Resource: BackendService
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.
For more information, see Backend Services.
JSON representation | |
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{ "id": string, "creationTimestamp": string, "name": string, "description": string, "selfLink": string, "backends": [ { "description": string, "group": string, "balancingMode": enum, "maxUtilization": number, "maxRate": integer, "maxRatePerInstance": number, "maxRatePerEndpoint": number, "maxConnections": integer, "maxConnectionsPerInstance": integer, "maxConnectionsPerEndpoint": integer, "capacityScaler": number, "failover": boolean } ], "healthChecks": [ string ], "timeoutSec": integer, "port": integer, "protocol": enum, "fingerprint": string, "portName": string, "enableCDN": boolean, "sessionAffinity": enum, "affinityCookieTtlSec": integer, "region": string, "failoverPolicy": { "disableConnectionDrainOnFailover": boolean, "dropTrafficIfUnhealthy": boolean, "failoverRatio": number }, "loadBalancingScheme": enum, "connectionDraining": { "drainingTimeoutSec": integer }, "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, "cacheMode": enum, "defaultTtl": integer, "maxTtl": integer, "clientTtl": integer }, "customRequestHeaders": [ string ], "customResponseHeaders": [ string ], "securityPolicy": string, "logConfig": { "enable": boolean, "sampleRate": number }, "securitySettings": { "clientTlsPolicy": string, "subjectAltNames": [ string ] }, "localityLbPolicy": enum, "consistentHash": { "httpCookie": { "name": string, "path": string, "ttl": { "seconds": string, "nanos": integer } }, "httpHeaderName": string, "minimumRingSize": string }, "circuitBreakers": { "maxRequestsPerConnection": integer, "maxConnections": integer, "maxPendingRequests": integer, "maxRequests": integer, "maxRetries": integer }, "outlierDetection": { "consecutiveErrors": integer, "interval": { "seconds": string, "nanos": integer }, "baseEjectionTime": { "seconds": string, "nanos": integer }, "maxEjectionPercent": integer, "enforcingConsecutiveErrors": integer, "enforcingSuccessRate": integer, "successRateMinimumHosts": integer, "successRateRequestVolume": integer, "successRateStdevFactor": integer, "consecutiveGatewayFailure": integer, "enforcingConsecutiveGatewayFailure": integer }, "network": string, "kind": string } |
Fields | |
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id |
[Output Only] The unique identifier for the resource. This identifier is defined by the server. |
creationTimestamp |
[Output Only] Creation timestamp in RFC3339 text format. |
name |
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 |
description |
An optional description of this resource. Provide this property when you create the resource. |
selfLink |
[Output Only] Server-defined URL for the resource. |
backends[] |
The list of backends that serve this BackendService. |
backends[].description |
An optional description of this resource. Provide this property when you create the resource. |
backends[].group |
The fully-qualified URL of an instance group or network endpoint group (NEG) resource. The type of backend that a backend service supports depends on the backend service's
For regional services, the backend must be in the same region as the backend service. You must use the fully-qualified URL (starting with |
backends[].balancingMode |
Specifies the balancing mode for the backend. When choosing a balancing mode, you need to consider the
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backends[].maxUtilization |
Defines the maximum average backend utilization of a backend VM in an instance group. The valid range is This parameter can be used in conjunction with |
backends[].maxRate |
Defines a maximum number of HTTP requests per second (RPS) that the backend can handle. Valid for network endpoint group and instance group backends (except for regional managed instance groups). Must not be defined if the backend is a managed instance group that uses autoscaling based on load balancing. If the backend's Not available if the backend's |
backends[].maxRatePerInstance |
Defines a maximum target for requests per second (RPS) for a single VM in a backend instance group. This is multiplied by the number of instances in the instance group to implicitly calculate a target maximum rate for the whole instance group. If the backend's Not available if the backend's |
backends[].maxRatePerEndpoint |
Defines a maximum target for requests per second (RPS) for an endpoint of a NEG. This is multiplied by the number of endpoints in the NEG to implicitly calculate a target maximum rate for the NEG. If the backend's Not available if the backend's |
backends[].maxConnections |
Defines a target maximum number of simultaneous connections that the backend can handle. Valid for network endpoint group and instance group backends (except for regional managed instance groups). If the backend's Not available if the backend's |
backends[].maxConnectionsPerInstance |
Defines a target maximum number of simultaneous connections for a single VM in a backend instance group. This is multiplied by the number of instances in the instance group to implicitly calculate a target maximum number of simultaneous connections for the whole instance group. If the backend's Not available if the backend's |
backends[].maxConnectionsPerEndpoint |
Defines a target maximum number of simultaneous connections for an endpoint of a NEG. This is multiplied by the number of endpoints in the NEG to implicitly calculate a maximum number of target maximum simultaneous connections for the NEG. If the backend's Not available if the backend's |
backends[].capacityScaler |
A multiplier applied to the group's maximum servicing capacity (based on This cannot be used for Internal TCP/UDP Load Balancing and Network Load Balancing. |
backends[].failover |
This field designates whether this is a failover backend. More than one failover backend can be configured for a given BackendService. |
healthChecks[] |
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. Backend services with internet or serverless NEG backends must not have a health check. |
timeoutSec |
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. |
port |
Deprecated in favor of This cannot be used if the |
protocol |
The protocol this BackendService uses to communicate with backends. Possible values are HTTP, HTTPS, HTTP2, TCP, SSL, UDP or GRPC. depending on the chosen load balancer or Traffic Director configuration. Refer to the documentation for the load balancer or for Traffic Director for more information. Must be set to GRPC when the backend service is referenced by a URL map that is bound to target gRPC proxy. |
fingerprint |
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 To see the latest fingerprint, make a A base64-encoded string. |
portName |
A named port on a backend instance group representing the port for communication to the backend VMs in that group. Required when the Backend services for Internal TCP/UDP Load Balancing and Network Load Balancing require you omit |
enableCDN |
If |
sessionAffinity |
Type of session affinity to use. The default is When the When the When the Not supported when the backend service is referenced by a URL map that is bound to target gRPC proxy that has validateForProxyless field set to true. |
affinityCookieTtlSec |
Lifetime of cookies in seconds. Only applicable if the If set to Not supported when the backend service is referenced by a URL map that is bound to target gRPC proxy that has validateForProxyless field set to true. |
region |
[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 |
Applicable only to Failover for Internal TCP/UDP Load Balancing and Network Load Balancing. Requires at least one backend instance group to be defined as a backup (failover) backend. |
failoverPolicy.disableConnectionDrainOnFailover |
This can be set to The default is |
failoverPolicy.dropTrafficIfUnhealthy |
Applicable only to Failover for Internal TCP/UDP Load Balancing and Network Load Balancing, If set to |
failoverPolicy.failoverRatio |
Applicable only to Failover for Internal TCP/UDP Load Balancing and Network Load Balancing. The value of the field must be in the range |
loadBalancingScheme |
Specifies the load balancer type. Choose |
connectionDraining |
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connectionDraining.drainingTimeoutSec |
The amount of time in seconds to allow existing connections to persist while on unhealthy backend VMs. Only applicable if the |
iap |
The configurations for Identity-Aware Proxy on this resource. Not available for Internal TCP/UDP Load Balancing and Network Load Balancing. |
iap.enabled |
Whether the serving infrastructure will authenticate and authorize all incoming requests. If true, the oauth2ClientId and oauth2ClientSecret fields must be non-empty. |
iap.oauth2ClientId |
OAuth2 client ID to use for the authentication flow. |
iap.oauth2ClientSecret |
OAuth2 client secret to use for the authentication flow. For security reasons, this value cannot be retrieved via the API. Instead, the SHA-256 hash of the value is returned in the oauth2ClientSecretSha256 field. @InputOnly |
iap.oauth2ClientSecretSha256 |
[Output Only] SHA256 hash value for the field oauth2ClientSecret above. |
cdnPolicy |
Cloud CDN configuration for this BackendService. Not available for Internal TCP/UDP Load Balancing and Network Load Balancing. |
cdnPolicy.cacheKeyPolicy |
The CacheKeyPolicy for this CdnPolicy. |
cdnPolicy.cacheKeyPolicy.includeProtocol |
If true, http and https requests will be cached separately. |
cdnPolicy.cacheKeyPolicy.includeHost |
If true, requests to different hosts will be cached separately. |
cdnPolicy.cacheKeyPolicy.includeQueryString |
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[] |
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[] |
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[] |
[Output Only] Names of the keys for signing request URLs. |
cdnPolicy.signedUrlCacheMaxAgeSec |
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 |
cdnPolicy.cacheMode |
Specifies the cache setting for all responses from this backend. The possible values are: |
cdnPolicy.defaultTtl |
Specifies the default TTL for cached content served by this origin for responses that do not have an existing valid TTL (max-age or s-max-age). Setting a TTL of "0" means "always revalidate". The value of defaultTTL cannot be set to a value greater than that of maxTTL, but can be equal. When the cacheMode is set to |
cdnPolicy.maxTtl |
Specifies the maximum allowed TTL for cached content served by this origin. Cache directives that attempt to set a max-age or s-maxage higher than this, or an Expires header more than maxTTL seconds in the future will be capped at the value of maxTTL, as if it were the value of an s-maxage Cache-Control directive. Headers sent to the client will not be modified. Setting a TTL of "0" means "always revalidate". The maximum allowed value is 31,622,400s (1 year), noting that infrequently accessed objects may be evicted from the cache before the defined TTL. |
cdnPolicy.clientTtl |
Specifies a separate client (e.g. browser client) TTL, separate from the TTL for Cloud CDN's edge caches. Leaving this empty will use the same cache TTL for both Cloud CDN and the client-facing response. The maximum allowed value is 86400s (1 day). |
customRequestHeaders[] |
Headers that the HTTP/S load balancer should add to proxied requests. |
customResponseHeaders[] |
Headers that the HTTP/S load balancer should add to proxied responses. |
securityPolicy |
[Output Only] The resource URL for the security policy associated with this backend service. |
logConfig |
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 |
This field denotes whether to enable logging for the load balancer traffic served by this backend service. |
logConfig.sampleRate |
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. |
securitySettings |
This field specifies the security policy that applies to this backend service. This field is applicable to either:
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securitySettings.clientTlsPolicy |
Optional. A URL referring to a networksecurity.ClientTlsPolicy resource that describes how clients should authenticate with this service's backends. If left blank, communications are not encrypted. Note: This field currently has no impact. |
securitySettings.subjectAltNames[] |
Optional. A list of Subject Alternative Names (SANs) that the client verifies during a mutual TLS handshake with an server/endpoint for this Note that the contents of the server certificate's Only applies to a global Note: This field currently has no impact. |
localityLbPolicy |
The load balancing algorithm used within the scope of the locality. The possible values are:
This field is applicable to either: If Only the default |
consistentHash |
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 when This field is applicable to either:
Not supported when the backend service is referenced by a URL map that is bound to target gRPC proxy that has validateForProxyless field set to true. |
consistentHash.httpCookie |
Hash is based on HTTP Cookie. This field describes a HTTP cookie that will be used as the hash key for the consistent hash load balancer. If the cookie is not present, it will be generated. This field is applicable if the |
consistentHash.httpCookie.name |
Name of the cookie. |
consistentHash.httpCookie.path |
Path to set for the cookie. |
consistentHash.httpCookie.ttl |
Lifetime of the cookie. |
consistentHash.httpCookie.ttl.seconds |
Span of time at a resolution of a second. Must be from 0 to 315,576,000,000 inclusive. Note: these bounds are computed from: 60 sec/min * 60 min/hr * 24 hr/day * 365.25 days/year * 10000 years |
consistentHash.httpCookie.ttl.nanos |
Span of time that's a fraction of a second at nanosecond resolution. Durations less than one second are represented with a 0 |
consistentHash.httpHeaderName |
The hash based on the value of the specified header field. This field is applicable if the |
consistentHash.minimumRingSize |
The minimum number of virtual nodes to use for the hash ring. Defaults to 1024. Larger ring sizes result in more granular load distributions. If the number of hosts in the load balancing pool is larger than the ring size, each host will be assigned a single virtual node. |
circuitBreakers |
Settings controlling the volume of connections to a backend service. If not set, this feature is considered disabled. This field is applicable to either:
Not supported when the backend service is referenced by a URL map that is bound to target gRPC proxy that has validateForProxyless field set to true. |
circuitBreakers.maxRequestsPerConnection |
Maximum requests for a single connection to the backend service. This parameter is respected by both the HTTP/1.1 and HTTP/2 implementations. If not specified, there is no limit. Setting this parameter to 1 will effectively disable keep alive. |
circuitBreakers.maxConnections |
The maximum number of connections to the backend service. If not specified, there is no limit. |
circuitBreakers.maxPendingRequests |
The maximum number of pending requests allowed to the backend service. If not specified, there is no limit. |
circuitBreakers.maxRequests |
The maximum number of parallel requests that allowed to the backend service. If not specified, there is no limit. |
circuitBreakers.maxRetries |
The maximum number of parallel retries allowed to the backend cluster. If not specified, the default is 1. |
outlierDetection |
Settings controlling the eviction of unhealthy hosts from the load balancing pool for the backend service. If not set, this feature is considered disabled. This field is applicable to either:
Not supported when the backend service is referenced by a URL map that is bound to target gRPC proxy that has validateForProxyless field set to true. |
outlierDetection.consecutiveErrors |
Number of errors before a host is ejected from the connection pool. When the backend host is accessed over HTTP, a 5xx return code qualifies as an error. Defaults to 5. |
outlierDetection.interval |
Time interval between ejection analysis sweeps. This can result in both new ejections as well as hosts being returned to service. Defaults to 1 second. |
outlierDetection.interval.seconds |
Span of time at a resolution of a second. Must be from 0 to 315,576,000,000 inclusive. Note: these bounds are computed from: 60 sec/min * 60 min/hr * 24 hr/day * 365.25 days/year * 10000 years |
outlierDetection.interval.nanos |
Span of time that's a fraction of a second at nanosecond resolution. Durations less than one second are represented with a 0 |
outlierDetection.baseEjectionTime |
The base time that a host is ejected for. The real ejection time is equal to the base ejection time multiplied by the number of times the host has been ejected. Defaults to 30000ms or 30s. |
outlierDetection.baseEjectionTime.seconds |
Span of time at a resolution of a second. Must be from 0 to 315,576,000,000 inclusive. Note: these bounds are computed from: 60 sec/min * 60 min/hr * 24 hr/day * 365.25 days/year * 10000 years |
outlierDetection.baseEjectionTime.nanos |
Span of time that's a fraction of a second at nanosecond resolution. Durations less than one second are represented with a 0 |
outlierDetection.maxEjectionPercent |
Maximum percentage of hosts in the load balancing pool for the backend service that can be ejected. Defaults to 50%. |
outlierDetection.enforcingConsecutiveErrors |
The percentage chance that a host will be actually ejected when an outlier status is detected through consecutive 5xx. This setting can be used to disable ejection or to ramp it up slowly. Defaults to 0. |
outlierDetection.enforcingSuccessRate |
The percentage chance that a host will be actually ejected when an outlier status is detected through success rate statistics. This setting can be used to disable ejection or to ramp it up slowly. Defaults to 100. |
outlierDetection.successRateMinimumHosts |
The number of hosts in a cluster that must have enough request volume to detect success rate outliers. If the number of hosts is less than this setting, outlier detection via success rate statistics is not performed for any host in the cluster. Defaults to 5. |
outlierDetection.successRateRequestVolume |
The minimum number of total requests that must be collected in one interval (as defined by the interval duration above) to include this host in success rate based outlier detection. If the volume is lower than this setting, outlier detection via success rate statistics is not performed for that host. Defaults to 100. |
outlierDetection.successRateStdevFactor |
This factor is used to determine the ejection threshold for success rate outlier ejection. The ejection threshold is the difference between the mean success rate, and the product of this factor and the standard deviation of the mean success rate: mean - (stdev * successRateStdevFactor). This factor is divided by a thousand to get a double. That is, if the desired factor is 1.9, the runtime value should be 1900. Defaults to 1900. |
outlierDetection.consecutiveGatewayFailure |
The number of consecutive gateway failures (502, 503, 504 status or connection errors that are mapped to one of those status codes) before a consecutive gateway failure ejection occurs. Defaults to 3. |
outlierDetection.enforcingConsecutiveGatewayFailure |
The percentage chance that a host will be actually ejected when an outlier status is detected through consecutive gateway failures. This setting can be used to disable ejection or to ramp it up slowly. Defaults to 100. |
network |
The URL of the network to which this backend service belongs. This field can only be specified when the load balancing scheme is set to |
kind |
[Output Only] Type of resource. Always |
Methods |
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Deletes the specified regional BackendService resource. |
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Returns the specified regional BackendService resource. |
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Gets the most recent health check results for this regional BackendService. |
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Creates a regional BackendService resource in the specified project using the data included in the request. |
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Retrieves the list of regional BackendService resources available to the specified project in the given region. |
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Updates the specified regional BackendService resource with the data included in the request. |
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Updates the specified regional BackendService resource with the data included in the request. |