# Compute Engine API . targetPools

## Instance Methods

Adds health check URLs to a target pool.

Adds an instance to a target pool.

Retrieves an aggregated list of target pools.

Retrieves the next page of results.

Deletes the specified target pool.

Returns the specified target pool. Get a list of available target pools by making a list() request.

Gets the most recent health check results for each IP for the instance that is referenced by the given target pool.

Creates a target pool in the specified project and region using the data included in the request.

Retrieves a list of target pools available to the specified project and region.

Retrieves the next page of results.

Removes health check URL from a target pool.

Removes instance URL from a target pool.

Changes a backup target pool's configurations.

### Method Details

`addHealthCheck(project, region, targetPool, body)`

    Adds health check URLs to a target pool.

    Args:
      project: string, Project ID for this request. (required)
      region: string, Name of the region scoping this request. (required)
      targetPool: string, Name of the target pool to add a health check to. (required)
      body: object, The request body. (required)
        The object takes the form of:

    {
        "healthChecks": [ # A list of HttpHealthCheck resources to add to the target pool.
          { # A full or valid partial URL to a health check. For example, the following are valid URLs:
              # - https://www.googleapis.com/compute/beta/projects/project-id/global/httpHealthChecks/health-check
              # - projects/project-id/global/httpHealthChecks/health-check
              # - global/httpHealthChecks/health-check
            "healthCheck": "A String",
          },
        ],
      }

    Returns:
      An object of the form:

        { # An Operation resource, used to manage asynchronous API requests.
        "targetId": "A String", # [Output Only] The unique target ID, which identifies a specific incarnation of the target resource.
        "clientOperationId": "A String", # [Output Only] Reserved for future use.
        "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.
        "zone": "A String", # [Output Only] The URL of the zone where the operation resides. Only available when performing per-zone operations.
        "insertTime": "A String", # [Output Only] The time that this operation was requested. This value is in RFC3339 text format.
        "operationType": "A String", # [Output Only] The type of operation, such as insert, update, or delete, and so on.
        "httpErrorMessage": "A String", # [Output Only] If the operation fails, this field contains the HTTP error message that was returned, such as NOT FOUND.
        "progress": 42, # [Output Only] An optional progress indicator that ranges from 0 to 100. There is no requirement that this be linear or support any granularity of operations. This should not be used to guess when the operation will be complete. This number should monotonically increase as the operation progresses.
        "httpErrorStatusCode": 42, # [Output Only] If the operation fails, this field contains the HTTP error status code that was returned. For example, a 404 means the resource was not found.
        "statusMessage": "A String", # [Output Only] An optional textual description of the current status of the operation.
        "status": "A String", # [Output Only] The status of the operation, which can be one of the following: PENDING, RUNNING, or DONE.
        "description": "A String", # [Output Only] A textual description of the operation, which is set when the operation is created.
        "warnings": [ # [Output Only] If warning messages are generated during processing of the operation, this field will be populated.
          {
            "message": "A String", # [Output Only] A human-readable description of the warning code.
            "code": "A String", # [Output Only] A warning code, if applicable. For example, Compute Engine returns NO_RESULTS_ON_PAGE if there are no results in the response.
            "data": [ # [Output Only] Metadata about this warning in key: value format. For example:
                # "data": [ { "key": "scope", "value": "zones/us-east1-d" }
              {
                "value": "A String", # [Output Only] A warning data value corresponding to the key.
                "key": "A String", # [Output Only] A key that provides more detail on the warning being returned. For example, for warnings where there are no results in a list request for a particular zone, this key might be scope and the key value might be the zone name. Other examples might be a key indicating a deprecated resource and a suggested replacement, or a warning about invalid network settings (for example, if an instance attempts to perform IP forwarding but is not enabled for IP forwarding).
              },
            ],
          },
        ],
        "user": "A String", # [Output Only] User who requested the operation, for example: user@example.com.
        "startTime": "A String", # [Output Only] The time that this operation was started by the server. This value is in RFC3339 text format.
        "kind": "compute#operation", # [Output Only] Type of the resource. Always compute#operation for Operation resources.
        "name": "A String", # [Output Only] Name of the resource.
        "region": "A String", # [Output Only] The URL of the region where the operation resides. Only available when performing regional operations.
        "error": { # [Output Only] If errors are generated during processing of the operation, this field will be populated.
          "errors": [ # [Output Only] The array of errors encountered while processing this operation.
            {
              "message": "A String", # [Output Only] An optional, human-readable error message.
              "code": "A String", # [Output Only] The error type identifier for this error.
              "location": "A String", # [Output Only] Indicates the field in the request that caused the error. This property is optional.
            },
          ],
        },
        "endTime": "A String", # [Output Only] The time that this operation was completed. This value is in RFC3339 text format.
        "selfLink": "A String", # [Output Only] Server-defined URL for the resource.
        "targetLink": "A String", # [Output Only] The URL of the resource that the operation modifies.
      }

`addInstance(project, region, targetPool, body)`

    Adds an instance to a target pool.

    Args:
      project: string, Project ID for this request. (required)
      region: string, Name of the region scoping this request. (required)
      targetPool: string, Name of the TargetPool resource to add instances to. (required)
      body: object, The request body. (required)
        The object takes the form of:

    {
        "instances": [ # A full or partial URL to an instance to add to this target pool. This can be a full or partial URL. For example, the following are valid URLs:
            # - https://www.googleapis.com/compute/v1/projects/project-id/zones/zone/instances/instance-name
            # - projects/project-id/zones/zone/instances/instance-name
            # - zones/zone/instances/instance-name
          {
            "instance": "A String", # The URL for a specific instance.
          },
        ],
      }

    Returns:
      An object of the form:

        { # An Operation resource, used to manage asynchronous API requests.
        "targetId": "A String", # [Output Only] The unique target ID, which identifies a specific incarnation of the target resource.
        "clientOperationId": "A String", # [Output Only] Reserved for future use.
        "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.
        "zone": "A String", # [Output Only] The URL of the zone where the operation resides. Only available when performing per-zone operations.
        "insertTime": "A String", # [Output Only] The time that this operation was requested. This value is in RFC3339 text format.
        "operationType": "A String", # [Output Only] The type of operation, such as insert, update, or delete, and so on.
        "httpErrorMessage": "A String", # [Output Only] If the operation fails, this field contains the HTTP error message that was returned, such as NOT FOUND.
        "progress": 42, # [Output Only] An optional progress indicator that ranges from 0 to 100. There is no requirement that this be linear or support any granularity of operations. This should not be used to guess when the operation will be complete. This number should monotonically increase as the operation progresses.
        "httpErrorStatusCode": 42, # [Output Only] If the operation fails, this field contains the HTTP error status code that was returned. For example, a 404 means the resource was not found.
        "statusMessage": "A String", # [Output Only] An optional textual description of the current status of the operation.
        "status": "A String", # [Output Only] The status of the operation, which can be one of the following: PENDING, RUNNING, or DONE.
        "description": "A String", # [Output Only] A textual description of the operation, which is set when the operation is created.
        "warnings": [ # [Output Only] If warning messages are generated during processing of the operation, this field will be populated.
          {
            "message": "A String", # [Output Only] A human-readable description of the warning code.
            "code": "A String", # [Output Only] A warning code, if applicable. For example, Compute Engine returns NO_RESULTS_ON_PAGE if there are no results in the response.
            "data": [ # [Output Only] Metadata about this warning in key: value format. For example:
                # "data": [ { "key": "scope", "value": "zones/us-east1-d" }
              {
                "value": "A String", # [Output Only] A warning data value corresponding to the key.
                "key": "A String", # [Output Only] A key that provides more detail on the warning being returned. For example, for warnings where there are no results in a list request for a particular zone, this key might be scope and the key value might be the zone name. Other examples might be a key indicating a deprecated resource and a suggested replacement, or a warning about invalid network settings (for example, if an instance attempts to perform IP forwarding but is not enabled for IP forwarding).
              },
            ],
          },
        ],
        "user": "A String", # [Output Only] User who requested the operation, for example: user@example.com.
        "startTime": "A String", # [Output Only] The time that this operation was started by the server. This value is in RFC3339 text format.
        "kind": "compute#operation", # [Output Only] Type of the resource. Always compute#operation for Operation resources.
        "name": "A String", # [Output Only] Name of the resource.
        "region": "A String", # [Output Only] The URL of the region where the operation resides. Only available when performing regional operations.
        "error": { # [Output Only] If errors are generated during processing of the operation, this field will be populated.
          "errors": [ # [Output Only] The array of errors encountered while processing this operation.
            {
              "message": "A String", # [Output Only] An optional, human-readable error message.
              "code": "A String", # [Output Only] The error type identifier for this error.
              "location": "A String", # [Output Only] Indicates the field in the request that caused the error. This property is optional.
            },
          ],
        },
        "endTime": "A String", # [Output Only] The time that this operation was completed. This value is in RFC3339 text format.
        "selfLink": "A String", # [Output Only] Server-defined URL for the resource.
        "targetLink": "A String", # [Output Only] The URL of the resource that the operation modifies.
      }

`aggregatedList(project, maxResults=None, pageToken=None, filter=None)`

    Retrieves an aggregated list of target pools.

    Args:
      project: string, Project ID for this request. (required)
      maxResults: integer, The maximum number of results per page that should be returned. If the number of available results is larger than maxResults, Compute Engine returns a nextPageToken that can be used to get the next page of results in subsequent list requests.
      pageToken: string, Specifies a page token to use. Set pageToken to the nextPageToken returned by a previous list request to get the next page of results.
      filter: string, Sets a filter expression for filtering listed resources, in the form filter={expression}. Your {expression} must be in the format: field_name comparison_string literal_string.

    The field_name is the name of the field you want to compare. Only atomic field types are supported (string, number, boolean). The comparison_string must be either eq (equals) or ne (not equals). The literal_string is the string value to filter to. The literal value must be valid for the type of field you are filtering by (string, number, boolean). For string fields, the literal value is interpreted as a regular expression using RE2 syntax. The literal value must match the entire field.

    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.

    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.

    Returns:
      An object of the form:

        {
        "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.
        "items": { # [Output Only] A map of scoped target pool lists.
          "a_key": { # Name of the scope containing this set of target pools.
            "warning": { # Informational warning which replaces the list of addresses when the list is empty.
              "message": "A String", # [Output Only] A human-readable description of the warning code.
              "code": "A String", # [Output Only] A warning code, if applicable. For example, Compute Engine returns NO_RESULTS_ON_PAGE if there are no results in the response.
              "data": [ # [Output Only] Metadata about this warning in key: value format. For example:
                  # "data": [ { "key": "scope", "value": "zones/us-east1-d" }
                {
                  "value": "A String", # [Output Only] A warning data value corresponding to the key.
                  "key": "A String", # [Output Only] A key that provides more detail on the warning being returned. For example, for warnings where there are no results in a list request for a particular zone, this key might be scope and the key value might be the zone name. Other examples might be a key indicating a deprecated resource and a suggested replacement, or a warning about invalid network settings (for example, if an instance attempts to perform IP forwarding but is not enabled for IP forwarding).
                },
              ],
            },
            "targetPools": [ # List of target pools contained in this scope.
              { # A TargetPool resource. This resource defines a pool of instances, associated HttpHealthCheck resources, and the fallback target pool.
                  "failoverRatio": 3.14, # This field is applicable only when the containing target pool is serving a forwarding rule as the primary pool (i.e., not as a backup pool to some other target pool). The value of the field must be in [0, 1].
                      #
                      # If set, backupPool must also be set. They together define the fallback behavior of the primary target pool: if the ratio of the healthy instances in the primary pool is at or below this number, traffic arriving at the load-balanced IP will be directed to the backup pool.
                      #
                      # In case where failoverRatio is not set or all the instances in the backup pool are unhealthy, the traffic will be directed back to the primary pool in the "force" mode, where traffic will be spread to the healthy instances with the best effort, or to all instances when no instance is healthy.
                  "description": "A String", # An optional description of this resource. Provide this property when you create the resource.
                  "region": "A String", # [Output Only] URL of the region where the target pool resides.
                  "kind": "compute#targetPool", # [Output Only] Type of the resource. Always compute#targetPool for target pools.
                  "sessionAffinity": "A String", # Sesssion affinity option, must be one of the following values:
                      # NONE: Connections from the same client IP may go to any instance in the pool.
                      # CLIENT_IP: Connections from the same client IP will go to the same instance in the pool while that instance remains healthy.
                      # CLIENT_IP_PROTO: Connections from the same client IP with the same IP protocol will go to the same instance in the pool while that instance remains healthy.
                  "instances": [ # A list of resource URLs to the virtual machine instances serving this pool. They must live in zones contained in the same region as this pool.
                    "A String",
                  ],
                  "backupPool": "A String", # This field is applicable only when the containing target pool is serving a forwarding rule as the primary pool, and its failoverRatio field is properly set to a value between [0, 1].
                      #
                      # backupPool and failoverRatio together define the fallback behavior of the primary target pool: if the ratio of the healthy instances in the primary pool is at or below failoverRatio, traffic arriving at the load-balanced IP will be directed to the backup pool.
                      #
                      # In case where failoverRatio and backupPool are not set, or all the instances in the backup pool are unhealthy, the traffic will be directed back to the primary pool in the "force" mode, where traffic will be spread to the healthy instances with the best effort, or to all instances when no instance is healthy.
                  "healthChecks": [ # A list of URLs to the HttpHealthCheck resource. A member instance in this pool is considered healthy if and only if all specified health checks pass. An empty list means all member instances will be considered healthy at all times.
                    "A String",
                  ],
                  "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.
                  "name": "A String", # Name of the resource. Provided by the client when the resource is created. The name must be 1-63 characters long, and comply with RFC1035. Specifically, the name must be 1-63 characters long and match the regular expression [a-z]([-a-z0-9]*[a-z0-9])? which means the first character must be a lowercase letter, and all following characters must be a dash, lowercase letter, or digit, except the last character, which cannot be a dash.
                },
            ],
          },
        },
        "kind": "compute#targetPoolAggregatedList", # [Output Only] Type of resource. Always compute#targetPoolAggregatedList for aggregated lists of target pools.
        "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.
      }

`aggregatedList_next(previous_request, previous_response)`

    Retrieves the next page of results.

    Args:
      previous_request: The request for the previous page. (required)
      previous_response: The response from the request for the previous page. (required)

    Returns:
      A request object that you can call 'execute()' on to request the next
      page. Returns None if there are no more items in the collection.

`delete(project, region, targetPool)`

    Deletes the specified target pool.

    Args:
      project: string, Project ID for this request. (required)
      region: string, Name of the region scoping this request. (required)
      targetPool: string, Name of the TargetPool resource to delete. (required)

    Returns:
      An object of the form:

        { # An Operation resource, used to manage asynchronous API requests.
        "targetId": "A String", # [Output Only] The unique target ID, which identifies a specific incarnation of the target resource.
        "clientOperationId": "A String", # [Output Only] Reserved for future use.
        "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.
        "zone": "A String", # [Output Only] The URL of the zone where the operation resides. Only available when performing per-zone operations.
        "insertTime": "A String", # [Output Only] The time that this operation was requested. This value is in RFC3339 text format.
        "operationType": "A String", # [Output Only] The type of operation, such as insert, update, or delete, and so on.
        "httpErrorMessage": "A String", # [Output Only] If the operation fails, this field contains the HTTP error message that was returned, such as NOT FOUND.
        "progress": 42, # [Output Only] An optional progress indicator that ranges from 0 to 100. There is no requirement that this be linear or support any granularity of operations. This should not be used to guess when the operation will be complete. This number should monotonically increase as the operation progresses.
        "httpErrorStatusCode": 42, # [Output Only] If the operation fails, this field contains the HTTP error status code that was returned. For example, a 404 means the resource was not found.
        "statusMessage": "A String", # [Output Only] An optional textual description of the current status of the operation.
        "status": "A String", # [Output Only] The status of the operation, which can be one of the following: PENDING, RUNNING, or DONE.
        "description": "A String", # [Output Only] A textual description of the operation, which is set when the operation is created.
        "warnings": [ # [Output Only] If warning messages are generated during processing of the operation, this field will be populated.
          {
            "message": "A String", # [Output Only] A human-readable description of the warning code.
            "code": "A String", # [Output Only] A warning code, if applicable. For example, Compute Engine returns NO_RESULTS_ON_PAGE if there are no results in the response.
            "data": [ # [Output Only] Metadata about this warning in key: value format. For example:
                # "data": [ { "key": "scope", "value": "zones/us-east1-d" }
              {
                "value": "A String", # [Output Only] A warning data value corresponding to the key.
                "key": "A String", # [Output Only] A key that provides more detail on the warning being returned. For example, for warnings where there are no results in a list request for a particular zone, this key might be scope and the key value might be the zone name. Other examples might be a key indicating a deprecated resource and a suggested replacement, or a warning about invalid network settings (for example, if an instance attempts to perform IP forwarding but is not enabled for IP forwarding).
              },
            ],
          },
        ],
        "user": "A String", # [Output Only] User who requested the operation, for example: user@example.com.
        "startTime": "A String", # [Output Only] The time that this operation was started by the server. This value is in RFC3339 text format.
        "kind": "compute#operation", # [Output Only] Type of the resource. Always compute#operation for Operation resources.
        "name": "A String", # [Output Only] Name of the resource.
        "region": "A String", # [Output Only] The URL of the region where the operation resides. Only available when performing regional operations.
        "error": { # [Output Only] If errors are generated during processing of the operation, this field will be populated.
          "errors": [ # [Output Only] The array of errors encountered while processing this operation.
            {
              "message": "A String", # [Output Only] An optional, human-readable error message.
              "code": "A String", # [Output Only] The error type identifier for this error.
              "location": "A String", # [Output Only] Indicates the field in the request that caused the error. This property is optional.
            },
          ],
        },
        "endTime": "A String", # [Output Only] The time that this operation was completed. This value is in RFC3339 text format.
        "selfLink": "A String", # [Output Only] Server-defined URL for the resource.
        "targetLink": "A String", # [Output Only] The URL of the resource that the operation modifies.
      }

`get(project, region, targetPool)`

    Returns the specified target pool. Get a list of available target pools by making a list() request.

    Args:
      project: string, Project ID for this request. (required)
      region: string, Name of the region scoping this request. (required)
      targetPool: string, Name of the TargetPool resource to return. (required)

    Returns:
      An object of the form:

        { # A TargetPool resource. This resource defines a pool of instances, associated HttpHealthCheck resources, and the fallback target pool.
          "failoverRatio": 3.14, # This field is applicable only when the containing target pool is serving a forwarding rule as the primary pool (i.e., not as a backup pool to some other target pool). The value of the field must be in [0, 1].
              #
              # If set, backupPool must also be set. They together define the fallback behavior of the primary target pool: if the ratio of the healthy instances in the primary pool is at or below this number, traffic arriving at the load-balanced IP will be directed to the backup pool.
              #
              # In case where failoverRatio is not set or all the instances in the backup pool are unhealthy, the traffic will be directed back to the primary pool in the "force" mode, where traffic will be spread to the healthy instances with the best effort, or to all instances when no instance is healthy.
          "description": "A String", # An optional description of this resource. Provide this property when you create the resource.
          "region": "A String", # [Output Only] URL of the region where the target pool resides.
          "kind": "compute#targetPool", # [Output Only] Type of the resource. Always compute#targetPool for target pools.
          "sessionAffinity": "A String", # Sesssion affinity option, must be one of the following values:
              # NONE: Connections from the same client IP may go to any instance in the pool.
              # CLIENT_IP: Connections from the same client IP will go to the same instance in the pool while that instance remains healthy.
              # CLIENT_IP_PROTO: Connections from the same client IP with the same IP protocol will go to the same instance in the pool while that instance remains healthy.
          "instances": [ # A list of resource URLs to the virtual machine instances serving this pool. They must live in zones contained in the same region as this pool.
            "A String",
          ],
          "backupPool": "A String", # This field is applicable only when the containing target pool is serving a forwarding rule as the primary pool, and its failoverRatio field is properly set to a value between [0, 1].
              #
              # backupPool and failoverRatio together define the fallback behavior of the primary target pool: if the ratio of the healthy instances in the primary pool is at or below failoverRatio, traffic arriving at the load-balanced IP will be directed to the backup pool.
              #
              # In case where failoverRatio and backupPool are not set, or all the instances in the backup pool are unhealthy, the traffic will be directed back to the primary pool in the "force" mode, where traffic will be spread to the healthy instances with the best effort, or to all instances when no instance is healthy.
          "healthChecks": [ # A list of URLs to the HttpHealthCheck resource. A member instance in this pool is considered healthy if and only if all specified health checks pass. An empty list means all member instances will be considered healthy at all times.
            "A String",
          ],
          "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.
          "name": "A String", # Name of the resource. Provided by the client when the resource is created. The name must be 1-63 characters long, and comply with RFC1035. Specifically, the name must be 1-63 characters long and match the regular expression [a-z]([-a-z0-9]*[a-z0-9])? which means the first character must be a lowercase letter, and all following characters must be a dash, lowercase letter, or digit, except the last character, which cannot be a dash.
        }

`getHealth(project, region, targetPool, body)`

    Gets the most recent health check results for each IP for the instance that is referenced by the given target pool.

    Args:
      project: string, Project ID for this request. (required)
      region: string, Name of the region scoping this request. (required)
      targetPool: string, Name of the TargetPool resource to which the queried instance belongs. (required)
      body: object, The request body. (required)
        The object takes the form of:

    {
      "instance": "A String", # The URL for a specific instance.
    }

    Returns:
      An object of the form:

        {
        "kind": "compute#targetPoolInstanceHealth", # [Output Only] Type of resource. Always compute#targetPoolInstanceHealth when checking the health of an instance.
        "healthStatus": [
          {
            "instance": "A String", # URL of the instance resource.
            "healthState": "A String", # Health state of the instance.
            "ipAddress": "A String", # The IP address represented by this resource.
            "port": 42, # The port on the instance.
          },
        ],
      }

`insert(project, region, body)`

    Creates a target pool in the specified project and region using the data included in the request.

    Args:
      project: string, Project ID for this request. (required)
      region: string, Name of the region scoping this request. (required)
      body: object, The request body. (required)
        The object takes the form of:

    { # A TargetPool resource. This resource defines a pool of instances, associated HttpHealthCheck resources, and the fallback target pool.
        "failoverRatio": 3.14, # This field is applicable only when the containing target pool is serving a forwarding rule as the primary pool (i.e., not as a backup pool to some other target pool). The value of the field must be in [0, 1].
            #
            # If set, backupPool must also be set. They together define the fallback behavior of the primary target pool: if the ratio of the healthy instances in the primary pool is at or below this number, traffic arriving at the load-balanced IP will be directed to the backup pool.
            #
            # In case where failoverRatio is not set or all the instances in the backup pool are unhealthy, the traffic will be directed back to the primary pool in the "force" mode, where traffic will be spread to the healthy instances with the best effort, or to all instances when no instance is healthy.
        "description": "A String", # An optional description of this resource. Provide this property when you create the resource.
        "region": "A String", # [Output Only] URL of the region where the target pool resides.
        "kind": "compute#targetPool", # [Output Only] Type of the resource. Always compute#targetPool for target pools.
        "sessionAffinity": "A String", # Sesssion affinity option, must be one of the following values:
            # NONE: Connections from the same client IP may go to any instance in the pool.
            # CLIENT_IP: Connections from the same client IP will go to the same instance in the pool while that instance remains healthy.
            # CLIENT_IP_PROTO: Connections from the same client IP with the same IP protocol will go to the same instance in the pool while that instance remains healthy.
        "instances": [ # A list of resource URLs to the virtual machine instances serving this pool. They must live in zones contained in the same region as this pool.
          "A String",
        ],
        "backupPool": "A String", # This field is applicable only when the containing target pool is serving a forwarding rule as the primary pool, and its failoverRatio field is properly set to a value between [0, 1].
            #
            # backupPool and failoverRatio together define the fallback behavior of the primary target pool: if the ratio of the healthy instances in the primary pool is at or below failoverRatio, traffic arriving at the load-balanced IP will be directed to the backup pool.
            #
            # In case where failoverRatio and backupPool are not set, or all the instances in the backup pool are unhealthy, the traffic will be directed back to the primary pool in the "force" mode, where traffic will be spread to the healthy instances with the best effort, or to all instances when no instance is healthy.
        "healthChecks": [ # A list of URLs to the HttpHealthCheck resource. A member instance in this pool is considered healthy if and only if all specified health checks pass. An empty list means all member instances will be considered healthy at all times.
          "A String",
        ],
        "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.
        "name": "A String", # Name of the resource. Provided by the client when the resource is created. The name must be 1-63 characters long, and comply with RFC1035. Specifically, the name must be 1-63 characters long and match the regular expression [a-z]([-a-z0-9]*[a-z0-9])? which means the first character must be a lowercase letter, and all following characters must be a dash, lowercase letter, or digit, except the last character, which cannot be a dash.
      }

    Returns:
      An object of the form:

        { # An Operation resource, used to manage asynchronous API requests.
        "targetId": "A String", # [Output Only] The unique target ID, which identifies a specific incarnation of the target resource.
        "clientOperationId": "A String", # [Output Only] Reserved for future use.
        "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.
        "zone": "A String", # [Output Only] The URL of the zone where the operation resides. Only available when performing per-zone operations.
        "insertTime": "A String", # [Output Only] The time that this operation was requested. This value is in RFC3339 text format.
        "operationType": "A String", # [Output Only] The type of operation, such as insert, update, or delete, and so on.
        "httpErrorMessage": "A String", # [Output Only] If the operation fails, this field contains the HTTP error message that was returned, such as NOT FOUND.
        "progress": 42, # [Output Only] An optional progress indicator that ranges from 0 to 100. There is no requirement that this be linear or support any granularity of operations. This should not be used to guess when the operation will be complete. This number should monotonically increase as the operation progresses.
        "httpErrorStatusCode": 42, # [Output Only] If the operation fails, this field contains the HTTP error status code that was returned. For example, a 404 means the resource was not found.
        "statusMessage": "A String", # [Output Only] An optional textual description of the current status of the operation.
        "status": "A String", # [Output Only] The status of the operation, which can be one of the following: PENDING, RUNNING, or DONE.
        "description": "A String", # [Output Only] A textual description of the operation, which is set when the operation is created.
        "warnings": [ # [Output Only] If warning messages are generated during processing of the operation, this field will be populated.
          {
            "message": "A String", # [Output Only] A human-readable description of the warning code.
            "code": "A String", # [Output Only] A warning code, if applicable. For example, Compute Engine returns NO_RESULTS_ON_PAGE if there are no results in the response.
            "data": [ # [Output Only] Metadata about this warning in key: value format. For example:
                # "data": [ { "key": "scope", "value": "zones/us-east1-d" }
              {
                "value": "A String", # [Output Only] A warning data value corresponding to the key.
                "key": "A String", # [Output Only] A key that provides more detail on the warning being returned. For example, for warnings where there are no results in a list request for a particular zone, this key might be scope and the key value might be the zone name. Other examples might be a key indicating a deprecated resource and a suggested replacement, or a warning about invalid network settings (for example, if an instance attempts to perform IP forwarding but is not enabled for IP forwarding).
              },
            ],
          },
        ],
        "user": "A String", # [Output Only] User who requested the operation, for example: user@example.com.
        "startTime": "A String", # [Output Only] The time that this operation was started by the server. This value is in RFC3339 text format.
        "kind": "compute#operation", # [Output Only] Type of the resource. Always compute#operation for Operation resources.
        "name": "A String", # [Output Only] Name of the resource.
        "region": "A String", # [Output Only] The URL of the region where the operation resides. Only available when performing regional operations.
        "error": { # [Output Only] If errors are generated during processing of the operation, this field will be populated.
          "errors": [ # [Output Only] The array of errors encountered while processing this operation.
            {
              "message": "A String", # [Output Only] An optional, human-readable error message.
              "code": "A String", # [Output Only] The error type identifier for this error.
              "location": "A String", # [Output Only] Indicates the field in the request that caused the error. This property is optional.
            },
          ],
        },
        "endTime": "A String", # [Output Only] The time that this operation was completed. This value is in RFC3339 text format.
        "selfLink": "A String", # [Output Only] Server-defined URL for the resource.
        "targetLink": "A String", # [Output Only] The URL of the resource that the operation modifies.
      }

`list(project, region, maxResults=None, pageToken=None, filter=None)`

    Retrieves a list of target pools available to the specified project and region.

    Args:
      project: string, Project ID for this request. (required)
      region: string, Name of the region scoping this request. (required)
      maxResults: integer, The maximum number of results per page that should be returned. If the number of available results is larger than maxResults, Compute Engine returns a nextPageToken that can be used to get the next page of results in subsequent list requests.
      pageToken: string, Specifies a page token to use. Set pageToken to the nextPageToken returned by a previous list request to get the next page of results.
      filter: string, Sets a filter expression for filtering listed resources, in the form filter={expression}. Your {expression} must be in the format: field_name comparison_string literal_string.

    The field_name is the name of the field you want to compare. Only atomic field types are supported (string, number, boolean). The comparison_string must be either eq (equals) or ne (not equals). The literal_string is the string value to filter to. The literal value must be valid for the type of field you are filtering by (string, number, boolean). For string fields, the literal value is interpreted as a regular expression using RE2 syntax. The literal value must match the entire field.

    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.

    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.

    Returns:
      An object of the form:

        { # Contains a list of TargetPool 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.
        "items": [ # A list of TargetPool resources.
          { # A TargetPool resource. This resource defines a pool of instances, associated HttpHealthCheck resources, and the fallback target pool.
              "failoverRatio": 3.14, # This field is applicable only when the containing target pool is serving a forwarding rule as the primary pool (i.e., not as a backup pool to some other target pool). The value of the field must be in [0, 1].
                  #
                  # If set, backupPool must also be set. They together define the fallback behavior of the primary target pool: if the ratio of the healthy instances in the primary pool is at or below this number, traffic arriving at the load-balanced IP will be directed to the backup pool.
                  #
                  # In case where failoverRatio is not set or all the instances in the backup pool are unhealthy, the traffic will be directed back to the primary pool in the "force" mode, where traffic will be spread to the healthy instances with the best effort, or to all instances when no instance is healthy.
              "description": "A String", # An optional description of this resource. Provide this property when you create the resource.
              "region": "A String", # [Output Only] URL of the region where the target pool resides.
              "kind": "compute#targetPool", # [Output Only] Type of the resource. Always compute#targetPool for target pools.
              "sessionAffinity": "A String", # Sesssion affinity option, must be one of the following values:
                  # NONE: Connections from the same client IP may go to any instance in the pool.
                  # CLIENT_IP: Connections from the same client IP will go to the same instance in the pool while that instance remains healthy.
                  # CLIENT_IP_PROTO: Connections from the same client IP with the same IP protocol will go to the same instance in the pool while that instance remains healthy.
              "instances": [ # A list of resource URLs to the virtual machine instances serving this pool. They must live in zones contained in the same region as this pool.
                "A String",
              ],
              "backupPool": "A String", # This field is applicable only when the containing target pool is serving a forwarding rule as the primary pool, and its failoverRatio field is properly set to a value between [0, 1].
                  #
                  # backupPool and failoverRatio together define the fallback behavior of the primary target pool: if the ratio of the healthy instances in the primary pool is at or below failoverRatio, traffic arriving at the load-balanced IP will be directed to the backup pool.
                  #
                  # In case where failoverRatio and backupPool are not set, or all the instances in the backup pool are unhealthy, the traffic will be directed back to the primary pool in the "force" mode, where traffic will be spread to the healthy instances with the best effort, or to all instances when no instance is healthy.
              "healthChecks": [ # A list of URLs to the HttpHealthCheck resource. A member instance in this pool is considered healthy if and only if all specified health checks pass. An empty list means all member instances will be considered healthy at all times.
                "A String",
              ],
              "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.
              "name": "A String", # Name of the resource. Provided by the client when the resource is created. The name must be 1-63 characters long, and comply with RFC1035. Specifically, the name must be 1-63 characters long and match the regular expression [a-z]([-a-z0-9]*[a-z0-9])? which means the first character must be a lowercase letter, and all following characters must be a dash, lowercase letter, or digit, except the last character, which cannot be a dash.
            },
        ],
        "kind": "compute#targetPoolList", # [Output Only] Type of resource. Always compute#targetPoolList for lists of target pools.
        "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.
      }

`list_next(previous_request, previous_response)`

    Retrieves the next page of results.

    Args:
      previous_request: The request for the previous page. (required)
      previous_response: The response from the request for the previous page. (required)

    Returns:
      A request object that you can call 'execute()' on to request the next
      page. Returns None if there are no more items in the collection.

`removeHealthCheck(project, region, targetPool, body)`

    Removes health check URL from a target pool.

    Args:
      project: string, Project ID for this request. (required)
      region: string, Name of the region for this request. (required)
      targetPool: string, Name of the target pool to remove health checks from. (required)
      body: object, The request body. (required)
        The object takes the form of:

    {
        "healthChecks": [ # Health check URL to be removed. This can be a full or valid partial URL. For example, the following are valid URLs:
            # - https://www.googleapis.com/compute/beta/projects/project/global/httpHealthChecks/health-check
            # - projects/project/global/httpHealthChecks/health-check
            # - global/httpHealthChecks/health-check
          { # A full or valid partial URL to a health check. For example, the following are valid URLs:
              # - https://www.googleapis.com/compute/beta/projects/project-id/global/httpHealthChecks/health-check
              # - projects/project-id/global/httpHealthChecks/health-check
              # - global/httpHealthChecks/health-check
            "healthCheck": "A String",
          },
        ],
      }

    Returns:
      An object of the form:

        { # An Operation resource, used to manage asynchronous API requests.
        "targetId": "A String", # [Output Only] The unique target ID, which identifies a specific incarnation of the target resource.
        "clientOperationId": "A String", # [Output Only] Reserved for future use.
        "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.
        "zone": "A String", # [Output Only] The URL of the zone where the operation resides. Only available when performing per-zone operations.
        "insertTime": "A String", # [Output Only] The time that this operation was requested. This value is in RFC3339 text format.
        "operationType": "A String", # [Output Only] The type of operation, such as insert, update, or delete, and so on.
        "httpErrorMessage": "A String", # [Output Only] If the operation fails, this field contains the HTTP error message that was returned, such as NOT FOUND.
        "progress": 42, # [Output Only] An optional progress indicator that ranges from 0 to 100. There is no requirement that this be linear or support any granularity of operations. This should not be used to guess when the operation will be complete. This number should monotonically increase as the operation progresses.
        "httpErrorStatusCode": 42, # [Output Only] If the operation fails, this field contains the HTTP error status code that was returned. For example, a 404 means the resource was not found.
        "statusMessage": "A String", # [Output Only] An optional textual description of the current status of the operation.
        "status": "A String", # [Output Only] The status of the operation, which can be one of the following: PENDING, RUNNING, or DONE.
        "description": "A String", # [Output Only] A textual description of the operation, which is set when the operation is created.
        "warnings": [ # [Output Only] If warning messages are generated during processing of the operation, this field will be populated.
          {
            "message": "A String", # [Output Only] A human-readable description of the warning code.
            "code": "A String", # [Output Only] A warning code, if applicable. For example, Compute Engine returns NO_RESULTS_ON_PAGE if there are no results in the response.
            "data": [ # [Output Only] Metadata about this warning in key: value format. For example:
                # "data": [ { "key": "scope", "value": "zones/us-east1-d" }
              {
                "value": "A String", # [Output Only] A warning data value corresponding to the key.
                "key": "A String", # [Output Only] A key that provides more detail on the warning being returned. For example, for warnings where there are no results in a list request for a particular zone, this key might be scope and the key value might be the zone name. Other examples might be a key indicating a deprecated resource and a suggested replacement, or a warning about invalid network settings (for example, if an instance attempts to perform IP forwarding but is not enabled for IP forwarding).
              },
            ],
          },
        ],
        "user": "A String", # [Output Only] User who requested the operation, for example: user@example.com.
        "startTime": "A String", # [Output Only] The time that this operation was started by the server. This value is in RFC3339 text format.
        "kind": "compute#operation", # [Output Only] Type of the resource. Always compute#operation for Operation resources.
        "name": "A String", # [Output Only] Name of the resource.
        "region": "A String", # [Output Only] The URL of the region where the operation resides. Only available when performing regional operations.
        "error": { # [Output Only] If errors are generated during processing of the operation, this field will be populated.
          "errors": [ # [Output Only] The array of errors encountered while processing this operation.
            {
              "message": "A String", # [Output Only] An optional, human-readable error message.
              "code": "A String", # [Output Only] The error type identifier for this error.
              "location": "A String", # [Output Only] Indicates the field in the request that caused the error. This property is optional.
            },
          ],
        },
        "endTime": "A String", # [Output Only] The time that this operation was completed. This value is in RFC3339 text format.
        "selfLink": "A String", # [Output Only] Server-defined URL for the resource.
        "targetLink": "A String", # [Output Only] The URL of the resource that the operation modifies.
      }

`removeInstance(project, region, targetPool, body)`

    Removes instance URL from a target pool.

    Args:
      project: string, Project ID for this request. (required)
      region: string, Name of the region scoping this request. (required)
      targetPool: string, Name of the TargetPool resource to remove instances from. (required)
      body: object, The request body. (required)
        The object takes the form of:

    {
        "instances": [ # URLs of the instances to be removed from target pool.
          {
            "instance": "A String", # The URL for a specific instance.
          },
        ],
      }

    Returns:
      An object of the form:

        { # An Operation resource, used to manage asynchronous API requests.
        "targetId": "A String", # [Output Only] The unique target ID, which identifies a specific incarnation of the target resource.
        "clientOperationId": "A String", # [Output Only] Reserved for future use.
        "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.
        "zone": "A String", # [Output Only] The URL of the zone where the operation resides. Only available when performing per-zone operations.
        "insertTime": "A String", # [Output Only] The time that this operation was requested. This value is in RFC3339 text format.
        "operationType": "A String", # [Output Only] The type of operation, such as insert, update, or delete, and so on.
        "httpErrorMessage": "A String", # [Output Only] If the operation fails, this field contains the HTTP error message that was returned, such as NOT FOUND.
        "progress": 42, # [Output Only] An optional progress indicator that ranges from 0 to 100. There is no requirement that this be linear or support any granularity of operations. This should not be used to guess when the operation will be complete. This number should monotonically increase as the operation progresses.
        "httpErrorStatusCode": 42, # [Output Only] If the operation fails, this field contains the HTTP error status code that was returned. For example, a 404 means the resource was not found.
        "statusMessage": "A String", # [Output Only] An optional textual description of the current status of the operation.
        "status": "A String", # [Output Only] The status of the operation, which can be one of the following: PENDING, RUNNING, or DONE.
        "description": "A String", # [Output Only] A textual description of the operation, which is set when the operation is created.
        "warnings": [ # [Output Only] If warning messages are generated during processing of the operation, this field will be populated.
          {
            "message": "A String", # [Output Only] A human-readable description of the warning code.
            "code": "A String", # [Output Only] A warning code, if applicable. For example, Compute Engine returns NO_RESULTS_ON_PAGE if there are no results in the response.
            "data": [ # [Output Only] Metadata about this warning in key: value format. For example:
                # "data": [ { "key": "scope", "value": "zones/us-east1-d" }
              {
                "value": "A String", # [Output Only] A warning data value corresponding to the key.
                "key": "A String", # [Output Only] A key that provides more detail on the warning being returned. For example, for warnings where there are no results in a list request for a particular zone, this key might be scope and the key value might be the zone name. Other examples might be a key indicating a deprecated resource and a suggested replacement, or a warning about invalid network settings (for example, if an instance attempts to perform IP forwarding but is not enabled for IP forwarding).
              },
            ],
          },
        ],
        "user": "A String", # [Output Only] User who requested the operation, for example: user@example.com.
        "startTime": "A String", # [Output Only] The time that this operation was started by the server. This value is in RFC3339 text format.
        "kind": "compute#operation", # [Output Only] Type of the resource. Always compute#operation for Operation resources.
        "name": "A String", # [Output Only] Name of the resource.
        "region": "A String", # [Output Only] The URL of the region where the operation resides. Only available when performing regional operations.
        "error": { # [Output Only] If errors are generated during processing of the operation, this field will be populated.
          "errors": [ # [Output Only] The array of errors encountered while processing this operation.
            {
              "message": "A String", # [Output Only] An optional, human-readable error message.
              "code": "A String", # [Output Only] The error type identifier for this error.
              "location": "A String", # [Output Only] Indicates the field in the request that caused the error. This property is optional.
            },
          ],
        },
        "endTime": "A String", # [Output Only] The time that this operation was completed. This value is in RFC3339 text format.
        "selfLink": "A String", # [Output Only] Server-defined URL for the resource.
        "targetLink": "A String", # [Output Only] The URL of the resource that the operation modifies.
      }

`setBackup(project, region, targetPool, body, failoverRatio=None)`

    Changes a backup target pool's configurations.

    Args:
      project: string, Project ID for this request. (required)
      region: string, Name of the region scoping this request. (required)
      targetPool: string, Name of the TargetPool resource to set a backup pool for. (required)
      body: object, The request body. (required)
        The object takes the form of:

    {
        "target": "A String",
      }

      failoverRatio: number, New failoverRatio value for the target pool.

    Returns:
      An object of the form:

        { # An Operation resource, used to manage asynchronous API requests.
        "targetId": "A String", # [Output Only] The unique target ID, which identifies a specific incarnation of the target resource.
        "clientOperationId": "A String", # [Output Only] Reserved for future use.
        "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.
        "zone": "A String", # [Output Only] The URL of the zone where the operation resides. Only available when performing per-zone operations.
        "insertTime": "A String", # [Output Only] The time that this operation was requested. This value is in RFC3339 text format.
        "operationType": "A String", # [Output Only] The type of operation, such as insert, update, or delete, and so on.
        "httpErrorMessage": "A String", # [Output Only] If the operation fails, this field contains the HTTP error message that was returned, such as NOT FOUND.
        "progress": 42, # [Output Only] An optional progress indicator that ranges from 0 to 100. There is no requirement that this be linear or support any granularity of operations. This should not be used to guess when the operation will be complete. This number should monotonically increase as the operation progresses.
        "httpErrorStatusCode": 42, # [Output Only] If the operation fails, this field contains the HTTP error status code that was returned. For example, a 404 means the resource was not found.
        "statusMessage": "A String", # [Output Only] An optional textual description of the current status of the operation.
        "status": "A String", # [Output Only] The status of the operation, which can be one of the following: PENDING, RUNNING, or DONE.
        "description": "A String", # [Output Only] A textual description of the operation, which is set when the operation is created.
        "warnings": [ # [Output Only] If warning messages are generated during processing of the operation, this field will be populated.
          {
            "message": "A String", # [Output Only] A human-readable description of the warning code.
            "code": "A String", # [Output Only] A warning code, if applicable. For example, Compute Engine returns NO_RESULTS_ON_PAGE if there are no results in the response.
            "data": [ # [Output Only] Metadata about this warning in key: value format. For example:
                # "data": [ { "key": "scope", "value": "zones/us-east1-d" }
              {
                "value": "A String", # [Output Only] A warning data value corresponding to the key.
                "key": "A String", # [Output Only] A key that provides more detail on the warning being returned. For example, for warnings where there are no results in a list request for a particular zone, this key might be scope and the key value might be the zone name. Other examples might be a key indicating a deprecated resource and a suggested replacement, or a warning about invalid network settings (for example, if an instance attempts to perform IP forwarding but is not enabled for IP forwarding).
              },
            ],
          },
        ],
        "user": "A String", # [Output Only] User who requested the operation, for example: user@example.com.
        "startTime": "A String", # [Output Only] The time that this operation was started by the server. This value is in RFC3339 text format.
        "kind": "compute#operation", # [Output Only] Type of the resource. Always compute#operation for Operation resources.
        "name": "A String", # [Output Only] Name of the resource.
        "region": "A String", # [Output Only] The URL of the region where the operation resides. Only available when performing regional operations.
        "error": { # [Output Only] If errors are generated during processing of the operation, this field will be populated.
          "errors": [ # [Output Only] The array of errors encountered while processing this operation.
            {
              "message": "A String", # [Output Only] An optional, human-readable error message.
              "code": "A String", # [Output Only] The error type identifier for this error.
              "location": "A String", # [Output Only] Indicates the field in the request that caused the error. This property is optional.
            },
          ],
        },
        "endTime": "A String", # [Output Only] The time that this operation was completed. This value is in RFC3339 text format.
        "selfLink": "A String", # [Output Only] Server-defined URL for the resource.
        "targetLink": "A String", # [Output Only] The URL of the resource that the operation modifies.
      }