Application Load Balancer API, REST: BackendGroup.UpdateBackend

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Updated at January 14, 2025

HTTP request
Path parameters
Body parameters
HttpBackend
LoadBalancingConfig
TargetGroupsBackend
StorageBucketBackend
HealthCheck
StreamHealthCheck
Payload
HttpHealthCheck
GrpcHealthCheck
SecureTransportSettings
ValidationContext
BackendTls
GrpcBackend
StreamBackend
Response
UpdateBackendMetadata
Status
BackendGroup
HttpBackendGroup
HttpBackend
LoadBalancingConfig
TargetGroupsBackend
StorageBucketBackend
HealthCheck
StreamHealthCheck
Payload
HttpHealthCheck
GrpcHealthCheck
SecureTransportSettings
ValidationContext
BackendTls
ConnectionSessionAffinity
HeaderSessionAffinity
CookieSessionAffinity
GrpcBackendGroup
GrpcBackend
StreamBackendGroup
StreamBackend

Updates the specified backend.

HTTP request

POST https://alb.api.cloud.yandex.net/apploadbalancer/v1/backendGroups/{backendGroupId}:updateBackend

Path parameters

Field

Description

backendGroupId

string

Required field. ID of the backend group to update the backend in.

Body parameters

{
  "updateMask": "string",
  // Includes only one of the fields `http`, `grpc`, `stream`
  "http": {
    "name": "string",
    "backendWeight": "string",
    "loadBalancingConfig": {
      "panicThreshold": "string",
      "localityAwareRoutingPercent": "string",
      "strictLocality": "boolean",
      "mode": "string"
    },
    "port": "string",
    // Includes only one of the fields `targetGroups`, `storageBucket`
    "targetGroups": {
      "targetGroupIds": [
        "string"
      ]
    },
    "storageBucket": {
      "bucket": "string"
    },
    // end of the list of possible fields
    "healthchecks": [
      {
        "timeout": "string",
        "interval": "string",
        "intervalJitterPercent": "string",
        "healthyThreshold": "string",
        "unhealthyThreshold": "string",
        "healthcheckPort": "string",
        // Includes only one of the fields `stream`, `http`, `grpc`
        "stream": {
          "send": {
            // Includes only one of the fields `text`
            "text": "string"
            // end of the list of possible fields
          },
          "receive": {
            // Includes only one of the fields `text`
            "text": "string"
            // end of the list of possible fields
          }
        },
        "http": {
          "host": "string",
          "path": "string",
          "useHttp2": "boolean",
          "expectedStatuses": [
            "string"
          ]
        },
        "grpc": {
          "serviceName": "string"
        },
        // end of the list of possible fields
        // Includes only one of the fields `plaintext`, `tls`
        "plaintext": "object",
        "tls": {
          "sni": "string",
          "validationContext": {
            // Includes only one of the fields `trustedCaId`, `trustedCaBytes`
            "trustedCaId": "string",
            "trustedCaBytes": "string"
            // end of the list of possible fields
          }
        }
        // end of the list of possible fields
      }
    ],
    "tls": {
      "sni": "string",
      "validationContext": {
        // Includes only one of the fields `trustedCaId`, `trustedCaBytes`
        "trustedCaId": "string",
        "trustedCaBytes": "string"
        // end of the list of possible fields
      }
    },
    "useHttp2": "boolean"
  },
  "grpc": {
    "name": "string",
    "backendWeight": "string",
    "loadBalancingConfig": {
      "panicThreshold": "string",
      "localityAwareRoutingPercent": "string",
      "strictLocality": "boolean",
      "mode": "string"
    },
    "port": "string",
    // Includes only one of the fields `targetGroups`
    "targetGroups": {
      "targetGroupIds": [
        "string"
      ]
    },
    // end of the list of possible fields
    "healthchecks": [
      {
        "timeout": "string",
        "interval": "string",
        "intervalJitterPercent": "string",
        "healthyThreshold": "string",
        "unhealthyThreshold": "string",
        "healthcheckPort": "string",
        // Includes only one of the fields `stream`, `http`, `grpc`
        "stream": {
          "send": {
            // Includes only one of the fields `text`
            "text": "string"
            // end of the list of possible fields
          },
          "receive": {
            // Includes only one of the fields `text`
            "text": "string"
            // end of the list of possible fields
          }
        },
        "http": {
          "host": "string",
          "path": "string",
          "useHttp2": "boolean",
          "expectedStatuses": [
            "string"
          ]
        },
        "grpc": {
          "serviceName": "string"
        },
        // end of the list of possible fields
        // Includes only one of the fields `plaintext`, `tls`
        "plaintext": "object",
        "tls": {
          "sni": "string",
          "validationContext": {
            // Includes only one of the fields `trustedCaId`, `trustedCaBytes`
            "trustedCaId": "string",
            "trustedCaBytes": "string"
            // end of the list of possible fields
          }
        }
        // end of the list of possible fields
      }
    ],
    "tls": {
      "sni": "string",
      "validationContext": {
        // Includes only one of the fields `trustedCaId`, `trustedCaBytes`
        "trustedCaId": "string",
        "trustedCaBytes": "string"
        // end of the list of possible fields
      }
    }
  },
  "stream": {
    "name": "string",
    "backendWeight": "string",
    "loadBalancingConfig": {
      "panicThreshold": "string",
      "localityAwareRoutingPercent": "string",
      "strictLocality": "boolean",
      "mode": "string"
    },
    "port": "string",
    // Includes only one of the fields `targetGroups`
    "targetGroups": {
      "targetGroupIds": [
        "string"
      ]
    },
    // end of the list of possible fields
    "healthchecks": [
      {
        "timeout": "string",
        "interval": "string",
        "intervalJitterPercent": "string",
        "healthyThreshold": "string",
        "unhealthyThreshold": "string",
        "healthcheckPort": "string",
        // Includes only one of the fields `stream`, `http`, `grpc`
        "stream": {
          "send": {
            // Includes only one of the fields `text`
            "text": "string"
            // end of the list of possible fields
          },
          "receive": {
            // Includes only one of the fields `text`
            "text": "string"
            // end of the list of possible fields
          }
        },
        "http": {
          "host": "string",
          "path": "string",
          "useHttp2": "boolean",
          "expectedStatuses": [
            "string"
          ]
        },
        "grpc": {
          "serviceName": "string"
        },
        // end of the list of possible fields
        // Includes only one of the fields `plaintext`, `tls`
        "plaintext": "object",
        "tls": {
          "sni": "string",
          "validationContext": {
            // Includes only one of the fields `trustedCaId`, `trustedCaBytes`
            "trustedCaId": "string",
            "trustedCaBytes": "string"
            // end of the list of possible fields
          }
        }
        // end of the list of possible fields
      }
    ],
    "tls": {
      "sni": "string",
      "validationContext": {
        // Includes only one of the fields `trustedCaId`, `trustedCaBytes`
        "trustedCaId": "string",
        "trustedCaBytes": "string"
        // end of the list of possible fields
      }
    },
    "enableProxyProtocol": "boolean",
    "keepConnectionsOnHostHealthFailure": "boolean"
  }
  // end of the list of possible fields
}

Field	Description
updateMask	string (field-mask) A comma-separated names off ALL fields to be updated. Only the specified fields will be changed. The others will be left untouched. If the field is specified in `updateMask` and no value for that field was sent in the request, the field's value will be reset to the default. The default value for most fields is null or 0. If `updateMask` is not sent in the request, all fields' values will be updated. Fields specified in the request will be updated to provided values. The rest of the fields will be reset to the default.
http	HttpBackend New settings for the HTTP backend. Includes only one of the fields `http`, `grpc`, `stream`. Name of the backend to update (required) and new settings for the backend.
grpc	GrpcBackend New settings for the gRPC backend. Includes only one of the fields `http`, `grpc`, `stream`. Name of the backend to update (required) and new settings for the backend.
stream	StreamBackend New settings for the stream (TCP) backend. Includes only one of the fields `http`, `grpc`, `stream`. Name of the backend to update (required) and new settings for the backend.

HttpBackend

An HTTP backend resource.

Field	Description
name	string Required field. Name of the backend.
backendWeight	string (int64) Backend weight. Traffic is distributed between backends of a backend group according to their weights. Weights must be set either for all backends in a group or for none of them. Setting no weights is the same as setting equal non-zero weights for all backends. If the weight is non-positive, traffic is not sent to the backend.
loadBalancingConfig	LoadBalancingConfig Load balancing configuration for the backend.
port	string (int64) Port used by all targets to receive traffic.
targetGroups	TargetGroupsBackend Target groups that belong to the backend. For details about target groups, see documentation. Includes only one of the fields `targetGroups`, `storageBucket`. Reference to targets that belong to the backend. A backend may be a set of target groups or an Object Storage bucket. For details about backend types, see documentation.
storageBucket	StorageBucketBackend Object Storage bucket to use as the backend. For details about buckets, see documentation. If a bucket is used as a backend, the list of bucket objects and the objects themselves must be publicly accessible. For instructions, see documentation. Includes only one of the fields `targetGroups`, `storageBucket`. Reference to targets that belong to the backend. A backend may be a set of target groups or an Object Storage bucket. For details about backend types, see documentation.
healthchecks[]	HealthCheck Health checks to perform on targets from target groups. For details about health checking, see documentation. If no health checks are specified, active health checking is not performed.
tls	BackendTls Settings for TLS connections between load balancer nodes and backend targets. If specified, the load balancer establishes HTTPS (HTTP over TLS) connections with targets and compares received certificates with the one specified in BackendTls.validationContext. If not specified, the load balancer establishes unencrypted HTTP connections with targets.
useHttp2	boolean Enables HTTP/2 usage in connections between load balancer nodes and backend targets. Default value: `false`, HTTP/1.1 is used.

LoadBalancingConfig

A load balancing configuration resource.

Field	Description
panicThreshold	string (int64) Threshold for panic mode. If percentage of healthy backends in the group drops below threshold, panic mode will be activated and traffic will be routed to all backends, regardless of their health check status. This helps to avoid overloading healthy backends. For details about panic mode, see documentation. If the value is `0`, panic mode will never be activated and traffic is routed only to healthy backends at all times. Default value: `0`.
localityAwareRoutingPercent	string (int64) Percentage of traffic that a load balancer node sends to healthy backends in its availability zone. The rest is divided equally between other zones. For details about zone-aware routing, see documentation. If there are no healthy backends in an availability zone, all the traffic is divided between other zones. If `strictLocality` is `true`, the specified value is ignored. A load balancer node sends all the traffic within its availability zone, regardless of backends' health. Default value: `0`.
strictLocality	boolean Specifies whether a load balancer node should only send traffic to backends in its availability zone, regardless of their health, and ignore backends in other zones. If set to `true` and there are no healthy backends in the zone, the node in this zone will respond to incoming traffic with errors. For details about strict locality, see documentation. If `strict_locality` is `true`, the value specified in `localityAwareRoutingPercent` is ignored. Default value: `false`.
mode	enum (LoadBalancingMode) Load balancing mode for the backend. For details about load balancing modes, see documentation. `ROUND_ROBIN`: Round robin load balancing mode. All endpoints of the backend take their turns to receive requests attributed to the backend. `RANDOM`: Random load balancing mode. Default value. For a request attributed to the backend, an endpoint that receives it is picked at random. `LEAST_REQUEST`: Least request load balancing mode. To pick an endpoint that receives a request attributed to the backend, the power of two choices algorithm is used; that is, two endpoints are picked at random, and the request is sent to the one which has the fewest active requests. `MAGLEV_HASH`: Maglev hashing load balancing mode. Each endpoint is hashed, and a hash table with 65537 rows is filled accordingly, so that every endpoint occupies the same amount of rows. An attribute of each request is also hashed by the same function (if session affinity is enabled for the backend group, the attribute to hash is specified in session affinity configuration). The row with the same number as the resulting value is looked up in the table to determine the endpoint that receives the request. If the backend group with session affinity enabled contains more than one backend with positive weight, endpoints for backends with `MAGLEV_HASH` load balancing mode are picked at `RANDOM` instead.

TargetGroupsBackend

A resource for target groups that belong to the backend.

Field

Description

targetGroupIds[]

string

List of ID's of target groups that belong to the backend.

To get the ID's of all available target groups, make a TargetGroupService.List request.

StorageBucketBackend

A resource for Object Storage bucket used as a backend. For details about the concept,
see documentation.

Field

Description

bucket

string

Required field. Name of the bucket.

HealthCheck

A health check resource.
For details about the concept, see documentation.

Field	Description
timeout	string (duration) Required field. Health check timeout. The timeout is the time allowed for the target to respond to a check. If the target doesn't respond in time, the check is considered failed.
interval	string (duration) Required field. Base interval between consecutive health checks.
intervalJitterPercent	string
healthyThreshold	string (int64) Number of consecutive successful health checks required to mark an unhealthy target as healthy. Both `0` and `1` values amount to one successful check required. The value is ignored when a load balancer is initialized; a target is marked healthy after one successful check. Default value: `0`.
unhealthyThreshold	string (int64) Number of consecutive failed health checks required to mark a healthy target as unhealthy. Both `0` and `1` values amount to one unsuccessful check required. The value is ignored if a health check is failed due to an HTTP `503 Service Unavailable` response from the target (not applicable to TCP stream health checks). The target is immediately marked unhealthy. Default value: `0`.
healthcheckPort	string (int64) Port used for health checks. If not specified, the backend port (HttpBackend.port or GrpcBackend.port) is used for health checks.
stream	StreamHealthCheck TCP stream health check settings. Includes only one of the fields `stream`, `http`, `grpc`. Protocol-specific health check settings. The protocols of the backend and of its health check may differ, e.g. a gRPC health check may be specified for an HTTP backend.
http	HttpHealthCheck HTTP health check settings. Includes only one of the fields `stream`, `http`, `grpc`. Protocol-specific health check settings. The protocols of the backend and of its health check may differ, e.g. a gRPC health check may be specified for an HTTP backend.
grpc	GrpcHealthCheck gRPC health check settings. Includes only one of the fields `stream`, `http`, `grpc`. Protocol-specific health check settings. The protocols of the backend and of its health check may differ, e.g. a gRPC health check may be specified for an HTTP backend.
plaintext	object Includes only one of the fields `plaintext`, `tls`. Optional transport protocol for health checks. When not set, health checks use the same protocol as the proxied traffic. Use this when health checks' protocol settings differ from their backend, e.g. plaintext health checks for a TLS backend.
tls	SecureTransportSettings Includes only one of the fields `plaintext`, `tls`. Optional transport protocol for health checks. When not set, health checks use the same protocol as the proxied traffic. Use this when health checks' protocol settings differ from their backend, e.g. plaintext health checks for a TLS backend.

StreamHealthCheck

A resource for TCP stream health check settings.

Field

Description

send

Payload

Message sent to targets during TCP data transfer.

If not specified, no data is sent to the target.

receive

Payload

Data that must be contained in the messages received from targets for a successful health check.

If not specified, no messages are expected from targets, and those that are received are not checked.

Payload

A health check payload resource.

Field

Description

text

string

Payload text.

Includes only one of the fields text.

Payload.

HttpHealthCheck

A resource for HTTP health check settings.

Field	Description
host	string Value for the HTTP/1.1 `Host` header or the HTTP/2 `:authority` pseudo-header used in requests to targets.
path	string Required field. HTTP path used in requests to targets: request URI for HTTP/1.1 request line or value for the HTTP/2 `:path` pseudo-header.
useHttp2	boolean Enables HTTP/2 usage in health checks. Default value: `false`, HTTP/1.1 is used.
expectedStatuses[]	string (int64) A list of HTTP response statuses considered healthy. By default only 200 HTTP status code considered healthy.

GrpcHealthCheck

A resource for gRPC health check settings.

Field

Description

serviceName

string

Name of the gRPC service to be checked.

If not specified, overall health is checked.

For details about the concept, see GRPC Health Checking Protocol.

SecureTransportSettings

Transport settings to be used instead of the settings configured per-cluster

Field

Description

sni

string

SNI string for TLS connections.

validationContext

ValidationContext

Validation context for backend TLS connections.

ValidationContext

A TLS validation context resource.

Field

Description

trustedCaId

string

Includes only one of the fields trustedCaId, trustedCaBytes.

TLS certificate issued by a trusted certificate authority (CA).

trustedCaBytes

string

X.509 certificate contents in PEM format.

Includes only one of the fields trustedCaId, trustedCaBytes.

TLS certificate issued by a trusted certificate authority (CA).

BackendTls

A resource for backend TLS settings.

Field

Description

sni

string

Server Name Indication (SNI) string for TLS connections.

validationContext

ValidationContext

Validation context for TLS connections.

GrpcBackend

A gRPC backend resource.

Field	Description
name	string Required field. Name of the backend.
backendWeight	string (int64) Backend weight. Traffic is distributed between backends of a backend group according to their weights. Weights must be set either for all backends of a group or for none of them. Setting no weights is the same as setting equal non-zero weights for all backends. If the weight is non-positive, traffic is not sent to the backend.
loadBalancingConfig	LoadBalancingConfig Load balancing configuration for the backend.
port	string (int64) Port used by all targets to receive traffic.
targetGroups	TargetGroupsBackend Target groups that belong to the backend. Includes only one of the fields `targetGroups`. Reference to targets that belong to the backend. For now, targets are referenced via target groups.
healthchecks[]	HealthCheck Health checks to perform on targets from target groups. For details about health checking, see documentation. If no health checks are specified, active health checking is not performed.
tls	BackendTls Settings for TLS connections between load balancer nodes and backend targets. If specified, the load balancer establishes HTTPS (HTTP over TLS) connections with targets and compares received certificates with the one specified in BackendTls.validationContext. If not specified, the load balancer establishes unencrypted HTTP connections with targets.

StreamBackend

A stream (TCP) backend resource.

Field	Description
name	string Name of the backend.
backendWeight	string (int64) Backend weight. Traffic is distributed between backends of a backend group according to their weights. Weights must be set either for all backends in a group or for none of them. Setting no weights is the same as setting equal non-zero weights for all backends. If the weight is non-positive, traffic is not sent to the backend.
loadBalancingConfig	LoadBalancingConfig Load balancing configuration for the backend.
port	string (int64) Port used by all targets to receive traffic.
targetGroups	TargetGroupsBackend Target groups that belong to the backend. For details about target groups, see documentation. Includes only one of the fields `targetGroups`. Reference to targets that belong to the backend.
healthchecks[]	HealthCheck Health checks to perform on targets from target groups. For details about health checking, see documentation. If no health checks are specified, active health checking is not performed.
tls	BackendTls Settings for TLS connections between load balancer nodes and backend targets. If specified, the load balancer establishes TLS-encrypted TCP connections with targets and compares received certificates with the one specified in BackendTls.validationContext. If not specified, the load balancer establishes unencrypted TCP connections with targets.
enableProxyProtocol	boolean If set, proxy protocol will be enabled for this backend.
keepConnectionsOnHostHealthFailure	boolean If a backend host becomes unhealthy (as determined by the configured health checks), keep connections to the failed host.

Response

HTTP Code: 200 - OK

{
  "id": "string",
  "description": "string",
  "createdAt": "string",
  "createdBy": "string",
  "modifiedAt": "string",
  "done": "boolean",
  "metadata": {
    "backendGroupId": "string",
    "backendName": "string"
  },
  // Includes only one of the fields `error`, `response`
  "error": {
    "code": "integer",
    "message": "string",
    "details": [
      "object"
    ]
  },
  "response": {
    "id": "string",
    "name": "string",
    "description": "string",
    "folderId": "string",
    "labels": "object",
    // Includes only one of the fields `http`, `grpc`, `stream`
    "http": {
      "backends": [
        {
          "name": "string",
          "backendWeight": "string",
          "loadBalancingConfig": {
            "panicThreshold": "string",
            "localityAwareRoutingPercent": "string",
            "strictLocality": "boolean",
            "mode": "string"
          },
          "port": "string",
          // Includes only one of the fields `targetGroups`, `storageBucket`
          "targetGroups": {
            "targetGroupIds": [
              "string"
            ]
          },
          "storageBucket": {
            "bucket": "string"
          },
          // end of the list of possible fields
          "healthchecks": [
            {
              "timeout": "string",
              "interval": "string",
              "intervalJitterPercent": "string",
              "healthyThreshold": "string",
              "unhealthyThreshold": "string",
              "healthcheckPort": "string",
              // Includes only one of the fields `stream`, `http`, `grpc`
              "stream": {
                "send": {
                  // Includes only one of the fields `text`
                  "text": "string"
                  // end of the list of possible fields
                },
                "receive": {
                  // Includes only one of the fields `text`
                  "text": "string"
                  // end of the list of possible fields
                }
              },
              "http": {
                "host": "string",
                "path": "string",
                "useHttp2": "boolean",
                "expectedStatuses": [
                  "string"
                ]
              },
              "grpc": {
                "serviceName": "string"
              },
              // end of the list of possible fields
              // Includes only one of the fields `plaintext`, `tls`
              "plaintext": "object",
              "tls": {
                "sni": "string",
                "validationContext": {
                  // Includes only one of the fields `trustedCaId`, `trustedCaBytes`
                  "trustedCaId": "string",
                  "trustedCaBytes": "string"
                  // end of the list of possible fields
                }
              }
              // end of the list of possible fields
            }
          ],
          "tls": {
            "sni": "string",
            "validationContext": {
              // Includes only one of the fields `trustedCaId`, `trustedCaBytes`
              "trustedCaId": "string",
              "trustedCaBytes": "string"
              // end of the list of possible fields
            }
          },
          "useHttp2": "boolean"
        }
      ],
      // Includes only one of the fields `connection`, `header`, `cookie`
      "connection": {
        "sourceIp": "boolean"
      },
      "header": {
        "headerName": "string"
      },
      "cookie": {
        "name": "string",
        "ttl": "string"
      }
      // end of the list of possible fields
    },
    "grpc": {
      "backends": [
        {
          "name": "string",
          "backendWeight": "string",
          "loadBalancingConfig": {
            "panicThreshold": "string",
            "localityAwareRoutingPercent": "string",
            "strictLocality": "boolean",
            "mode": "string"
          },
          "port": "string",
          // Includes only one of the fields `targetGroups`
          "targetGroups": {
            "targetGroupIds": [
              "string"
            ]
          },
          // end of the list of possible fields
          "healthchecks": [
            {
              "timeout": "string",
              "interval": "string",
              "intervalJitterPercent": "string",
              "healthyThreshold": "string",
              "unhealthyThreshold": "string",
              "healthcheckPort": "string",
              // Includes only one of the fields `stream`, `http`, `grpc`
              "stream": {
                "send": {
                  // Includes only one of the fields `text`
                  "text": "string"
                  // end of the list of possible fields
                },
                "receive": {
                  // Includes only one of the fields `text`
                  "text": "string"
                  // end of the list of possible fields
                }
              },
              "http": {
                "host": "string",
                "path": "string",
                "useHttp2": "boolean",
                "expectedStatuses": [
                  "string"
                ]
              },
              "grpc": {
                "serviceName": "string"
              },
              // end of the list of possible fields
              // Includes only one of the fields `plaintext`, `tls`
              "plaintext": "object",
              "tls": {
                "sni": "string",
                "validationContext": {
                  // Includes only one of the fields `trustedCaId`, `trustedCaBytes`
                  "trustedCaId": "string",
                  "trustedCaBytes": "string"
                  // end of the list of possible fields
                }
              }
              // end of the list of possible fields
            }
          ],
          "tls": {
            "sni": "string",
            "validationContext": {
              // Includes only one of the fields `trustedCaId`, `trustedCaBytes`
              "trustedCaId": "string",
              "trustedCaBytes": "string"
              // end of the list of possible fields
            }
          }
        }
      ],
      // Includes only one of the fields `connection`, `header`, `cookie`
      "connection": {
        "sourceIp": "boolean"
      },
      "header": {
        "headerName": "string"
      },
      "cookie": {
        "name": "string",
        "ttl": "string"
      }
      // end of the list of possible fields
    },
    "stream": {
      "backends": [
        {
          "name": "string",
          "backendWeight": "string",
          "loadBalancingConfig": {
            "panicThreshold": "string",
            "localityAwareRoutingPercent": "string",
            "strictLocality": "boolean",
            "mode": "string"
          },
          "port": "string",
          // Includes only one of the fields `targetGroups`
          "targetGroups": {
            "targetGroupIds": [
              "string"
            ]
          },
          // end of the list of possible fields
          "healthchecks": [
            {
              "timeout": "string",
              "interval": "string",
              "intervalJitterPercent": "string",
              "healthyThreshold": "string",
              "unhealthyThreshold": "string",
              "healthcheckPort": "string",
              // Includes only one of the fields `stream`, `http`, `grpc`
              "stream": {
                "send": {
                  // Includes only one of the fields `text`
                  "text": "string"
                  // end of the list of possible fields
                },
                "receive": {
                  // Includes only one of the fields `text`
                  "text": "string"
                  // end of the list of possible fields
                }
              },
              "http": {
                "host": "string",
                "path": "string",
                "useHttp2": "boolean",
                "expectedStatuses": [
                  "string"
                ]
              },
              "grpc": {
                "serviceName": "string"
              },
              // end of the list of possible fields
              // Includes only one of the fields `plaintext`, `tls`
              "plaintext": "object",
              "tls": {
                "sni": "string",
                "validationContext": {
                  // Includes only one of the fields `trustedCaId`, `trustedCaBytes`
                  "trustedCaId": "string",
                  "trustedCaBytes": "string"
                  // end of the list of possible fields
                }
              }
              // end of the list of possible fields
            }
          ],
          "tls": {
            "sni": "string",
            "validationContext": {
              // Includes only one of the fields `trustedCaId`, `trustedCaBytes`
              "trustedCaId": "string",
              "trustedCaBytes": "string"
              // end of the list of possible fields
            }
          },
          "enableProxyProtocol": "boolean",
          "keepConnectionsOnHostHealthFailure": "boolean"
        }
      ],
      // Includes only one of the fields `connection`
      "connection": {
        "sourceIp": "boolean"
      }
      // end of the list of possible fields
    },
    // end of the list of possible fields
    "createdAt": "string"
  }
  // end of the list of possible fields
}

An Operation resource. For more information, see Operation.

Field	Description
id	string ID of the operation.
description	string Description of the operation. 0-256 characters long.
createdAt	string (date-time) Creation timestamp. String in RFC3339 text format. The range of possible values is from `0001-01-01T00:00:00Z` to `9999-12-31T23:59:59.999999999Z`, i.e. from 0 to 9 digits for fractions of a second. To work with values in this field, use the APIs described in the Protocol Buffers reference. In some languages, built-in datetime utilities do not support nanosecond precision (9 digits).
createdBy	string ID of the user or service account who initiated the operation.
modifiedAt	string (date-time) The time when the Operation resource was last modified. String in RFC3339 text format. The range of possible values is from `0001-01-01T00:00:00Z` to `9999-12-31T23:59:59.999999999Z`, i.e. from 0 to 9 digits for fractions of a second. To work with values in this field, use the APIs described in the Protocol Buffers reference. In some languages, built-in datetime utilities do not support nanosecond precision (9 digits).
done	boolean If the value is `false`, it means the operation is still in progress. If `true`, the operation is completed, and either `error` or `response` is available.
metadata	UpdateBackendMetadata Service-specific metadata associated with the operation. It typically contains the ID of the target resource that the operation is performed on. Any method that returns a long-running operation should document the metadata type, if any.
error	Status The error result of the operation in case of failure or cancellation. Includes only one of the fields `error`, `response`. The operation result. If `done == false` and there was no failure detected, neither `error` nor `response` is set. If `done == false` and there was a failure detected, `error` is set. If `done == true`, exactly one of `error` or `response` is set.
response	BackendGroup The normal response of the operation in case of success. If the original method returns no data on success, such as Delete, the response is google.protobuf.Empty. If the original method is the standard Create/Update, the response should be the target resource of the operation. Any method that returns a long-running operation should document the response type, if any. Includes only one of the fields `error`, `response`. The operation result. If `done == false` and there was no failure detected, neither `error` nor `response` is set. If `done == false` and there was a failure detected, `error` is set. If `done == true`, exactly one of `error` or `response` is set.

UpdateBackendMetadata

Field

Description

backendGroupId

string

ID of the backend group that the backend is being updated it.

backendName

string

Name of the backend that is being updated.

Status

The error result of the operation in case of failure or cancellation.

Field	Description
code	integer (int32) Error code. An enum value of google.rpc.Code.
message	string An error message.
details[]	object A list of messages that carry the error details.

BackendGroup

A backend group resource.
For details about the concept, see documentation.

Field	Description
id	string ID of the backend group. Generated at creation time.
name	string Name of the backend group. The name is unique within the folder. The string length in characters is 3-63.
description	string Description of the backend group. The string is 0-256 characters long.
folderId	string ID of the folder that the backend group belongs to.
labels	object (map<string, string>) Backend group labels as `key:value` pairs. For details about the concept, see documentation. The maximum number of labels is 64.
http	HttpBackendGroup List of HTTP backends that the backend group consists of. Includes only one of the fields `http`, `grpc`, `stream`. Backends that the backend group consists of.
grpc	GrpcBackendGroup List of gRPC backends that the backend group consists of. Includes only one of the fields `http`, `grpc`, `stream`. Backends that the backend group consists of.
stream	StreamBackendGroup List of stream (TCP) backends that the backend group consists of. Includes only one of the fields `http`, `grpc`, `stream`. Backends that the backend group consists of.
createdAt	string (date-time) Creation timestamp. String in RFC3339 text format. The range of possible values is from `0001-01-01T00:00:00Z` to `9999-12-31T23:59:59.999999999Z`, i.e. from 0 to 9 digits for fractions of a second. To work with values in this field, use the APIs described in the Protocol Buffers reference. In some languages, built-in datetime utilities do not support nanosecond precision (9 digits).

HttpBackendGroup

An HTTP backend group resource.

Field	Description
backends[]	HttpBackend List of HTTP backends.
connection	ConnectionSessionAffinity Connection-based session affinity configuration. For now, a connection is defined only by an IP address of the client. Includes only one of the fields `connection`, `header`, `cookie`. Session affinity configuration for the backend group. For details about the concept, see documentation. If session affinity is configured, the backend group should contain exactly one active backend (i.e. with positive HttpBackend.backendWeight), its HttpBackend.backendType should be TargetGroupsBackend, and its [LoadBalancingConfig.load_balancing_mode] should be `MAGLEV_HASH`. If any of these conditions are not met, session affinity will not work.
header	HeaderSessionAffinity HTTP-header-field-based session affinity configuration. Includes only one of the fields `connection`, `header`, `cookie`. Session affinity configuration for the backend group. For details about the concept, see documentation. If session affinity is configured, the backend group should contain exactly one active backend (i.e. with positive HttpBackend.backendWeight), its HttpBackend.backendType should be TargetGroupsBackend, and its [LoadBalancingConfig.load_balancing_mode] should be `MAGLEV_HASH`. If any of these conditions are not met, session affinity will not work.
cookie	CookieSessionAffinity Cookie-based session affinity configuration. Includes only one of the fields `connection`, `header`, `cookie`. Session affinity configuration for the backend group. For details about the concept, see documentation. If session affinity is configured, the backend group should contain exactly one active backend (i.e. with positive HttpBackend.backendWeight), its HttpBackend.backendType should be TargetGroupsBackend, and its [LoadBalancingConfig.load_balancing_mode] should be `MAGLEV_HASH`. If any of these conditions are not met, session affinity will not work.

HttpBackend

An HTTP backend resource.

Field	Description
name	string Required field. Name of the backend.
backendWeight	string (int64) Backend weight. Traffic is distributed between backends of a backend group according to their weights. Weights must be set either for all backends in a group or for none of them. Setting no weights is the same as setting equal non-zero weights for all backends. If the weight is non-positive, traffic is not sent to the backend.
loadBalancingConfig	LoadBalancingConfig Load balancing configuration for the backend.
port	string (int64) Port used by all targets to receive traffic.
targetGroups	TargetGroupsBackend Target groups that belong to the backend. For details about target groups, see documentation. Includes only one of the fields `targetGroups`, `storageBucket`. Reference to targets that belong to the backend. A backend may be a set of target groups or an Object Storage bucket. For details about backend types, see documentation.
storageBucket	StorageBucketBackend Object Storage bucket to use as the backend. For details about buckets, see documentation. If a bucket is used as a backend, the list of bucket objects and the objects themselves must be publicly accessible. For instructions, see documentation. Includes only one of the fields `targetGroups`, `storageBucket`. Reference to targets that belong to the backend. A backend may be a set of target groups or an Object Storage bucket. For details about backend types, see documentation.
healthchecks[]	HealthCheck Health checks to perform on targets from target groups. For details about health checking, see documentation. If no health checks are specified, active health checking is not performed.
tls	BackendTls Settings for TLS connections between load balancer nodes and backend targets. If specified, the load balancer establishes HTTPS (HTTP over TLS) connections with targets and compares received certificates with the one specified in BackendTls.validationContext. If not specified, the load balancer establishes unencrypted HTTP connections with targets.
useHttp2	boolean Enables HTTP/2 usage in connections between load balancer nodes and backend targets. Default value: `false`, HTTP/1.1 is used.

LoadBalancingConfig

A load balancing configuration resource.

Field	Description
panicThreshold	string (int64) Threshold for panic mode. If percentage of healthy backends in the group drops below threshold, panic mode will be activated and traffic will be routed to all backends, regardless of their health check status. This helps to avoid overloading healthy backends. For details about panic mode, see documentation. If the value is `0`, panic mode will never be activated and traffic is routed only to healthy backends at all times. Default value: `0`.
localityAwareRoutingPercent	string (int64) Percentage of traffic that a load balancer node sends to healthy backends in its availability zone. The rest is divided equally between other zones. For details about zone-aware routing, see documentation. If there are no healthy backends in an availability zone, all the traffic is divided between other zones. If `strictLocality` is `true`, the specified value is ignored. A load balancer node sends all the traffic within its availability zone, regardless of backends' health. Default value: `0`.
strictLocality	boolean Specifies whether a load balancer node should only send traffic to backends in its availability zone, regardless of their health, and ignore backends in other zones. If set to `true` and there are no healthy backends in the zone, the node in this zone will respond to incoming traffic with errors. For details about strict locality, see documentation. If `strict_locality` is `true`, the value specified in `localityAwareRoutingPercent` is ignored. Default value: `false`.
mode	enum (LoadBalancingMode) Load balancing mode for the backend. For details about load balancing modes, see documentation. `ROUND_ROBIN`: Round robin load balancing mode. All endpoints of the backend take their turns to receive requests attributed to the backend. `RANDOM`: Random load balancing mode. Default value. For a request attributed to the backend, an endpoint that receives it is picked at random. `LEAST_REQUEST`: Least request load balancing mode. To pick an endpoint that receives a request attributed to the backend, the power of two choices algorithm is used; that is, two endpoints are picked at random, and the request is sent to the one which has the fewest active requests. `MAGLEV_HASH`: Maglev hashing load balancing mode. Each endpoint is hashed, and a hash table with 65537 rows is filled accordingly, so that every endpoint occupies the same amount of rows. An attribute of each request is also hashed by the same function (if session affinity is enabled for the backend group, the attribute to hash is specified in session affinity configuration). The row with the same number as the resulting value is looked up in the table to determine the endpoint that receives the request. If the backend group with session affinity enabled contains more than one backend with positive weight, endpoints for backends with `MAGLEV_HASH` load balancing mode are picked at `RANDOM` instead.

TargetGroupsBackend

A resource for target groups that belong to the backend.

Field

Description

targetGroupIds[]

string

List of ID's of target groups that belong to the backend.

To get the ID's of all available target groups, make a TargetGroupService.List request.

StorageBucketBackend

A resource for Object Storage bucket used as a backend. For details about the concept,
see documentation.

Field

Description

bucket

string

Required field. Name of the bucket.

HealthCheck

A health check resource.
For details about the concept, see documentation.

Field	Description
timeout	string (duration) Required field. Health check timeout. The timeout is the time allowed for the target to respond to a check. If the target doesn't respond in time, the check is considered failed.
interval	string (duration) Required field. Base interval between consecutive health checks.
intervalJitterPercent	string
healthyThreshold	string (int64) Number of consecutive successful health checks required to mark an unhealthy target as healthy. Both `0` and `1` values amount to one successful check required. The value is ignored when a load balancer is initialized; a target is marked healthy after one successful check. Default value: `0`.
unhealthyThreshold	string (int64) Number of consecutive failed health checks required to mark a healthy target as unhealthy. Both `0` and `1` values amount to one unsuccessful check required. The value is ignored if a health check is failed due to an HTTP `503 Service Unavailable` response from the target (not applicable to TCP stream health checks). The target is immediately marked unhealthy. Default value: `0`.
healthcheckPort	string (int64) Port used for health checks. If not specified, the backend port (HttpBackend.port or GrpcBackend.port) is used for health checks.
stream	StreamHealthCheck TCP stream health check settings. Includes only one of the fields `stream`, `http`, `grpc`. Protocol-specific health check settings. The protocols of the backend and of its health check may differ, e.g. a gRPC health check may be specified for an HTTP backend.
http	HttpHealthCheck HTTP health check settings. Includes only one of the fields `stream`, `http`, `grpc`. Protocol-specific health check settings. The protocols of the backend and of its health check may differ, e.g. a gRPC health check may be specified for an HTTP backend.
grpc	GrpcHealthCheck gRPC health check settings. Includes only one of the fields `stream`, `http`, `grpc`. Protocol-specific health check settings. The protocols of the backend and of its health check may differ, e.g. a gRPC health check may be specified for an HTTP backend.
plaintext	object Includes only one of the fields `plaintext`, `tls`. Optional transport protocol for health checks. When not set, health checks use the same protocol as the proxied traffic. Use this when health checks' protocol settings differ from their backend, e.g. plaintext health checks for a TLS backend.
tls	SecureTransportSettings Includes only one of the fields `plaintext`, `tls`. Optional transport protocol for health checks. When not set, health checks use the same protocol as the proxied traffic. Use this when health checks' protocol settings differ from their backend, e.g. plaintext health checks for a TLS backend.

StreamHealthCheck

A resource for TCP stream health check settings.

Field

Description

send

Payload

Message sent to targets during TCP data transfer.

If not specified, no data is sent to the target.

receive

Payload

Data that must be contained in the messages received from targets for a successful health check.

If not specified, no messages are expected from targets, and those that are received are not checked.

Payload

A health check payload resource.

Field

Description

text

string

Payload text.

Includes only one of the fields text.

Payload.

HttpHealthCheck

A resource for HTTP health check settings.

Field	Description
host	string Value for the HTTP/1.1 `Host` header or the HTTP/2 `:authority` pseudo-header used in requests to targets.
path	string Required field. HTTP path used in requests to targets: request URI for HTTP/1.1 request line or value for the HTTP/2 `:path` pseudo-header.
useHttp2	boolean Enables HTTP/2 usage in health checks. Default value: `false`, HTTP/1.1 is used.
expectedStatuses[]	string (int64) A list of HTTP response statuses considered healthy. By default only 200 HTTP status code considered healthy.

GrpcHealthCheck

A resource for gRPC health check settings.

Field

Description

serviceName

string

Name of the gRPC service to be checked.

If not specified, overall health is checked.

For details about the concept, see GRPC Health Checking Protocol.

SecureTransportSettings

Transport settings to be used instead of the settings configured per-cluster

Field

Description

sni

string

SNI string for TLS connections.

validationContext

ValidationContext

Validation context for backend TLS connections.

ValidationContext

A TLS validation context resource.

Field

Description

trustedCaId

string

Includes only one of the fields trustedCaId, trustedCaBytes.

TLS certificate issued by a trusted certificate authority (CA).

trustedCaBytes

string

X.509 certificate contents in PEM format.

Includes only one of the fields trustedCaId, trustedCaBytes.

TLS certificate issued by a trusted certificate authority (CA).

BackendTls

A resource for backend TLS settings.

Field

Description

sni

string

Server Name Indication (SNI) string for TLS connections.

validationContext

ValidationContext

Validation context for TLS connections.

ConnectionSessionAffinity

A resource for connection-based session affinity configuration.

Field

Description

sourceIp

boolean

Specifies whether an IP address of the client is used to define a connection for session affinity.

HeaderSessionAffinity

A resource for HTTP-header-field-based session affinity configuration.

Field

Description

headerName

string

Name of the HTTP header field that is used for session affinity.

CookieSessionAffinity

A resource for cookie-based session affinity configuration.

Field

Description

name

string

Name of the cookie that is used for session affinity.

ttl

string (duration)

Maximum age of cookies that are generated for sessions.

If set to 0, session cookies are used, which are stored by clients in temporary memory and are deleted
on client restarts.

If not set, the balancer does not generate cookies and only uses incoming ones for establishing session affinity.

GrpcBackendGroup

A gRPC backend group resource.

Field	Description
backends[]	GrpcBackend List of gRPC backends.
connection	ConnectionSessionAffinity Connection-based session affinity configuration. For now, a connection is defined only by an IP address of the client. Includes only one of the fields `connection`, `header`, `cookie`. Session affinity configuration for the backend group. For details about the concept, see documentation. If session affinity is configured, the backend group should contain exactly one active backend (i.e. with positive GrpcBackend.backendWeight), and its [LoadBalancingConfig.load_balancing_mode] should be `MAGLEV_HASH`. If any of these conditions are not met, session affinity will not work.
header	HeaderSessionAffinity HTTP-header-field-based session affinity configuration. Includes only one of the fields `connection`, `header`, `cookie`. Session affinity configuration for the backend group. For details about the concept, see documentation. If session affinity is configured, the backend group should contain exactly one active backend (i.e. with positive GrpcBackend.backendWeight), and its [LoadBalancingConfig.load_balancing_mode] should be `MAGLEV_HASH`. If any of these conditions are not met, session affinity will not work.
cookie	CookieSessionAffinity Cookie-based session affinity configuration. Includes only one of the fields `connection`, `header`, `cookie`. Session affinity configuration for the backend group. For details about the concept, see documentation. If session affinity is configured, the backend group should contain exactly one active backend (i.e. with positive GrpcBackend.backendWeight), and its [LoadBalancingConfig.load_balancing_mode] should be `MAGLEV_HASH`. If any of these conditions are not met, session affinity will not work.

GrpcBackend

A gRPC backend resource.

Field	Description
name	string Required field. Name of the backend.
backendWeight	string (int64) Backend weight. Traffic is distributed between backends of a backend group according to their weights. Weights must be set either for all backends of a group or for none of them. Setting no weights is the same as setting equal non-zero weights for all backends. If the weight is non-positive, traffic is not sent to the backend.
loadBalancingConfig	LoadBalancingConfig Load balancing configuration for the backend.
port	string (int64) Port used by all targets to receive traffic.
targetGroups	TargetGroupsBackend Target groups that belong to the backend. Includes only one of the fields `targetGroups`. Reference to targets that belong to the backend. For now, targets are referenced via target groups.
healthchecks[]	HealthCheck Health checks to perform on targets from target groups. For details about health checking, see documentation. If no health checks are specified, active health checking is not performed.
tls	BackendTls Settings for TLS connections between load balancer nodes and backend targets. If specified, the load balancer establishes HTTPS (HTTP over TLS) connections with targets and compares received certificates with the one specified in BackendTls.validationContext. If not specified, the load balancer establishes unencrypted HTTP connections with targets.

StreamBackendGroup

A stream (TCP) backend group resource.

Field

Description

backends[]

StreamBackend

List of stream (TCP) backends.

connection

ConnectionSessionAffinity

Connection-based session affinity configuration.

For now, a connection is defined only by an IP address of the client.

Includes only one of the fields connection.

Session affinity configuration for the backend group.

For details about the concept, see
documentation.

If session affinity is configured, the backend group should contain exactly one active backend (i.e. with positive
HttpBackend.backendWeight), its HttpBackend.backendType should be TargetGroupsBackend, and its
[LoadBalancingConfig.load_balancing_mode] should be MAGLEV_HASH. If any of these conditions are not met, session
affinity will not work.

StreamBackend

A stream (TCP) backend resource.

Field	Description
name	string Name of the backend.
backendWeight	string (int64) Backend weight. Traffic is distributed between backends of a backend group according to their weights. Weights must be set either for all backends in a group or for none of them. Setting no weights is the same as setting equal non-zero weights for all backends. If the weight is non-positive, traffic is not sent to the backend.
loadBalancingConfig	LoadBalancingConfig Load balancing configuration for the backend.
port	string (int64) Port used by all targets to receive traffic.
targetGroups	TargetGroupsBackend Target groups that belong to the backend. For details about target groups, see documentation. Includes only one of the fields `targetGroups`. Reference to targets that belong to the backend.
healthchecks[]	HealthCheck Health checks to perform on targets from target groups. For details about health checking, see documentation. If no health checks are specified, active health checking is not performed.
tls	BackendTls Settings for TLS connections between load balancer nodes and backend targets. If specified, the load balancer establishes TLS-encrypted TCP connections with targets and compares received certificates with the one specified in BackendTls.validationContext. If not specified, the load balancer establishes unencrypted TCP connections with targets.
enableProxyProtocol	boolean If set, proxy protocol will be enabled for this backend.
keepConnectionsOnHostHealthFailure	boolean If a backend host becomes unhealthy (as determined by the configured health checks), keep connections to the failed host.

Application Load Balancer API, REST: BackendGroup.UpdateBackend

HTTP requestHTTP request

Path parametersPath parameters

Body parametersBody parameters

HttpBackendHttpBackend

LoadBalancingConfigLoadBalancingConfig

TargetGroupsBackendTargetGroupsBackend

StorageBucketBackendStorageBucketBackend

HealthCheckHealthCheck

StreamHealthCheckStreamHealthCheck

PayloadPayload

HttpHealthCheckHttpHealthCheck

GrpcHealthCheckGrpcHealthCheck

SecureTransportSettingsSecureTransportSettings

ValidationContextValidationContext

BackendTlsBackendTls

GrpcBackendGrpcBackend

StreamBackendStreamBackend

ResponseResponse

UpdateBackendMetadataUpdateBackendMetadata

StatusStatus

BackendGroupBackendGroup

HttpBackendGroupHttpBackendGroup

HttpBackendHttpBackend

LoadBalancingConfigLoadBalancingConfig

TargetGroupsBackendTargetGroupsBackend

StorageBucketBackendStorageBucketBackend

HealthCheckHealthCheck

StreamHealthCheckStreamHealthCheck

PayloadPayload

HttpHealthCheckHttpHealthCheck

GrpcHealthCheckGrpcHealthCheck

SecureTransportSettingsSecureTransportSettings

ValidationContextValidationContext

BackendTlsBackendTls

ConnectionSessionAffinityConnectionSessionAffinity

HeaderSessionAffinityHeaderSessionAffinity

CookieSessionAffinityCookieSessionAffinity

GrpcBackendGroupGrpcBackendGroup

GrpcBackendGrpcBackend

StreamBackendGroupStreamBackendGroup

StreamBackendStreamBackend

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HTTP request

Path parameters

Body parameters

HttpBackend

LoadBalancingConfig

TargetGroupsBackend

StorageBucketBackend

HealthCheck

StreamHealthCheck

Payload

HttpHealthCheck

GrpcHealthCheck

SecureTransportSettings

ValidationContext

BackendTls

GrpcBackend

StreamBackend

Response

UpdateBackendMetadata

Status

BackendGroup

HttpBackendGroup

HttpBackend

LoadBalancingConfig

TargetGroupsBackend

StorageBucketBackend

HealthCheck

StreamHealthCheck

Payload

HttpHealthCheck

GrpcHealthCheck

SecureTransportSettings

ValidationContext

BackendTls

ConnectionSessionAffinity

HeaderSessionAffinity

CookieSessionAffinity

GrpcBackendGroup

GrpcBackend

StreamBackendGroup

StreamBackend