Adding kvm-block-migration feature.

I wrote some description the below URL. I hope it may help for reviewing.
<http://etherpad.openstack.org/kvm-block-migration>

3 files changed, 8 insertions, 68 deletions

diff --git a/nova/db/api.py b/nova/db/api.py
index 0f2218752..b9ea8757c 100644
--- a/nova/db/api.py
+++ b/nova/db/api.py
@@ -570,27 +570,6 @@ def instance_add_security_group(context, instance_id, security_group_id):
                                             security_group_id)
 
 
-def instance_get_vcpu_sum_by_host_and_project(context, hostname, proj_id):
-    """Get instances.vcpus by host and project."""
-    return IMPL.instance_get_vcpu_sum_by_host_and_project(context,
-                                                          hostname,
-                                                          proj_id)
-
-
-def instance_get_memory_sum_by_host_and_project(context, hostname, proj_id):
-    """Get amount of memory by host and project."""
-    return IMPL.instance_get_memory_sum_by_host_and_project(context,
-                                                            hostname,
-                                                            proj_id)
-
-
-def instance_get_disk_sum_by_host_and_project(context, hostname, proj_id):
-    """Get total amount of disk by host and project."""
-    return IMPL.instance_get_disk_sum_by_host_and_project(context,
-                                                          hostname,
-                                                          proj_id)
-
-
 def instance_action_create(context, values):
     """Create an instance action from the values dictionary."""
     return IMPL.instance_action_create(context, values)
diff --git a/nova/db/sqlalchemy/api.py b/nova/db/sqlalchemy/api.py
index e5d35a20b..57a4370d8 100644
--- a/nova/db/sqlalchemy/api.py
+++ b/nova/db/sqlalchemy/api.py
@@ -1483,45 +1483,6 @@ def instance_add_security_group(context, instance_id, security_group_id):
 
 
 @require_context
-def instance_get_vcpu_sum_by_host_and_project(context, hostname, proj_id):
-    session = get_session()
-    result = session.query(models.Instance).\
-                      filter_by(host=hostname).\
-                      filter_by(project_id=proj_id).\
-                      filter_by(deleted=False).\
-                      value(func.sum(models.Instance.vcpus))
-    if not result:
-        return 0
-    return result
-
-
-@require_context
-def instance_get_memory_sum_by_host_and_project(context, hostname, proj_id):
-    session = get_session()
-    result = session.query(models.Instance).\
-                      filter_by(host=hostname).\
-                      filter_by(project_id=proj_id).\
-                      filter_by(deleted=False).\
-                      value(func.sum(models.Instance.memory_mb))
-    if not result:
-        return 0
-    return result
-
-
-@require_context
-def instance_get_disk_sum_by_host_and_project(context, hostname, proj_id):
-    session = get_session()
-    result = session.query(models.Instance).\
-                      filter_by(host=hostname).\
-                      filter_by(project_id=proj_id).\
-                      filter_by(deleted=False).\
-                      value(func.sum(models.Instance.local_gb))
-    if not result:
-        return 0
-    return result
-
-
-@require_context
 def instance_action_create(context, values):
     """Create an instance action from the values dictionary."""
     action_ref = models.InstanceActions()
diff --git a/nova/db/sqlalchemy/models.py b/nova/db/sqlalchemy/models.py
index 64b1bd5cd..f2a4680b0 100644
--- a/nova/db/sqlalchemy/models.py
+++ b/nova/db/sqlalchemy/models.py
@@ -127,14 +127,14 @@ class ComputeNode(BASE, NovaBase):
                                 'ComputeNode.service_id == Service.id,'
                                 'ComputeNode.deleted == False)')
 
-    vcpus = Column(Integer, nullable=True)
-    memory_mb = Column(Integer, nullable=True)
-    local_gb = Column(Integer, nullable=True)
-    vcpus_used = Column(Integer, nullable=True)
-    memory_mb_used = Column(Integer, nullable=True)
-    local_gb_used = Column(Integer, nullable=True)
-    hypervisor_type = Column(Text, nullable=True)
-    hypervisor_version = Column(Integer, nullable=True)
+    vcpus = Column(Integer)
+    memory_mb = Column(Integer)
+    local_gb = Column(Integer)
+    vcpus_used = Column(Integer)
+    memory_mb_used = Column(Integer)
+    local_gb_used = Column(Integer)
+    hypervisor_type = Column(Text)
+    hypervisor_version = Column(Integer)
 
     # Note(masumotok): Expected Strings example:
     #