diff --git a/nova/scheduler/solvers/linearconstraints/server_group_affinity_constraint.py b/nova/scheduler/solvers/linearconstraints/server_group_affinity_constraint.py
new file mode 100644
index 0000000..bdf730f
--- /dev/null
+++ b/nova/scheduler/solvers/linearconstraints/server_group_affinity_constraint.py
@@ -0,0 +1,70 @@
+# Copyright (c) 2014 Cisco Systems, Inc.
+# 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.
+
+from nova.openstack.common import log as logging
+from nova.scheduler.solvers import linearconstraints
+
+LOG = logging.getLogger(__name__)
+
+
+class ServerGroupAffinityConstraint(linearconstraints.AffinityConstraint):
+    """Force to select hosts which host given server group."""
+
+    # The linear constraint should be formed as:
+    # coeff_matrix * var_matrix' (operator) constant_vector
+    # where (operator) is ==, >, >=, <, <=, !=, etc.
+    # For convenience, the constant_vector is merged into left-hand-side,
+    # thus the right-hand-side is always 0.
+
+    def __init__(self, *args, **kwargs):
+        super(ServerGroupAffinityConstraint, self).__init__(*args, **kwargs)
+        self.policy_name = 'affinity'
+
+    def get_coefficient_vectors(self, variables, hosts, instance_uuids,
+                                request_spec, filter_properties):
+        coefficient_vectors = []
+        policies = filter_properties.get('group_policies', [])
+        if self.policy_name not in policies:
+            coefficient_vectors = [[0 for j in range(self.num_instances)]
+                                    for i in range(self.num_hosts)]
+            return coefficient_vectors
+
+        group_hosts = filter_properties.get('group_hosts')
+        if not group_hosts:
+            # when the group is empty, we need to place all the instances in
+            # a same host.
+            coefficient_vectors = [[1 - self.num_instances] +
+                                [1 for j in range(self.num_instances - 1)] for
+                                i in range(self.num_hosts)]
+        for host in hosts:
+            if host.host in group_hosts:
+                coefficient_vectors.append([0 for j
+                                            in range(self.num_instances)])
+            else:
+                coefficient_vectors.append([1 for j
+                                            in range(self.num_instances)])
+        return coefficient_vectors
+
+    def get_variable_vectors(self, variables, hosts, instance_uuids,
+                            request_spec, filter_properties):
+        variable_vectors = []
+        variable_vectors = [[variables[i][j] for j in range(
+                        self.num_instances)] for i in range(self.num_hosts)]
+        return variable_vectors
+
+    def get_operations(self, variables, hosts, instance_uuids,
+                        request_spec, filter_properties):
+        operations = [(lambda x: x == 0) for i in range(self.num_hosts)]
+        return operations
diff --git a/nova/scheduler/solvers/linearconstraints/server_group_anti_affinity_constraint.py b/nova/scheduler/solvers/linearconstraints/server_group_anti_affinity_constraint.py
new file mode 100644
index 0000000..fb62c6c
--- /dev/null
+++ b/nova/scheduler/solvers/linearconstraints/server_group_anti_affinity_constraint.py
@@ -0,0 +1,65 @@
+# Copyright (c) 2014 Cisco Systems, Inc.
+# 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.
+
+from nova.openstack.common import log as logging
+from nova.scheduler.solvers import linearconstraints
+
+LOG = logging.getLogger(__name__)
+
+
+class ServerGroupAntiAffinityConstraint(linearconstraints.AffinityConstraint):
+    """Force to select hosts which host given server group."""
+
+    # The linear constraint should be formed as:
+    # coeff_matrix * var_matrix' (operator) constant_vector
+    # where (operator) is ==, >, >=, <, <=, !=, etc.
+    # For convenience, the constant_vector is merged into left-hand-side,
+    # thus the right-hand-side is always 0.
+
+    def __init__(self, *args, **kwargs):
+        super(ServerGroupAntiAffinityConstraint, self).__init__(
+                                                            *args, **kwargs)
+        self.policy_name = 'anti-affinity'
+
+    def get_coefficient_vectors(self, variables, hosts, instance_uuids,
+                                request_spec, filter_properties):
+        coefficient_vectors = []
+        policies = filter_properties.get('group_policies', [])
+        if self.policy_name not in policies:
+            coefficient_vectors = [[0 for j in range(self.num_instances)] + [0]
+                                    for i in range(self.num_hosts)]
+            return coefficient_vectors
+
+        group_hosts = filter_properties.get('group_hosts')
+        for host in hosts:
+            if host.host in group_hosts:
+                coefficient_vectors.append([1 for j
+                                        in range(self.num_instances)] + [1])
+            else:
+                coefficient_vectors.append([1 for j
+                                        in range(self.num_instances)] + [0])
+        return coefficient_vectors
+
+    def get_variable_vectors(self, variables, hosts, instance_uuids,
+                            request_spec, filter_properties):
+        variable_vectors = []
+        variable_vectors = [[variables[i][j] for j in range(
+                    self.num_instances)] + [1] for i in range(self.num_hosts)]
+        return variable_vectors
+
+    def get_operations(self, variables, hosts, instance_uuids,
+                        request_spec, filter_properties):
+        operations = [(lambda x: x <= 1) for i in range(self.num_hosts)]
+        return operations