BackendService class final

Represents a Backend Service resource.

A backend service defines how Google Cloud load balancers distribute traffic. The backend service configuration contains a set of values, such as the protocol used to connect to backends, various distribution and session settings, health checks, and timeouts. These settings provide fine-grained control over how your load balancer behaves. Most of the settings have default values that allow for easy configuration if you need to get started quickly.

Backend services in Google Compute Engine can be either regionally or globally scoped.

• Global
• Regional

For more information, seeBackend Services.

Constructors

BackendService({int? affinityCookieTtlSec, List<Backend> backends = const [], BackendServiceCdnPolicy? cdnPolicy, CircuitBreakers? circuitBreakers, String? compressionMode, ConnectionDraining? connectionDraining, BackendServiceConnectionTrackingPolicy? connectionTrackingPolicy, ConsistentHashLoadBalancerSettings? consistentHash, String? creationTimestamp, List<BackendServiceCustomMetric> customMetrics = const [], List<String> customRequestHeaders = const [], List<String> customResponseHeaders = const [], String? description, String? edgeSecurityPolicy, bool? enableCDN, String? externalManagedMigrationState, double? externalManagedMigrationTestingPercentage, BackendServiceFailoverPolicy? failoverPolicy, String? fingerprint, BackendServiceHapolicy? haPolicy, List<String> healthChecks = const [], BackendServiceIap? iap, BigInt? id, String? ipAddressSelectionPolicy, String? kind, String? loadBalancingScheme, List<BackendServiceLocalityLoadBalancingPolicyConfig> localityLbPolicies = const [], String? localityLbPolicy, BackendServiceLogConfig? logConfig, Duration? maxStreamDuration, Map<String, String> metadatas = const {}, String? name, String? network, BackendServiceNetworkPassThroughLbTrafficPolicy? networkPassThroughLbTrafficPolicy, BackendServiceOrchestrationInfo? orchestrationInfo, OutlierDetection? outlierDetection, BackendServiceParams? params, int? port, String? portName, String? protocol, String? region, String? securityPolicy, SecuritySettings? securitySettings, String? selfLink, List<String> serviceBindings = const [], String? serviceLbPolicy, String? sessionAffinity, BackendServiceHttpCookie? strongSessionAffinityCookie, Subsetting? subsetting, int? timeoutSec, BackendServiceTlsSettings? tlsSettings, List<BackendServiceUsedBy> usedBy = const []})

BackendService.fromJson(Object? j)

factory

Properties

affinityCookieTtlSec → int?

Lifetime of cookies in seconds. This setting is applicable to Application Load Balancers and Traffic Director and requires GENERATED_COOKIE or HTTP_COOKIE session affinity.

final

backends → List<Backend>

The list of backends that serve this BackendService.

final

cdnPolicy → BackendServiceCdnPolicy?

Cloud CDN configuration for this BackendService. Only available for specified load balancer types.

final

circuitBreakers → CircuitBreakers?

final

compressionMode → String?

Compress text responses using Brotli or gzip compression, based on the client's Accept-Encoding header. Check the CompressionMode enum for the list of possible values.

final

connectionDraining → ConnectionDraining?

connectionDraining cannot be specified with haPolicy.

final

connectionTrackingPolicy → BackendServiceConnectionTrackingPolicy?

Connection Tracking configuration for this BackendService. Connection tracking policy settings are only available for external passthrough Network Load Balancers and internal passthrough Network Load Balancers.

final

consistentHash → ConsistentHashLoadBalancerSettings?

Consistent Hash-based load balancing can be used to provide soft session affinity based on HTTP headers, cookies or other properties. This load balancing policy is applicable only for HTTP connections. The affinity to a particular destination host will be lost when one or more hosts are added/removed from the destination service. This field specifies parameters that control consistent hashing. This field is only applicable whenlocalityLbPolicy is set to MAGLEV orRING_HASH.

final

creationTimestamp → String?

Output only. Output Only Creation timestamp inRFC3339 text format.

final

customMetrics → List<BackendServiceCustomMetric>

List of custom metrics that are used for theWEIGHTED_ROUND_ROBIN locality_lb_policy.

final

customRequestHeaders → List<String>

Headers that the load balancer adds to proxied requests. See Creating custom headers.

final

customResponseHeaders → List<String>

Headers that the load balancer adds to proxied responses. See Creating custom headers.

final

description → String?

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

final

edgeSecurityPolicy → String?

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

final

enableCDN → bool?

If true, enables Cloud CDN for the backend service of a global external Application Load Balancer.

final

externalManagedMigrationState → String?

Specifies the canary migration state. Possible values are PREPARE, TEST_BY_PERCENTAGE, and TEST_ALL_TRAFFIC.

final

externalManagedMigrationTestingPercentage → double?

Determines the fraction of requests that should be processed by the Global external Application Load Balancer.

final

failoverPolicy → BackendServiceFailoverPolicy?

Requires at least one backend instance group to be defined as a backup (failover) backend. For load balancers that have configurable failover: Internal passthrough Network Load Balancers and external passthrough Network Load Balancers.

final

fingerprint → 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, otherwise the request will fail with error 412 conditionNotMet.

final

haPolicy → BackendServiceHapolicy?

Configures self-managed High Availability (HA) for External and Internal Protocol Forwarding.

final

hashCode → int

The hash code for this object.

no setter, inherited

healthChecks → List<String>

The list of URLs to the healthChecks, httpHealthChecks (legacy), or httpsHealthChecks (legacy) resource for health checking this backend service. Not all backend services support legacy health checks. See Load balancer guide. Currently, at most one health check can be specified for each backend service. Backend services with instance group or zonal NEG backends must have a health check unless haPolicy is specified. Backend services with internet or serverless NEG backends must not have a health check.

final

iap → BackendServiceIap?

The configurations for Identity-Aware Proxy on this resource. Not available for internal passthrough Network Load Balancers and external passthrough Network Load Balancers.

final

id → BigInt?

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

final

ipAddressSelectionPolicy → String?

Specifies a preference for traffic sent from the proxy to the backend (or from the client to the backend for proxyless gRPC). The possible values are:

final

kind → String?

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

final

loadBalancingScheme → String?

Specifies the load balancer type. A backend service created for one type of load balancer cannot be used with another. For more information, refer toChoosing a load balancer. Check the LoadBalancingScheme enum for the list of possible values.

final

localityLbPolicies → List<BackendServiceLocalityLoadBalancingPolicyConfig>

A list of locality load-balancing policies to be used in order of preference. When you use localityLbPolicies, you must set at least one value for either the localityLbPolicies[].policy or the localityLbPolicies[].customPolicy field. localityLbPolicies overrides any value set in the localityLbPolicy field.

final

localityLbPolicy → String?

The load balancing algorithm used within the scope of the locality. The possible values are:

final

logConfig → BackendServiceLogConfig?

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.

final

maxStreamDuration → Duration?

Specifies the default maximum duration (timeout) for streams to this service. Duration is computed from the beginning of the stream until the response has been completely processed, including all retries. A stream that does not complete in this duration is closed.

final

metadatas → Map<String, String>

Deployment metadata associated with the resource to be set by a GKE hub controller and read by the backend RCTH

final

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 withRFC1035. 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.

final

network → String?

The URL of the network to which this backend service belongs.

final

networkPassThroughLbTrafficPolicy → BackendServiceNetworkPassThroughLbTrafficPolicy?

Configures traffic steering properties of internal passthrough Network Load Balancers.

final

orchestrationInfo → BackendServiceOrchestrationInfo?

Information about the resource or system that manages the backend service.

final

outlierDetection → OutlierDetection?

Settings controlling the ejection of unhealthy backend endpoints from the load balancing pool of each individual proxy instance that processes the traffic for the given backend service. If not set, this feature is considered disabled.

final

params → BackendServiceParams?

Input only. Input Only Additional params passed with the request, but not persisted as part of resource payload.

final

port → int?

Deprecated in favor of portName. The TCP port to connect on the backend. The default value is 80. For internal passthrough Network Load Balancers and external passthrough Network Load Balancers, omit port.

final

portName → String?

A named port on a backend instance group representing the port for communication to the backend VMs in that group. The named port must be defined on each backend instance group. This parameter has no meaning if the backends are NEGs. For internal passthrough Network Load Balancers and external passthrough Network Load Balancers, omit port_name.

final

protocol → String?

The protocol this BackendService uses to communicate with backends.

final

qualifiedName → String

The fully qualified name of this message, i.e., google.protobuf.Duration or google.rpc.ErrorInfo.

final, inherited

region → String?

Output only. 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.

final

runtimeType → Type

A representation of the runtime type of the object.

no setter, inherited

securityPolicy → String?

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

final

securitySettings → SecuritySettings?

This field specifies the security settings that apply to this backend service. This field is applicable to a global backend service with the load_balancing_scheme set to INTERNAL_SELF_MANAGED.

final

selfLink → String?

Output Only Server-defined URL for the resource.

final

serviceBindings → List<String>

URLs of networkservices.ServiceBinding resources.

final

serviceLbPolicy → String?

URL to networkservices.ServiceLbPolicy resource.

final

sessionAffinity → String?

Type of session affinity to use. The default is NONE.

final

strongSessionAffinityCookie → BackendServiceHttpCookie?

Describes the HTTP cookie used for stateful session affinity. This field is applicable and required if the sessionAffinity is set toSTRONG_COOKIE_AFFINITY.

final

subsetting → Subsetting?

subsetting cannot be specified with haPolicy.

final

timeoutSec → int?

The backend service timeout has a different meaning depending on the type of load balancer. For more information see, Backend service settings. The default is 30 seconds. The full range of timeout values allowed goes from 1 through 2,147,483,647 seconds.

final

tlsSettings → BackendServiceTlsSettings?

Configuration for Backend Authenticated TLS and mTLS. May only be specified when the backend protocol is SSL, HTTPS or HTTP2.

final

usedBy → List<BackendServiceUsedBy>

Output only. Output Only List of resources referencing given backend service.

final

Methods

noSuchMethod(Invocation invocation) → dynamic

Invoked when a nonexistent method or property is accessed.

inherited

toJson() → Object

toString() → String

A string representation of this object.

override

Operators

operator ==(Object other) → bool

The equality operator.

inherited

Constants

fullyQualifiedName → const String