Update documentation
diff --git a/docs/dyn/compute_v1.backendServices.html b/docs/dyn/compute_v1.backendServices.html
index 12a57dd..08fe6f6 100644
--- a/docs/dyn/compute_v1.backendServices.html
+++ b/docs/dyn/compute_v1.backendServices.html
@@ -172,29 +172,62 @@
       "kind": "compute#backendService", # [Output Only] Type of resource. Always compute#backendService for backend services.
       "protocol": "A String", # The protocol this BackendService uses to communicate with backends.
           #
-          # Possible values are HTTP, HTTPS, HTTP2, TCP and SSL.
+          # Possible values are HTTP, HTTPS, HTTP2, TCP and SSL. The default is HTTP.
+          #
+          # For internal load balancing, the possible values are TCP and UDP, and the default is TCP.
       "description": "A String", # An optional description of this resource. Provide this property when you create the resource.
       "timeoutSec": 42, # How many seconds to wait for the backend before considering it a failed request. Default is 30 seconds.
+      "enableCDN": True or False, # If true, enable Cloud CDN for this BackendService.
+          #
+          # When the load balancing scheme is INTERNAL, this field is not used.
       "region": "A String", # [Output Only] URL of the region where the regional backend service resides. This field is not applicable to global backend services.
+      "affinityCookieTtlSec": 42, # Lifetime of cookies in seconds if session_affinity is GENERATED_COOKIE. If set to 0, the cookie is non-persistent and lasts only until the end of the browser session (or equivalent). The maximum allowed value for TTL is one day.
+          #
+          # When the load balancing scheme is INTERNAL, this field is not used.
       "port": 42, # Deprecated in favor of portName. The TCP port to connect on the backend. The default value is 80.
+          #
+          # This cannot be used for internal load balancing.
       "backends": [ # The list of backends that serve this BackendService.
         { # Message containing information of one individual backend.
           "group": "A String", # The fully-qualified URL of a zonal Instance Group resource. This instance group defines the list of instances that serve traffic. Member virtual machine instances from each instance group must live in the same zone as the instance group itself. No two backends in a backend service are allowed to use same Instance Group resource.
               #
               # Note that you must specify an Instance Group resource using the fully-qualified URL, rather than a partial URL.
+              #
+              # When the BackendService has load balancing scheme INTERNAL, the instance group must be in a zone within the same region as the BackendService.
           "description": "A String", # An optional description of this resource. Provide this property when you create the resource.
           "maxUtilization": 3.14, # Used when balancingMode is UTILIZATION. This ratio defines the CPU utilization target for the group. The default is 0.8. Valid range is [0.0, 1.0].
+              #
+              # This cannot be used for internal load balancing.
           "maxRatePerInstance": 3.14, # The max requests per second (RPS) that a single backend instance can handle.This is used to calculate the capacity of the group. Can be used in either balancing mode. For RATE mode, either maxRate or maxRatePerInstance must be set.
+              #
+              # This cannot be used for internal load balancing.
           "capacityScaler": 3.14, # A multiplier applied to the group's maximum servicing capacity (either UTILIZATION or RATE). Default value is 1, which means the group will serve up to 100% of its configured CPU or RPS (depending on balancingMode). A setting of 0 means the group is completely drained, offering 0% of its available CPU or RPS. Valid range is [0.0,1.0].
+              #
+              # This cannot be used for internal load balancing.
           "maxRate": 42, # The max requests per second (RPS) of the group. Can be used with either RATE or UTILIZATION balancing modes, but required if RATE mode. For RATE mode, either maxRate or maxRatePerInstance must be set.
+              #
+              # This cannot be used for internal load balancing.
           "balancingMode": "A String", # Specifies the balancing mode for this backend. For global HTTP(S) load balancing, the default is UTILIZATION. Valid values are UTILIZATION and RATE.
+              #
+              # This cannot be used for internal load balancing.
         },
       ],
       "fingerprint": "A String", # Fingerprint of this resource. A hash of the contents stored in this object. This field is used in optimistic locking. This field will be ignored when inserting a BackendService. An up-to-date fingerprint must be provided in order to update the BackendService.
-      "portName": "A String", # Name of backend port. The same name should appear in the instance groups referenced by this service. Required.
+      "portName": "A String", # Name of backend port. The same name should appear in the instance groups referenced by this service. Required when the load balancing scheme is EXTERNAL.
+          #
+          # When the load balancing scheme is INTERNAL, this field is not used.
       "healthChecks": [ # The list of URLs to the HttpHealthCheck or HttpsHealthCheck resource for health checking this BackendService. Currently at most one health check can be specified, and a health check is required.
+          #
+          # For internal load balancing, a URL to a HealthCheck resource must be specified instead.
         "A String",
       ],
+      "sessionAffinity": "A String", # Type of session affinity to use. The default is NONE.
+          #
+          # When the load balancing scheme is EXTERNAL, can be NONE, CLIENT_IP, or GENERATED_COOKIE.
+          #
+          # When the load balancing scheme is INTERNAL, can be NONE, CLIENT_IP, CLIENT_IP_PROTO, or CLIENT_IP_PORT_PROTO.
+          #
+          # When the protocol is UDP, this field is not used.
       "creationTimestamp": "A String", # [Output Only] Creation timestamp in RFC3339 text format.
       "id": "A String", # [Output Only] The unique identifier for the resource. This identifier is defined by the server.
       "selfLink": "A String", # [Output Only] Server-defined URL for the resource.
@@ -246,29 +279,62 @@
     "kind": "compute#backendService", # [Output Only] Type of resource. Always compute#backendService for backend services.
     "protocol": "A String", # The protocol this BackendService uses to communicate with backends.
         # 
-        # Possible values are HTTP, HTTPS, HTTP2, TCP and SSL.
+        # Possible values are HTTP, HTTPS, HTTP2, TCP and SSL. The default is HTTP.
+        # 
+        # For internal load balancing, the possible values are TCP and UDP, and the default is TCP.
     "description": "A String", # An optional description of this resource. Provide this property when you create the resource.
     "timeoutSec": 42, # How many seconds to wait for the backend before considering it a failed request. Default is 30 seconds.
+    "enableCDN": True or False, # If true, enable Cloud CDN for this BackendService.
+        # 
+        # When the load balancing scheme is INTERNAL, this field is not used.
     "region": "A String", # [Output Only] URL of the region where the regional backend service resides. This field is not applicable to global backend services.
+    "affinityCookieTtlSec": 42, # Lifetime of cookies in seconds if session_affinity is GENERATED_COOKIE. If set to 0, the cookie is non-persistent and lasts only until the end of the browser session (or equivalent). The maximum allowed value for TTL is one day.
+        # 
+        # When the load balancing scheme is INTERNAL, this field is not used.
     "port": 42, # Deprecated in favor of portName. The TCP port to connect on the backend. The default value is 80.
+        # 
+        # This cannot be used for internal load balancing.
     "backends": [ # The list of backends that serve this BackendService.
       { # Message containing information of one individual backend.
         "group": "A String", # The fully-qualified URL of a zonal Instance Group resource. This instance group defines the list of instances that serve traffic. Member virtual machine instances from each instance group must live in the same zone as the instance group itself. No two backends in a backend service are allowed to use same Instance Group resource.
             #
             # Note that you must specify an Instance Group resource using the fully-qualified URL, rather than a partial URL.
+            #
+            # When the BackendService has load balancing scheme INTERNAL, the instance group must be in a zone within the same region as the BackendService.
         "description": "A String", # An optional description of this resource. Provide this property when you create the resource.
         "maxUtilization": 3.14, # Used when balancingMode is UTILIZATION. This ratio defines the CPU utilization target for the group. The default is 0.8. Valid range is [0.0, 1.0].
+            #
+            # This cannot be used for internal load balancing.
         "maxRatePerInstance": 3.14, # The max requests per second (RPS) that a single backend instance can handle.This is used to calculate the capacity of the group. Can be used in either balancing mode. For RATE mode, either maxRate or maxRatePerInstance must be set.
+            #
+            # This cannot be used for internal load balancing.
         "capacityScaler": 3.14, # A multiplier applied to the group's maximum servicing capacity (either UTILIZATION or RATE). Default value is 1, which means the group will serve up to 100% of its configured CPU or RPS (depending on balancingMode). A setting of 0 means the group is completely drained, offering 0% of its available CPU or RPS. Valid range is [0.0,1.0].
+            #
+            # This cannot be used for internal load balancing.
         "maxRate": 42, # The max requests per second (RPS) of the group. Can be used with either RATE or UTILIZATION balancing modes, but required if RATE mode. For RATE mode, either maxRate or maxRatePerInstance must be set.
+            #
+            # This cannot be used for internal load balancing.
         "balancingMode": "A String", # Specifies the balancing mode for this backend. For global HTTP(S) load balancing, the default is UTILIZATION. Valid values are UTILIZATION and RATE.
+            #
+            # This cannot be used for internal load balancing.
       },
     ],
     "fingerprint": "A String", # Fingerprint of this resource. A hash of the contents stored in this object. This field is used in optimistic locking. This field will be ignored when inserting a BackendService. An up-to-date fingerprint must be provided in order to update the BackendService.
-    "portName": "A String", # Name of backend port. The same name should appear in the instance groups referenced by this service. Required.
+    "portName": "A String", # Name of backend port. The same name should appear in the instance groups referenced by this service. Required when the load balancing scheme is EXTERNAL.
+        # 
+        # When the load balancing scheme is INTERNAL, this field is not used.
     "healthChecks": [ # The list of URLs to the HttpHealthCheck or HttpsHealthCheck resource for health checking this BackendService. Currently at most one health check can be specified, and a health check is required.
+        # 
+        # For internal load balancing, a URL to a HealthCheck resource must be specified instead.
       "A String",
     ],
+    "sessionAffinity": "A String", # Type of session affinity to use. The default is NONE.
+        # 
+        # When the load balancing scheme is EXTERNAL, can be NONE, CLIENT_IP, or GENERATED_COOKIE.
+        # 
+        # When the load balancing scheme is INTERNAL, can be NONE, CLIENT_IP, CLIENT_IP_PROTO, or CLIENT_IP_PORT_PROTO.
+        # 
+        # When the protocol is UDP, this field is not used.
     "creationTimestamp": "A String", # [Output Only] Creation timestamp in RFC3339 text format.
     "id": "A String", # [Output Only] The unique identifier for the resource. This identifier is defined by the server.
     "selfLink": "A String", # [Output Only] Server-defined URL for the resource.
@@ -340,43 +406,76 @@
 
 For example, to filter for instances that do not have a name of example-instance, you would use filter=name ne example-instance.
 
-Compute Engine Beta API Only: When filtering in the Beta API, you can also filter on nested fields. For example, you could filter on instances that have set the scheduling.automaticRestart field to true. Use filtering on nested fields to take advantage of labels to organize and search for results based on label values.
+You can filter on nested fields. For example, you could filter on instances that have set the scheduling.automaticRestart field to true. Use filtering on nested fields to take advantage of labels to organize and search for results based on label values.
 
-The Beta API also supports filtering on multiple expressions by providing each separate expression within parentheses. For example, (scheduling.automaticRestart eq true) (zone eq us-central1-f). Multiple expressions are treated as AND expressions, meaning that resources must match all expressions to pass the filters.
+To filter on multiple expressions, provide each separate expression within parentheses. For example, (scheduling.automaticRestart eq true) (zone eq us-central1-f). Multiple expressions are treated as AND expressions, meaning that resources must match all expressions to pass the filters.
 
 Returns:
   An object of the form:
 
     { # Contains a list of BackendService resources.
-    "nextPageToken": "A String", # [Output Only] This token allows you to get the next page of results for list requests. If the number of results is larger than maxResults, use the nextPageToken as a value for the query parameter pageToken in the next list request. Subsequent list requests will have their own nextPageToken to continue paging through the results.
+    "nextPageToken": "A String", # [Output Only] A token used to continue a truncated list request.
     "items": [ # A list of BackendService resources.
       { # A BackendService resource. This resource defines a group of backend virtual machines and their serving capacity.
           "kind": "compute#backendService", # [Output Only] Type of resource. Always compute#backendService for backend services.
           "protocol": "A String", # The protocol this BackendService uses to communicate with backends.
               #
-              # Possible values are HTTP, HTTPS, HTTP2, TCP and SSL.
+              # Possible values are HTTP, HTTPS, HTTP2, TCP and SSL. The default is HTTP.
+              #
+              # For internal load balancing, the possible values are TCP and UDP, and the default is TCP.
           "description": "A String", # An optional description of this resource. Provide this property when you create the resource.
           "timeoutSec": 42, # How many seconds to wait for the backend before considering it a failed request. Default is 30 seconds.
+          "enableCDN": True or False, # If true, enable Cloud CDN for this BackendService.
+              #
+              # When the load balancing scheme is INTERNAL, this field is not used.
           "region": "A String", # [Output Only] URL of the region where the regional backend service resides. This field is not applicable to global backend services.
+          "affinityCookieTtlSec": 42, # Lifetime of cookies in seconds if session_affinity is GENERATED_COOKIE. If set to 0, the cookie is non-persistent and lasts only until the end of the browser session (or equivalent). The maximum allowed value for TTL is one day.
+              #
+              # When the load balancing scheme is INTERNAL, this field is not used.
           "port": 42, # Deprecated in favor of portName. The TCP port to connect on the backend. The default value is 80.
+              #
+              # This cannot be used for internal load balancing.
           "backends": [ # The list of backends that serve this BackendService.
             { # Message containing information of one individual backend.
               "group": "A String", # The fully-qualified URL of a zonal Instance Group resource. This instance group defines the list of instances that serve traffic. Member virtual machine instances from each instance group must live in the same zone as the instance group itself. No two backends in a backend service are allowed to use same Instance Group resource.
                   #
                   # Note that you must specify an Instance Group resource using the fully-qualified URL, rather than a partial URL.
+                  #
+                  # When the BackendService has load balancing scheme INTERNAL, the instance group must be in a zone within the same region as the BackendService.
               "description": "A String", # An optional description of this resource. Provide this property when you create the resource.
               "maxUtilization": 3.14, # Used when balancingMode is UTILIZATION. This ratio defines the CPU utilization target for the group. The default is 0.8. Valid range is [0.0, 1.0].
+                  #
+                  # This cannot be used for internal load balancing.
               "maxRatePerInstance": 3.14, # The max requests per second (RPS) that a single backend instance can handle.This is used to calculate the capacity of the group. Can be used in either balancing mode. For RATE mode, either maxRate or maxRatePerInstance must be set.
+                  #
+                  # This cannot be used for internal load balancing.
               "capacityScaler": 3.14, # A multiplier applied to the group's maximum servicing capacity (either UTILIZATION or RATE). Default value is 1, which means the group will serve up to 100% of its configured CPU or RPS (depending on balancingMode). A setting of 0 means the group is completely drained, offering 0% of its available CPU or RPS. Valid range is [0.0,1.0].
+                  #
+                  # This cannot be used for internal load balancing.
               "maxRate": 42, # The max requests per second (RPS) of the group. Can be used with either RATE or UTILIZATION balancing modes, but required if RATE mode. For RATE mode, either maxRate or maxRatePerInstance must be set.
+                  #
+                  # This cannot be used for internal load balancing.
               "balancingMode": "A String", # Specifies the balancing mode for this backend. For global HTTP(S) load balancing, the default is UTILIZATION. Valid values are UTILIZATION and RATE.
+                  #
+                  # This cannot be used for internal load balancing.
             },
           ],
           "fingerprint": "A String", # Fingerprint of this resource. A hash of the contents stored in this object. This field is used in optimistic locking. This field will be ignored when inserting a BackendService. An up-to-date fingerprint must be provided in order to update the BackendService.
-          "portName": "A String", # Name of backend port. The same name should appear in the instance groups referenced by this service. Required.
+          "portName": "A String", # Name of backend port. The same name should appear in the instance groups referenced by this service. Required when the load balancing scheme is EXTERNAL.
+              #
+              # When the load balancing scheme is INTERNAL, this field is not used.
           "healthChecks": [ # The list of URLs to the HttpHealthCheck or HttpsHealthCheck resource for health checking this BackendService. Currently at most one health check can be specified, and a health check is required.
+              #
+              # For internal load balancing, a URL to a HealthCheck resource must be specified instead.
             "A String",
           ],
+          "sessionAffinity": "A String", # Type of session affinity to use. The default is NONE.
+              #
+              # When the load balancing scheme is EXTERNAL, can be NONE, CLIENT_IP, or GENERATED_COOKIE.
+              #
+              # When the load balancing scheme is INTERNAL, can be NONE, CLIENT_IP, CLIENT_IP_PROTO, or CLIENT_IP_PORT_PROTO.
+              #
+              # When the protocol is UDP, this field is not used.
           "creationTimestamp": "A String", # [Output Only] Creation timestamp in RFC3339 text format.
           "id": "A String", # [Output Only] The unique identifier for the resource. This identifier is defined by the server.
           "selfLink": "A String", # [Output Only] Server-defined URL for the resource.
@@ -384,7 +483,7 @@
         },
     ],
     "kind": "compute#backendServiceList", # [Output Only] Type of resource. Always compute#backendServiceList for lists of backend services.
-    "id": "A String", # [Output Only] The unique identifier for the resource. This identifier is defined by the server.
+    "id": "A String", # [Output Only] Unique identifier for the resource; defined by the server.
     "selfLink": "A String", # [Output Only] Server-defined URL for this resource.
   }</pre>
 </div>
@@ -417,29 +516,62 @@
     "kind": "compute#backendService", # [Output Only] Type of resource. Always compute#backendService for backend services.
     "protocol": "A String", # The protocol this BackendService uses to communicate with backends.
         # 
-        # Possible values are HTTP, HTTPS, HTTP2, TCP and SSL.
+        # Possible values are HTTP, HTTPS, HTTP2, TCP and SSL. The default is HTTP.
+        # 
+        # For internal load balancing, the possible values are TCP and UDP, and the default is TCP.
     "description": "A String", # An optional description of this resource. Provide this property when you create the resource.
     "timeoutSec": 42, # How many seconds to wait for the backend before considering it a failed request. Default is 30 seconds.
+    "enableCDN": True or False, # If true, enable Cloud CDN for this BackendService.
+        # 
+        # When the load balancing scheme is INTERNAL, this field is not used.
     "region": "A String", # [Output Only] URL of the region where the regional backend service resides. This field is not applicable to global backend services.
+    "affinityCookieTtlSec": 42, # Lifetime of cookies in seconds if session_affinity is GENERATED_COOKIE. If set to 0, the cookie is non-persistent and lasts only until the end of the browser session (or equivalent). The maximum allowed value for TTL is one day.
+        # 
+        # When the load balancing scheme is INTERNAL, this field is not used.
     "port": 42, # Deprecated in favor of portName. The TCP port to connect on the backend. The default value is 80.
+        # 
+        # This cannot be used for internal load balancing.
     "backends": [ # The list of backends that serve this BackendService.
       { # Message containing information of one individual backend.
         "group": "A String", # The fully-qualified URL of a zonal Instance Group resource. This instance group defines the list of instances that serve traffic. Member virtual machine instances from each instance group must live in the same zone as the instance group itself. No two backends in a backend service are allowed to use same Instance Group resource.
             #
             # Note that you must specify an Instance Group resource using the fully-qualified URL, rather than a partial URL.
+            #
+            # When the BackendService has load balancing scheme INTERNAL, the instance group must be in a zone within the same region as the BackendService.
         "description": "A String", # An optional description of this resource. Provide this property when you create the resource.
         "maxUtilization": 3.14, # Used when balancingMode is UTILIZATION. This ratio defines the CPU utilization target for the group. The default is 0.8. Valid range is [0.0, 1.0].
+            #
+            # This cannot be used for internal load balancing.
         "maxRatePerInstance": 3.14, # The max requests per second (RPS) that a single backend instance can handle.This is used to calculate the capacity of the group. Can be used in either balancing mode. For RATE mode, either maxRate or maxRatePerInstance must be set.
+            #
+            # This cannot be used for internal load balancing.
         "capacityScaler": 3.14, # A multiplier applied to the group's maximum servicing capacity (either UTILIZATION or RATE). Default value is 1, which means the group will serve up to 100% of its configured CPU or RPS (depending on balancingMode). A setting of 0 means the group is completely drained, offering 0% of its available CPU or RPS. Valid range is [0.0,1.0].
+            #
+            # This cannot be used for internal load balancing.
         "maxRate": 42, # The max requests per second (RPS) of the group. Can be used with either RATE or UTILIZATION balancing modes, but required if RATE mode. For RATE mode, either maxRate or maxRatePerInstance must be set.
+            #
+            # This cannot be used for internal load balancing.
         "balancingMode": "A String", # Specifies the balancing mode for this backend. For global HTTP(S) load balancing, the default is UTILIZATION. Valid values are UTILIZATION and RATE.
+            #
+            # This cannot be used for internal load balancing.
       },
     ],
     "fingerprint": "A String", # Fingerprint of this resource. A hash of the contents stored in this object. This field is used in optimistic locking. This field will be ignored when inserting a BackendService. An up-to-date fingerprint must be provided in order to update the BackendService.
-    "portName": "A String", # Name of backend port. The same name should appear in the instance groups referenced by this service. Required.
+    "portName": "A String", # Name of backend port. The same name should appear in the instance groups referenced by this service. Required when the load balancing scheme is EXTERNAL.
+        # 
+        # When the load balancing scheme is INTERNAL, this field is not used.
     "healthChecks": [ # The list of URLs to the HttpHealthCheck or HttpsHealthCheck resource for health checking this BackendService. Currently at most one health check can be specified, and a health check is required.
+        # 
+        # For internal load balancing, a URL to a HealthCheck resource must be specified instead.
       "A String",
     ],
+    "sessionAffinity": "A String", # Type of session affinity to use. The default is NONE.
+        # 
+        # When the load balancing scheme is EXTERNAL, can be NONE, CLIENT_IP, or GENERATED_COOKIE.
+        # 
+        # When the load balancing scheme is INTERNAL, can be NONE, CLIENT_IP, CLIENT_IP_PROTO, or CLIENT_IP_PORT_PROTO.
+        # 
+        # When the protocol is UDP, this field is not used.
     "creationTimestamp": "A String", # [Output Only] Creation timestamp in RFC3339 text format.
     "id": "A String", # [Output Only] The unique identifier for the resource. This identifier is defined by the server.
     "selfLink": "A String", # [Output Only] Server-defined URL for the resource.
@@ -511,29 +643,62 @@
     "kind": "compute#backendService", # [Output Only] Type of resource. Always compute#backendService for backend services.
     "protocol": "A String", # The protocol this BackendService uses to communicate with backends.
         # 
-        # Possible values are HTTP, HTTPS, HTTP2, TCP and SSL.
+        # Possible values are HTTP, HTTPS, HTTP2, TCP and SSL. The default is HTTP.
+        # 
+        # For internal load balancing, the possible values are TCP and UDP, and the default is TCP.
     "description": "A String", # An optional description of this resource. Provide this property when you create the resource.
     "timeoutSec": 42, # How many seconds to wait for the backend before considering it a failed request. Default is 30 seconds.
+    "enableCDN": True or False, # If true, enable Cloud CDN for this BackendService.
+        # 
+        # When the load balancing scheme is INTERNAL, this field is not used.
     "region": "A String", # [Output Only] URL of the region where the regional backend service resides. This field is not applicable to global backend services.
+    "affinityCookieTtlSec": 42, # Lifetime of cookies in seconds if session_affinity is GENERATED_COOKIE. If set to 0, the cookie is non-persistent and lasts only until the end of the browser session (or equivalent). The maximum allowed value for TTL is one day.
+        # 
+        # When the load balancing scheme is INTERNAL, this field is not used.
     "port": 42, # Deprecated in favor of portName. The TCP port to connect on the backend. The default value is 80.
+        # 
+        # This cannot be used for internal load balancing.
     "backends": [ # The list of backends that serve this BackendService.
       { # Message containing information of one individual backend.
         "group": "A String", # The fully-qualified URL of a zonal Instance Group resource. This instance group defines the list of instances that serve traffic. Member virtual machine instances from each instance group must live in the same zone as the instance group itself. No two backends in a backend service are allowed to use same Instance Group resource.
             #
             # Note that you must specify an Instance Group resource using the fully-qualified URL, rather than a partial URL.
+            #
+            # When the BackendService has load balancing scheme INTERNAL, the instance group must be in a zone within the same region as the BackendService.
         "description": "A String", # An optional description of this resource. Provide this property when you create the resource.
         "maxUtilization": 3.14, # Used when balancingMode is UTILIZATION. This ratio defines the CPU utilization target for the group. The default is 0.8. Valid range is [0.0, 1.0].
+            #
+            # This cannot be used for internal load balancing.
         "maxRatePerInstance": 3.14, # The max requests per second (RPS) that a single backend instance can handle.This is used to calculate the capacity of the group. Can be used in either balancing mode. For RATE mode, either maxRate or maxRatePerInstance must be set.
+            #
+            # This cannot be used for internal load balancing.
         "capacityScaler": 3.14, # A multiplier applied to the group's maximum servicing capacity (either UTILIZATION or RATE). Default value is 1, which means the group will serve up to 100% of its configured CPU or RPS (depending on balancingMode). A setting of 0 means the group is completely drained, offering 0% of its available CPU or RPS. Valid range is [0.0,1.0].
+            #
+            # This cannot be used for internal load balancing.
         "maxRate": 42, # The max requests per second (RPS) of the group. Can be used with either RATE or UTILIZATION balancing modes, but required if RATE mode. For RATE mode, either maxRate or maxRatePerInstance must be set.
+            #
+            # This cannot be used for internal load balancing.
         "balancingMode": "A String", # Specifies the balancing mode for this backend. For global HTTP(S) load balancing, the default is UTILIZATION. Valid values are UTILIZATION and RATE.
+            #
+            # This cannot be used for internal load balancing.
       },
     ],
     "fingerprint": "A String", # Fingerprint of this resource. A hash of the contents stored in this object. This field is used in optimistic locking. This field will be ignored when inserting a BackendService. An up-to-date fingerprint must be provided in order to update the BackendService.
-    "portName": "A String", # Name of backend port. The same name should appear in the instance groups referenced by this service. Required.
+    "portName": "A String", # Name of backend port. The same name should appear in the instance groups referenced by this service. Required when the load balancing scheme is EXTERNAL.
+        # 
+        # When the load balancing scheme is INTERNAL, this field is not used.
     "healthChecks": [ # The list of URLs to the HttpHealthCheck or HttpsHealthCheck resource for health checking this BackendService. Currently at most one health check can be specified, and a health check is required.
+        # 
+        # For internal load balancing, a URL to a HealthCheck resource must be specified instead.
       "A String",
     ],
+    "sessionAffinity": "A String", # Type of session affinity to use. The default is NONE.
+        # 
+        # When the load balancing scheme is EXTERNAL, can be NONE, CLIENT_IP, or GENERATED_COOKIE.
+        # 
+        # When the load balancing scheme is INTERNAL, can be NONE, CLIENT_IP, CLIENT_IP_PROTO, or CLIENT_IP_PORT_PROTO.
+        # 
+        # When the protocol is UDP, this field is not used.
     "creationTimestamp": "A String", # [Output Only] Creation timestamp in RFC3339 text format.
     "id": "A String", # [Output Only] The unique identifier for the resource. This identifier is defined by the server.
     "selfLink": "A String", # [Output Only] Server-defined URL for the resource.