Method: backendServices.get

Returns the specified BackendService resource. Gets a list of available backend services.

HTTP request

GET https://www.googleapis.com/compute/beta/projects/{project}/global/backendServices/{resourceId}

The URL uses gRPC Transcoding syntax.

Path parameters

Parameters
project

string

Project ID for this request.

resourceId

string

Name of the BackendService resource to return.

Request body

The request body must be empty.

Response body

If successful, the response body contains data with the following structure:

A BackendService resource. This resource defines a group of backend virtual machines and their serving capacity.

JSON representation
{
  "id": string,
  "creationTimestamp": string,
  "name": string,
  "description": string,
  "selfLink": string,
  "backends": [
    {
      "description": string,
      "group": string,
      "balancingMode": enum,
      "maxUtilization": number,
      "maxRate": number,
      "maxRatePerInstance": number,
      "maxRatePerEndpoint": number,
      "maxConnections": number,
      "maxConnectionsPerInstance": number,
      "maxConnectionsPerEndpoint": number,
      "capacityScaler": number,
      "failover": boolean
    }
  ],
  "healthChecks": [
    string
  ],
  "timeoutSec": number,
  "port": number,
  "protocol": enum,
  "fingerprint": string,
  "portName": string,
  "enableCDN": boolean,
  "sessionAffinity": enum,
  "affinityCookieTtlSec": number,
  "region": string,
  "failoverPolicy": {
    "disableConnectionDrainOnFailover": boolean,
    "dropTrafficIfUnhealthy": boolean,
    "failoverRatio": number
  },
  "loadBalancingScheme": enum,
  "connectionDraining": {
    "drainingTimeoutSec": number
  },
  "iap": {
    "enabled": boolean,
    "oauth2ClientId": string,
    "oauth2ClientSecret": string,
    "oauth2ClientSecretSha256": string
  },
  "cdnPolicy": {
    "cacheKeyPolicy": {
      "includeProtocol": boolean,
      "includeHost": boolean,
      "includeQueryString": boolean,
      "queryStringWhitelist": [
        string
      ],
      "queryStringBlacklist": [
        string
      ]
    },
    "signedUrlKeyNames": [
      string
    ],
    "signedUrlCacheMaxAgeSec": string
  },
  "customRequestHeaders": [
    string
  ],
  "securityPolicy": string,
  "logConfig": {
    "enable": boolean,
    "sampleRate": number
  },
  "kind": string
}
Fields
id

string (fixed64 format)

[Output Only] The unique identifier for the resource. This identifier is defined by the server.

creationTimestamp

string

[Output Only] Creation timestamp in RFC3339 text format.

name

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.

description

string

An optional description of this resource. Provide this property when you create the resource.

backends[]

object

The list of backends that serve this BackendService.

backends[].description

string

An optional description of this resource. Provide this property when you create the resource.

backends[].group

string

The fully-qualified URL of an Instance Group or Network Endpoint Group resource. In case of instance group this 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.

For Network Endpoint Groups this defines list of endpoints. All endpoints of Network Endpoint Group must be hosted on instances located in the same zone as the Network Endpoint Group.

Backend service can not contain mix of Instance Group and Network Endpoint Group backends.

Note that you must specify an Instance Group or Network Endpoint 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 within the same region as the BackendService. Network Endpoint Groups are not supported for INTERNAL load balancing scheme.

backends[].balancingMode

enum

Specifies the balancing mode for this backend. For global HTTP(S) or TCP/SSL load balancing, the default is UTILIZATION. Valid values are UTILIZATION, RATE (for HTTP(S)) and CONNECTION (for TCP/SSL).

For Internal Load Balancing, the default and only supported mode is CONNECTION.

backends[].maxUtilization

number

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.

backends[].maxRate

number

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.

backends[].maxRatePerInstance

number

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.

backends[].maxRatePerEndpoint

number

The max requests per second (RPS) that a single backend network endpoint 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 maxRatePerEndpoint must be set.

This cannot be used for internal load balancing.

backends[].maxConnections

number

The max number of simultaneous connections for the group. Can be used with either CONNECTION or UTILIZATION balancing modes. For CONNECTION mode, either maxConnections or maxConnectionsPerInstance must be set.

This cannot be used for internal load balancing.

backends[].maxConnectionsPerInstance

number

The max number of simultaneous connections that a single backend instance can handle. This is used to calculate the capacity of the group. Can be used in either CONNECTION or UTILIZATION balancing modes. For CONNECTION mode, either maxConnections or maxConnectionsPerInstance must be set.

This cannot be used for internal load balancing.

backends[].maxConnectionsPerEndpoint

number

The max number of simultaneous connections that a single backend network endpoint can handle. This is used to calculate the capacity of the group. Can be used in either CONNECTION or UTILIZATION balancing modes. For CONNECTION mode, either maxConnections or maxConnectionsPerEndpoint must be set.

This cannot be used for internal load balancing.

backends[].capacityScaler

number

A multiplier applied to the group's maximum servicing capacity (based on UTILIZATION, RATE or CONNECTION). Default value is 1, which means the group will serve up to 100% of its configured capacity (depending on balancingMode). A setting of 0 means the group is completely drained, offering 0% of its available Capacity. Valid range is [0.0,1.0].

This cannot be used for internal load balancing.

backends[].failover

boolean

This field designates whether this is a failover backend. More than one failover backend can be configured for a given BackendService.

healthChecks[]

string

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 Compute Engine backend services. A health check must not be specified for App Engine backend and Cloud Function backend.

For internal load balancing, a URL to a HealthCheck resource must be specified instead.

timeoutSec

number

How many seconds to wait for the backend before considering it a failed request. Default is 30 seconds.

port
(deprecated)

number

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.

protocol

enum

The protocol this BackendService uses to communicate with backends.

Possible values are HTTP, HTTPS, TCP, and SSL. The default is HTTP.

For internal load balancing, the possible values are TCP and UDP, and the default is TCP.

fingerprint

string (bytes format)

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, otherwise the request will fail with error 412 conditionNotMet.

To see the latest fingerprint, make a get() request to retrieve a BackendService.

A base64-encoded string.

portName

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.

enableCDN

boolean

If true, enable Cloud CDN for this BackendService.

When the load balancing scheme is INTERNAL, this field is not used.

sessionAffinity

enum

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.

region

string

[Output Only] URL of the region where the regional backend service resides. This field is not applicable to global backend services. You must specify this field as part of the HTTP request URL. It is not settable as a field in the request body.

failoverPolicy

object

failoverPolicy.disableConnectionDrainOnFailover

boolean

On failover or failback, this field indicates whether connection drain will be honored. Setting this to true has the following effect: connections to the old active pool are not drained. Connections to the new active pool use the timeout of 10 min (currently fixed). Setting to false has the following effect: both old and new connections will have a drain timeout of 10 min.

This can be set to true only if the protocol is TCP.

The default is false.

failoverPolicy.dropTrafficIfUnhealthy

boolean

This option is used only when no healthy VMs are detected in the primary and backup instance groups. When set to true, traffic is dropped. When set to false, new connections are sent across all VMs in the primary group.

The default is false.

failoverPolicy.failoverRatio

number

The value of the field must be in [0, 1]. If the ratio of the healthy VMs in the primary backend is at or below this number, traffic arriving at the load-balanced IP will be directed to the failover backend.

In case where 'failoverRatio' is not set or all the VMs in the backup backend are unhealthy, the traffic will be directed back to the primary backend in the "force" mode, where traffic will be spread to the healthy VMs with the best effort, or to all VMs when no VM is healthy.

This field is only used with l4 load balancing.

loadBalancingScheme

enum

Indicates whether the backend service will be used with internal or external load balancing. A backend service created for one type of load balancing cannot be used with the other. Possible values are INTERNAL and EXTERNAL.

connectionDraining

object

connectionDraining.drainingTimeoutSec

number

Time for which instance will be drained (not accept new connections, but still work to finish started).

iap

object

iap.enabled

boolean

iap.oauth2ClientId

string

iap.oauth2ClientSecret

string

iap.oauth2ClientSecretSha256

string

[Output Only] SHA256 hash value for the field oauth2ClientSecret above.

cdnPolicy

object

Cloud CDN configuration for this BackendService.

cdnPolicy.cacheKeyPolicy

object

The CacheKeyPolicy for this CdnPolicy.

cdnPolicy.cacheKeyPolicy.includeProtocol

boolean

If true, http and https requests will be cached separately.

cdnPolicy.cacheKeyPolicy.includeHost

boolean

If true, requests to different hosts will be cached separately.

cdnPolicy.cacheKeyPolicy.includeQueryString

boolean

If true, include query string parameters in the cache key according to queryStringWhitelist and queryStringBlacklist. If neither is set, the entire query string will be included. If false, the query string will be excluded from the cache key entirely.

cdnPolicy.cacheKeyPolicy.queryStringWhitelist[]

string

Names of query string parameters to include in cache keys. All other parameters will be excluded. Either specify queryStringWhitelist or queryStringBlacklist, not both. '&' and '=' will be percent encoded and not treated as delimiters.

cdnPolicy.cacheKeyPolicy.queryStringBlacklist[]

string

Names of query string parameters to exclude in cache keys. All other parameters will be included. Either specify queryStringWhitelist or queryStringBlacklist, not both. '&' and '=' will be percent encoded and not treated as delimiters.

cdnPolicy.signedUrlKeyNames[]

string

[Output Only] Names of the keys for signing request URLs.

cdnPolicy.signedUrlCacheMaxAgeSec

string (int64 format)

Maximum number of seconds the response to a signed URL request will be considered fresh. After this time period, the response will be revalidated before being served. Defaults to 1hr (3600s). When serving responses to signed URL requests, Cloud CDN will internally behave as though all responses from this backend had a "Cache-Control: public, max-age=[TTL]" header, regardless of any existing Cache-Control header. The actual headers served in responses will not be altered.

customRequestHeaders[]

string

Headers that the HTTP/S load balancer should add to proxied requests.

securityPolicy

string

[Output Only] The resource URL for the security policy associated with this backend service.

logConfig

object

This field denotes the logging options for the load balancer traffic served by this backend service. If logging is enabled, logs will be exported to Stackdriver.

logConfig.enable

boolean

This field denotes whether to enable logging for the load balancer traffic served by this backend service.

logConfig.sampleRate

number

This field can only be specified if logging is enabled for this backend service. The value of the field must be in [0, 1]. This configures the sampling rate of requests to the load balancer where 1.0 means all logged requests are reported and 0.0 means no logged requests are reported. The default value is 1.0.

kind

string

[Output Only] Type of resource. Always compute#backendService for backend services.

Authorization Scopes

Requires one of the following OAuth scopes:

  • https://www.googleapis.com/auth/compute
  • https://www.googleapis.com/auth/cloud-platform

For more information, see the Authentication Overview.

IAM Permissions

In addition to any permissions specified on the fields above, authorization requires one or more of the following Google IAM permissions:

  • compute.backendServices.get

To find predefined roles that contain those permissions, see Compute Engine IAM Roles.

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