Merge branch 'master' into health

39 files changed, 1314 insertions, 711 deletions

diff --git a/examples/python/helloworld/greeter_client.py b/examples/python/helloworld/greeter_client.py
index 44d42c102b..281a68f3c3 100644
--- a/examples/python/helloworld/greeter_client.py
+++ b/examples/python/helloworld/greeter_client.py
@@ -34,11 +34,12 @@ from __future__ import print_function
 import grpc
 
 import helloworld_pb2
+import helloworld_pb2_grpc
 
 
 def run():
   channel = grpc.insecure_channel('localhost:50051')
-  stub = helloworld_pb2.GreeterStub(channel)
+  stub = helloworld_pb2_grpc.GreeterStub(channel)
   response = stub.SayHello(helloworld_pb2.HelloRequest(name='you'))
   print("Greeter client received: " + response.message)
 
diff --git a/examples/python/helloworld/greeter_server.py b/examples/python/helloworld/greeter_server.py
index 37d8bd49cc..0afc21d243 100644
--- a/examples/python/helloworld/greeter_server.py
+++ b/examples/python/helloworld/greeter_server.py
@@ -35,11 +35,12 @@ import time
 import grpc
 
 import helloworld_pb2
+import helloworld_pb2_grpc
 
 _ONE_DAY_IN_SECONDS = 60 * 60 * 24
 
 
-class Greeter(helloworld_pb2.GreeterServicer):
+class Greeter(helloworld_pb2_grpc.GreeterServicer):
 
   def SayHello(self, request, context):
     return helloworld_pb2.HelloReply(message='Hello, %s!' % request.name)
@@ -47,7 +48,7 @@ class Greeter(helloworld_pb2.GreeterServicer):
 
 def serve():
   server = grpc.server(futures.ThreadPoolExecutor(max_workers=10))
-  helloworld_pb2.add_GreeterServicer_to_server(Greeter(), server)
+  helloworld_pb2_grpc.add_GreeterServicer_to_server(Greeter(), server)
   server.add_insecure_port('[::]:50051')
   server.start()
   try:
diff --git a/examples/python/helloworld/helloworld_pb2.py b/examples/python/helloworld/helloworld_pb2.py
index 3ce33fbf2b..6665b1f687 100644
--- a/examples/python/helloworld/helloworld_pb2.py
+++ b/examples/python/helloworld/helloworld_pb2.py
@@ -107,98 +107,123 @@ _sym_db.RegisterMessage(HelloReply)
 
 DESCRIPTOR.has_options = True
 DESCRIPTOR._options = _descriptor._ParseOptions(descriptor_pb2.FileOptions(), _b('\n\033io.grpc.examples.helloworldB\017HelloWorldProtoP\001\242\002\003HLW'))
-import grpc
-from grpc.beta import implementations as beta_implementations
-from grpc.beta import interfaces as beta_interfaces
-from grpc.framework.common import cardinality
-from grpc.framework.interfaces.face import utilities as face_utilities
+try:
+  # THESE ELEMENTS WILL BE DEPRECATED.
+  # Please use the generated *_pb2_grpc.py files instead.
+  import grpc
+  from grpc.framework.common import cardinality
+  from grpc.framework.interfaces.face import utilities as face_utilities
+  from grpc.beta import implementations as beta_implementations
+  from grpc.beta import interfaces as beta_interfaces
+
+
+  class GreeterStub(object):
+    """The greeting service definition.
+    """
 
+    def __init__(self, channel):
+      """Constructor.
 
-class GreeterStub(object):
-  """The greeting service definition.
-  """
+      Args:
+        channel: A grpc.Channel.
+      """
+      self.SayHello = channel.unary_unary(
+          '/helloworld.Greeter/SayHello',
+          request_serializer=HelloRequest.SerializeToString,
+          response_deserializer=HelloReply.FromString,
+          )
 
-  def __init__(self, channel):
-    """Constructor.
 
-    Args:
-      channel: A grpc.Channel.
+  class GreeterServicer(object):
+    """The greeting service definition.
     """
-    self.SayHello = channel.unary_unary(
-        '/helloworld.Greeter/SayHello',
-        request_serializer=HelloRequest.SerializeToString,
-        response_deserializer=HelloReply.FromString,
-        )
-
-
-class GreeterServicer(object):
-  """The greeting service definition.
-  """
 
-  def SayHello(self, request, context):
-    """Sends a greeting
+    def SayHello(self, request, context):
+      """Sends a greeting
+      """
+      context.set_code(grpc.StatusCode.UNIMPLEMENTED)
+      context.set_details('Method not implemented!')
+      raise NotImplementedError('Method not implemented!')
+
+
+  def add_GreeterServicer_to_server(servicer, server):
+    rpc_method_handlers = {
+        'SayHello': grpc.unary_unary_rpc_method_handler(
+            servicer.SayHello,
+            request_deserializer=HelloRequest.FromString,
+            response_serializer=HelloReply.SerializeToString,
+        ),
+    }
+    generic_handler = grpc.method_handlers_generic_handler(
+        'helloworld.Greeter', rpc_method_handlers)
+    server.add_generic_rpc_handlers((generic_handler,))
+
+
+  class BetaGreeterServicer(object):
+    """The Beta API is deprecated for 0.15.0 and later.
+
+    It is recommended to use the GA API (classes and functions in this
+    file not marked beta) for all further purposes. This class was generated
+    only to ease transition from grpcio<0.15.0 to grpcio>=0.15.0."""
+    """The greeting service definition.
     """
-    context.set_code(grpc.StatusCode.UNIMPLEMENTED)
-    context.set_details('Method not implemented!')
-    raise NotImplementedError('Method not implemented!')
-
-
-def add_GreeterServicer_to_server(servicer, server):
-  rpc_method_handlers = {
-      'SayHello': grpc.unary_unary_rpc_method_handler(
-          servicer.SayHello,
-          request_deserializer=HelloRequest.FromString,
-          response_serializer=HelloReply.SerializeToString,
-      ),
-  }
-  generic_handler = grpc.method_handlers_generic_handler(
-      'helloworld.Greeter', rpc_method_handlers)
-  server.add_generic_rpc_handlers((generic_handler,))
-
-
-class BetaGreeterServicer(object):
-  """The greeting service definition.
-  """
-  def SayHello(self, request, context):
-    """Sends a greeting
-    """
-    context.code(beta_interfaces.StatusCode.UNIMPLEMENTED)
+    def SayHello(self, request, context):
+      """Sends a greeting
+      """
+      context.code(beta_interfaces.StatusCode.UNIMPLEMENTED)
+
 
+  class BetaGreeterStub(object):
+    """The Beta API is deprecated for 0.15.0 and later.
 
-class BetaGreeterStub(object):
-  """The greeting service definition.
-  """
-  def SayHello(self, request, timeout, metadata=None, with_call=False, protocol_options=None):
-    """Sends a greeting
+    It is recommended to use the GA API (classes and functions in this
+    file not marked beta) for all further purposes. This class was generated
+    only to ease transition from grpcio<0.15.0 to grpcio>=0.15.0."""
+    """The greeting service definition.
     """
-    raise NotImplementedError()
-  SayHello.future = None
-
-
-def beta_create_Greeter_server(servicer, pool=None, pool_size=None, default_timeout=None, maximum_timeout=None):
-  request_deserializers = {
-    ('helloworld.Greeter', 'SayHello'): HelloRequest.FromString,
-  }
-  response_serializers = {
-    ('helloworld.Greeter', 'SayHello'): HelloReply.SerializeToString,
-  }
-  method_implementations = {
-    ('helloworld.Greeter', 'SayHello'): face_utilities.unary_unary_inline(servicer.SayHello),
-  }
-  server_options = beta_implementations.server_options(request_deserializers=request_deserializers, response_serializers=response_serializers, thread_pool=pool, thread_pool_size=pool_size, default_timeout=default_timeout, maximum_timeout=maximum_timeout)
-  return beta_implementations.server(method_implementations, options=server_options)
-
-
-def beta_create_Greeter_stub(channel, host=None, metadata_transformer=None, pool=None, pool_size=None):
-  request_serializers = {
-    ('helloworld.Greeter', 'SayHello'): HelloRequest.SerializeToString,
-  }
-  response_deserializers = {
-    ('helloworld.Greeter', 'SayHello'): HelloReply.FromString,
-  }
-  cardinalities = {
-    'SayHello': cardinality.Cardinality.UNARY_UNARY,
-  }
-  stub_options = beta_implementations.stub_options(host=host, metadata_transformer=metadata_transformer, request_serializers=request_serializers, response_deserializers=response_deserializers, thread_pool=pool, thread_pool_size=pool_size)
-  return beta_implementations.dynamic_stub(channel, 'helloworld.Greeter', cardinalities, options=stub_options)
+    def SayHello(self, request, timeout, metadata=None, with_call=False, protocol_options=None):
+      """Sends a greeting
+      """
+      raise NotImplementedError()
+    SayHello.future = None
+
+
+  def beta_create_Greeter_server(servicer, pool=None, pool_size=None, default_timeout=None, maximum_timeout=None):
+    """The Beta API is deprecated for 0.15.0 and later.
+
+    It is recommended to use the GA API (classes and functions in this
+    file not marked beta) for all further purposes. This function was
+    generated only to ease transition from grpcio<0.15.0 to grpcio>=0.15.0"""
+    request_deserializers = {
+      ('helloworld.Greeter', 'SayHello'): HelloRequest.FromString,
+    }
+    response_serializers = {
+      ('helloworld.Greeter', 'SayHello'): HelloReply.SerializeToString,
+    }
+    method_implementations = {
+      ('helloworld.Greeter', 'SayHello'): face_utilities.unary_unary_inline(servicer.SayHello),
+    }
+    server_options = beta_implementations.server_options(request_deserializers=request_deserializers, response_serializers=response_serializers, thread_pool=pool, thread_pool_size=pool_size, default_timeout=default_timeout, maximum_timeout=maximum_timeout)
+    return beta_implementations.server(method_implementations, options=server_options)
+
+
+  def beta_create_Greeter_stub(channel, host=None, metadata_transformer=None, pool=None, pool_size=None):
+    """The Beta API is deprecated for 0.15.0 and later.
+
+    It is recommended to use the GA API (classes and functions in this
+    file not marked beta) for all further purposes. This function was
+    generated only to ease transition from grpcio<0.15.0 to grpcio>=0.15.0"""
+    request_serializers = {
+      ('helloworld.Greeter', 'SayHello'): HelloRequest.SerializeToString,
+    }
+    response_deserializers = {
+      ('helloworld.Greeter', 'SayHello'): HelloReply.FromString,
+    }
+    cardinalities = {
+      'SayHello': cardinality.Cardinality.UNARY_UNARY,
+    }
+    stub_options = beta_implementations.stub_options(host=host, metadata_transformer=metadata_transformer, request_serializers=request_serializers, response_deserializers=response_deserializers, thread_pool=pool, thread_pool_size=pool_size)
+    return beta_implementations.dynamic_stub(channel, 'helloworld.Greeter', cardinalities, options=stub_options)
+except ImportError:
+  pass
 # @@protoc_insertion_point(module_scope)
diff --git a/examples/python/helloworld/helloworld_pb2_grpc.py b/examples/python/helloworld/helloworld_pb2_grpc.py
new file mode 100644
index 0000000000..682dc36cd8
--- /dev/null
+++ b/examples/python/helloworld/helloworld_pb2_grpc.py
@@ -0,0 +1,47 @@
+import grpc
+from grpc.framework.common import cardinality
+from grpc.framework.interfaces.face import utilities as face_utilities
+
+import helloworld_pb2 as helloworld__pb2
+
+
+class GreeterStub(object):
+  """The greeting service definition.
+  """
+
+  def __init__(self, channel):
+    """Constructor.
+
+    Args:
+      channel: A grpc.Channel.
+    """
+    self.SayHello = channel.unary_unary(
+        '/helloworld.Greeter/SayHello',
+        request_serializer=helloworld__pb2.HelloRequest.SerializeToString,
+        response_deserializer=helloworld__pb2.HelloReply.FromString,
+        )
+
+
+class GreeterServicer(object):
+  """The greeting service definition.
+  """
+
+  def SayHello(self, request, context):
+    """Sends a greeting
+    """
+    context.set_code(grpc.StatusCode.UNIMPLEMENTED)
+    context.set_details('Method not implemented!')
+    raise NotImplementedError('Method not implemented!')
+
+
+def add_GreeterServicer_to_server(servicer, server):
+  rpc_method_handlers = {
+      'SayHello': grpc.unary_unary_rpc_method_handler(
+          servicer.SayHello,
+          request_deserializer=helloworld__pb2.HelloRequest.FromString,
+          response_serializer=helloworld__pb2.HelloReply.SerializeToString,
+      ),
+  }
+  generic_handler = grpc.method_handlers_generic_handler(
+      'helloworld.Greeter', rpc_method_handlers)
+  server.add_generic_rpc_handlers((generic_handler,))
diff --git a/examples/python/multiplex/helloworld_pb2.py b/examples/python/multiplex/helloworld_pb2.py
index 3ce33fbf2b..6665b1f687 100644
--- a/examples/python/multiplex/helloworld_pb2.py
+++ b/examples/python/multiplex/helloworld_pb2.py
@@ -107,98 +107,123 @@ _sym_db.RegisterMessage(HelloReply)
 
 DESCRIPTOR.has_options = True
 DESCRIPTOR._options = _descriptor._ParseOptions(descriptor_pb2.FileOptions(), _b('\n\033io.grpc.examples.helloworldB\017HelloWorldProtoP\001\242\002\003HLW'))
-import grpc
-from grpc.beta import implementations as beta_implementations
-from grpc.beta import interfaces as beta_interfaces
-from grpc.framework.common import cardinality
-from grpc.framework.interfaces.face import utilities as face_utilities
+try:
+  # THESE ELEMENTS WILL BE DEPRECATED.
+  # Please use the generated *_pb2_grpc.py files instead.
+  import grpc
+  from grpc.framework.common import cardinality
+  from grpc.framework.interfaces.face import utilities as face_utilities
+  from grpc.beta import implementations as beta_implementations
+  from grpc.beta import interfaces as beta_interfaces
+
+
+  class GreeterStub(object):
+    """The greeting service definition.
+    """
 
+    def __init__(self, channel):
+      """Constructor.
 
-class GreeterStub(object):
-  """The greeting service definition.
-  """
+      Args:
+        channel: A grpc.Channel.
+      """
+      self.SayHello = channel.unary_unary(
+          '/helloworld.Greeter/SayHello',
+          request_serializer=HelloRequest.SerializeToString,
+          response_deserializer=HelloReply.FromString,
+          )
 
-  def __init__(self, channel):
-    """Constructor.
 
-    Args:
-      channel: A grpc.Channel.
+  class GreeterServicer(object):
+    """The greeting service definition.
     """
-    self.SayHello = channel.unary_unary(
-        '/helloworld.Greeter/SayHello',
-        request_serializer=HelloRequest.SerializeToString,
-        response_deserializer=HelloReply.FromString,
-        )
-
-
-class GreeterServicer(object):
-  """The greeting service definition.
-  """
 
-  def SayHello(self, request, context):
-    """Sends a greeting
+    def SayHello(self, request, context):
+      """Sends a greeting
+      """
+      context.set_code(grpc.StatusCode.UNIMPLEMENTED)
+      context.set_details('Method not implemented!')
+      raise NotImplementedError('Method not implemented!')
+
+
+  def add_GreeterServicer_to_server(servicer, server):
+    rpc_method_handlers = {
+        'SayHello': grpc.unary_unary_rpc_method_handler(
+            servicer.SayHello,
+            request_deserializer=HelloRequest.FromString,
+            response_serializer=HelloReply.SerializeToString,
+        ),
+    }
+    generic_handler = grpc.method_handlers_generic_handler(
+        'helloworld.Greeter', rpc_method_handlers)
+    server.add_generic_rpc_handlers((generic_handler,))
+
+
+  class BetaGreeterServicer(object):
+    """The Beta API is deprecated for 0.15.0 and later.
+
+    It is recommended to use the GA API (classes and functions in this
+    file not marked beta) for all further purposes. This class was generated
+    only to ease transition from grpcio<0.15.0 to grpcio>=0.15.0."""
+    """The greeting service definition.
     """
-    context.set_code(grpc.StatusCode.UNIMPLEMENTED)
-    context.set_details('Method not implemented!')
-    raise NotImplementedError('Method not implemented!')
-
-
-def add_GreeterServicer_to_server(servicer, server):
-  rpc_method_handlers = {
-      'SayHello': grpc.unary_unary_rpc_method_handler(
-          servicer.SayHello,
-          request_deserializer=HelloRequest.FromString,
-          response_serializer=HelloReply.SerializeToString,
-      ),
-  }
-  generic_handler = grpc.method_handlers_generic_handler(
-      'helloworld.Greeter', rpc_method_handlers)
-  server.add_generic_rpc_handlers((generic_handler,))
-
-
-class BetaGreeterServicer(object):
-  """The greeting service definition.
-  """
-  def SayHello(self, request, context):
-    """Sends a greeting
-    """
-    context.code(beta_interfaces.StatusCode.UNIMPLEMENTED)
+    def SayHello(self, request, context):
+      """Sends a greeting
+      """
+      context.code(beta_interfaces.StatusCode.UNIMPLEMENTED)
+
 
+  class BetaGreeterStub(object):
+    """The Beta API is deprecated for 0.15.0 and later.
 
-class BetaGreeterStub(object):
-  """The greeting service definition.
-  """
-  def SayHello(self, request, timeout, metadata=None, with_call=False, protocol_options=None):
-    """Sends a greeting
+    It is recommended to use the GA API (classes and functions in this
+    file not marked beta) for all further purposes. This class was generated
+    only to ease transition from grpcio<0.15.0 to grpcio>=0.15.0."""
+    """The greeting service definition.
     """
-    raise NotImplementedError()
-  SayHello.future = None
-
-
-def beta_create_Greeter_server(servicer, pool=None, pool_size=None, default_timeout=None, maximum_timeout=None):
-  request_deserializers = {
-    ('helloworld.Greeter', 'SayHello'): HelloRequest.FromString,
-  }
-  response_serializers = {
-    ('helloworld.Greeter', 'SayHello'): HelloReply.SerializeToString,
-  }
-  method_implementations = {
-    ('helloworld.Greeter', 'SayHello'): face_utilities.unary_unary_inline(servicer.SayHello),
-  }
-  server_options = beta_implementations.server_options(request_deserializers=request_deserializers, response_serializers=response_serializers, thread_pool=pool, thread_pool_size=pool_size, default_timeout=default_timeout, maximum_timeout=maximum_timeout)
-  return beta_implementations.server(method_implementations, options=server_options)
-
-
-def beta_create_Greeter_stub(channel, host=None, metadata_transformer=None, pool=None, pool_size=None):
-  request_serializers = {
-    ('helloworld.Greeter', 'SayHello'): HelloRequest.SerializeToString,
-  }
-  response_deserializers = {
-    ('helloworld.Greeter', 'SayHello'): HelloReply.FromString,
-  }
-  cardinalities = {
-    'SayHello': cardinality.Cardinality.UNARY_UNARY,
-  }
-  stub_options = beta_implementations.stub_options(host=host, metadata_transformer=metadata_transformer, request_serializers=request_serializers, response_deserializers=response_deserializers, thread_pool=pool, thread_pool_size=pool_size)
-  return beta_implementations.dynamic_stub(channel, 'helloworld.Greeter', cardinalities, options=stub_options)
+    def SayHello(self, request, timeout, metadata=None, with_call=False, protocol_options=None):
+      """Sends a greeting
+      """
+      raise NotImplementedError()
+    SayHello.future = None
+
+
+  def beta_create_Greeter_server(servicer, pool=None, pool_size=None, default_timeout=None, maximum_timeout=None):
+    """The Beta API is deprecated for 0.15.0 and later.
+
+    It is recommended to use the GA API (classes and functions in this
+    file not marked beta) for all further purposes. This function was
+    generated only to ease transition from grpcio<0.15.0 to grpcio>=0.15.0"""
+    request_deserializers = {
+      ('helloworld.Greeter', 'SayHello'): HelloRequest.FromString,
+    }
+    response_serializers = {
+      ('helloworld.Greeter', 'SayHello'): HelloReply.SerializeToString,
+    }
+    method_implementations = {
+      ('helloworld.Greeter', 'SayHello'): face_utilities.unary_unary_inline(servicer.SayHello),
+    }
+    server_options = beta_implementations.server_options(request_deserializers=request_deserializers, response_serializers=response_serializers, thread_pool=pool, thread_pool_size=pool_size, default_timeout=default_timeout, maximum_timeout=maximum_timeout)
+    return beta_implementations.server(method_implementations, options=server_options)
+
+
+  def beta_create_Greeter_stub(channel, host=None, metadata_transformer=None, pool=None, pool_size=None):
+    """The Beta API is deprecated for 0.15.0 and later.
+
+    It is recommended to use the GA API (classes and functions in this
+    file not marked beta) for all further purposes. This function was
+    generated only to ease transition from grpcio<0.15.0 to grpcio>=0.15.0"""
+    request_serializers = {
+      ('helloworld.Greeter', 'SayHello'): HelloRequest.SerializeToString,
+    }
+    response_deserializers = {
+      ('helloworld.Greeter', 'SayHello'): HelloReply.FromString,
+    }
+    cardinalities = {
+      'SayHello': cardinality.Cardinality.UNARY_UNARY,
+    }
+    stub_options = beta_implementations.stub_options(host=host, metadata_transformer=metadata_transformer, request_serializers=request_serializers, response_deserializers=response_deserializers, thread_pool=pool, thread_pool_size=pool_size)
+    return beta_implementations.dynamic_stub(channel, 'helloworld.Greeter', cardinalities, options=stub_options)
+except ImportError:
+  pass
 # @@protoc_insertion_point(module_scope)
diff --git a/examples/python/multiplex/helloworld_pb2_grpc.py b/examples/python/multiplex/helloworld_pb2_grpc.py
new file mode 100644
index 0000000000..682dc36cd8
--- /dev/null
+++ b/examples/python/multiplex/helloworld_pb2_grpc.py
@@ -0,0 +1,47 @@
+import grpc
+from grpc.framework.common import cardinality
+from grpc.framework.interfaces.face import utilities as face_utilities
+
+import helloworld_pb2 as helloworld__pb2
+
+
+class GreeterStub(object):
+  """The greeting service definition.
+  """
+
+  def __init__(self, channel):
+    """Constructor.
+
+    Args:
+      channel: A grpc.Channel.
+    """
+    self.SayHello = channel.unary_unary(
+        '/helloworld.Greeter/SayHello',
+        request_serializer=helloworld__pb2.HelloRequest.SerializeToString,
+        response_deserializer=helloworld__pb2.HelloReply.FromString,
+        )
+
+
+class GreeterServicer(object):
+  """The greeting service definition.
+  """
+
+  def SayHello(self, request, context):
+    """Sends a greeting
+    """
+    context.set_code(grpc.StatusCode.UNIMPLEMENTED)
+    context.set_details('Method not implemented!')
+    raise NotImplementedError('Method not implemented!')
+
+
+def add_GreeterServicer_to_server(servicer, server):
+  rpc_method_handlers = {
+      'SayHello': grpc.unary_unary_rpc_method_handler(
+          servicer.SayHello,
+          request_deserializer=helloworld__pb2.HelloRequest.FromString,
+          response_serializer=helloworld__pb2.HelloReply.SerializeToString,
+      ),
+  }
+  generic_handler = grpc.method_handlers_generic_handler(
+      'helloworld.Greeter', rpc_method_handlers)
+  server.add_generic_rpc_handlers((generic_handler,))
diff --git a/examples/python/multiplex/multiplex_client.py b/examples/python/multiplex/multiplex_client.py
index 2e8162926b..b2d2021e02 100644
--- a/examples/python/multiplex/multiplex_client.py
+++ b/examples/python/multiplex/multiplex_client.py
@@ -37,7 +37,9 @@ import time
 import grpc
 
 import helloworld_pb2
+import helloworld_pb2_grpc
 import route_guide_pb2
+import route_guide_pb2_grpc
 import route_guide_resources
 
 
@@ -120,8 +122,8 @@ def guide_route_chat(route_guide_stub):
 
 def run():
   channel = grpc.insecure_channel('localhost:50051')
-  greeter_stub = helloworld_pb2.GreeterStub(channel)
-  route_guide_stub = route_guide_pb2.RouteGuideStub(channel)
+  greeter_stub = helloworld_pb2_grpc.GreeterStub(channel)
+  route_guide_stub = route_guide_pb2_grpc.RouteGuideStub(channel)
   greeter_response = greeter_stub.SayHello(
       helloworld_pb2.HelloRequest(name='you'))
   print("Greeter client received: " + greeter_response.message)
diff --git a/examples/python/multiplex/multiplex_server.py b/examples/python/multiplex/multiplex_server.py
index 32a4ee4a49..b8b32e7bf8 100644
--- a/examples/python/multiplex/multiplex_server.py
+++ b/examples/python/multiplex/multiplex_server.py
@@ -36,7 +36,9 @@ import math
 import grpc
 
 import helloworld_pb2
+import helloworld_pb2_grpc
 import route_guide_pb2
+import route_guide_pb2_grpc
 import route_guide_resources
 
 _ONE_DAY_IN_SECONDS = 60 * 60 * 24
@@ -70,13 +72,13 @@ def _get_distance(start, end):
   return R * c;
 
 
-class _GreeterServicer(helloworld_pb2.GreeterServicer):
+class _GreeterServicer(helloworld_pb2_grpc.GreeterServicer):
 
   def SayHello(self, request, context):
     return helloworld_pb2.HelloReply(message='Hello, {}!'.format(request.name))
 
 
-class _RouteGuideServicer(route_guide_pb2.RouteGuideServicer):
+class _RouteGuideServicer(route_guide_pb2_grpc.RouteGuideServicer):
   """Provides methods that implement functionality of route guide server."""
 
   def __init__(self):
@@ -133,8 +135,8 @@ class _RouteGuideServicer(route_guide_pb2.RouteGuideServicer):
 
 def serve():
   server = grpc.server(futures.ThreadPoolExecutor(max_workers=10))
-  helloworld_pb2.add_GreeterServicer_to_server(_GreeterServicer(), server)
-  route_guide_pb2.add_RouteGuideServicer_to_server(
+  helloworld_pb2_grpc.add_GreeterServicer_to_server(_GreeterServicer(), server)
+  route_guide_pb2_grpc.add_RouteGuideServicer_to_server(
       _RouteGuideServicer(), server)
   server.add_insecure_port('[::]:50051')
   server.start()
diff --git a/examples/python/multiplex/route_guide_pb2.py b/examples/python/multiplex/route_guide_pb2.py
index 924e186e06..e6775eb814 100644
--- a/examples/python/multiplex/route_guide_pb2.py
+++ b/examples/python/multiplex/route_guide_pb2.py
@@ -277,240 +277,265 @@ _sym_db.RegisterMessage(RouteSummary)
 
 DESCRIPTOR.has_options = True
 DESCRIPTOR._options = _descriptor._ParseOptions(descriptor_pb2.FileOptions(), _b('\n\033io.grpc.examples.routeguideB\017RouteGuideProtoP\001\242\002\003RTG'))
-import grpc
-from grpc.beta import implementations as beta_implementations
-from grpc.beta import interfaces as beta_interfaces
-from grpc.framework.common import cardinality
-from grpc.framework.interfaces.face import utilities as face_utilities
-
-
-class RouteGuideStub(object):
-  """Interface exported by the server.
-  """
-
-  def __init__(self, channel):
-    """Constructor.
-
-    Args:
-      channel: A grpc.Channel.
+try:
+  # THESE ELEMENTS WILL BE DEPRECATED.
+  # Please use the generated *_pb2_grpc.py files instead.
+  import grpc
+  from grpc.framework.common import cardinality
+  from grpc.framework.interfaces.face import utilities as face_utilities
+  from grpc.beta import implementations as beta_implementations
+  from grpc.beta import interfaces as beta_interfaces
+
+
+  class RouteGuideStub(object):
+    """Interface exported by the server.
     """
-    self.GetFeature = channel.unary_unary(
-        '/routeguide.RouteGuide/GetFeature',
-        request_serializer=Point.SerializeToString,
-        response_deserializer=Feature.FromString,
-        )
-    self.ListFeatures = channel.unary_stream(
-        '/routeguide.RouteGuide/ListFeatures',
-        request_serializer=Rectangle.SerializeToString,
-        response_deserializer=Feature.FromString,
-        )
-    self.RecordRoute = channel.stream_unary(
-        '/routeguide.RouteGuide/RecordRoute',
-        request_serializer=Point.SerializeToString,
-        response_deserializer=RouteSummary.FromString,
-        )
-    self.RouteChat = channel.stream_stream(
-        '/routeguide.RouteGuide/RouteChat',
-        request_serializer=RouteNote.SerializeToString,
-        response_deserializer=RouteNote.FromString,
-        )
-
-
-class RouteGuideServicer(object):
-  """Interface exported by the server.
-  """
-
-  def GetFeature(self, request, context):
-    """A simple RPC.
-
-    Obtains the feature at a given position.
-
-    A feature with an empty name is returned if there's no feature at the given
-    position.
-    """
-    context.set_code(grpc.StatusCode.UNIMPLEMENTED)
-    context.set_details('Method not implemented!')
-    raise NotImplementedError('Method not implemented!')
-
-  def ListFeatures(self, request, context):
-    """A server-to-client streaming RPC.
 
-    Obtains the Features available within the given Rectangle.  Results are
-    streamed rather than returned at once (e.g. in a response message with a
-    repeated field), as the rectangle may cover a large area and contain a
-    huge number of features.
+    def __init__(self, channel):
+      """Constructor.
+
+      Args:
+        channel: A grpc.Channel.
+      """
+      self.GetFeature = channel.unary_unary(
+          '/routeguide.RouteGuide/GetFeature',
+          request_serializer=Point.SerializeToString,
+          response_deserializer=Feature.FromString,
+          )
+      self.ListFeatures = channel.unary_stream(
+          '/routeguide.RouteGuide/ListFeatures',
+          request_serializer=Rectangle.SerializeToString,
+          response_deserializer=Feature.FromString,
+          )
+      self.RecordRoute = channel.stream_unary(
+          '/routeguide.RouteGuide/RecordRoute',
+          request_serializer=Point.SerializeToString,
+          response_deserializer=RouteSummary.FromString,
+          )
+      self.RouteChat = channel.stream_stream(
+          '/routeguide.RouteGuide/RouteChat',
+          request_serializer=RouteNote.SerializeToString,
+          response_deserializer=RouteNote.FromString,
+          )
+
+
+  class RouteGuideServicer(object):
+    """Interface exported by the server.
     """
-    context.set_code(grpc.StatusCode.UNIMPLEMENTED)
-    context.set_details('Method not implemented!')
-    raise NotImplementedError('Method not implemented!')
-
-  def RecordRoute(self, request_iterator, context):
-    """A client-to-server streaming RPC.
 
-    Accepts a stream of Points on a route being traversed, returning a
-    RouteSummary when traversal is completed.
+    def GetFeature(self, request, context):
+      """A simple RPC.
+
+      Obtains the feature at a given position.
+
+      A feature with an empty name is returned if there's no feature at the given
+      position.
+      """
+      context.set_code(grpc.StatusCode.UNIMPLEMENTED)
+      context.set_details('Method not implemented!')
+      raise NotImplementedError('Method not implemented!')
+
+    def ListFeatures(self, request, context):
+      """A server-to-client streaming RPC.
+
+      Obtains the Features available within the given Rectangle.  Results are
+      streamed rather than returned at once (e.g. in a response message with a
+      repeated field), as the rectangle may cover a large area and contain a
+      huge number of features.
+      """
+      context.set_code(grpc.StatusCode.UNIMPLEMENTED)
+      context.set_details('Method not implemented!')
+      raise NotImplementedError('Method not implemented!')
+
+    def RecordRoute(self, request_iterator, context):
+      """A client-to-server streaming RPC.
+
+      Accepts a stream of Points on a route being traversed, returning a
+      RouteSummary when traversal is completed.
+      """
+      context.set_code(grpc.StatusCode.UNIMPLEMENTED)
+      context.set_details('Method not implemented!')
+      raise NotImplementedError('Method not implemented!')
+
+    def RouteChat(self, request_iterator, context):
+      """A Bidirectional streaming RPC.
+
+      Accepts a stream of RouteNotes sent while a route is being traversed,
+      while receiving other RouteNotes (e.g. from other users).
+      """
+      context.set_code(grpc.StatusCode.UNIMPLEMENTED)
+      context.set_details('Method not implemented!')
+      raise NotImplementedError('Method not implemented!')
+
+
+  def add_RouteGuideServicer_to_server(servicer, server):
+    rpc_method_handlers = {
+        'GetFeature': grpc.unary_unary_rpc_method_handler(
+            servicer.GetFeature,
+            request_deserializer=Point.FromString,
+            response_serializer=Feature.SerializeToString,
+        ),
+        'ListFeatures': grpc.unary_stream_rpc_method_handler(
+            servicer.ListFeatures,
+            request_deserializer=Rectangle.FromString,
+            response_serializer=Feature.SerializeToString,
+        ),
+        'RecordRoute': grpc.stream_unary_rpc_method_handler(
+            servicer.RecordRoute,
+            request_deserializer=Point.FromString,
+            response_serializer=RouteSummary.SerializeToString,
+        ),
+        'RouteChat': grpc.stream_stream_rpc_method_handler(
+            servicer.RouteChat,
+            request_deserializer=RouteNote.FromString,
+            response_serializer=RouteNote.SerializeToString,
+        ),
+    }
+    generic_handler = grpc.method_handlers_generic_handler(
+        'routeguide.RouteGuide', rpc_method_handlers)
+    server.add_generic_rpc_handlers((generic_handler,))
+
+
+  class BetaRouteGuideServicer(object):
+    """The Beta API is deprecated for 0.15.0 and later.
+
+    It is recommended to use the GA API (classes and functions in this
+    file not marked beta) for all further purposes. This class was generated
+    only to ease transition from grpcio<0.15.0 to grpcio>=0.15.0."""
+    """Interface exported by the server.
     """
-    context.set_code(grpc.StatusCode.UNIMPLEMENTED)
-    context.set_details('Method not implemented!')
-    raise NotImplementedError('Method not implemented!')
-
-  def RouteChat(self, request_iterator, context):
-    """A Bidirectional streaming RPC.
-
-    Accepts a stream of RouteNotes sent while a route is being traversed,
-    while receiving other RouteNotes (e.g. from other users).
-    """
-    context.set_code(grpc.StatusCode.UNIMPLEMENTED)
-    context.set_details('Method not implemented!')
-    raise NotImplementedError('Method not implemented!')
-
-
-def add_RouteGuideServicer_to_server(servicer, server):
-  rpc_method_handlers = {
-      'GetFeature': grpc.unary_unary_rpc_method_handler(
-          servicer.GetFeature,
-          request_deserializer=Point.FromString,
-          response_serializer=Feature.SerializeToString,
-      ),
-      'ListFeatures': grpc.unary_stream_rpc_method_handler(
-          servicer.ListFeatures,
-          request_deserializer=Rectangle.FromString,
-          response_serializer=Feature.SerializeToString,
-      ),
-      'RecordRoute': grpc.stream_unary_rpc_method_handler(
-          servicer.RecordRoute,
-          request_deserializer=Point.FromString,
-          response_serializer=RouteSummary.SerializeToString,
-      ),
-      'RouteChat': grpc.stream_stream_rpc_method_handler(
-          servicer.RouteChat,
-          request_deserializer=RouteNote.FromString,
-          response_serializer=RouteNote.SerializeToString,
-      ),
-  }
-  generic_handler = grpc.method_handlers_generic_handler(
-      'routeguide.RouteGuide', rpc_method_handlers)
-  server.add_generic_rpc_handlers((generic_handler,))
-
-
-class BetaRouteGuideServicer(object):
-  """Interface exported by the server.
-  """
-  def GetFeature(self, request, context):
-    """A simple RPC.
-
-    Obtains the feature at a given position.
-
-    A feature with an empty name is returned if there's no feature at the given
-    position.
-    """
-    context.code(beta_interfaces.StatusCode.UNIMPLEMENTED)
-  def ListFeatures(self, request, context):
-    """A server-to-client streaming RPC.
-
-    Obtains the Features available within the given Rectangle.  Results are
-    streamed rather than returned at once (e.g. in a response message with a
-    repeated field), as the rectangle may cover a large area and contain a
-    huge number of features.
-    """
-    context.code(beta_interfaces.StatusCode.UNIMPLEMENTED)
-  def RecordRoute(self, request_iterator, context):
-    """A client-to-server streaming RPC.
-
-    Accepts a stream of Points on a route being traversed, returning a
-    RouteSummary when traversal is completed.
-    """
-    context.code(beta_interfaces.StatusCode.UNIMPLEMENTED)
-  def RouteChat(self, request_iterator, context):
-    """A Bidirectional streaming RPC.
-
-    Accepts a stream of RouteNotes sent while a route is being traversed,
-    while receiving other RouteNotes (e.g. from other users).
-    """
-    context.code(beta_interfaces.StatusCode.UNIMPLEMENTED)
-
-
-class BetaRouteGuideStub(object):
-  """Interface exported by the server.
-  """
-  def GetFeature(self, request, timeout, metadata=None, with_call=False, protocol_options=None):
-    """A simple RPC.
-
-    Obtains the feature at a given position.
-
-    A feature with an empty name is returned if there's no feature at the given
-    position.
-    """
-    raise NotImplementedError()
-  GetFeature.future = None
-  def ListFeatures(self, request, timeout, metadata=None, with_call=False, protocol_options=None):
-    """A server-to-client streaming RPC.
-
-    Obtains the Features available within the given Rectangle.  Results are
-    streamed rather than returned at once (e.g. in a response message with a
-    repeated field), as the rectangle may cover a large area and contain a
-    huge number of features.
-    """
-    raise NotImplementedError()
-  def RecordRoute(self, request_iterator, timeout, metadata=None, with_call=False, protocol_options=None):
-    """A client-to-server streaming RPC.
-
-    Accepts a stream of Points on a route being traversed, returning a
-    RouteSummary when traversal is completed.
-    """
-    raise NotImplementedError()
-  RecordRoute.future = None
-  def RouteChat(self, request_iterator, timeout, metadata=None, with_call=False, protocol_options=None):
-    """A Bidirectional streaming RPC.
-
-    Accepts a stream of RouteNotes sent while a route is being traversed,
-    while receiving other RouteNotes (e.g. from other users).
+    def GetFeature(self, request, context):
+      """A simple RPC.
+
+      Obtains the feature at a given position.
+
+      A feature with an empty name is returned if there's no feature at the given
+      position.
+      """
+      context.code(beta_interfaces.StatusCode.UNIMPLEMENTED)
+    def ListFeatures(self, request, context):
+      """A server-to-client streaming RPC.
+
+      Obtains the Features available within the given Rectangle.  Results are
+      streamed rather than returned at once (e.g. in a response message with a
+      repeated field), as the rectangle may cover a large area and contain a
+      huge number of features.
+      """
+      context.code(beta_interfaces.StatusCode.UNIMPLEMENTED)
+    def RecordRoute(self, request_iterator, context):
+      """A client-to-server streaming RPC.
+
+      Accepts a stream of Points on a route being traversed, returning a
+      RouteSummary when traversal is completed.
+      """
+      context.code(beta_interfaces.StatusCode.UNIMPLEMENTED)
+    def RouteChat(self, request_iterator, context):
+      """A Bidirectional streaming RPC.
+
+      Accepts a stream of RouteNotes sent while a route is being traversed,
+      while receiving other RouteNotes (e.g. from other users).
+      """
+      context.code(beta_interfaces.StatusCode.UNIMPLEMENTED)
+
+
+  class BetaRouteGuideStub(object):
+    """The Beta API is deprecated for 0.15.0 and later.
+
+    It is recommended to use the GA API (classes and functions in this
+    file not marked beta) for all further purposes. This class was generated
+    only to ease transition from grpcio<0.15.0 to grpcio>=0.15.0."""
+    """Interface exported by the server.
     """
-    raise NotImplementedError()
-
-
-def beta_create_RouteGuide_server(servicer, pool=None, pool_size=None, default_timeout=None, maximum_timeout=None):
-  request_deserializers = {
-    ('routeguide.RouteGuide', 'GetFeature'): Point.FromString,
-    ('routeguide.RouteGuide', 'ListFeatures'): Rectangle.FromString,
-    ('routeguide.RouteGuide', 'RecordRoute'): Point.FromString,
-    ('routeguide.RouteGuide', 'RouteChat'): RouteNote.FromString,
-  }
-  response_serializers = {
-    ('routeguide.RouteGuide', 'GetFeature'): Feature.SerializeToString,
-    ('routeguide.RouteGuide', 'ListFeatures'): Feature.SerializeToString,
-    ('routeguide.RouteGuide', 'RecordRoute'): RouteSummary.SerializeToString,
-    ('routeguide.RouteGuide', 'RouteChat'): RouteNote.SerializeToString,
-  }
-  method_implementations = {
-    ('routeguide.RouteGuide', 'GetFeature'): face_utilities.unary_unary_inline(servicer.GetFeature),
-    ('routeguide.RouteGuide', 'ListFeatures'): face_utilities.unary_stream_inline(servicer.ListFeatures),
-    ('routeguide.RouteGuide', 'RecordRoute'): face_utilities.stream_unary_inline(servicer.RecordRoute),
-    ('routeguide.RouteGuide', 'RouteChat'): face_utilities.stream_stream_inline(servicer.RouteChat),
-  }
-  server_options = beta_implementations.server_options(request_deserializers=request_deserializers, response_serializers=response_serializers, thread_pool=pool, thread_pool_size=pool_size, default_timeout=default_timeout, maximum_timeout=maximum_timeout)
-  return beta_implementations.server(method_implementations, options=server_options)
-
-
-def beta_create_RouteGuide_stub(channel, host=None, metadata_transformer=None, pool=None, pool_size=None):
-  request_serializers = {
-    ('routeguide.RouteGuide', 'GetFeature'): Point.SerializeToString,
-    ('routeguide.RouteGuide', 'ListFeatures'): Rectangle.SerializeToString,
-    ('routeguide.RouteGuide', 'RecordRoute'): Point.SerializeToString,
-    ('routeguide.RouteGuide', 'RouteChat'): RouteNote.SerializeToString,
-  }
-  response_deserializers = {
-    ('routeguide.RouteGuide', 'GetFeature'): Feature.FromString,
-    ('routeguide.RouteGuide', 'ListFeatures'): Feature.FromString,
-    ('routeguide.RouteGuide', 'RecordRoute'): RouteSummary.FromString,
-    ('routeguide.RouteGuide', 'RouteChat'): RouteNote.FromString,
-  }
-  cardinalities = {
-    'GetFeature': cardinality.Cardinality.UNARY_UNARY,
-    'ListFeatures': cardinality.Cardinality.UNARY_STREAM,
-    'RecordRoute': cardinality.Cardinality.STREAM_UNARY,
-    'RouteChat': cardinality.Cardinality.STREAM_STREAM,
-  }
-  stub_options = beta_implementations.stub_options(host=host, metadata_transformer=metadata_transformer, request_serializers=request_serializers, response_deserializers=response_deserializers, thread_pool=pool, thread_pool_size=pool_size)
-  return beta_implementations.dynamic_stub(channel, 'routeguide.RouteGuide', cardinalities, options=stub_options)
+    def GetFeature(self, request, timeout, metadata=None, with_call=False, protocol_options=None):
+      """A simple RPC.
+
+      Obtains the feature at a given position.
+
+      A feature with an empty name is returned if there's no feature at the given
+      position.
+      """
+      raise NotImplementedError()
+    GetFeature.future = None
+    def ListFeatures(self, request, timeout, metadata=None, with_call=False, protocol_options=None):
+      """A server-to-client streaming RPC.
+
+      Obtains the Features available within the given Rectangle.  Results are
+      streamed rather than returned at once (e.g. in a response message with a
+      repeated field), as the rectangle may cover a large area and contain a
+      huge number of features.
+      """
+      raise NotImplementedError()
+    def RecordRoute(self, request_iterator, timeout, metadata=None, with_call=False, protocol_options=None):
+      """A client-to-server streaming RPC.
+
+      Accepts a stream of Points on a route being traversed, returning a
+      RouteSummary when traversal is completed.
+      """
+      raise NotImplementedError()
+    RecordRoute.future = None
+    def RouteChat(self, request_iterator, timeout, metadata=None, with_call=False, protocol_options=None):
+      """A Bidirectional streaming RPC.
+
+      Accepts a stream of RouteNotes sent while a route is being traversed,
+      while receiving other RouteNotes (e.g. from other users).
+      """
+      raise NotImplementedError()
+
+
+  def beta_create_RouteGuide_server(servicer, pool=None, pool_size=None, default_timeout=None, maximum_timeout=None):
+    """The Beta API is deprecated for 0.15.0 and later.
+
+    It is recommended to use the GA API (classes and functions in this
+    file not marked beta) for all further purposes. This function was
+    generated only to ease transition from grpcio<0.15.0 to grpcio>=0.15.0"""
+    request_deserializers = {
+      ('routeguide.RouteGuide', 'GetFeature'): Point.FromString,
+      ('routeguide.RouteGuide', 'ListFeatures'): Rectangle.FromString,
+      ('routeguide.RouteGuide', 'RecordRoute'): Point.FromString,
+      ('routeguide.RouteGuide', 'RouteChat'): RouteNote.FromString,
+    }
+    response_serializers = {
+      ('routeguide.RouteGuide', 'GetFeature'): Feature.SerializeToString,
+      ('routeguide.RouteGuide', 'ListFeatures'): Feature.SerializeToString,
+      ('routeguide.RouteGuide', 'RecordRoute'): RouteSummary.SerializeToString,
+      ('routeguide.RouteGuide', 'RouteChat'): RouteNote.SerializeToString,
+    }
+    method_implementations = {
+      ('routeguide.RouteGuide', 'GetFeature'): face_utilities.unary_unary_inline(servicer.GetFeature),
+      ('routeguide.RouteGuide', 'ListFeatures'): face_utilities.unary_stream_inline(servicer.ListFeatures),
+      ('routeguide.RouteGuide', 'RecordRoute'): face_utilities.stream_unary_inline(servicer.RecordRoute),
+      ('routeguide.RouteGuide', 'RouteChat'): face_utilities.stream_stream_inline(servicer.RouteChat),
+    }
+    server_options = beta_implementations.server_options(request_deserializers=request_deserializers, response_serializers=response_serializers, thread_pool=pool, thread_pool_size=pool_size, default_timeout=default_timeout, maximum_timeout=maximum_timeout)
+    return beta_implementations.server(method_implementations, options=server_options)
+
+
+  def beta_create_RouteGuide_stub(channel, host=None, metadata_transformer=None, pool=None, pool_size=None):
+    """The Beta API is deprecated for 0.15.0 and later.
+
+    It is recommended to use the GA API (classes and functions in this
+    file not marked beta) for all further purposes. This function was
+    generated only to ease transition from grpcio<0.15.0 to grpcio>=0.15.0"""
+    request_serializers = {
+      ('routeguide.RouteGuide', 'GetFeature'): Point.SerializeToString,
+      ('routeguide.RouteGuide', 'ListFeatures'): Rectangle.SerializeToString,
+      ('routeguide.RouteGuide', 'RecordRoute'): Point.SerializeToString,
+      ('routeguide.RouteGuide', 'RouteChat'): RouteNote.SerializeToString,
+    }
+    response_deserializers = {
+      ('routeguide.RouteGuide', 'GetFeature'): Feature.FromString,
+      ('routeguide.RouteGuide', 'ListFeatures'): Feature.FromString,
+      ('routeguide.RouteGuide', 'RecordRoute'): RouteSummary.FromString,
+      ('routeguide.RouteGuide', 'RouteChat'): RouteNote.FromString,
+    }
+    cardinalities = {
+      'GetFeature': cardinality.Cardinality.UNARY_UNARY,
+      'ListFeatures': cardinality.Cardinality.UNARY_STREAM,
+      'RecordRoute': cardinality.Cardinality.STREAM_UNARY,
+      'RouteChat': cardinality.Cardinality.STREAM_STREAM,
+    }
+    stub_options = beta_implementations.stub_options(host=host, metadata_transformer=metadata_transformer, request_serializers=request_serializers, response_deserializers=response_deserializers, thread_pool=pool, thread_pool_size=pool_size)
+    return beta_implementations.dynamic_stub(channel, 'routeguide.RouteGuide', cardinalities, options=stub_options)
+except ImportError:
+  pass
 # @@protoc_insertion_point(module_scope)
diff --git a/examples/python/multiplex/route_guide_pb2_grpc.py b/examples/python/multiplex/route_guide_pb2_grpc.py
new file mode 100644
index 0000000000..27b24c747d
--- /dev/null
+++ b/examples/python/multiplex/route_guide_pb2_grpc.py
@@ -0,0 +1,114 @@
+import grpc
+from grpc.framework.common import cardinality
+from grpc.framework.interfaces.face import utilities as face_utilities
+
+import route_guide_pb2 as route__guide__pb2
+
+
+class RouteGuideStub(object):
+  """Interface exported by the server.
+  """
+
+  def __init__(self, channel):
+    """Constructor.
+
+    Args:
+      channel: A grpc.Channel.
+    """
+    self.GetFeature = channel.unary_unary(
+        '/routeguide.RouteGuide/GetFeature',
+        request_serializer=route__guide__pb2.Point.SerializeToString,
+        response_deserializer=route__guide__pb2.Feature.FromString,
+        )
+    self.ListFeatures = channel.unary_stream(
+        '/routeguide.RouteGuide/ListFeatures',
+        request_serializer=route__guide__pb2.Rectangle.SerializeToString,
+        response_deserializer=route__guide__pb2.Feature.FromString,
+        )
+    self.RecordRoute = channel.stream_unary(
+        '/routeguide.RouteGuide/RecordRoute',
+        request_serializer=route__guide__pb2.Point.SerializeToString,
+        response_deserializer=route__guide__pb2.RouteSummary.FromString,
+        )
+    self.RouteChat = channel.stream_stream(
+        '/routeguide.RouteGuide/RouteChat',
+        request_serializer=route__guide__pb2.RouteNote.SerializeToString,
+        response_deserializer=route__guide__pb2.RouteNote.FromString,
+        )
+
+
+class RouteGuideServicer(object):
+  """Interface exported by the server.
+  """
+
+  def GetFeature(self, request, context):
+    """A simple RPC.
+
+    Obtains the feature at a given position.
+
+    A feature with an empty name is returned if there's no feature at the given
+    position.
+    """
+    context.set_code(grpc.StatusCode.UNIMPLEMENTED)
+    context.set_details('Method not implemented!')
+    raise NotImplementedError('Method not implemented!')
+
+  def ListFeatures(self, request, context):
+    """A server-to-client streaming RPC.
+
+    Obtains the Features available within the given Rectangle.  Results are
+    streamed rather than returned at once (e.g. in a response message with a
+    repeated field), as the rectangle may cover a large area and contain a
+    huge number of features.
+    """
+    context.set_code(grpc.StatusCode.UNIMPLEMENTED)
+    context.set_details('Method not implemented!')
+    raise NotImplementedError('Method not implemented!')
+
+  def RecordRoute(self, request_iterator, context):
+    """A client-to-server streaming RPC.
+
+    Accepts a stream of Points on a route being traversed, returning a
+    RouteSummary when traversal is completed.
+    """
+    context.set_code(grpc.StatusCode.UNIMPLEMENTED)
+    context.set_details('Method not implemented!')
+    raise NotImplementedError('Method not implemented!')
+
+  def RouteChat(self, request_iterator, context):
+    """A Bidirectional streaming RPC.
+
+    Accepts a stream of RouteNotes sent while a route is being traversed,
+    while receiving other RouteNotes (e.g. from other users).
+    """
+    context.set_code(grpc.StatusCode.UNIMPLEMENTED)
+    context.set_details('Method not implemented!')
+    raise NotImplementedError('Method not implemented!')
+
+
+def add_RouteGuideServicer_to_server(servicer, server):
+  rpc_method_handlers = {
+      'GetFeature': grpc.unary_unary_rpc_method_handler(
+          servicer.GetFeature,
+          request_deserializer=route__guide__pb2.Point.FromString,
+          response_serializer=route__guide__pb2.Feature.SerializeToString,
+      ),
+      'ListFeatures': grpc.unary_stream_rpc_method_handler(
+          servicer.ListFeatures,
+          request_deserializer=route__guide__pb2.Rectangle.FromString,
+          response_serializer=route__guide__pb2.Feature.SerializeToString,
+      ),
+      'RecordRoute': grpc.stream_unary_rpc_method_handler(
+          servicer.RecordRoute,
+          request_deserializer=route__guide__pb2.Point.FromString,
+          response_serializer=route__guide__pb2.RouteSummary.SerializeToString,
+      ),
+      'RouteChat': grpc.stream_stream_rpc_method_handler(
+          servicer.RouteChat,
+          request_deserializer=route__guide__pb2.RouteNote.FromString,
+          response_serializer=route__guide__pb2.RouteNote.SerializeToString,
+      ),
+  }
+  generic_handler = grpc.method_handlers_generic_handler(
+      'routeguide.RouteGuide', rpc_method_handlers)
+  server.add_generic_rpc_handlers((generic_handler,))
diff --git a/examples/python/multiplex/run_codegen.py b/examples/python/multiplex/run_codegen.py
index 89ac9c8fae..89ac9c8fae 100755..100644
--- a/examples/python/multiplex/run_codegen.py
+++ b/examples/python/multiplex/run_codegen.py
diff --git a/examples/python/route_guide/route_guide_client.py b/examples/python/route_guide/route_guide_client.py
index 8a80ed892d..d2955231c3 100644
--- a/examples/python/route_guide/route_guide_client.py
+++ b/examples/python/route_guide/route_guide_client.py
@@ -37,6 +37,7 @@ import time
 import grpc
 
 import route_guide_pb2
+import route_guide_pb2_grpc
 import route_guide_resources
 
 
@@ -116,7 +117,7 @@ def guide_route_chat(stub):
 
 def run():
   channel = grpc.insecure_channel('localhost:50051')
-  stub = route_guide_pb2.RouteGuideStub(channel)
+  stub = route_guide_pb2_grpc.RouteGuideStub(channel)
   print("-------------- GetFeature --------------")
   guide_get_feature(stub)
   print("-------------- ListFeatures --------------")
diff --git a/examples/python/route_guide/route_guide_pb2.py b/examples/python/route_guide/route_guide_pb2.py
index 924e186e06..e6775eb814 100644
--- a/examples/python/route_guide/route_guide_pb2.py
+++ b/examples/python/route_guide/route_guide_pb2.py
@@ -277,240 +277,265 @@ _sym_db.RegisterMessage(RouteSummary)
 
 DESCRIPTOR.has_options = True
 DESCRIPTOR._options = _descriptor._ParseOptions(descriptor_pb2.FileOptions(), _b('\n\033io.grpc.examples.routeguideB\017RouteGuideProtoP\001\242\002\003RTG'))
-import grpc
-from grpc.beta import implementations as beta_implementations
-from grpc.beta import interfaces as beta_interfaces
-from grpc.framework.common import cardinality
-from grpc.framework.interfaces.face import utilities as face_utilities
-
-
-class RouteGuideStub(object):
-  """Interface exported by the server.
-  """
-
-  def __init__(self, channel):
-    """Constructor.
-
-    Args:
-      channel: A grpc.Channel.
+try:
+  # THESE ELEMENTS WILL BE DEPRECATED.
+  # Please use the generated *_pb2_grpc.py files instead.
+  import grpc
+  from grpc.framework.common import cardinality
+  from grpc.framework.interfaces.face import utilities as face_utilities
+  from grpc.beta import implementations as beta_implementations
+  from grpc.beta import interfaces as beta_interfaces
+
+
+  class RouteGuideStub(object):
+    """Interface exported by the server.
     """
-    self.GetFeature = channel.unary_unary(
-        '/routeguide.RouteGuide/GetFeature',
-        request_serializer=Point.SerializeToString,
-        response_deserializer=Feature.FromString,
-        )
-    self.ListFeatures = channel.unary_stream(
-        '/routeguide.RouteGuide/ListFeatures',
-        request_serializer=Rectangle.SerializeToString,
-        response_deserializer=Feature.FromString,
-        )
-    self.RecordRoute = channel.stream_unary(
-        '/routeguide.RouteGuide/RecordRoute',
-        request_serializer=Point.SerializeToString,
-        response_deserializer=RouteSummary.FromString,
-        )
-    self.RouteChat = channel.stream_stream(
-        '/routeguide.RouteGuide/RouteChat',
-        request_serializer=RouteNote.SerializeToString,
-        response_deserializer=RouteNote.FromString,
-        )
-
-
-class RouteGuideServicer(object):
-  """Interface exported by the server.
-  """
-
-  def GetFeature(self, request, context):
-    """A simple RPC.
-
-    Obtains the feature at a given position.
-
-    A feature with an empty name is returned if there's no feature at the given
-    position.
-    """
-    context.set_code(grpc.StatusCode.UNIMPLEMENTED)
-    context.set_details('Method not implemented!')
-    raise NotImplementedError('Method not implemented!')
-
-  def ListFeatures(self, request, context):
-    """A server-to-client streaming RPC.
 
-    Obtains the Features available within the given Rectangle.  Results are
-    streamed rather than returned at once (e.g. in a response message with a
-    repeated field), as the rectangle may cover a large area and contain a
-    huge number of features.
+    def __init__(self, channel):
+      """Constructor.
+
+      Args:
+        channel: A grpc.Channel.
+      """
+      self.GetFeature = channel.unary_unary(
+          '/routeguide.RouteGuide/GetFeature',
+          request_serializer=Point.SerializeToString,
+          response_deserializer=Feature.FromString,
+          )
+      self.ListFeatures = channel.unary_stream(
+          '/routeguide.RouteGuide/ListFeatures',
+          request_serializer=Rectangle.SerializeToString,
+          response_deserializer=Feature.FromString,
+          )
+      self.RecordRoute = channel.stream_unary(
+          '/routeguide.RouteGuide/RecordRoute',
+          request_serializer=Point.SerializeToString,
+          response_deserializer=RouteSummary.FromString,
+          )
+      self.RouteChat = channel.stream_stream(
+          '/routeguide.RouteGuide/RouteChat',
+          request_serializer=RouteNote.SerializeToString,
+          response_deserializer=RouteNote.FromString,
+          )
+
+
+  class RouteGuideServicer(object):
+    """Interface exported by the server.
     """
-    context.set_code(grpc.StatusCode.UNIMPLEMENTED)
-    context.set_details('Method not implemented!')
-    raise NotImplementedError('Method not implemented!')
-
-  def RecordRoute(self, request_iterator, context):
-    """A client-to-server streaming RPC.
 
-    Accepts a stream of Points on a route being traversed, returning a
-    RouteSummary when traversal is completed.
+    def GetFeature(self, request, context):
+      """A simple RPC.
+
+      Obtains the feature at a given position.
+
+      A feature with an empty name is returned if there's no feature at the given
+      position.
+      """
+      context.set_code(grpc.StatusCode.UNIMPLEMENTED)
+      context.set_details('Method not implemented!')
+      raise NotImplementedError('Method not implemented!')
+
+    def ListFeatures(self, request, context):
+      """A server-to-client streaming RPC.
+
+      Obtains the Features available within the given Rectangle.  Results are
+      streamed rather than returned at once (e.g. in a response message with a
+      repeated field), as the rectangle may cover a large area and contain a
+      huge number of features.
+      """
+      context.set_code(grpc.StatusCode.UNIMPLEMENTED)
+      context.set_details('Method not implemented!')
+      raise NotImplementedError('Method not implemented!')
+
+    def RecordRoute(self, request_iterator, context):
+      """A client-to-server streaming RPC.
+
+      Accepts a stream of Points on a route being traversed, returning a
+      RouteSummary when traversal is completed.
+      """
+      context.set_code(grpc.StatusCode.UNIMPLEMENTED)
+      context.set_details('Method not implemented!')
+      raise NotImplementedError('Method not implemented!')
+
+    def RouteChat(self, request_iterator, context):
+      """A Bidirectional streaming RPC.
+
+      Accepts a stream of RouteNotes sent while a route is being traversed,
+      while receiving other RouteNotes (e.g. from other users).
+      """
+      context.set_code(grpc.StatusCode.UNIMPLEMENTED)
+      context.set_details('Method not implemented!')
+      raise NotImplementedError('Method not implemented!')
+
+
+  def add_RouteGuideServicer_to_server(servicer, server):
+    rpc_method_handlers = {
+        'GetFeature': grpc.unary_unary_rpc_method_handler(
+            servicer.GetFeature,
+            request_deserializer=Point.FromString,
+            response_serializer=Feature.SerializeToString,
+        ),
+        'ListFeatures': grpc.unary_stream_rpc_method_handler(
+            servicer.ListFeatures,
+            request_deserializer=Rectangle.FromString,
+            response_serializer=Feature.SerializeToString,
+        ),
+        'RecordRoute': grpc.stream_unary_rpc_method_handler(
+            servicer.RecordRoute,
+            request_deserializer=Point.FromString,
+            response_serializer=RouteSummary.SerializeToString,
+        ),
+        'RouteChat': grpc.stream_stream_rpc_method_handler(
+            servicer.RouteChat,
+            request_deserializer=RouteNote.FromString,
+            response_serializer=RouteNote.SerializeToString,
+        ),
+    }
+    generic_handler = grpc.method_handlers_generic_handler(
+        'routeguide.RouteGuide', rpc_method_handlers)
+    server.add_generic_rpc_handlers((generic_handler,))
+
+
+  class BetaRouteGuideServicer(object):
+    """The Beta API is deprecated for 0.15.0 and later.
+
+    It is recommended to use the GA API (classes and functions in this
+    file not marked beta) for all further purposes. This class was generated
+    only to ease transition from grpcio<0.15.0 to grpcio>=0.15.0."""
+    """Interface exported by the server.
     """
-    context.set_code(grpc.StatusCode.UNIMPLEMENTED)
-    context.set_details('Method not implemented!')
-    raise NotImplementedError('Method not implemented!')
-
-  def RouteChat(self, request_iterator, context):
-    """A Bidirectional streaming RPC.
-
-    Accepts a stream of RouteNotes sent while a route is being traversed,
-    while receiving other RouteNotes (e.g. from other users).
-    """
-    context.set_code(grpc.StatusCode.UNIMPLEMENTED)
-    context.set_details('Method not implemented!')
-    raise NotImplementedError('Method not implemented!')
-
-
-def add_RouteGuideServicer_to_server(servicer, server):
-  rpc_method_handlers = {
-      'GetFeature': grpc.unary_unary_rpc_method_handler(
-          servicer.GetFeature,
-          request_deserializer=Point.FromString,
-          response_serializer=Feature.SerializeToString,
-      ),
-      'ListFeatures': grpc.unary_stream_rpc_method_handler(
-          servicer.ListFeatures,
-          request_deserializer=Rectangle.FromString,
-          response_serializer=Feature.SerializeToString,
-      ),
-      'RecordRoute': grpc.stream_unary_rpc_method_handler(
-          servicer.RecordRoute,
-          request_deserializer=Point.FromString,
-          response_serializer=RouteSummary.SerializeToString,
-      ),
-      'RouteChat': grpc.stream_stream_rpc_method_handler(
-          servicer.RouteChat,
-          request_deserializer=RouteNote.FromString,
-          response_serializer=RouteNote.SerializeToString,
-      ),
-  }
-  generic_handler = grpc.method_handlers_generic_handler(
-      'routeguide.RouteGuide', rpc_method_handlers)
-  server.add_generic_rpc_handlers((generic_handler,))
-
-
-class BetaRouteGuideServicer(object):
-  """Interface exported by the server.
-  """
-  def GetFeature(self, request, context):
-    """A simple RPC.
-
-    Obtains the feature at a given position.
-
-    A feature with an empty name is returned if there's no feature at the given
-    position.
-    """
-    context.code(beta_interfaces.StatusCode.UNIMPLEMENTED)
-  def ListFeatures(self, request, context):
-    """A server-to-client streaming RPC.
-
-    Obtains the Features available within the given Rectangle.  Results are
-    streamed rather than returned at once (e.g. in a response message with a
-    repeated field), as the rectangle may cover a large area and contain a
-    huge number of features.
-    """
-    context.code(beta_interfaces.StatusCode.UNIMPLEMENTED)
-  def RecordRoute(self, request_iterator, context):
-    """A client-to-server streaming RPC.
-
-    Accepts a stream of Points on a route being traversed, returning a
-    RouteSummary when traversal is completed.
-    """
-    context.code(beta_interfaces.StatusCode.UNIMPLEMENTED)
-  def RouteChat(self, request_iterator, context):
-    """A Bidirectional streaming RPC.
-
-    Accepts a stream of RouteNotes sent while a route is being traversed,
-    while receiving other RouteNotes (e.g. from other users).
-    """
-    context.code(beta_interfaces.StatusCode.UNIMPLEMENTED)
-
-
-class BetaRouteGuideStub(object):
-  """Interface exported by the server.
-  """
-  def GetFeature(self, request, timeout, metadata=None, with_call=False, protocol_options=None):
-    """A simple RPC.
-
-    Obtains the feature at a given position.
-
-    A feature with an empty name is returned if there's no feature at the given
-    position.
-    """
-    raise NotImplementedError()
-  GetFeature.future = None
-  def ListFeatures(self, request, timeout, metadata=None, with_call=False, protocol_options=None):
-    """A server-to-client streaming RPC.
-
-    Obtains the Features available within the given Rectangle.  Results are
-    streamed rather than returned at once (e.g. in a response message with a
-    repeated field), as the rectangle may cover a large area and contain a
-    huge number of features.
-    """
-    raise NotImplementedError()
-  def RecordRoute(self, request_iterator, timeout, metadata=None, with_call=False, protocol_options=None):
-    """A client-to-server streaming RPC.
-
-    Accepts a stream of Points on a route being traversed, returning a
-    RouteSummary when traversal is completed.
-    """
-    raise NotImplementedError()
-  RecordRoute.future = None
-  def RouteChat(self, request_iterator, timeout, metadata=None, with_call=False, protocol_options=None):
-    """A Bidirectional streaming RPC.
-
-    Accepts a stream of RouteNotes sent while a route is being traversed,
-    while receiving other RouteNotes (e.g. from other users).
+    def GetFeature(self, request, context):
+      """A simple RPC.
+
+      Obtains the feature at a given position.
+
+      A feature with an empty name is returned if there's no feature at the given
+      position.
+      """
+      context.code(beta_interfaces.StatusCode.UNIMPLEMENTED)
+    def ListFeatures(self, request, context):
+      """A server-to-client streaming RPC.
+
+      Obtains the Features available within the given Rectangle.  Results are
+      streamed rather than returned at once (e.g. in a response message with a
+      repeated field), as the rectangle may cover a large area and contain a
+      huge number of features.
+      """
+      context.code(beta_interfaces.StatusCode.UNIMPLEMENTED)
+    def RecordRoute(self, request_iterator, context):
+      """A client-to-server streaming RPC.
+
+      Accepts a stream of Points on a route being traversed, returning a
+      RouteSummary when traversal is completed.
+      """
+      context.code(beta_interfaces.StatusCode.UNIMPLEMENTED)
+    def RouteChat(self, request_iterator, context):
+      """A Bidirectional streaming RPC.
+
+      Accepts a stream of RouteNotes sent while a route is being traversed,
+      while receiving other RouteNotes (e.g. from other users).
+      """
+      context.code(beta_interfaces.StatusCode.UNIMPLEMENTED)
+
+
+  class BetaRouteGuideStub(object):
+    """The Beta API is deprecated for 0.15.0 and later.
+
+    It is recommended to use the GA API (classes and functions in this
+    file not marked beta) for all further purposes. This class was generated
+    only to ease transition from grpcio<0.15.0 to grpcio>=0.15.0."""
+    """Interface exported by the server.
     """
-    raise NotImplementedError()
-
-
-def beta_create_RouteGuide_server(servicer, pool=None, pool_size=None, default_timeout=None, maximum_timeout=None):
-  request_deserializers = {
-    ('routeguide.RouteGuide', 'GetFeature'): Point.FromString,
-    ('routeguide.RouteGuide', 'ListFeatures'): Rectangle.FromString,
-    ('routeguide.RouteGuide', 'RecordRoute'): Point.FromString,
-    ('routeguide.RouteGuide', 'RouteChat'): RouteNote.FromString,
-  }
-  response_serializers = {
-    ('routeguide.RouteGuide', 'GetFeature'): Feature.SerializeToString,
-    ('routeguide.RouteGuide', 'ListFeatures'): Feature.SerializeToString,
-    ('routeguide.RouteGuide', 'RecordRoute'): RouteSummary.SerializeToString,
-    ('routeguide.RouteGuide', 'RouteChat'): RouteNote.SerializeToString,
-  }
-  method_implementations = {
-    ('routeguide.RouteGuide', 'GetFeature'): face_utilities.unary_unary_inline(servicer.GetFeature),
-    ('routeguide.RouteGuide', 'ListFeatures'): face_utilities.unary_stream_inline(servicer.ListFeatures),
-    ('routeguide.RouteGuide', 'RecordRoute'): face_utilities.stream_unary_inline(servicer.RecordRoute),
-    ('routeguide.RouteGuide', 'RouteChat'): face_utilities.stream_stream_inline(servicer.RouteChat),
-  }
-  server_options = beta_implementations.server_options(request_deserializers=request_deserializers, response_serializers=response_serializers, thread_pool=pool, thread_pool_size=pool_size, default_timeout=default_timeout, maximum_timeout=maximum_timeout)
-  return beta_implementations.server(method_implementations, options=server_options)
-
-
-def beta_create_RouteGuide_stub(channel, host=None, metadata_transformer=None, pool=None, pool_size=None):
-  request_serializers = {
-    ('routeguide.RouteGuide', 'GetFeature'): Point.SerializeToString,
-    ('routeguide.RouteGuide', 'ListFeatures'): Rectangle.SerializeToString,
-    ('routeguide.RouteGuide', 'RecordRoute'): Point.SerializeToString,
-    ('routeguide.RouteGuide', 'RouteChat'): RouteNote.SerializeToString,
-  }
-  response_deserializers = {
-    ('routeguide.RouteGuide', 'GetFeature'): Feature.FromString,
-    ('routeguide.RouteGuide', 'ListFeatures'): Feature.FromString,
-    ('routeguide.RouteGuide', 'RecordRoute'): RouteSummary.FromString,
-    ('routeguide.RouteGuide', 'RouteChat'): RouteNote.FromString,
-  }
-  cardinalities = {
-    'GetFeature': cardinality.Cardinality.UNARY_UNARY,
-    'ListFeatures': cardinality.Cardinality.UNARY_STREAM,
-    'RecordRoute': cardinality.Cardinality.STREAM_UNARY,
-    'RouteChat': cardinality.Cardinality.STREAM_STREAM,
-  }
-  stub_options = beta_implementations.stub_options(host=host, metadata_transformer=metadata_transformer, request_serializers=request_serializers, response_deserializers=response_deserializers, thread_pool=pool, thread_pool_size=pool_size)
-  return beta_implementations.dynamic_stub(channel, 'routeguide.RouteGuide', cardinalities, options=stub_options)
+    def GetFeature(self, request, timeout, metadata=None, with_call=False, protocol_options=None):
+      """A simple RPC.
+
+      Obtains the feature at a given position.
+
+      A feature with an empty name is returned if there's no feature at the given
+      position.
+      """
+      raise NotImplementedError()
+    GetFeature.future = None
+    def ListFeatures(self, request, timeout, metadata=None, with_call=False, protocol_options=None):
+      """A server-to-client streaming RPC.
+
+      Obtains the Features available within the given Rectangle.  Results are
+      streamed rather than returned at once (e.g. in a response message with a
+      repeated field), as the rectangle may cover a large area and contain a
+      huge number of features.
+      """
+      raise NotImplementedError()
+    def RecordRoute(self, request_iterator, timeout, metadata=None, with_call=False, protocol_options=None):
+      """A client-to-server streaming RPC.
+
+      Accepts a stream of Points on a route being traversed, returning a
+      RouteSummary when traversal is completed.
+      """
+      raise NotImplementedError()
+    RecordRoute.future = None
+    def RouteChat(self, request_iterator, timeout, metadata=None, with_call=False, protocol_options=None):
+      """A Bidirectional streaming RPC.
+
+      Accepts a stream of RouteNotes sent while a route is being traversed,
+      while receiving other RouteNotes (e.g. from other users).
+      """
+      raise NotImplementedError()
+
+
+  def beta_create_RouteGuide_server(servicer, pool=None, pool_size=None, default_timeout=None, maximum_timeout=None):
+    """The Beta API is deprecated for 0.15.0 and later.
+
+    It is recommended to use the GA API (classes and functions in this
+    file not marked beta) for all further purposes. This function was
+    generated only to ease transition from grpcio<0.15.0 to grpcio>=0.15.0"""
+    request_deserializers = {
+      ('routeguide.RouteGuide', 'GetFeature'): Point.FromString,
+      ('routeguide.RouteGuide', 'ListFeatures'): Rectangle.FromString,
+      ('routeguide.RouteGuide', 'RecordRoute'): Point.FromString,
+      ('routeguide.RouteGuide', 'RouteChat'): RouteNote.FromString,
+    }
+    response_serializers = {
+      ('routeguide.RouteGuide', 'GetFeature'): Feature.SerializeToString,
+      ('routeguide.RouteGuide', 'ListFeatures'): Feature.SerializeToString,
+      ('routeguide.RouteGuide', 'RecordRoute'): RouteSummary.SerializeToString,
+      ('routeguide.RouteGuide', 'RouteChat'): RouteNote.SerializeToString,
+    }
+    method_implementations = {
+      ('routeguide.RouteGuide', 'GetFeature'): face_utilities.unary_unary_inline(servicer.GetFeature),
+      ('routeguide.RouteGuide', 'ListFeatures'): face_utilities.unary_stream_inline(servicer.ListFeatures),
+      ('routeguide.RouteGuide', 'RecordRoute'): face_utilities.stream_unary_inline(servicer.RecordRoute),
+      ('routeguide.RouteGuide', 'RouteChat'): face_utilities.stream_stream_inline(servicer.RouteChat),
+    }
+    server_options = beta_implementations.server_options(request_deserializers=request_deserializers, response_serializers=response_serializers, thread_pool=pool, thread_pool_size=pool_size, default_timeout=default_timeout, maximum_timeout=maximum_timeout)
+    return beta_implementations.server(method_implementations, options=server_options)
+
+
+  def beta_create_RouteGuide_stub(channel, host=None, metadata_transformer=None, pool=None, pool_size=None):
+    """The Beta API is deprecated for 0.15.0 and later.
+
+    It is recommended to use the GA API (classes and functions in this
+    file not marked beta) for all further purposes. This function was
+    generated only to ease transition from grpcio<0.15.0 to grpcio>=0.15.0"""
+    request_serializers = {
+      ('routeguide.RouteGuide', 'GetFeature'): Point.SerializeToString,
+      ('routeguide.RouteGuide', 'ListFeatures'): Rectangle.SerializeToString,
+      ('routeguide.RouteGuide', 'RecordRoute'): Point.SerializeToString,
+      ('routeguide.RouteGuide', 'RouteChat'): RouteNote.SerializeToString,
+    }
+    response_deserializers = {
+      ('routeguide.RouteGuide', 'GetFeature'): Feature.FromString,
+      ('routeguide.RouteGuide', 'ListFeatures'): Feature.FromString,
+      ('routeguide.RouteGuide', 'RecordRoute'): RouteSummary.FromString,
+      ('routeguide.RouteGuide', 'RouteChat'): RouteNote.FromString,
+    }
+    cardinalities = {
+      'GetFeature': cardinality.Cardinality.UNARY_UNARY,
+      'ListFeatures': cardinality.Cardinality.UNARY_STREAM,
+      'RecordRoute': cardinality.Cardinality.STREAM_UNARY,
+      'RouteChat': cardinality.Cardinality.STREAM_STREAM,
+    }
+    stub_options = beta_implementations.stub_options(host=host, metadata_transformer=metadata_transformer, request_serializers=request_serializers, response_deserializers=response_deserializers, thread_pool=pool, thread_pool_size=pool_size)
+    return beta_implementations.dynamic_stub(channel, 'routeguide.RouteGuide', cardinalities, options=stub_options)
+except ImportError:
+  pass
 # @@protoc_insertion_point(module_scope)
diff --git a/examples/python/route_guide/route_guide_pb2_grpc.py b/examples/python/route_guide/route_guide_pb2_grpc.py
new file mode 100644
index 0000000000..27b24c747d
--- /dev/null
+++ b/examples/python/route_guide/route_guide_pb2_grpc.py
@@ -0,0 +1,114 @@
+import grpc
+from grpc.framework.common import cardinality
+from grpc.framework.interfaces.face import utilities as face_utilities
+
+import route_guide_pb2 as route__guide__pb2
+
+
+class RouteGuideStub(object):
+  """Interface exported by the server.
+  """
+
+  def __init__(self, channel):
+    """Constructor.
+
+    Args:
+      channel: A grpc.Channel.
+    """
+    self.GetFeature = channel.unary_unary(
+        '/routeguide.RouteGuide/GetFeature',
+        request_serializer=route__guide__pb2.Point.SerializeToString,
+        response_deserializer=route__guide__pb2.Feature.FromString,
+        )
+    self.ListFeatures = channel.unary_stream(
+        '/routeguide.RouteGuide/ListFeatures',
+        request_serializer=route__guide__pb2.Rectangle.SerializeToString,
+        response_deserializer=route__guide__pb2.Feature.FromString,
+        )
+    self.RecordRoute = channel.stream_unary(
+        '/routeguide.RouteGuide/RecordRoute',
+        request_serializer=route__guide__pb2.Point.SerializeToString,
+        response_deserializer=route__guide__pb2.RouteSummary.FromString,
+        )
+    self.RouteChat = channel.stream_stream(
+        '/routeguide.RouteGuide/RouteChat',
+        request_serializer=route__guide__pb2.RouteNote.SerializeToString,
+        response_deserializer=route__guide__pb2.RouteNote.FromString,
+        )
+
+
+class RouteGuideServicer(object):
+  """Interface exported by the server.
+  """
+
+  def GetFeature(self, request, context):
+    """A simple RPC.
+
+    Obtains the feature at a given position.
+
+    A feature with an empty name is returned if there's no feature at the given
+    position.
+    """
+    context.set_code(grpc.StatusCode.UNIMPLEMENTED)
+    context.set_details('Method not implemented!')
+    raise NotImplementedError('Method not implemented!')
+
+  def ListFeatures(self, request, context):
+    """A server-to-client streaming RPC.
+
+    Obtains the Features available within the given Rectangle.  Results are
+    streamed rather than returned at once (e.g. in a response message with a
+    repeated field), as the rectangle may cover a large area and contain a
+    huge number of features.
+    """
+    context.set_code(grpc.StatusCode.UNIMPLEMENTED)
+    context.set_details('Method not implemented!')
+    raise NotImplementedError('Method not implemented!')
+
+  def RecordRoute(self, request_iterator, context):
+    """A client-to-server streaming RPC.
+
+    Accepts a stream of Points on a route being traversed, returning a
+    RouteSummary when traversal is completed.
+    """
+    context.set_code(grpc.StatusCode.UNIMPLEMENTED)
+    context.set_details('Method not implemented!')
+    raise NotImplementedError('Method not implemented!')
+
+  def RouteChat(self, request_iterator, context):
+    """A Bidirectional streaming RPC.
+
+    Accepts a stream of RouteNotes sent while a route is being traversed,
+    while receiving other RouteNotes (e.g. from other users).
+    """
+    context.set_code(grpc.StatusCode.UNIMPLEMENTED)
+    context.set_details('Method not implemented!')
+    raise NotImplementedError('Method not implemented!')
+
+
+def add_RouteGuideServicer_to_server(servicer, server):
+  rpc_method_handlers = {
+      'GetFeature': grpc.unary_unary_rpc_method_handler(
+          servicer.GetFeature,
+          request_deserializer=route__guide__pb2.Point.FromString,
+          response_serializer=route__guide__pb2.Feature.SerializeToString,
+      ),
+      'ListFeatures': grpc.unary_stream_rpc_method_handler(
+          servicer.ListFeatures,
+          request_deserializer=route__guide__pb2.Rectangle.FromString,
+          response_serializer=route__guide__pb2.Feature.SerializeToString,
+      ),
+      'RecordRoute': grpc.stream_unary_rpc_method_handler(
+          servicer.RecordRoute,
+          request_deserializer=route__guide__pb2.Point.FromString,
+          response_serializer=route__guide__pb2.RouteSummary.SerializeToString,
+      ),
+      'RouteChat': grpc.stream_stream_rpc_method_handler(
+          servicer.RouteChat,
+          request_deserializer=route__guide__pb2.RouteNote.FromString,
+          response_serializer=route__guide__pb2.RouteNote.SerializeToString,
+      ),
+  }
+  generic_handler = grpc.method_handlers_generic_handler(
+      'routeguide.RouteGuide', rpc_method_handlers)
+  server.add_generic_rpc_handlers((generic_handler,))
diff --git a/examples/python/route_guide/route_guide_server.py b/examples/python/route_guide/route_guide_server.py
index 3ffe678476..bf49217932 100644
--- a/examples/python/route_guide/route_guide_server.py
+++ b/examples/python/route_guide/route_guide_server.py
@@ -36,6 +36,7 @@ import math
 import grpc
 
 import route_guide_pb2
+import route_guide_pb2_grpc
 import route_guide_resources
 
 _ONE_DAY_IN_SECONDS = 60 * 60 * 24
@@ -68,7 +69,7 @@ def get_distance(start, end):
   R = 6371000; # metres
   return R * c;
 
-class RouteGuideServicer(route_guide_pb2.RouteGuideServicer):
+class RouteGuideServicer(route_guide_pb2_grpc.RouteGuideServicer):
   """Provides methods that implement functionality of route guide server."""
 
   def __init__(self):
@@ -125,7 +126,7 @@ class RouteGuideServicer(route_guide_pb2.RouteGuideServicer):
 
 def serve():
   server = grpc.server(futures.ThreadPoolExecutor(max_workers=10))
-  route_guide_pb2.add_RouteGuideServicer_to_server(
+  route_guide_pb2_grpc.add_RouteGuideServicer_to_server(
       RouteGuideServicer(), server)
   server.add_insecure_port('[::]:50051')
   server.start()
diff --git a/src/compiler/python_generator.cc b/src/compiler/python_generator.cc
index 0fac1b88cd..4841da8da8 100644
--- a/src/compiler/python_generator.cc
+++ b/src/compiler/python_generator.cc
@@ -724,6 +724,9 @@ pair<bool, grpc::string> PrivateGenerator::GetGrpcServices() {
     out = &out_printer;
 
     if (generate_in_pb2_grpc) {
+      out->Print(
+          "# Generated by the gRPC Python protocol compiler plugin. "
+          "DO NOT EDIT!\n");
       if (!PrintPreamble()) {
         return make_pair(false, "");
       }
diff --git a/src/core/lib/security/credentials/jwt/jwt_verifier.c b/src/core/lib/security/credentials/jwt/jwt_verifier.c
index 42bd89dd0a..03097a57c0 100644
--- a/src/core/lib/security/credentials/jwt/jwt_verifier.c
+++ b/src/core/lib/security/credentials/jwt/jwt_verifier.c
@@ -39,6 +39,7 @@
 #include "src/core/lib/http/httpcli.h"
 #include "src/core/lib/iomgr/polling_entity.h"
 #include "src/core/lib/security/util/b64.h"
+#include "src/core/lib/support/string.h"
 #include "src/core/lib/tsi/ssl_types.h"
 
 #include <grpc/support/alloc.h>
@@ -305,6 +306,17 @@ grpc_jwt_verifier_status grpc_jwt_claims_check(const grpc_jwt_claims *claims,
     return GRPC_JWT_VERIFIER_TIME_CONSTRAINT_FAILURE;
   }
 
+  /* This should be probably up to the upper layer to decide but let's harcode
+     the 99% use case here for email issuers, where the JWT must be self
+     issued. */
+  if (grpc_jwt_issuer_email_domain(claims->iss) != NULL &&
+      claims->sub != NULL && strcmp(claims->iss, claims->sub) != 0) {
+    gpr_log(GPR_ERROR,
+            "Email issuer (%s) cannot assert another subject (%s) than itself.",
+            claims->iss, claims->sub);
+    return GRPC_JWT_VERIFIER_BAD_SUBJECT;
+  }
+
   if (audience == NULL) {
     audience_ok = claims->aud == NULL;
   } else {
@@ -705,10 +717,26 @@ static void verifier_put_mapping(grpc_jwt_verifier *v, const char *email_domain,
   GPR_ASSERT(v->num_mappings <= v->allocated_mappings);
 }
 
+/* Very non-sophisticated way to detect an email address. Should be good
+   enough for now... */
+const char *grpc_jwt_issuer_email_domain(const char *issuer) {
+  const char *at_sign = strchr(issuer, '@');
+  if (at_sign == NULL) return NULL;
+  const char *email_domain = at_sign + 1;
+  if (*email_domain == '\0') return NULL;
+  const char *dot = strrchr(email_domain, '.');
+  if (dot == NULL || dot == email_domain) return email_domain;
+  GPR_ASSERT(dot > email_domain);
+  /* There may be a subdomain, we just want the domain. */
+  dot = gpr_memrchr(email_domain, '.', (size_t)(dot - email_domain));
+  if (dot == NULL) return email_domain;
+  return dot + 1;
+}
+
 /* Takes ownership of ctx. */
 static void retrieve_key_and_verify(grpc_exec_ctx *exec_ctx,
                                     verifier_cb_ctx *ctx) {
-  const char *at_sign;
+  const char *email_domain;
   grpc_closure *http_cb;
   char *path_prefix = NULL;
   const char *iss;
@@ -733,13 +761,9 @@ static void retrieve_key_and_verify(grpc_exec_ctx *exec_ctx,
      Nobody seems to implement the account/email/webfinger part 2. of the spec
      so we will rely instead on email/url mappings if we detect such an issuer.
      Part 4, on the other hand is implemented by both google and salesforce. */
-
-  /* Very non-sophisticated way to detect an email address. Should be good
-     enough for now... */
-  at_sign = strchr(iss, '@');
-  if (at_sign != NULL) {
+  email_domain = grpc_jwt_issuer_email_domain(iss);
+  if (email_domain != NULL) {
     email_key_mapping *mapping;
-    const char *email_domain = at_sign + 1;
     GPR_ASSERT(ctx->verifier != NULL);
     mapping = verifier_get_mapping(ctx->verifier, email_domain);
     if (mapping == NULL) {
diff --git a/src/core/lib/security/credentials/jwt/jwt_verifier.h b/src/core/lib/security/credentials/jwt/jwt_verifier.h
index f09f9d5d47..54ff9b05e5 100644
--- a/src/core/lib/security/credentials/jwt/jwt_verifier.h
+++ b/src/core/lib/security/credentials/jwt/jwt_verifier.h
@@ -43,8 +43,7 @@
 /* --- Constants. --- */
 
 #define GRPC_OPENID_CONFIG_URL_SUFFIX "/.well-known/openid-configuration"
-#define GRPC_GOOGLE_SERVICE_ACCOUNTS_EMAIL_DOMAIN \
-  "developer.gserviceaccount.com"
+#define GRPC_GOOGLE_SERVICE_ACCOUNTS_EMAIL_DOMAIN "gserviceaccount.com"
 #define GRPC_GOOGLE_SERVICE_ACCOUNTS_KEY_URL_PREFIX \
   "www.googleapis.com/robot/v1/metadata/x509"
 
@@ -57,6 +56,7 @@ typedef enum {
   GRPC_JWT_VERIFIER_BAD_AUDIENCE,
   GRPC_JWT_VERIFIER_KEY_RETRIEVAL_ERROR,
   GRPC_JWT_VERIFIER_TIME_CONSTRAINT_FAILURE,
+  GRPC_JWT_VERIFIER_BAD_SUBJECT,
   GRPC_JWT_VERIFIER_GENERIC_ERROR
 } grpc_jwt_verifier_status;
 
@@ -132,5 +132,6 @@ void grpc_jwt_verifier_verify(grpc_exec_ctx *exec_ctx,
 grpc_jwt_claims *grpc_jwt_claims_from_json(grpc_json *json, grpc_slice buffer);
 grpc_jwt_verifier_status grpc_jwt_claims_check(const grpc_jwt_claims *claims,
                                                const char *audience);
+const char *grpc_jwt_issuer_email_domain(const char *issuer);
 
 #endif /* GRPC_CORE_LIB_SECURITY_CREDENTIALS_JWT_JWT_VERIFIER_H */
diff --git a/src/core/lib/support/string.c b/src/core/lib/support/string.c
index f10a30f0fd..426fce28f8 100644
--- a/src/core/lib/support/string.c
+++ b/src/core/lib/support/string.c
@@ -275,3 +275,15 @@ int gpr_stricmp(const char *a, const char *b) {
   } while (ca == cb && ca && cb);
   return ca - cb;
 }
+
+void *gpr_memrchr(const void *s, int c, size_t n) {
+  if (s == NULL) return NULL;
+  char *b = (char *)s;
+  size_t i;
+  for (i = 0; i < n; i++) {
+    if (b[n - i - 1] == c) {
+      return &b[n - i - 1];
+    }
+  }
+  return NULL;
+}
diff --git a/src/core/lib/support/string.h b/src/core/lib/support/string.h
index e933e2eb46..6d1f7cc632 100644
--- a/src/core/lib/support/string.h
+++ b/src/core/lib/support/string.h
@@ -118,6 +118,8 @@ char *gpr_strvec_flatten(gpr_strvec *strs, size_t *total_length);
     lower(a)==lower(b), >0 if lower(a)>lower(b) */
 int gpr_stricmp(const char *a, const char *b);
 
+void *gpr_memrchr(const void *s, int c, size_t n);
+
 #ifdef __cplusplus
 }
 #endif
diff --git a/src/core/lib/surface/validate_metadata.c b/src/core/lib/surface/validate_metadata.c
index 84f0a083bc..f49dd8584b 100644
--- a/src/core/lib/surface/validate_metadata.c
+++ b/src/core/lib/surface/validate_metadata.c
@@ -53,7 +53,7 @@ int grpc_header_key_is_legal(const char *key, size_t length) {
       0x00, 0x00, 0x00, 0x00, 0x00, 0x60, 0xff, 0x03, 0x00, 0x00, 0x00,
       0x80, 0xfe, 0xff, 0xff, 0x07, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
       0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00};
-  if (length == 0) {
+  if (length == 0 || key[0] == ':') {
     return 0;
   }
   return conforms_to(key, length, legal_header_bits);
diff --git a/src/php/lib/Grpc/AbstractCall.php b/src/php/lib/Grpc/AbstractCall.php
index c4d56790f7..9f0b02b8bb 100644
--- a/src/php/lib/Grpc/AbstractCall.php
+++ b/src/php/lib/Grpc/AbstractCall.php
@@ -62,7 +62,7 @@ abstract class AbstractCall
         Channel $channel,
         $method,
         $deserialize,
-        $options = []
+        array $options = []
     ) {
         if (array_key_exists('timeout', $options) &&
             is_numeric($timeout = $options['timeout'])
@@ -89,7 +89,7 @@ abstract class AbstractCall
     }
 
     /**
-     * @return mixed The metadata sent by the server.
+     * @return mixed The metadata sent by the server
      */
     public function getMetadata()
     {
@@ -97,7 +97,7 @@ abstract class AbstractCall
     }
 
     /**
-     * @return mixed The trailing metadata sent by the server.
+     * @return mixed The trailing metadata sent by the server
      */
     public function getTrailingMetadata()
     {
@@ -105,7 +105,7 @@ abstract class AbstractCall
     }
 
     /**
-     * @return string The URI of the endpoint.
+     * @return string The URI of the endpoint
      */
     public function getPeer()
     {
@@ -167,8 +167,7 @@ abstract class AbstractCall
     /**
      * Set the CallCredentials for the underlying Call.
      *
-     * @param CallCredentials $call_credentials The CallCredentials
-     *                                          object
+     * @param CallCredentials $call_credentials The CallCredentials object
      */
     public function setCallCredentials($call_credentials)
     {
diff --git a/src/php/lib/Grpc/BaseStub.php b/src/php/lib/Grpc/BaseStub.php
index d0baeae955..aec60af094 100644
--- a/src/php/lib/Grpc/BaseStub.php
+++ b/src/php/lib/Grpc/BaseStub.php
@@ -48,14 +48,14 @@ class BaseStub
     private $update_metadata;
 
     /**
-     * @param $hostname string
-     * @param $opts array
+     * @param string  $hostname
+     * @param array   $opts
      *  - 'update_metadata': (optional) a callback function which takes in a
      * metadata array, and returns an updated metadata array
      *  - 'grpc.primary_user_agent': (optional) a user-agent string
-     * @param $channel Channel An already created Channel object
+     * @param Channel $channel An already created Channel object (optional)
      */
-    public function __construct($hostname, $opts, $channel = null)
+    public function __construct($hostname, $opts, Channel $channel = null)
     {
         $ssl_roots = file_get_contents(
             dirname(__FILE__).'/../../../../etc/roots.pem');
@@ -98,7 +98,7 @@ class BaseStub
     }
 
     /**
-     * @return string The URI of the endpoint.
+     * @return string The URI of the endpoint
      */
     public function getTarget()
     {
@@ -106,7 +106,7 @@ class BaseStub
     }
 
     /**
-     * @param $try_to_connect bool
+     * @param bool $try_to_connect (optional)
      *
      * @return int The grpc connectivity state
      */
@@ -145,6 +145,12 @@ class BaseStub
         return $this->_checkConnectivityState($new_state);
     }
 
+    /**
+     * @param $new_state Connect state
+     *
+     * @return bool true if state is CHANNEL_READY
+     * @throw Exception if state is CHANNEL_FATAL_FAILURE
+     */
     private function _checkConnectivityState($new_state)
     {
         if ($new_state == \Grpc\CHANNEL_READY) {
@@ -167,6 +173,10 @@ class BaseStub
 
     /**
      * constructs the auth uri for the jwt.
+     *
+     * @param string $method The method string
+     *
+     * @return string The URL string
      */
     private function _get_jwt_aud_uri($method)
     {
@@ -191,7 +201,7 @@ class BaseStub
      *
      * @param array $metadata The metadata map
      *
-     * @return $metadata Validated and key-normalized metadata map
+     * @return array $metadata Validated and key-normalized metadata map
      * @throw InvalidArgumentException if key contains invalid characters
      */
     private function _validate_and_normalize_metadata($metadata)
@@ -220,14 +230,16 @@ class BaseStub
      * @param mixed    $argument    The argument to the method
      * @param callable $deserialize A function that deserializes the response
      * @param array    $metadata    A metadata map to send to the server
+     *                              (optional)
+     * @param array    $options     An array of options (optional)
      *
      * @return SimpleSurfaceActiveCall The active call object
      */
     public function _simpleRequest($method,
                                    $argument,
                                    $deserialize,
-                                   $metadata = [],
-                                   $options = [])
+                                   array $metadata = [],
+                                   array $options = [])
     {
         $call = new UnaryCall($this->channel,
                               $method,
@@ -251,17 +263,17 @@ class BaseStub
      * output.
      *
      * @param string   $method      The name of the method to call
-     * @param array    $arguments   An array or Traversable of arguments to stream to the
-     *                              server
      * @param callable $deserialize A function that deserializes the response
      * @param array    $metadata    A metadata map to send to the server
+     *                              (optional)
+     * @param array    $options     An array of options (optional)
      *
      * @return ClientStreamingSurfaceActiveCall The active call object
      */
     public function _clientStreamRequest($method,
                                          callable $deserialize,
-                                         $metadata = [],
-                                         $options = [])
+                                         array $metadata = [],
+                                         array $options = [])
     {
         $call = new ClientStreamingCall($this->channel,
                                         $method,
@@ -281,21 +293,23 @@ class BaseStub
     }
 
     /**
-     * Call a remote method that takes a single argument and returns a stream of
-     * responses.
+     * Call a remote method that takes a single argument and returns a stream
+     * of responses.
      *
      * @param string   $method      The name of the method to call
      * @param mixed    $argument    The argument to the method
      * @param callable $deserialize A function that deserializes the responses
      * @param array    $metadata    A metadata map to send to the server
+     *                              (optional)
+     * @param array    $options     An array of options (optional)
      *
      * @return ServerStreamingSurfaceActiveCall The active call object
      */
     public function _serverStreamRequest($method,
                                          $argument,
                                          callable $deserialize,
-                                         $metadata = [],
-                                         $options = [])
+                                         array $metadata = [],
+                                         array $options = [])
     {
         $call = new ServerStreamingCall($this->channel,
                                         $method,
@@ -320,13 +334,15 @@ class BaseStub
      * @param string   $method      The name of the method to call
      * @param callable $deserialize A function that deserializes the responses
      * @param array    $metadata    A metadata map to send to the server
+     *                              (optional)
+     * @param array    $options     An array of options (optional)
      *
      * @return BidiStreamingSurfaceActiveCall The active call object
      */
     public function _bidiRequest($method,
                                  callable $deserialize,
-                                 $metadata = [],
-                                 $options = [])
+                                 array $metadata = [],
+                                 array $options = [])
     {
         $call = new BidiStreamingCall($this->channel,
                                       $method,
diff --git a/src/php/lib/Grpc/BidiStreamingCall.php b/src/php/lib/Grpc/BidiStreamingCall.php
index f0e1e811de..b03bbd204f 100644
--- a/src/php/lib/Grpc/BidiStreamingCall.php
+++ b/src/php/lib/Grpc/BidiStreamingCall.php
@@ -35,8 +35,8 @@
 namespace Grpc;
 
 /**
- * Represents an active call that allows for sending and recieving messages in
- * streams in any order.
+ * Represents an active call that allows for sending and recieving messages
+ * in streams in any order.
  */
 class BidiStreamingCall extends AbstractCall
 {
@@ -44,6 +44,7 @@ class BidiStreamingCall extends AbstractCall
      * Start the call.
      *
      * @param array $metadata Metadata to send with the call, if applicable
+     *                        (optional)
      */
     public function start(array $metadata = [])
     {
@@ -76,10 +77,10 @@ class BidiStreamingCall extends AbstractCall
      * writesDone is called.
      *
      * @param ByteBuffer $data    The data to write
-     * @param array      $options an array of options, possible keys:
-     *                            'flags' => a number
+     * @param array      $options An array of options, possible keys:
+     *                            'flags' => a number (optional)
      */
-    public function write($data, $options = [])
+    public function write($data, array $options = [])
     {
         $message_array = ['message' => $this->serializeMessage($data)];
         if (array_key_exists('flags', $options)) {
@@ -103,8 +104,8 @@ class BidiStreamingCall extends AbstractCall
     /**
      * Wait for the server to send the status, and return it.
      *
-     * @return \stdClass The status object, with integer $code, string $details,
-     *                   and array $metadata members
+     * @return \stdClass The status object, with integer $code, string
+     *                   $details, and array $metadata members
      */
     public function getStatus()
     {
diff --git a/src/php/lib/Grpc/ClientStreamingCall.php b/src/php/lib/Grpc/ClientStreamingCall.php
index 20db809ea3..c542f08872 100644
--- a/src/php/lib/Grpc/ClientStreamingCall.php
+++ b/src/php/lib/Grpc/ClientStreamingCall.php
@@ -35,8 +35,8 @@
 namespace Grpc;
 
 /**
- * Represents an active call that sends a stream of messages and then gets a
- * single response.
+ * Represents an active call that sends a stream of messages and then gets
+ * a single response.
  */
 class ClientStreamingCall extends AbstractCall
 {
@@ -44,8 +44,9 @@ class ClientStreamingCall extends AbstractCall
      * Start the call.
      *
      * @param array $metadata Metadata to send with the call, if applicable
+     *                        (optional)
      */
-    public function start($metadata = [])
+    public function start(array $metadata = [])
     {
         $this->call->startBatch([
             OP_SEND_INITIAL_METADATA => $metadata,
@@ -57,8 +58,8 @@ class ClientStreamingCall extends AbstractCall
      * wait is called.
      *
      * @param ByteBuffer $data    The data to write
-     * @param array      $options an array of options, possible keys:
-     *                            'flags' => a number
+     * @param array      $options An array of options, possible keys:
+     *                            'flags' => a number (optional)
      */
     public function write($data, array $options = [])
     {
diff --git a/src/php/lib/Grpc/ServerStreamingCall.php b/src/php/lib/Grpc/ServerStreamingCall.php
index 5aeeafa94a..406512bf57 100644
--- a/src/php/lib/Grpc/ServerStreamingCall.php
+++ b/src/php/lib/Grpc/ServerStreamingCall.php
@@ -35,8 +35,8 @@
 namespace Grpc;
 
 /**
- * Represents an active call that sends a single message and then gets a stream
- * of responses.
+ * Represents an active call that sends a single message and then gets a
+ * stream of responses.
  */
 class ServerStreamingCall extends AbstractCall
 {
@@ -45,10 +45,11 @@ class ServerStreamingCall extends AbstractCall
      *
      * @param mixed $data     The data to send
      * @param array $metadata Metadata to send with the call, if applicable
-     * @param array $options  an array of options, possible keys:
-     *                        'flags' => a number
+     *                        (optional)
+     * @param array $options  An array of options, possible keys:
+     *                        'flags' => a number (optional)
      */
-    public function start($data, $metadata = [], $options = [])
+    public function start($data, array $metadata = [], array $options = [])
     {
         $message_array = ['message' => $this->serializeMessage($data)];
         if (array_key_exists('flags', $options)) {
@@ -82,8 +83,8 @@ class ServerStreamingCall extends AbstractCall
     /**
      * Wait for the server to send the status, and return it.
      *
-     * @return \stdClass The status object, with integer $code, string $details,
-     *                   and array $metadata members
+     * @return \stdClass The status object, with integer $code, string
+     *                   $details, and array $metadata members
      */
     public function getStatus()
     {
diff --git a/src/php/lib/Grpc/UnaryCall.php b/src/php/lib/Grpc/UnaryCall.php
index e8eb6487a8..3c1cb158ea 100644
--- a/src/php/lib/Grpc/UnaryCall.php
+++ b/src/php/lib/Grpc/UnaryCall.php
@@ -35,8 +35,8 @@
 namespace Grpc;
 
 /**
- * Represents an active call that sends a single message and then gets a single
- * response.
+ * Represents an active call that sends a single message and then gets a
+ * single response.
  */
 class UnaryCall extends AbstractCall
 {
@@ -45,10 +45,11 @@ class UnaryCall extends AbstractCall
      *
      * @param mixed $data     The data to send
      * @param array $metadata Metadata to send with the call, if applicable
-     * @param array $options  an array of options, possible keys:
-     *                        'flags' => a number
+     *                        (optional)
+     * @param array $options  An array of options, possible keys:
+     *                        'flags' => a number (optional)
      */
-    public function start($data, $metadata = [], $options = [])
+    public function start($data, array $metadata = [], array $options = [])
     {
         $message_array = ['message' => $this->serializeMessage($data)];
         if (isset($options['flags'])) {
diff --git a/src/python/grpcio/commands.py b/src/python/grpcio/commands.py
index ea3b6f3391..701c6af017 100644
--- a/src/python/grpcio/commands.py
+++ b/src/python/grpcio/commands.py
@@ -62,6 +62,7 @@ napoleon_numpy_docstring = True
 napoleon_include_special_with_doc = True
 
 html_theme = 'sphinx_rtd_theme'
+copyright = "2016, The gRPC Authors"
 """
 
 API_GLOSSARY = """
diff --git a/src/python/grpcio_tests/tests/interop/_insecure_interop_test.py b/src/python/grpcio_tests/tests/interop/_insecure_intraop_test.py
index 936c895bd2..4fb22b4d9d 100644
--- a/src/python/grpcio_tests/tests/interop/_insecure_interop_test.py
+++ b/src/python/grpcio_tests/tests/interop/_insecure_intraop_test.py
@@ -35,13 +35,13 @@ import unittest
 import grpc
 from src.proto.grpc.testing import test_pb2
 
-from tests.interop import _interop_test_case
+from tests.interop import _intraop_test_case
 from tests.interop import methods
 from tests.interop import server
 
 
-class InsecureInteropTest(
-    _interop_test_case.InteropTestCase,
+class InsecureIntraopTest(
+    _intraop_test_case.IntraopTestCase,
     unittest.TestCase):
 
   def setUp(self):
diff --git a/src/python/grpcio_tests/tests/interop/_interop_test_case.py b/src/python/grpcio_tests/tests/interop/_intraop_test_case.py
index ccea17a66d..fe1c173992 100644
--- a/src/python/grpcio_tests/tests/interop/_interop_test_case.py
+++ b/src/python/grpcio_tests/tests/interop/_intraop_test_case.py
@@ -32,7 +32,7 @@
 from tests.interop import methods
 
 
-class InteropTestCase(object):
+class IntraopTestCase(object):
   """Unit test methods.
 
   This class must be mixed in with unittest.TestCase and a class that defines
diff --git a/src/python/grpcio_tests/tests/interop/_secure_interop_test.py b/src/python/grpcio_tests/tests/interop/_secure_intraop_test.py
index eaca553e1b..3665c69726 100644
--- a/src/python/grpcio_tests/tests/interop/_secure_interop_test.py
+++ b/src/python/grpcio_tests/tests/interop/_secure_intraop_test.py
@@ -35,15 +35,15 @@ import unittest
 import grpc
 from src.proto.grpc.testing import test_pb2
 
-from tests.interop import _interop_test_case
+from tests.interop import _intraop_test_case
 from tests.interop import methods
 from tests.interop import resources
 
 _SERVER_HOST_OVERRIDE = 'foo.test.google.fr'
 
 
-class SecureInteropTest(
-    _interop_test_case.InteropTestCase,
+class SecureIntraopTest(
+    _intraop_test_case.IntraopTestCase,
     unittest.TestCase):
 
   def setUp(self):
diff --git a/src/python/grpcio_tests/tests/tests.json b/src/python/grpcio_tests/tests/tests.json
index c31a5f9d33..0109ee2173 100644
--- a/src/python/grpcio_tests/tests/tests.json
+++ b/src/python/grpcio_tests/tests/tests.json
@@ -1,7 +1,7 @@
 [
   "health_check._health_servicer_test.HealthServicerTest",
-  "interop._insecure_interop_test.InsecureInteropTest",
-  "interop._secure_interop_test.SecureInteropTest",
+  "interop._insecure_intraop_test.InsecureIntraopTest",
+  "interop._secure_intraop_test.SecureIntraopTest",
   "protoc_plugin._python_plugin_test.PythonPluginTest",
   "protoc_plugin._split_definitions_test.SameCommonTest",
   "protoc_plugin._split_definitions_test.SameSeparateTest",
diff --git a/test/core/end2end/invalid_call_argument_test.c b/test/core/end2end/invalid_call_argument_test.c
index 765b6ad1be..d974d2c8ff 100644
--- a/test/core/end2end/invalid_call_argument_test.c
+++ b/test/core/end2end/invalid_call_argument_test.c
@@ -573,6 +573,29 @@ static void test_recv_close_on_server_twice() {
   cleanup_test();
 }
 
+static void test_invalid_initial_metadata_reserved_key() {
+  gpr_log(GPR_INFO, "test_invalid_initial_metadata_reserved_key");
+
+  grpc_metadata metadata;
+  metadata.key = ":start_with_colon";
+  metadata.value = "value";
+  metadata.value_length = 6;
+
+  grpc_op *op;
+  prepare_test(1);
+  op = g_state.ops;
+  op->op = GRPC_OP_SEND_INITIAL_METADATA;
+  op->data.send_initial_metadata.count = 1;
+  op->data.send_initial_metadata.metadata = &metadata;
+  op->flags = 0;
+  op->reserved = NULL;
+  op++;
+  GPR_ASSERT(GRPC_CALL_ERROR_INVALID_METADATA ==
+             grpc_call_start_batch(g_state.call, g_state.ops,
+                                   (size_t)(op - g_state.ops), tag(1), NULL));
+  cleanup_test();
+}
+
 int main(int argc, char **argv) {
   grpc_test_init(argc, argv);
   grpc_init();
@@ -595,6 +618,7 @@ int main(int argc, char **argv) {
   test_send_server_status_twice();
   test_recv_close_on_server_with_invalid_flags();
   test_recv_close_on_server_twice();
+  test_invalid_initial_metadata_reserved_key();
   grpc_shutdown();
 
   return 0;
diff --git a/test/core/security/create_jwt.c b/test/core/security/create_jwt.c
index 741ace9bdd..ac795f29d2 100644
--- a/test/core/security/create_jwt.c
+++ b/test/core/security/create_jwt.c
@@ -72,6 +72,7 @@ int main(int argc, char **argv) {
   char *scope = NULL;
   char *json_key_file_path = NULL;
   char *service_url = NULL;
+  grpc_init();
   gpr_cmdline *cl = gpr_cmdline_create("create_jwt");
   gpr_cmdline_add_string(cl, "json_key", "File path of the json key.",
                          &json_key_file_path);
@@ -102,5 +103,6 @@ int main(int argc, char **argv) {
   create_jwt(json_key_file_path, service_url, scope);
 
   gpr_cmdline_destroy(cl);
+  grpc_shutdown();
   return 0;
 }
diff --git a/test/core/security/jwt_verifier_test.c b/test/core/security/jwt_verifier_test.c
index f8afba8d6d..9a21814adc 100644
--- a/test/core/security/jwt_verifier_test.c
+++ b/test/core/security/jwt_verifier_test.c
@@ -166,6 +166,13 @@ static const char claims_without_time_constraint[] =
     "  \"jti\": \"jwtuniqueid\","
     "  \"foo\": \"bar\"}";
 
+static const char claims_with_bad_subject[] =
+    "{ \"aud\": \"https://foo.com\","
+    "  \"iss\": \"evil@blah.foo.com\","
+    "  \"sub\": \"juju@blah.foo.com\","
+    "  \"jti\": \"jwtuniqueid\","
+    "  \"foo\": \"bar\"}";
+
 static const char invalid_claims[] =
     "{ \"aud\": \"https://foo.com\","
     "  \"iss\": 46," /* Issuer cannot be a number. */
@@ -179,6 +186,38 @@ typedef struct {
   const char *expected_subject;
 } verifier_test_config;
 
+static void test_jwt_issuer_email_domain(void) {
+  const char *d = grpc_jwt_issuer_email_domain("https://foo.com");
+  GPR_ASSERT(d == NULL);
+  d = grpc_jwt_issuer_email_domain("foo.com");
+  GPR_ASSERT(d == NULL);
+  d = grpc_jwt_issuer_email_domain("");
+  GPR_ASSERT(d == NULL);
+  d = grpc_jwt_issuer_email_domain("@");
+  GPR_ASSERT(d == NULL);
+  d = grpc_jwt_issuer_email_domain("bar@foo");
+  GPR_ASSERT(strcmp(d, "foo") == 0);
+  d = grpc_jwt_issuer_email_domain("bar@foo.com");
+  GPR_ASSERT(strcmp(d, "foo.com") == 0);
+  d = grpc_jwt_issuer_email_domain("bar@blah.foo.com");
+  GPR_ASSERT(strcmp(d, "foo.com") == 0);
+  d = grpc_jwt_issuer_email_domain("bar.blah@blah.foo.com");
+  GPR_ASSERT(strcmp(d, "foo.com") == 0);
+  d = grpc_jwt_issuer_email_domain("bar.blah@baz.blah.foo.com");
+  GPR_ASSERT(strcmp(d, "foo.com") == 0);
+
+  /* This is not a very good parser but make sure we do not crash on these weird
+     inputs. */
+  d = grpc_jwt_issuer_email_domain("@foo");
+  GPR_ASSERT(strcmp(d, "foo") == 0);
+  d = grpc_jwt_issuer_email_domain("bar@.");
+  GPR_ASSERT(d != NULL);
+  d = grpc_jwt_issuer_email_domain("bar@..");
+  GPR_ASSERT(d != NULL);
+  d = grpc_jwt_issuer_email_domain("bar@...");
+  GPR_ASSERT(d != NULL);
+}
+
 static void test_claims_success(void) {
   grpc_jwt_claims *claims;
   grpc_slice s = grpc_slice_from_copied_string(claims_without_time_constraint);
@@ -242,6 +281,19 @@ static void test_bad_audience_claims_failure(void) {
   grpc_jwt_claims_destroy(claims);
 }
 
+static void test_bad_subject_claims_failure(void) {
+  grpc_jwt_claims *claims;
+  grpc_slice s = grpc_slice_from_copied_string(claims_with_bad_subject);
+  grpc_json *json = grpc_json_parse_string_with_len(
+      (char *)GRPC_SLICE_START_PTR(s), GRPC_SLICE_LENGTH(s));
+  GPR_ASSERT(json != NULL);
+  claims = grpc_jwt_claims_from_json(json, s);
+  GPR_ASSERT(claims != NULL);
+  GPR_ASSERT(grpc_jwt_claims_check(claims, "https://foo.com") ==
+             GRPC_JWT_VERIFIER_BAD_SUBJECT);
+  grpc_jwt_claims_destroy(claims);
+}
+
 static char *json_key_str(const char *last_part) {
   size_t result_len = strlen(json_key_str_part1) + strlen(json_key_str_part2) +
                       strlen(last_part);
@@ -563,10 +615,12 @@ static void test_jwt_verifier_bad_format(void) {
 int main(int argc, char **argv) {
   grpc_test_init(argc, argv);
   grpc_init();
+  test_jwt_issuer_email_domain();
   test_claims_success();
   test_expired_claims_failure();
   test_invalid_claims_failure();
   test_bad_audience_claims_failure();
+  test_bad_subject_claims_failure();
   test_jwt_verifier_google_email_issuer_success();
   test_jwt_verifier_custom_email_issuer_success();
   test_jwt_verifier_url_issuer_success();
diff --git a/test/core/security/verify_jwt.c b/test/core/security/verify_jwt.c
index 043d29e6bb..ccc85c9f32 100644
--- a/test/core/security/verify_jwt.c
+++ b/test/core/security/verify_jwt.c
@@ -93,6 +93,7 @@ int main(int argc, char **argv) {
   char *aud = NULL;
   grpc_exec_ctx exec_ctx = GRPC_EXEC_CTX_INIT;
 
+  grpc_init();
   cl = gpr_cmdline_create("JWT verifier tool");
   gpr_cmdline_add_string(cl, "jwt", "JSON web token to verify", &jwt);
   gpr_cmdline_add_string(cl, "aud", "Audience for the JWT", &aud);
@@ -131,5 +132,6 @@ int main(int argc, char **argv) {
 
   grpc_jwt_verifier_destroy(verifier);
   gpr_cmdline_destroy(cl);
+  grpc_shutdown();
   return !sync.success;
 }
diff --git a/test/core/support/string_test.c b/test/core/support/string_test.c
index 78b77fad8e..af232db350 100644
--- a/test/core/support/string_test.c
+++ b/test/core/support/string_test.c
@@ -243,6 +243,8 @@ static void test_int64toa() {
 static void test_leftpad() {
   char *padded;
 
+  LOG_TEST_NAME("test_leftpad");
+
   padded = gpr_leftpad("foo", ' ', 5);
   GPR_ASSERT(0 == strcmp("  foo", padded));
   gpr_free(padded);
@@ -273,12 +275,25 @@ static void test_leftpad() {
 }
 
 static void test_stricmp(void) {
+  LOG_TEST_NAME("test_stricmp");
+
   GPR_ASSERT(0 == gpr_stricmp("hello", "hello"));
   GPR_ASSERT(0 == gpr_stricmp("HELLO", "hello"));
   GPR_ASSERT(gpr_stricmp("a", "b") < 0);
   GPR_ASSERT(gpr_stricmp("b", "a") > 0);
 }
 
+static void test_memrchr(void) {
+  LOG_TEST_NAME("test_memrchr");
+
+  GPR_ASSERT(NULL == gpr_memrchr(NULL, 'a', 0));
+  GPR_ASSERT(NULL == gpr_memrchr("", 'a', 0));
+  GPR_ASSERT(NULL == gpr_memrchr("hello", 'b', 5));
+  GPR_ASSERT(0 == strcmp((const char *)gpr_memrchr("hello", 'h', 5), "hello"));
+  GPR_ASSERT(0 == strcmp((const char *)gpr_memrchr("hello", 'o', 5), "o"));
+  GPR_ASSERT(0 == strcmp((const char *)gpr_memrchr("hello", 'l', 5), "lo"));
+}
+
 int main(int argc, char **argv) {
   grpc_test_init(argc, argv);
   test_strdup();
@@ -291,5 +306,6 @@ int main(int argc, char **argv) {
   test_int64toa();
   test_leftpad();
   test_stricmp();
+  test_memrchr();
   return 0;
 }
diff --git a/tools/distrib/check_copyright.py b/tools/distrib/check_copyright.py
index f06e5f1d1a..51852adfd3 100755
--- a/tools/distrib/check_copyright.py
+++ b/tools/distrib/check_copyright.py
@@ -92,9 +92,20 @@ LICENSE_PREFIX = {
   'LICENSE':    '',
 }
 
-KNOWN_BAD = set([
+_EXEMPT = frozenset((
+  # Generated protocol compiler output.
+  'examples/python/helloworld/helloworld_pb2.py',
+  'examples/python/helloworld/helloworld_pb2_grpc.py',
+  'examples/python/multiplex/helloworld_pb2.py',
+  'examples/python/multiplex/helloworld_pb2_grpc.py',
+  'examples/python/multiplex/route_guide_pb2.py',
+  'examples/python/multiplex/route_guide_pb2_grpc.py',
+  'examples/python/route_guide/route_guide_pb2.py',
+  'examples/python/route_guide/route_guide_pb2_grpc.py',
+
+  # An older file originally from outside gRPC.
   'src/php/tests/bootstrap.php',
-])
+))
 
 
 RE_YEAR = r'Copyright (?P<first_year>[0-9]+\-)?(?P<last_year>[0-9]+), Google Inc\.'
@@ -140,7 +151,8 @@ except subprocess.CalledProcessError:
   sys.exit(0)
 
 for filename in filename_list:
-  if filename in KNOWN_BAD: continue
+  if filename in _EXEMPT:
+    continue
   ext = os.path.splitext(filename)[1]
   base = os.path.basename(filename)
   if ext in RE_LICENSE:
diff --git a/tools/distrib/python/docgen.py b/tools/distrib/python/docgen.py
index 622317920d..38ffcd6e0e 100755
--- a/tools/distrib/python/docgen.py
+++ b/tools/distrib/python/docgen.py
@@ -94,6 +94,7 @@ if args.submit:
   # specified repository, edit it, and push it. It's up to the user to then go
   # onto GitHub and make a PR against grpc/grpc:gh-pages.
   repo_parent_dir = tempfile.mkdtemp()
+  print('Documentation parent directory: {}'.format(repo_parent_dir))
   repo_dir = os.path.join(repo_parent_dir, 'grpc')
   python_doc_dir = os.path.join(repo_dir, 'python')
   doc_branch = args.doc_branch