Converted the instance table to use a uuid instead of a auto_increment ID and a random internal_id. I had to use a String(32) column with hex and not a String(16) with bytes because SQLAlchemy doesn't like non-unicode strings going in for String types. We could try another type, but I didn't want a primary_key on blob types.

3 files changed, 25 insertions, 38 deletions

diff --git a/nova/db/api.py b/nova/db/api.py
index 8f9dc2443..e607ac938 100644
--- a/nova/db/api.py
+++ b/nova/db/api.py
@@ -304,9 +304,9 @@ def instance_get_floating_address(context, instance_id):
     return IMPL.instance_get_floating_address(context, instance_id)
 
 
-def instance_get_by_internal_id(context, internal_id):
-    """Get an instance by internal id."""
-    return IMPL.instance_get_by_internal_id(context, internal_id)
+def instance_get_by_id(context, instance_id):
+    """Get an instance by id."""
+    return IMPL.instance_get_by_id(context, instance_id)
 
 
 def instance_is_vpn(context, instance_id):
@@ -658,7 +658,7 @@ def security_group_get_all(context):
 
 
 def security_group_get(context, security_group_id):
-    """Get security group by its internal id."""
+    """Get security group by its id."""
     return IMPL.security_group_get(context, security_group_id)
 
 
diff --git a/nova/db/sqlalchemy/api.py b/nova/db/sqlalchemy/api.py
index 55036d1d1..0505b77a6 100644
--- a/nova/db/sqlalchemy/api.py
+++ b/nova/db/sqlalchemy/api.py
@@ -19,7 +19,7 @@
 Implementation of SQLAlchemy backend.
 """
 
-import random
+import uuid
 import warnings
 
 from nova import db
@@ -525,28 +525,18 @@ def fixed_ip_update(context, address, values):
 ###################
 
 
-#TODO(gundlach): instance_create and volume_create are nearly identical
-#and should be refactored.  I expect there are other copy-and-paste
-#functions between the two of them as well.
 @require_context
 def instance_create(context, values):
     """Create a new Instance record in the database.
 
     context - request context object
     values - dict containing column values.
-             'internal_id' is auto-generated and should not be specified.
     """
     instance_ref = models.Instance()
     instance_ref.update(values)
 
     session = get_session()
     with session.begin():
-        while instance_ref.internal_id == None:
-            # Instances have integer internal ids.
-            internal_id = random.randint(0, 2 ** 31 - 1)
-            if not instance_internal_id_exists(context, internal_id,
-                                               session=session):
-                instance_ref.internal_id = internal_id
         instance_ref.save(session=session)
     return instance_ref
 
@@ -652,38 +642,32 @@ def instance_get_all_by_reservation(context, reservation_id):
 
 
 @require_context
-def instance_get_by_internal_id(context, internal_id):
+def instance_get_by_id(context, instance_id):
     session = get_session()
 
+    if type(instance_id) is int:
+        instance_id = uuid.UUID(int=instance_id).hex
+
     if is_admin_context(context):
         result = session.query(models.Instance).\
                          options(joinedload('security_groups')).\
-                         filter_by(internal_id=internal_id).\
+                         filter_by(id=instance_id).\
                          filter_by(deleted=can_read_deleted(context)).\
                          first()
     elif is_user_context(context):
         result = session.query(models.Instance).\
                          options(joinedload('security_groups')).\
                          filter_by(project_id=context.project_id).\
-                         filter_by(internal_id=internal_id).\
+                         filter_by(id=instance_id).\
                          filter_by(deleted=False).\
                          first()
     if not result:
-        raise exception.NotFound('Instance %s not found' % (internal_id))
+        raise exception.NotFound('Instance %s not found' % (instance_id))
 
     return result
 
 
 @require_context
-def instance_internal_id_exists(context, internal_id, session=None):
-    if not session:
-        session = get_session()
-    return session.query(exists().\
-                         where(models.Instance.internal_id == internal_id)).\
-                   one()[0]
-
-
-@require_context
 def instance_get_fixed_address(context, instance_id):
     session = get_session()
     with session.begin():
diff --git a/nova/db/sqlalchemy/models.py b/nova/db/sqlalchemy/models.py
index fe0a9a921..a0b6fff89 100644
--- a/nova/db/sqlalchemy/models.py
+++ b/nova/db/sqlalchemy/models.py
@@ -20,6 +20,7 @@ SQLAlchemy models for nova data.
 """
 
 import datetime
+import uuid
 
 from sqlalchemy.orm import relationship, backref, object_mapper
 from sqlalchemy import Column, Integer, String, schema
@@ -39,6 +40,10 @@ FLAGS = flags.FLAGS
 BASE = declarative_base()
 
 
+def make_uuid():
+    return uuid.uuid1().hex
+
+
 class NovaBase(object):
     """Base class for Nova Models."""
     __table_args__ = {'mysql_engine': 'InnoDB'}
@@ -154,11 +159,13 @@ class Service(BASE, NovaBase):
 class Instance(BASE, NovaBase):
     """Represents a guest vm."""
     __tablename__ = 'instances'
-    id = Column(Integer, primary_key=True)
-    internal_id = Column(Integer, unique=True)
+    id = Column(String(32), primary_key=True, default=make_uuid)
 
-    admin_pass = Column(String(255))
+    @property
+    def name(self):
+        return "instance-%s" % self.id
 
+    admin_pass = Column(String(255))
     user_id = Column(String(255))
     project_id = Column(String(255))
 
@@ -170,10 +177,6 @@ class Instance(BASE, NovaBase):
     def project(self):
         return auth.manager.AuthManager().get_project(self.project_id)
 
-    @property
-    def name(self):
-        return "instance-%d" % self.internal_id
-
     image_id = Column(String(255))
     kernel_id = Column(String(255))
     ramdisk_id = Column(String(255))
@@ -238,7 +241,7 @@ class Volume(BASE, NovaBase):
     host = Column(String(255))  # , ForeignKey('hosts.id'))
     size = Column(Integer)
     availability_zone = Column(String(255))  # TODO(vish): foreign key?
-    instance_id = Column(Integer, ForeignKey('instances.id'), nullable=True)
+    instance_id = Column(String(32), ForeignKey('instances.id'), nullable=True)
     instance = relationship(Instance,
                             backref=backref('volumes'),
                             foreign_keys=instance_id,
@@ -311,7 +314,7 @@ class SecurityGroupInstanceAssociation(BASE, NovaBase):
     __tablename__ = 'security_group_instance_association'
     id = Column(Integer, primary_key=True)
     security_group_id = Column(Integer, ForeignKey('security_groups.id'))
-    instance_id = Column(Integer, ForeignKey('instances.id'))
+    instance_id = Column(String(32), ForeignKey('instances.id'))
 
 
 class SecurityGroup(BASE, NovaBase):
@@ -431,7 +434,7 @@ class FixedIp(BASE, NovaBase):
     address = Column(String(255))
     network_id = Column(Integer, ForeignKey('networks.id'), nullable=True)
     network = relationship(Network, backref=backref('fixed_ips'))
-    instance_id = Column(Integer, ForeignKey('instances.id'), nullable=True)
+    instance_id = Column(String(32), ForeignKey('instances.id'), nullable=True)
     instance = relationship(Instance,
                             backref=backref('fixed_ip', uselist=False),
                             foreign_keys=instance_id,