            self._update_launched_at(context, instance_id)
-            self._update_state(context, instance_id)
+                return
+
+            current_power_state = self._get_power_state(context, instance)
+            self._instance_update(context,
+                                  instance_id,
+                                  power_state=current_power_state,
+                                  vm_state=vm_states.ACTIVE,
+                                  task_state=None,
+                                  launched_at=utils.utcnow())
+
             usage_info = utils.usage_from_instance(instance)
             notifier.notify('compute.%s' % self.host,
                             'compute.instance.create',
                             notifier.INFO, usage_info)
+
         except exception.InstanceNotFound:
             # FIXME(wwolf): We are just ignoring InstanceNotFound
             # exceptions here in case the instance was immediately
@@ -480,8 +476,7 @@
         for volume in volumes:
             self._detach_volume(context, instance_id, volume['id'], False)
 
-        if (instance['state'] == power_state.SHUTOFF and
-            instance['state_description'] != 'stopped'):
+        if instance['power_state'] == power_state.SHUTOFF:
             self.db.instance_destroy(context, instance_id)
             raise exception.Error(_('trying to destroy already destroyed'
                                     ' instance: %s') % instance_id)
@@ -496,9 +491,14 @@
         """Terminate an instance on this host."""
         self._shutdown_instance(context, instance_id, 'Terminating')
         instance = self.db.instance_get(context.elevated(), instance_id)
+        self._instance_update(context,
+                              instance_id,
+                              vm_state=vm_states.DELETED,
+                              task_state=None,
+                              terminated_at=utils.utcnow())
 
-        # TODO(ja): should we keep it in a terminated state for a bit?
         self.db.instance_destroy(context, instance_id)
+
         usage_info = utils.usage_from_instance(instance)
         notifier.notify('compute.%s' % self.host,
                         'compute.instance.delete',
@@ -509,7 +509,10 @@
     def stop_instance(self, context, instance_id):
         """Stopping an instance on this host."""
         self._shutdown_instance(context, instance_id, 'Stopping')
-        # instance state will be updated to stopped by _poll_instance_states()
+        self._instance_update(context,
+                              instance_id,
+                              vm_state=vm_states.STOPPED,
+                              task_state=None)
 
     @exception.wrap_exception(notifier=notifier, publisher_id=publisher_id())
     @checks_instance_lock
@@ -529,26 +532,46 @@
         instance_ref = self.db.instance_get(context, instance_id)
         LOG.audit(_("Rebuilding instance %s"), instance_id, context=context)
 
-        self._update_state(context, instance_id, power_state.BUILDING)
+        current_power_state = self._get_power_state(context, instance_ref)
+        self._instance_update(context,
+                              instance_id,
+                              power_state=current_power_state,
+                              vm_state=vm_states.REBUILDING,
+                              task_state=None)
 
         network_info = self._get_instance_nw_info(context, instance_ref)
-
         self.driver.destroy(instance_ref, network_info)
+
+        self._instance_update(context,
+                              instance_id,
+                              vm_state=vm_states.REBUILDING,
+                              task_state=task_states.BLOCK_DEVICE_MAPPING)
+
         instance_ref.injected_files = kwargs.get('injected_files', [])
         network_info = self.network_api.get_instance_nw_info(context,
                                                               instance_ref)
         bd_mapping = self._setup_block_device_mapping(context, instance_id)
 
+        self._instance_update(context,
+                              instance_id,
+                              vm_state=vm_states.REBUILDING,
+                              task_state=task_states.SPAWNING)
+
         # pull in new password here since the original password isn't in the db
         instance_ref.admin_pass = kwargs.get('new_pass',
                 utils.generate_password(FLAGS.password_length))
 
         self.driver.spawn(context, instance_ref, network_info, bd_mapping)
 
-        self._update_launched_at(context, instance_id)
-        self._update_state(context, instance_id)
+        current_power_state = self._get_power_state(context, instance_ref)
+        self._instance_update(context,
+                              instance_id,
+                              power_state=current_power_state,
+                              vm_state=vm_states.ACTIVE,
+                              task_state=None,
+                              launched_at=utils.utcnow())
+
         usage_info = utils.usage_from_instance(instance_ref)
-
         notifier.notify('compute.%s' % self.host,
                             'compute.instance.rebuild',
                             notifier.INFO,
@@ -558,26 +581,34 @@
     @checks_instance_lock
     def reboot_instance(self, context, instance_id):
         """Reboot an instance on this host."""
-        context = context.elevated()
-        self._update_state(context, instance_id)
-        instance_ref = self.db.instance_get(context, instance_id)
         LOG.audit(_("Rebooting instance %s"), instance_id, context=context)
-
-        if instance_ref['state'] != power_state.RUNNING:
-            state = instance_ref['state']
+        context = context.elevated()
+        instance_ref = self.db.instance_get(context, instance_id)
+
+        current_power_state = self._get_power_state(context, instance_ref)
+        self._instance_update(context,
+                              instance_id,
+                              power_state=current_power_state,
+                              vm_state=vm_states.ACTIVE,
+                              task_state=task_states.REBOOTING)
+
+        if instance_ref['power_state'] != power_state.RUNNING:
+            state = instance_ref['power_state']
             running = power_state.RUNNING
             LOG.warn(_('trying to reboot a non-running '
                      'instance: %(instance_id)s (state: %(state)s '
                      'expected: %(running)s)') % locals(),
                      context=context)
 
-        self.db.instance_set_state(context,
-                                   instance_id,
-                                   power_state.NOSTATE,
-                                   'rebooting')
         network_info = self._get_instance_nw_info(context, instance_ref)
         self.driver.reboot(instance_ref, network_info)
-        self._update_state(context, instance_id)
+
+        current_power_state = self._get_power_state(context, instance_ref)
+        self._instance_update(context,
+                              instance_id,
+                              power_state=current_power_state,
+                              vm_state=vm_states.ACTIVE,
+                              task_state=None)
 
     @exception.wrap_exception(notifier=notifier, publisher_id=publisher_id())
     def snapshot_instance(self, context, instance_id, image_id,
@@ -593,37 +624,45 @@
         :param rotation: int representing how many backups to keep around;
             None if rotation shouldn't be used (as in the case of snapshots)
         """
+        if image_type == "snapshot":
+            task_state = task_states.IMAGE_SNAPSHOT
+        elif image_type == "backup":
+            task_state = task_states.IMAGE_BACKUP
+        else:
+            raise Exception(_('Image type not recognized %s') % image_type)
+
         context = context.elevated()
         instance_ref = self.db.instance_get(context, instance_id)
 
-        #NOTE(sirp): update_state currently only refreshes the state field
-        # if we add is_snapshotting, we will need this refreshed too,
-        # potentially?
-        self._update_state(context, instance_id)
+        current_power_state = self._get_power_state(context, instance_ref)
+        self._instance_update(context,
+                              instance_id,
+                              power_state=current_power_state,
+                              vm_state=vm_states.ACTIVE,
+                              task_state=task_state)
 
         LOG.audit(_('instance %s: snapshotting'), instance_id,
                   context=context)
-        if instance_ref['state'] != power_state.RUNNING:
-            state = instance_ref['state']
+
+        if instance_ref['power_state'] != power_state.RUNNING:
+            state = instance_ref['power_state']
             running = power_state.RUNNING
             LOG.warn(_('trying to snapshot a non-running '
                        'instance: %(instance_id)s (state: %(state)s '
                        'expected: %(running)s)') % locals())
 
         self.driver.snapshot(context, instance_ref, image_id)
-
-        if image_type == 'snapshot':
-            if rotation:
-                raise exception.ImageRotationNotAllowed()
+        self._instance_update(context, instance_id, task_state=None)
+
+        if image_type == 'snapshot' and rotation:
+            raise exception.ImageRotationNotAllowed()
+
+        elif image_type == 'backup' and rotation:
+            instance_uuid = instance_ref['uuid']
+            self.rotate_backups(context, instance_uuid, backup_type, rotation)
+
         elif image_type == 'backup':
-            if rotation:
-                instance_uuid = instance_ref['uuid']
-                self.rotate_backups(context, instance_uuid, backup_type,
-                                    rotation)
-            else:
-                raise exception.RotationRequiredForBackup()
-        else:
-            raise Exception(_('Image type not recognized %s') % image_type)
+            raise exception.RotationRequiredForBackup()
 
     def rotate_backups(self, context, instance_uuid, backup_type, rotation):
         """Delete excess backups associated to an instance.
@@ -691,7 +730,7 @@
         for i in xrange(max_tries):
             instance_ref = self.db.instance_get(context, instance_id)
             instance_id = instance_ref["id"]
-            instance_state = instance_ref["state"]
+            instance_state = instance_ref["power_state"]
             expected_state = power_state.RUNNING
 
             if instance_state != expected_state:
@@ -726,7 +765,7 @@
         context = context.elevated()
         instance_ref = self.db.instance_get(context, instance_id)
         instance_id = instance_ref['id']
-        instance_state = instance_ref['state']
+        instance_state = instance_ref['power_state']
         expected_state = power_state.RUNNING
         if instance_state != expected_state:
             LOG.warn(_('trying to inject a file into a non-running '
@@ -744,7 +783,7 @@
         context = context.elevated()
         instance_ref = self.db.instance_get(context, instance_id)
         instance_id = instance_ref['id']
-        instance_state = instance_ref['state']
+        instance_state = instance_ref['power_state']
         expected_state = power_state.RUNNING
         if instance_state != expected_state:
             LOG.warn(_('trying to update agent on a non-running '
@@ -759,40 +798,41 @@
     @checks_instance_lock
     def rescue_instance(self, context, instance_id):
         """Rescue an instance on this host."""
-        context = context.elevated()
-        instance_ref = self.db.instance_get(context, instance_id)
         LOG.audit(_('instance %s: rescuing'), instance_id, context=context)
-        self.db.instance_set_state(context,
-                                   instance_id,
-                                   power_state.NOSTATE,
-                                   'rescuing')
-        _update_state = lambda result: self._update_state_callback(
-                self, context, instance_id, result)
+        context = context.elevated()
+
+        instance_ref = self.db.instance_get(context, instance_id)
         network_info = self._get_instance_nw_info(context, instance_ref)
-        self.driver.rescue(context, instance_ref, _update_state, network_info)
-        self._update_state(context, instance_id)
+
+        # NOTE(blamar): None of the virt drivers use the 'callback' param
+        self.driver.rescue(context, instance_ref, None, network_info)
+
+        current_power_state = self._get_power_state(context, instance_ref)
+        self._instance_update(context,
+                              instance_id,
+                              vm_state=vm_states.RESCUED,
+                              task_state=None,
+                              power_state=current_power_state)
 
     @exception.wrap_exception(notifier=notifier, publisher_id=publisher_id())
     @checks_instance_lock
     def unrescue_instance(self, context, instance_id):
         """Rescue an instance on this host."""
-        context = context.elevated()
-        instance_ref = self.db.instance_get(context, instance_id)
         LOG.audit(_('instance %s: unrescuing'), instance_id, context=context)
-        self.db.instance_set_state(context,
-                                   instance_id,
-                                   power_state.NOSTATE,
-                                   'unrescuing')
-        _update_state = lambda result: self._update_state_callback(
-                self, context, instance_id, result)
+        context = context.elevated()
+
+        instance_ref = self.db.instance_get(context, instance_id)
         network_info = self._get_instance_nw_info(context, instance_ref)
-        self.driver.unrescue(instance_ref, _update_state, network_info)
-        self._update_state(context, instance_id)
-
-    @staticmethod
-    def _update_state_callback(self, context, instance_id, result):
-        """Update instance state when async task completes."""
-        self._update_state(context, instance_id)
+
+        # NOTE(blamar): None of the virt drivers use the 'callback' param
+        self.driver.unrescue(instance_ref, None, network_info)
+
+        current_power_state = self._get_power_state(context, instance_ref)
+        self._instance_update(context,
+                              instance_id,
+                              vm_state=vm_states.ACTIVE,
+                              task_state=None,
+                              power_state=current_power_state)
 
     @exception.wrap_exception(notifier=notifier, publisher_id=publisher_id())
     @checks_instance_lock
@@ -851,11 +891,12 @@
 
         # Just roll back the record. There's no need to resize down since
         # the 'old' VM already has the preferred attributes
-        self.db.instance_update(context, instance_ref['uuid'],
-           dict(memory_mb=instance_type['memory_mb'],
-                vcpus=instance_type['vcpus'],
-                local_gb=instance_type['local_gb'],
-                instance_type_id=instance_type['id']))
+        self._instance_update(context,
+                              instance_ref["uuid"],
+                              memory_mb=instance_type['memory_mb'],
+                              vcpus=instance_type['vcpus'],
+                              local_gb=instance_type['local_gb'],
+                              instance_type_id=instance_type['id'])
 
         self.driver.revert_migration(instance_ref)
         self.db.migration_update(context, migration_id,
@@ -882,8 +923,11 @@
         instance_ref = self.db.instance_get_by_uuid(context, instance_id)
 
         if instance_ref['host'] == FLAGS.host:
-            raise exception.Error(_(
-                    'Migration error: destination same as source!'))
+            self._instance_update(context,
+                                  instance_id,
+                                  vm_state=vm_states.ERROR)
+            msg = _('Migration error: destination same as source!')
+            raise exception.Error(msg)
 
         old_instance_type = self.db.instance_type_get(context,
                 instance_ref['instance_type_id'])
@@ -977,6 +1021,11 @@
         self.driver.finish_migration(context, instance_ref, disk_info,
                                      network_info, resize_instance)
 
+        self._instance_update(context,
+                              instance_id,
+                              vm_state=vm_states.ACTIVE,
+                              task_state=task_states.RESIZE_VERIFY)
+
         self.db.migration_update(context, migration_id,
                 {'status': 'finished', })
 
@@ -1008,35 +1057,35 @@
     @checks_instance_lock
     def pause_instance(self, context, instance_id):
         """Pause an instance on this host."""
-        context = context.elevated()
-        instance_ref = self.db.instance_get(context, instance_id)
         LOG.audit(_('instance %s: pausing'), instance_id, context=context)
-        self.db.instance_set_state(context,
-                                   instance_id,
-                                   power_state.NOSTATE,
-                                   'pausing')
-        self.driver.pause(instance_ref,
-            lambda result: self._update_state_callback(self,
-                                                       context,
-                                                       instance_id,
-                                                       result))
+        context = context.elevated()
+
+        instance_ref = self.db.instance_get(context, instance_id)
+        self.driver.pause(instance_ref, lambda result: None)
+
+        current_power_state = self._get_power_state(context, instance_ref)
+        self._instance_update(context,
+                              instance_id,
+                              power_state=current_power_state,
+                              vm_state=vm_states.PAUSED,
+                              task_state=None)
 
     @exception.wrap_exception(notifier=notifier, publisher_id=publisher_id())
     @checks_instance_lock
     def unpause_instance(self, context, instance_id):
         """Unpause a paused instance on this host."""
-        context = context.elevated()
-        instance_ref = self.db.instance_get(context, instance_id)
         LOG.audit(_('instance %s: unpausing'), instance_id, context=context)
-        self.db.instance_set_state(context,
-                                   instance_id,
-                                   power_state.NOSTATE,
-                                   'unpausing')
-        self.driver.unpause(instance_ref,
-            lambda result: self._update_state_callback(self,
-                                                       context,
-                                                       instance_id,
-                                                       result))
+        context = context.elevated()
+
+        instance_ref = self.db.instance_get(context, instance_id)
+        self.driver.unpause(instance_ref, lambda result: None)
+
+        current_power_state = self._get_power_state(context, instance_ref)
+        self._instance_update(context,
+                              instance_id,
+                              power_state=current_power_state,
+                              vm_state=vm_states.ACTIVE,
+                              task_state=None)
 
     @exception.wrap_exception(notifier=notifier, publisher_id=publisher_id())
     def host_power_action(self, context, host=None, action=None):
@@ -1052,7 +1101,7 @@
     def get_diagnostics(self, context, instance_id):
         """Retrieve diagnostics for an instance on this host."""
         instance_ref = self.db.instance_get(context, instance_id)
-        if instance_ref["state"] == power_state.RUNNING:
+        if instance_ref["power_state"] == power_state.RUNNING:
             LOG.audit(_("instance %s: retrieving diagnostics"), instance_id,
                       context=context)
             return self.driver.get_diagnostics(instance_ref)
@@ -1061,33 +1110,35 @@
     @checks_instance_lock
     def suspend_instance(self, context, instance_id):
         """Suspend the given instance."""
-        context = context.elevated()
-        instance_ref = self.db.instance_get(context, instance_id)
         LOG.audit(_('instance %s: suspending'), instance_id, context=context)
-        self.db.instance_set_state(context, instance_id,
-                                            power_state.NOSTATE,
-                                            'suspending')
-        self.driver.suspend(instance_ref,
-            lambda result: self._update_state_callback(self,
-                                                       context,
-                                                       instance_id,
-                                                       result))
+        context = context.elevated()
+
+        instance_ref = self.db.instance_get(context, instance_id)
+        self.driver.suspend(instance_ref, lambda result: None)
+
+        current_power_state = self._get_power_state(context, instance_ref)
+        self._instance_update(context,
+                              instance_id,
+                              power_state=current_power_state,
+                              vm_state=vm_states.SUSPENDED,
+                              task_state=None)
 
     @exception.wrap_exception(notifier=notifier, publisher_id=publisher_id())
     @checks_instance_lock
     def resume_instance(self, context, instance_id):
         """Resume the given suspended instance."""
-        context = context.elevated()
-        instance_ref = self.db.instance_get(context, instance_id)
         LOG.audit(_('instance %s: resuming'), instance_id, context=context)
-        self.db.instance_set_state(context, instance_id,
-                                            power_state.NOSTATE,
-                                            'resuming')
-        self.driver.resume(instance_ref,
-            lambda result: self._update_state_callback(self,
-                                                       context,
-                                                       instance_id,
-                                                       result))
+        context = context.elevated()
+
+        instance_ref = self.db.instance_get(context, instance_id)
+        self.driver.resume(instance_ref, lambda result: None)
+
+        current_power_state = self._get_power_state(context, instance_ref)
+        self._instance_update(context,
+                              instance_id,
+                              power_state=current_power_state,
+                              vm_state=vm_states.ACTIVE,
+                              task_state=None)
 
     @exception.wrap_exception(notifier=notifier, publisher_id=publisher_id())
     def lock_instance(self, context, instance_id):
@@ -1498,11 +1549,14 @@
                                'block_migration': block_migration}})
 
         # Restore instance state
-        self.db.instance_update(ctxt,
-                                instance_ref['id'],
-                                {'state_description': 'running',
-                                 'state': power_state.RUNNING,
-                                 'host': dest})
+        current_power_state = self._get_power_state(ctxt, instance_ref)
+        self._instance_update(ctxt,
+                              instance_ref["id"],
+                              host=dest,
+                              power_state=current_power_state,
+                              vm_state=vm_states.ACTIVE,
+                              task_state=None)
+
         # Restore volume state
         for volume_ref in instance_ref['volumes']:
             volume_id = volume_ref['id']
@@ -1548,11 +1602,11 @@
             This param specifies destination host.
         """
         host = instance_ref['host']
-        self.db.instance_update(context,
-                                instance_ref['id'],
-                                {'state_description': 'running',
-                                 'state': power_state.RUNNING,
-                                 'host': host})
+        self._instance_update(context,
+                              instance_ref['id'],
+                              host=host,
+                              vm_state=vm_states.ACTIVE,
+                              task_state=None)
 
         for volume_ref in instance_ref['volumes']:
             volume_id = volume_ref['id']
@@ -1600,10 +1654,9 @@
             error_list.append(ex)
 
         try:
-            self._poll_instance_states(context)
+            self._sync_power_states(context)
         except Exception as ex:
-            LOG.warning(_("Error during instance poll: %s"),
-                        unicode(ex))
+            LOG.warning(_("Error during power_state sync: %s"), unicode(ex))
             error_list.append(ex)
 
         return error_list
@@ -1618,68 +1671,40 @@
             self.update_service_capabilities(
                 self.driver.get_host_stats(refresh=True))
 
-    def _poll_instance_states(self, context):
+    def _sync_power_states(self, context):
+        """Align power states between the database and the hypervisor.
+
+        The hypervisor is authoritative for the power_state data, so we
+        simply loop over all known instances for this host and update the
+        power_state according to the hypervisor. If the instance is not found
+        then it will be set to power_state.NOSTATE, because it doesn't exist
+        on the hypervisor.
+
+        """
         vm_instances = self.driver.list_instances_detail()
         vm_instances = dict((vm.name, vm) for vm in vm_instances)
-
-        # Keep a list of VMs not in the DB, cross them off as we find them
-        vms_not_found_in_db = list(vm_instances.keys())
-
         db_instances = self.db.instance_get_all_by_host(context, self.host)
 
+        num_vm_instances = len(vm_instances)
+        num_db_instances = len(db_instances)
+
+        if num_vm_instances != num_db_instances:
+            LOG.info(_("Found %(num_db_instances)s in the database and "
+                       "%(num_vm_instances)s on the hypervisor.") % locals())
+
         for db_instance in db_instances:
-            name = db_instance['name']
-            db_state = db_instance['state']
+            name = db_instance["name"]
+            db_power_state = db_instance['power_state']
             vm_instance = vm_instances.get(name)
 
             if vm_instance is None:
-                # NOTE(justinsb): We have to be very careful here, because a
-                # concurrent operation could be in progress (e.g. a spawn)
-                if db_state == power_state.BUILDING:
-                    # TODO(justinsb): This does mean that if we crash during a
-                    # spawn, the machine will never leave the spawning state,
-                    # but this is just the way nova is; this function isn't
-                    # trying to correct that problem.
-                    # We could have a separate task to correct this error.
-                    # TODO(justinsb): What happens during a live migration?
-                    LOG.info(_("Found instance '%(name)s' in DB but no VM. "
-                               "State=%(db_state)s, so assuming spawn is in "
-                               "progress.") % locals())
-                    vm_state = db_state
-                else:
-                    LOG.info(_("Found instance '%(name)s' in DB but no VM. "
-                               "State=%(db_state)s, so setting state to "
-                               "shutoff.") % locals())
-                    vm_state = power_state.SHUTOFF
-                    if db_instance['state_description'] == 'stopping':
-                        self.db.instance_stop(context, db_instance['id'])
-                        continue
+                vm_power_state = power_state.NOSTATE
             else:
-                vm_state = vm_instance.state
-                vms_not_found_in_db.remove(name)
+                vm_power_state = vm_instance.state
 
-            if (db_instance['state_description'] in ['migrating', 'stopping']):
-                # A situation which db record exists, but no instance"
-                # sometimes occurs while live-migration at src compute,
-                # this case should be ignored.
-                LOG.debug(_("Ignoring %(name)s, as it's currently being "
-                           "migrated.") % locals())
+            if vm_power_state == db_power_state:
                 continue
 
-            if vm_state != db_state:
-                LOG.info(_("DB/VM state mismatch. Changing state from "
-                           "'%(db_state)s' to '%(vm_state)s'") % locals())
-                self._update_state(context, db_instance['id'], vm_state)
-
-            # NOTE(justinsb): We no longer auto-remove SHUTOFF instances
-            # It's quite hard to get them back when we do.
-
-        # Are there VMs not in the DB?
-        for vm_not_found_in_db in vms_not_found_in_db:
-            name = vm_not_found_in_db
-
-            # We only care about instances that compute *should* know about
-            if name.startswith("instance-"):
-                # TODO(justinsb): What to do here?  Adopt it?  Shut it down?
-                LOG.warning(_("Found VM not in DB: '%(name)s'.  Ignoring")
-                            % locals())
+            self._instance_update(context,
+                                  db_instance["id"],
+                                  power_state=vm_power_state)

=== added file 'nova/compute/task_states.py'
--- nova/compute/task_states.py	1970-01-01 00:00:00 +0000
+++ nova/compute/task_states.py	2011-08-31 14:15:31 +0000
@@ -0,0 +1,59 @@
+# vim: tabstop=4 shiftwidth=4 softtabstop=4
+
+# Copyright 2010 OpenStack LLC.
+# All Rights Reserved.
+#
+#    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.
+
+"""Possible task states for instances.
+
+Compute instance task states represent what is happening to the instance at the
+current moment. These tasks can be generic, such as 'spawning', or specific,
+such as 'block_device_mapping'. These task states allow for a better view into
+what an instance is doing and should be displayed to users/administrators as
+necessary.
+
+"""
+
+SCHEDULING = 'scheduling'
+BLOCK_DEVICE_MAPPING = 'block_device_mapping'
+NETWORKING = 'networking'
+SPAWNING = 'spawning'
+
+IMAGE_SNAPSHOT = 'image_snapshot'
+IMAGE_BACKUP = 'image_backup'
+
+UPDATING_PASSWORD = 'updating_password'
+
+RESIZE_PREP = 'resize_prep'
+RESIZE_MIGRATING = 'resize_migrating'
+RESIZE_MIGRATED = 'resize_migrated'
+RESIZE_FINISH = 'resize_finish'
+RESIZE_REVERTING = 'resize_reverting'
+RESIZE_CONFIRMING = 'resize_confirming'
+RESIZE_VERIFY = 'resize_verify'
+
+REBUILDING = 'rebuilding'
+
+REBOOTING = 'rebooting'
+PAUSING = 'pausing'
+UNPAUSING = 'unpausing'
+SUSPENDING = 'suspending'
+RESUMING = 'resuming'
+
+RESCUING = 'rescuing'
+UNRESCUING = 'unrescuing'
+
+DELETING = 'deleting'
+STOPPING = 'stopping'
+STARTING = 'starting'

=== added file 'nova/compute/vm_states.py'
--- nova/compute/vm_states.py	1970-01-01 00:00:00 +0000
+++ nova/compute/vm_states.py	2011-08-31 14:15:31 +0000
@@ -0,0 +1,39 @@
+# vim: tabstop=4 shiftwidth=4 softtabstop=4
+
+# Copyright 2010 OpenStack LLC.
+# All Rights Reserved.
+#
+#    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.
+
+"""Possible vm states for instances.
+
+Compute instance vm states represent the state of an instance as it pertains to
+a user or administrator. When combined with task states (task_states.py), a
+better picture can be formed regarding the instance's health.
+
+"""
+
+ACTIVE = 'active'
+BUILDING = 'building'
+REBUILDING = 'rebuilding'
+
+PAUSED = 'paused'
+SUSPENDED = 'suspended'
+RESCUED = 'rescued'
+DELETED = 'deleted'
+STOPPED = 'stopped'
+
+MIGRATING = 'migrating'
+RESIZING = 'resizing'
+
+ERROR = 'error'

=== modified file 'nova/db/sqlalchemy/api.py'
--- nova/db/sqlalchemy/api.py	2011-08-26 02:18:46 +0000
+++ nova/db/sqlalchemy/api.py	2011-08-31 14:15:31 +0000
@@ -28,6 +28,7 @@
 from nova import ipv6
 from nova import utils
 from nova import log as logging
+from nova.compute import vm_states
 from nova.db.sqlalchemy import models
 from nova.db.sqlalchemy.session import get_session
 from sqlalchemy import or_
@@ -1102,12 +1103,11 @@
 def instance_stop(context, instance_id):
     session = get_session()
     with session.begin():
-        from nova.compute import power_state
         session.query(models.Instance).\
                 filter_by(id=instance_id).\
                 update({'host': None,
-                        'state': power_state.SHUTOFF,
-                        'state_description': 'stopped',
+                        'vm_state': vm_states.STOPPED,
+                        'task_state': None,
                         'updated_at': literal_column('updated_at')})
         session.query(models.SecurityGroupInstanceAssociation).\
                 filter_by(instance_id=instance_id).\
@@ -1266,7 +1266,7 @@
     # Filters for exact matches that we can do along with the SQL query...
     # For other filters that don't match this, we will do regexp matching
     exact_match_filter_names = ['project_id', 'user_id', 'image_ref',
-            'state', 'instance_type_id', 'deleted']
+            'vm_state', 'instance_type_id', 'deleted']
 
     query_filters = [key for key in filters.iterkeys()
             if key in exact_match_filter_names]
@@ -1484,18 +1484,6 @@
     return fixed_ip_refs[0].floating_ips[0]['address']
 
 
-@require_admin_context
-def instance_set_state(context, instance_id, state, description=None):
-    # TODO(devcamcar): Move this out of models and into driver
-    from nova.compute import power_state
-    if not description:
-        description = power_state.name(state)
-    db.instance_update(context,
-                       instance_id,
-                       {'state': state,
-                        'state_description': description})
-
-
 @require_context
 def instance_update(context, instance_id, values):
     session = get_session()

=== added file 'nova/db/sqlalchemy/migrate_repo/versions/044_update_instance_states.py'
--- nova/db/sqlalchemy/migrate_repo/versions/044_update_instance_states.py	1970-01-01 00:00:00 +0000
+++ nova/db/sqlalchemy/migrate_repo/versions/044_update_instance_states.py	2011-08-31 14:15:31 +0000
@@ -0,0 +1,138 @@
+# vim: tabstop=4 shiftwidth=4 softtabstop=4
+
+# Copyright 2010 OpenStack LLC.
+#
+#    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.
+
+import sqlalchemy
+from sqlalchemy import MetaData, Table, Column, String
+
+from nova.compute import task_states
+from nova.compute import vm_states
+
+
+meta = MetaData()
+
+
+c_task_state = Column('task_state',
+                      String(length=255, convert_unicode=False,
+                             assert_unicode=None, unicode_error=None,
+                             _warn_on_bytestring=False),
+                      nullable=True)
+
+
+_upgrade_translations = {
+    "stopping": {
+        "state_description": vm_states.ACTIVE,
+        "task_state": task_states.STOPPING,
+    },
+    "stopped": {
+        "state_description": vm_states.STOPPED,
+        "task_state": None,
+    },
+    "terminated": {
+        "state_description": vm_states.DELETED,
+        "task_state": None,
+    },
+    "terminating": {
+        "state_description": vm_states.ACTIVE,
+        "task_state": task_states.DELETING,
+    },
+    "running": {
+        "state_description": vm_states.ACTIVE,
+        "task_state": None,
+    },
+    "scheduling": {
+        "state_description": vm_states.BUILDING,
+        "task_state": task_states.SCHEDULING,
+    },
+    "migrating": {
+        "state_description": vm_states.MIGRATING,
+        "task_state": None,
+    },
+    "pending": {
+        "state_description": vm_states.BUILDING,
+        "task_state": task_states.SCHEDULING,
+    },
+}
+
+
+_downgrade_translations = {
+    vm_states.ACTIVE: {
+        None: "running",
+        task_states.DELETING: "terminating",
+        task_states.STOPPING: "stopping",
+    },
+    vm_states.BUILDING: {
+        None: "pending",
+        task_states.SCHEDULING: "scheduling",
+    },
+    vm_states.STOPPED: {
+        None: "stopped",
+    },
+    vm_states.REBUILDING: {
+        None: "pending",
+    },
+    vm_states.DELETED: {
+        None: "terminated",
+    },
+    vm_states.MIGRATING: {
+        None: "migrating",
+    },
+}
+
+
+def upgrade(migrate_engine):
+    meta.bind = migrate_engine
+
+    instance_table = Table('instances', meta, autoload=True,
+                           autoload_with=migrate_engine)
+
+    c_state = instance_table.c.state
+    c_state.alter(name='power_state')
+
+    c_vm_state = instance_table.c.state_description
+    c_vm_state.alter(name='vm_state')
+
+    instance_table.create_column(c_task_state)
+
+    for old_state, values in _upgrade_translations.iteritems():
+        instance_table.update().\
+            values(**values).\
+            where(c_vm_state == old_state).\
+            execute()
+
+
+def downgrade(migrate_engine):
+    meta.bind = migrate_engine
+
+    instance_table = Table('instances', meta, autoload=True,
+                           autoload_with=migrate_engine)
+
+    c_task_state = instance_table.c.task_state
+
+    c_state = instance_table.c.power_state
+    c_state.alter(name='state')
+
+    c_vm_state = instance_table.c.vm_state
+    c_vm_state.alter(name='state_description')
+
+    for old_vm_state, old_task_states in _downgrade_translations.iteritems():
+        for old_task_state, new_state_desc in old_task_states.iteritems():
+            instance_table.update().\
+                where(c_task_state == old_task_state).\
+                where(c_vm_state == old_vm_state).\
+                values(vm_state=new_state_desc).\
+                execute()
+
+    instance_table.drop_column('task_state')

=== modified file 'nova/db/sqlalchemy/models.py'
--- nova/db/sqlalchemy/models.py	2011-08-26 01:38:35 +0000
+++ nova/db/sqlalchemy/models.py	2011-08-31 14:15:31 +0000
@@ -193,8 +193,9 @@
     key_name = Column(String(255))
     key_data = Column(Text)
 
-    state = Column(Integer)
-    state_description = Column(String(255))
+    power_state = Column(Integer)
+    vm_state = Column(String(255))
+    task_state = Column(String(255))
 
     memory_mb = Column(Integer)
     vcpus = Column(Integer)
@@ -238,17 +239,6 @@
     access_ip_v4 = Column(String(255))
     access_ip_v6 = Column(String(255))
 
-    # TODO(vish): see Ewan's email about state improvements, probably
-    #             should be in a driver base class or some such
-    # vmstate_state = running, halted, suspended, paused
-    # power_state = what we have
-    # task_state = transitory and may trigger power state transition
-
-    #@validates('state')
-    #def validate_state(self, key, state):
-    #    assert(state in ['nostate', 'running', 'blocked', 'paused',
-    #                     'shutdown', 'shutoff', 'crashed'])
-
 
 class VirtualStorageArray(BASE, NovaBase):
     """

=== modified file 'nova/exception.py'
--- nova/exception.py	2011-08-26 01:38:35 +0000
+++ nova/exception.py	2011-08-31 14:15:31 +0000
@@ -61,7 +61,7 @@
         super(ApiError, self).__init__(outstr)
 
 
-class BuildInProgress(Error):
+class RebuildRequiresActiveInstance(Error):
     pass
 
 

=== modified file 'nova/scheduler/driver.py'
--- nova/scheduler/driver.py	2011-07-19 13:22:38 +0000
+++ nova/scheduler/driver.py	2011-08-31 14:15:31 +0000
@@ -30,6 +30,7 @@
 from nova import rpc
 from nova import utils
 from nova.compute import power_state
+from nova.compute import vm_states
 from nova.api.ec2 import ec2utils
 
 
@@ -104,10 +105,8 @@
                                           dest, block_migration)
 
         # Changing instance_state.
-        db.instance_set_state(context,
-                              instance_id,
-                              power_state.PAUSED,
-                              'migrating')
+        values = {"vm_state": vm_states.MIGRATING}
+        db.instance_update(context, instance_id, values)
 
         # Changing volume state
         for volume_ref in instance_ref['volumes']:
@@ -129,8 +128,7 @@
         """
 
         # Checking instance is running.
-        if (power_state.RUNNING != instance_ref['state'] or \
-           'running' != instance_ref['state_description']):
+        if instance_ref['power_state'] != power_state.RUNNING:
             instance_id = ec2utils.id_to_ec2_id(instance_ref['id'])
             raise exception.InstanceNotRunning(instance_id=instance_id)
 

=== modified file 'nova/tests/api/openstack/test_server_actions.py'
--- nova/tests/api/openstack/test_server_actions.py	2011-08-24 15:11:20 +0000
+++ nova/tests/api/openstack/test_server_actions.py	2011-08-31 14:15:31 +0000
@@ -10,8 +10,8 @@
 from nova import exception
 from nova import flags
 from nova.api.openstack import create_instance_helper
+from nova.compute import vm_states
 from nova.compute import instance_types
-from nova.compute import power_state
 import nova.db.api
 from nova import test
 from nova.tests.api.openstack import common
@@ -35,17 +35,19 @@
     return _return_server
 
 
-def return_server_with_power_state(power_state):
-    return return_server_with_attributes(power_state=power_state)
-
-
-def return_server_with_uuid_and_power_state(power_state):
-    return return_server_with_power_state(power_state)
-
-
-def stub_instance(id, power_state=0, metadata=None,
-                  image_ref="10", flavor_id="1", name=None):
-
+def return_server_with_state(vm_state, task_state=None):
+    return return_server_with_attributes(vm_state=vm_state,
+                                         task_state=task_state)
+
+
+def return_server_with_uuid_and_state(vm_state, task_state=None):
+    def _return_server(context, id):
+        return return_server_with_state(vm_state, task_state)
+    return _return_server
+
+
+def stub_instance(id, metadata=None, image_ref="10", flavor_id="1",
+                  name=None, vm_state=None, task_state=None):
     if metadata is not None:
         metadata_items = [{'key':k, 'value':v} for k, v in metadata.items()]
     else:
@@ -66,8 +68,8 @@
         "launch_index": 0,
         "key_name": "",
         "key_data": "",
-        "state": power_state,
-        "state_description": "",
+        "vm_state": vm_state or vm_states.ACTIVE,
+        "task_state": task_state,
         "memory_mb": 0,
         "vcpus": 0,
         "local_gb": 0,
@@ -175,11 +177,11 @@
             },
         }
 
-        state = power_state.BUILDING
-        new_return_server = return_server_with_power_state(state)
+        state = vm_states.BUILDING
+        new_return_server = return_server_with_state(state)
         self.stubs.Set(nova.db.api, 'instance_get', new_return_server)
         self.stubs.Set(nova.db, 'instance_get_by_uuid',
-                       return_server_with_uuid_and_power_state(state))
+                       return_server_with_uuid_and_state(state))
 
         req = webob.Request.blank('/v1.0/servers/1/action')
         req.method = 'POST'
@@ -242,19 +244,6 @@
         res = req.get_response(fakes.wsgi_app())
         self.assertEqual(res.status_int, 500)
 
-    def test_resized_server_has_correct_status(self):
-        req = self.webreq('/1', 'GET')
-
-        def fake_migration_get(*args):
-            return {}
-
-        self.stubs.Set(nova.db, 'migration_get_by_instance_and_status',
-                fake_migration_get)
-        res = req.get_response(fakes.wsgi_app())
-        self.assertEqual(res.status_int, 200)
-        body = json.loads(res.body)
-        self.assertEqual(body['server']['status'], 'RESIZE-CONFIRM')
-
     def test_confirm_resize_server(self):
         req = self.webreq('/1/action', 'POST', dict(confirmResize=None))
 
@@ -642,11 +631,11 @@
             },
         }
 
-        state = power_state.BUILDING
-        new_return_server = return_server_with_power_state(state)
+        state = vm_states.BUILDING
+        new_return_server = return_server_with_state(state)
         self.stubs.Set(nova.db.api, 'instance_get', new_return_server)
         self.stubs.Set(nova.db, 'instance_get_by_uuid',
-                       return_server_with_uuid_and_power_state(state))
+                       return_server_with_uuid_and_state(state))
 
         req = webob.Request.blank('/v1.1/fake/servers/1/action')
         req.method = 'POST'

=== modified file 'nova/tests/api/openstack/test_servers.py'
--- nova/tests/api/openstack/test_servers.py	2011-08-24 16:12:11 +0000
+++ nova/tests/api/openstack/test_servers.py	2011-08-31 14:15:31 +0000
@@ -37,7 +37,8 @@
 from nova.api.openstack import xmlutil
 import nova.compute.api
 from nova.compute import instance_types
-from nova.compute import power_state
+from nova.compute import task_states
+from nova.compute import vm_states
 import nova.db.api
 import nova.scheduler.api
 from nova.db.sqlalchemy.models import Instance
@@ -91,15 +92,18 @@
     return _return_server
 
 
-def return_server_with_power_state(power_state):
+def return_server_with_state(vm_state, task_state=None):
     def _return_server(context, id):
-        return stub_instance(id, power_state=power_state)
+        return stub_instance(id, vm_state=vm_state, task_state=task_state)
     return _return_server
 
 
-def return_server_with_uuid_and_power_state(power_state):
+def return_server_with_uuid_and_state(vm_state, task_state):
     def _return_server(context, id):
-        return stub_instance(id, uuid=FAKE_UUID, power_state=power_state)
+        return stub_instance(id,
+                             uuid=FAKE_UUID,
+                             vm_state=vm_state,
+                             task_state=task_state)
     return _return_server
 
 
@@ -148,7 +152,8 @@
 
 
 def stub_instance(id, user_id='fake', project_id='fake', private_address=None,
-                  public_addresses=None, host=None, power_state=0,
+                  public_addresses=None, host=None,
+                  vm_state=None, task_state=None,
                   reservation_id="", uuid=FAKE_UUID, image_ref="10",
                   flavor_id="1", interfaces=None, name=None,
                   access_ipv4=None, access_ipv6=None):
@@ -184,8 +189,8 @@
         "launch_index": 0,
         "key_name": "",
         "key_data": "",
-        "state": power_state,
-        "state_description": "",
+        "vm_state": vm_state or vm_states.BUILDING,
+        "task_state": task_state,
         "memory_mb": 0,
         "vcpus": 0,
         "local_gb": 0,
@@ -494,7 +499,7 @@
             },
         ]
         new_return_server = return_server_with_attributes(
-            interfaces=interfaces, power_state=1)
+            interfaces=interfaces, vm_state=vm_states.ACTIVE)
         self.stubs.Set(nova.db.api, 'instance_get', new_return_server)
 
         req = webob.Request.blank('/v1.1/fake/servers/1')
@@ -587,8 +592,8 @@
             },
         ]
         new_return_server = return_server_with_attributes(
-            interfaces=interfaces, power_state=1, image_ref=image_ref,
-            flavor_id=flavor_id)
+            interfaces=interfaces, vm_state=vm_states.ACTIVE,
+            image_ref=image_ref, flavor_id=flavor_id)
         self.stubs.Set(nova.db.api, 'instance_get', new_return_server)
 
         req = webob.Request.blank('/v1.1/fake/servers/1')
@@ -1209,9 +1214,8 @@
     def test_get_servers_allows_status_v1_1(self):
         def fake_get_all(compute_self, context, search_opts=None):
             self.assertNotEqual(search_opts, None)
-            self.assertTrue('state' in search_opts)
-            self.assertEqual(set(search_opts['state']),
-                    set([power_state.RUNNING, power_state.BLOCKED]))
+            self.assertTrue('vm_state' in search_opts)
+            self.assertEqual(search_opts['vm_state'], vm_states.ACTIVE)
             return [stub_instance(100)]
 
         self.stubs.Set(nova.compute.API, 'get_all', fake_get_all)
@@ -1228,13 +1232,9 @@
 
     def test_get_servers_invalid_status_v1_1(self):
         """Test getting servers by invalid status"""
-
         self.flags(allow_admin_api=False)
-
         req = webob.Request.blank('/v1.1/fake/servers?status=running')
         res = req.get_response(fakes.wsgi_app())
-        # The following assert will fail if either of the asserts in
-        # fake_get_all() fail
         self.assertEqual(res.status_int, 400)
         self.assertTrue(res.body.find('Invalid server status') > -1)
 
@@ -1738,6 +1738,7 @@
         server = json.loads(res.body)['server']
         self.assertEqual(16, len(server['adminPass']))
         self.assertEqual(1, server['id'])
+        self.assertEqual("BUILD", server["status"])
         self.assertEqual(0, server['progress'])
         self.assertEqual('server_test', server['name'])
         self.assertEqual(expected_flavor, server['flavor'])
@@ -2467,23 +2468,51 @@
         self.assertEqual(res.status_int, 204)
         self.assertEqual(self.server_delete_called, True)
 
-    def test_shutdown_status(self):
-        new_server = return_server_with_power_state(power_state.SHUTDOWN)
-        self.stubs.Set(nova.db.api, 'instance_get', new_server)
-        req = webob.Request.blank('/v1.0/servers/1')
-        res = req.get_response(fakes.wsgi_app())
-        self.assertEqual(res.status_int, 200)
-        res_dict = json.loads(res.body)
-        self.assertEqual(res_dict['server']['status'], 'SHUTDOWN')
-
-    def test_shutoff_status(self):
-        new_server = return_server_with_power_state(power_state.SHUTOFF)
-        self.stubs.Set(nova.db.api, 'instance_get', new_server)
-        req = webob.Request.blank('/v1.0/servers/1')
-        res = req.get_response(fakes.wsgi_app())
-        self.assertEqual(res.status_int, 200)
-        res_dict = json.loads(res.body)
-        self.assertEqual(res_dict['server']['status'], 'SHUTOFF')
+
+class TestServerStatus(test.TestCase):
+
+    def _get_with_state(self, vm_state, task_state=None):
+        new_server = return_server_with_state(vm_state, task_state)
+        self.stubs.Set(nova.db.api, 'instance_get', new_server)
+        request = webob.Request.blank('/v1.0/servers/1')
+        response = request.get_response(fakes.wsgi_app())
+        self.assertEqual(response.status_int, 200)
+        return json.loads(response.body)
+
+    def test_active(self):
+        response = self._get_with_state(vm_states.ACTIVE)
+        self.assertEqual(response['server']['status'], 'ACTIVE')
+
+    def test_reboot(self):
+        response = self._get_with_state(vm_states.ACTIVE,
+                                        task_states.REBOOTING)
+        self.assertEqual(response['server']['status'], 'REBOOT')
+
+    def test_rebuild(self):
+        response = self._get_with_state(vm_states.REBUILDING)
+        self.assertEqual(response['server']['status'], 'REBUILD')
+
+    def test_rebuild_error(self):
+        response = self._get_with_state(vm_states.ERROR)
+        self.assertEqual(response['server']['status'], 'ERROR')
+
+    def test_resize(self):
+        response = self._get_with_state(vm_states.RESIZING)
+        self.assertEqual(response['server']['status'], 'RESIZE')
+
+    def test_verify_resize(self):
+        response = self._get_with_state(vm_states.ACTIVE,
+                                        task_states.RESIZE_VERIFY)
+        self.assertEqual(response['server']['status'], 'VERIFY_RESIZE')
+
+    def test_password_update(self):
+        response = self._get_with_state(vm_states.ACTIVE,
+                                        task_states.UPDATING_PASSWORD)
+        self.assertEqual(response['server']['status'], 'PASSWORD')
+
+    def test_stopped(self):
+        response = self._get_with_state(vm_states.STOPPED)
+        self.assertEqual(response['server']['status'], 'STOPPED')
 
 
 class TestServerCreateRequestXMLDeserializerV10(unittest.TestCase):
@@ -3536,8 +3565,8 @@
             "launch_index": 0,
             "key_name": "",
             "key_data": "",
-            "state": 0,
-            "state_description": "",
+            "vm_state": vm_states.BUILDING,
+            "task_state": None,
             "memory_mb": 0,
             "vcpus": 0,
             "local_gb": 0,
@@ -3682,7 +3711,7 @@
 
     def test_build_server_detail_active_status(self):
         #set the power state of the instance to running
-        self.instance['state'] = 1
+        self.instance['vm_state'] = vm_states.ACTIVE
         image_bookmark = "http://localhost/images/5"
         flavor_bookmark = "http://localhost/flavors/1"
         expected_server = {

=== modified file 'nova/tests/integrated/test_servers.py'
--- nova/tests/integrated/test_servers.py	2011-08-26 13:54:53 +0000
+++ nova/tests/integrated/test_servers.py	2011-08-31 14:15:31 +0000
@@ -28,6 +28,17 @@
 
 class ServersTest(integrated_helpers._IntegratedTestBase):
 
+    def _wait_for_creation(self, server):
+        retries = 0
+        while server['status'] == 'BUILD':
+            time.sleep(1)
+            server = self.api.get_server(server['id'])
+            print server
+            retries = retries + 1
+            if retries > 5:
+                break
+        return server
+
     def test_get_servers(self):
         """Simple check that listing servers works."""
         servers = self.api.get_servers()
@@ -36,9 +47,9 @@
 
     def test_create_and_delete_server(self):
         """Creates and deletes a server."""
+        self.flags(stub_network=True)
 
         # Create server
-
         # Build the server data gradually, checking errors along the way
         server = {}
         good_server = self._build_minimal_create_server_request()
@@ -91,19 +102,11 @@
         server_ids = [server['id'] for server in servers]
         self.assertTrue(created_server_id in server_ids)
 
-        # Wait (briefly) for creation
-        retries = 0
-        while found_server['status'] == 'build':
-            LOG.debug("found server: %s" % found_server)
-            time.sleep(1)
-            found_server = self.api.get_server(created_server_id)
-            retries = retries + 1
-            if retries > 5:
-                break
+        found_server = self._wait_for_creation(found_server)
 
         # It should be available...
         # TODO(justinsb): Mock doesn't yet do this...
-        #self.assertEqual('available', found_server['status'])
+        self.assertEqual('ACTIVE', found_server['status'])
         servers = self.api.get_servers(detail=True)
         for server in servers:
             self.assertTrue("image" in server)
@@ -181,6 +184,7 @@
 
     def test_create_and_rebuild_server(self):
         """Rebuild a server."""
+        self.flags(stub_network=True)
 
         # create a server with initially has no metadata
         server = self._build_minimal_create_server_request()
@@ -190,6 +194,8 @@
         self.assertTrue(created_server['id'])
         created_server_id = created_server['id']
 
+        created_server = self._wait_for_creation(created_server)
+
         # rebuild the server with metadata
         post = {}
         post['rebuild'] = {
@@ -212,6 +218,7 @@
 
     def test_create_and_rebuild_server_with_metadata(self):
         """Rebuild a server with metadata."""
+        self.flags(stub_network=True)
 
         # create a server with initially has no metadata
         server = self._build_minimal_create_server_request()
@@ -221,6 +228,8 @@
         self.assertTrue(created_server['id'])
         created_server_id = created_server['id']
 
+        created_server = self._wait_for_creation(created_server)
+
         # rebuild the server with metadata
         post = {}
         post['rebuild'] = {
@@ -248,6 +257,7 @@
 
     def test_create_and_rebuild_server_with_metadata_removal(self):
         """Rebuild a server with metadata."""
+        self.flags(stub_network=True)
 
         # create a server with initially has no metadata
         server = self._build_minimal_create_server_request()
@@ -264,6 +274,8 @@
         self.assertTrue(created_server['id'])
         created_server_id = created_server['id']
 
+        created_server = self._wait_for_creation(created_server)
+
         # rebuild the server with metadata
         post = {}
         post['rebuild'] = {

=== modified file 'nova/tests/scheduler/test_scheduler.py'
--- nova/tests/scheduler/test_scheduler.py	2011-08-16 12:47:35 +0000
+++ nova/tests/scheduler/test_scheduler.py	2011-08-31 14:15:31 +0000
@@ -40,6 +40,7 @@
 from nova.scheduler import manager
 from nova.scheduler import multi
 from nova.compute import power_state
+from nova.compute import vm_states
 
 
 FLAGS = flags.FLAGS
@@ -94,6 +95,9 @@
         inst['vcpus'] = kwargs.get('vcpus', 1)
         inst['memory_mb'] = kwargs.get('memory_mb', 10)
         inst['local_gb'] = kwargs.get('local_gb', 20)
+        inst['vm_state'] = kwargs.get('vm_state', vm_states.ACTIVE)
+        inst['power_state'] = kwargs.get('power_state', power_state.RUNNING)
+        inst['task_state'] = kwargs.get('task_state', None)
         return db.instance_create(ctxt, inst)
 
     def test_fallback(self):
@@ -271,8 +275,9 @@
         inst['memory_mb'] = kwargs.get('memory_mb', 20)
         inst['local_gb'] = kwargs.get('local_gb', 30)
         inst['launched_on'] = kwargs.get('launghed_on', 'dummy')
-        inst['state_description'] = kwargs.get('state_description', 'running')
-        inst['state'] = kwargs.get('state', power_state.RUNNING)
+        inst['vm_state'] = kwargs.get('vm_state', vm_states.ACTIVE)
+        inst['task_state'] = kwargs.get('task_state', None)
+        inst['power_state'] = kwargs.get('power_state', power_state.RUNNING)
         return db.instance_create(self.context, inst)['id']
 
     def _create_volume(self):
@@ -664,14 +669,14 @@
                                       block_migration=False)
 
         i_ref = db.instance_get(self.context, instance_id)
-        self.assertTrue(i_ref['state_description'] == 'migrating')
+        self.assertTrue(i_ref['vm_state'] == vm_states.MIGRATING)
         db.instance_destroy(self.context, instance_id)
         db.volume_destroy(self.context, v_ref['id'])
 
     def test_live_migration_src_check_instance_not_running(self):
         """The instance given by instance_id is not running."""
 
-        instance_id = self._create_instance(state_description='migrating')
+        instance_id = self._create_instance(power_state=power_state.NOSTATE)
         i_ref = db.instance_get(self.context, instance_id)
 
         try:

=== modified file 'nova/tests/test_cloud.py'
--- nova/tests/test_cloud.py	2011-08-16 16:18:13 +0000
+++ nova/tests/test_cloud.py	2011-08-31 14:15:31 +0000
@@ -38,6 +38,7 @@
 from nova import utils
 from nova.api.ec2 import cloud
 from nova.api.ec2 import ec2utils
+from nova.compute import vm_states
 from nova.image import fake
 
 
@@ -1163,7 +1164,7 @@
             self.compute = self.start_service('compute')
 
     def _wait_for_state(self, ctxt, instance_id, predicate):
-        """Wait for an stopping instance to be a given state"""
+        """Wait for a stopped instance to be a given state"""
         id = ec2utils.ec2_id_to_id(instance_id)
         while True:
             info = self.cloud.compute_api.get(context=ctxt, instance_id=id)
@@ -1174,12 +1175,16 @@
 
     def _wait_for_running(self, instance_id):
         def is_running(info):
-            return info['state_description'] == 'running'
+            vm_state = info["vm_state"]
+            task_state = info["task_state"]
+            return vm_state == vm_states.ACTIVE and task_state == None
         self._wait_for_state(self.context, instance_id, is_running)
 
     def _wait_for_stopped(self, instance_id):
         def is_stopped(info):
-            return info['state_description'] == 'stopped'
+            vm_state = info["vm_state"]
+            task_state = info["task_state"]
+            return vm_state == vm_states.STOPPED and task_state == None
         self._wait_for_state(self.context, instance_id, is_stopped)
 
     def _wait_for_terminate(self, instance_id):
@@ -1562,7 +1567,7 @@
                 'id': 0,
                 'root_device_name': '/dev/sdh',
                 'security_groups': [{'name': 'fake0'}, {'name': 'fake1'}],
-                'state_description': 'stopping',
+                'vm_state': vm_states.STOPPED,
                 'instance_type': {'name': 'fake_type'},
                 'kernel_id': 1,
                 'ramdisk_id': 2,
@@ -1606,7 +1611,7 @@
         self.assertEqual(groupSet, expected_groupSet)
         self.assertEqual(get_attribute('instanceInitiatedShutdownBehavior'),
                          {'instance_id': 'i-12345678',
-                          'instanceInitiatedShutdownBehavior': 'stop'})
+                          'instanceInitiatedShutdownBehavior': 'stopped'})
         self.assertEqual(get_attribute('instanceType'),
                          {'instance_id': 'i-12345678',
                           'instanceType': 'fake_type'})

=== modified file 'nova/tests/test_compute.py'
--- nova/tests/test_compute.py	2011-08-24 23:48:04 +0000
+++ nova/tests/test_compute.py	2011-08-31 14:15:31 +0000
@@ -24,6 +24,7 @@
 from nova.compute import instance_types
 from nova.compute import manager as compute_manager
 from nova.compute import power_state
+from nova.compute import vm_states
 from nova import context
 from nova import db
 from nova.db.sqlalchemy import models
@@ -763,8 +764,8 @@
                                      'block_migration': False,
                                      'disk': None}}).\
                             AndRaise(rpc.RemoteError('', '', ''))
-        dbmock.instance_update(c, i_ref['id'], {'state_description': 'running',
-                                                'state': power_state.RUNNING,
+        dbmock.instance_update(c, i_ref['id'], {'vm_state': vm_states.ACTIVE,
+                                                'task_state': None,
                                                 'host': i_ref['host']})
         for v in i_ref['volumes']:
             dbmock.volume_update(c, v['id'], {'status': 'in-use'})
@@ -795,8 +796,8 @@
                                      'block_migration': False,
                                      'disk': None}}).\
                             AndRaise(rpc.RemoteError('', '', ''))
-        dbmock.instance_update(c, i_ref['id'], {'state_description': 'running',
-                                                'state': power_state.RUNNING,
+        dbmock.instance_update(c, i_ref['id'], {'vm_state': vm_states.ACTIVE,
+                                                'task_state': None,
                                                 'host': i_ref['host']})
 
         self.compute.db = dbmock
@@ -841,8 +842,8 @@
         c = context.get_admin_context()
         instance_id = self._create_instance()
         i_ref = db.instance_get(c, instance_id)
-        db.instance_update(c, i_ref['id'], {'state_description': 'migrating',
-                                            'state': power_state.PAUSED})
+        db.instance_update(c, i_ref['id'], {'vm_state': vm_states.MIGRATING,
+                                            'power_state': power_state.PAUSED})
         v_ref = db.volume_create(c, {'size': 1, 'instance_id': instance_id})
         fix_addr = db.fixed_ip_create(c, {'address': '1.1.1.1',
                                           'instance_id': instance_id})
@@ -903,7 +904,7 @@
         instances = db.instance_get_all(context.get_admin_context())
         LOG.info(_("After force-killing instances: %s"), instances)
         self.assertEqual(len(instances), 1)
-        self.assertEqual(power_state.SHUTOFF, instances[0]['state'])
+        self.assertEqual(power_state.NOSTATE, instances[0]['power_state'])
 
     def test_get_all_by_name_regexp(self):
         """Test searching instances by name (display_name)"""
@@ -1323,25 +1324,28 @@
         """Test searching instances by state"""
 
         c = context.get_admin_context()
-        instance_id1 = self._create_instance({'state': power_state.SHUTDOWN})
+        instance_id1 = self._create_instance({
+            'power_state': power_state.SHUTDOWN,
+        })
         instance_id2 = self._create_instance({
-                'id': 2,
-                'state': power_state.RUNNING})
+            'id': 2,
+            'power_state': power_state.RUNNING,
+        })
         instance_id3 = self._create_instance({
-                'id': 10,
-                'state': power_state.RUNNING})
-
+            'id': 10,
+            'power_state': power_state.RUNNING,
+        })
         instances = self.compute_api.get_all(c,
-                search_opts={'state': power_state.SUSPENDED})
+                search_opts={'power_state': power_state.SUSPENDED})
         self.assertEqual(len(instances), 0)
 
         instances = self.compute_api.get_all(c,
-                search_opts={'state': power_state.SHUTDOWN})
+                search_opts={'power_state': power_state.SHUTDOWN})
         self.assertEqual(len(instances), 1)
         self.assertEqual(instances[0].id, instance_id1)
 
         instances = self.compute_api.get_all(c,
-                search_opts={'state': power_state.RUNNING})
+                search_opts={'power_state': power_state.RUNNING})
         self.assertEqual(len(instances), 2)
         instance_ids = [instance.id for instance in instances]
         self.assertTrue(instance_id2 in instance_ids)
@@ -1349,7 +1353,7 @@
 
         # Test passing a list as search arg
         instances = self.compute_api.get_all(c,
-                search_opts={'state': [power_state.SHUTDOWN,
+                search_opts={'power_state': [power_state.SHUTDOWN,
                         power_state.RUNNING]})
         self.assertEqual(len(instances), 3)
 

=== modified file 'nova/tests/vmwareapi/db_fakes.py'
--- nova/tests/vmwareapi/db_fakes.py	2011-07-27 00:40:50 +0000
+++ nova/tests/vmwareapi/db_fakes.py	2011-08-31 14:15:31 +0000
@@ -23,6 +23,8 @@
 
 from nova import db
 from nova import utils
+from nova.compute import task_states
+from nova.compute import vm_states
 
 
 def stub_out_db_instance_api(stubs):
@@ -64,7 +66,8 @@
             'image_ref': values['image_ref'],
             'kernel_id': values['kernel_id'],
             'ramdisk_id': values['ramdisk_id'],
-            'state_description': 'scheduling',
+            'vm_state': vm_states.BUILDING,
+            'task_state': task_states.SCHEDULING,
             'user_id': values['user_id'],
             'project_id': values['project_id'],
             'launch_time': time.strftime('%Y-%m-%dT%H:%M:%SZ', time.gmtime()),