gcloud compute backend-services update-backend - update an existing backend of a load balancer or Traffic Director

gcloud compute backend-services update-backendBACKEND_SERVICE_NAME([--instance-group=INSTANCE_GROUP :--instance-group-region=INSTANCE_GROUP_REGION |--instance-group-zone=INSTANCE_GROUP_ZONE]    | [--network-endpoint-group=NETWORK_ENDPOINT_GROUP :--network-endpoint-group-zone=NETWORK_ENDPOINT_GROUP_ZONE])[--balancing-mode=BALANCING_MODE][--capacity-scaler=CAPACITY_SCALER][--description=DESCRIPTION][--failover][--max-utilization=MAX_UTILIZATION][--preference=PREFERENCE][--clear-custom-metrics    |--custom-metrics=[CUSTOM_METRICS,…]    |--custom-metrics-file=[CUSTOM_METRICS,…]][--global    |--region=REGION][--max-connections=MAX_CONNECTIONS    |--max-connections-per-endpoint=MAX_CONNECTIONS_PER_ENDPOINT    |--max-connections-per-instance=MAX_CONNECTIONS_PER_INSTANCE    |--max-rate=MAX_RATE    |--max-rate-per-endpoint=MAX_RATE_PER_ENDPOINT    |--max-rate-per-instance=MAX_RATE_PER_INSTANCE][GCLOUD_WIDE_FLAG …]

To add, remove, or swap backends, use thegcloud compute backend-servicesremove-backend andgcloud computebackend-services add-backend commands.

BACKEND_SERVICE_NAME

Name of the backend service to operate on.

Exactly one of these must be specified:

Instance Group

--instance-group=INSTANCE_GROUP

Name of the instance group to update in the backend service. For details onvalid instance names, refer to the criteria documented under the field 'name'at:https://cloud.google.com/compute/docs/reference/rest/v1/instances

This flag argument must be specified if any of the other arguments in this groupare specified.

At most one of these can be specified:

--instance-group-region=INSTANCE_GROUP_REGION

Region of the instance group to update in the backend service. If not specified,you might be prompted to select a region (interactive mode only).

To avoid prompting when this flag is omitted, you can set thecompute/region property:

gcloudconfigsetcompute/regionREGION

A list of regions can be fetched by running:

gcloudcomputeregionslist

To unset the property, run:

gcloudconfigunsetcompute/region

Alternatively, the region can be stored in the environment variableCLOUDSDK_COMPUTE_REGION.

--instance-group-zone=INSTANCE_GROUP_ZONE

Zone of the instance group to update in the backend service. If not specifiedand thecompute/zone property isn't set,you might be prompted to select a zone (interactive mode only).

To avoid prompting when this flag is omitted, you can set thecompute/zone property:

gcloudconfigsetcompute/zoneZONE

A list of zones can be fetched by running:

gcloudcomputezoneslist

To unset the property, run:

gcloudconfigunsetcompute/zone

Alternatively, the zone can be stored in the environment variableCLOUDSDK_COMPUTE_ZONE.

Network Endpoint Group

--network-endpoint-group=NETWORK_ENDPOINT_GROUP

Name of the network endpoint group to update in the backend service.

This flag argument must be specified if any of the other arguments in this groupare specified.

--network-endpoint-group-zone=NETWORK_ENDPOINT_GROUP_ZONE

Zone of the network endpoint group to update in the backend service. If notspecified and thecompute/zone propertyisn't set, you might be prompted to select a zone (interactive mode only).

To avoid prompting when this flag is omitted, you can set thecompute/zone property:

gcloudconfigsetcompute/zoneZONE

A list of zones can be fetched by running:

gcloudcomputezoneslist

To unset the property, run:

gcloudconfigunsetcompute/zone

Alternatively, the zone can be stored in the environment variableCLOUDSDK_COMPUTE_ZONE.

--balancing-mode=BALANCING_MODE

Defines how to measure whether a backend can handle additional traffic or isfully loaded. For more information, seehttps://cloud.google.com/load-balancing/docs/backend-service#balancing-mode.BALANCING_MODE must be one of:

CONNECTION

Available if the backend service's load balancing scheme is eitherINTERNAL orEXTERNAL. Available if the backendservice's protocol is one ofSSL,TCP, orUDP.

Spreads load based on how many concurrent connections the backend can handle.

For backend services with --load-balancing-schemeEXTERNAL, youmust specify exactly one of these additional parameters:--max-connections,--max-connections-per-instance, or--max-connections-per-endpoint.

For backend services where--load-balancing-scheme isINTERNAL, you must omit all of these parameters.

CUSTOM_METRICS

Spreads load based on custom defined and reported metrics.

RATE

Available if the backend service's load balancing scheme isINTERNAL_MANAGED,INTERNAL_SELF_MANAGED, orEXTERNAL. Available if the backend service's protocol is one ofHTTP, HTTPS, or HTTP/2.

Spreads load based on how many HTTP requests per second (RPS) the backend canhandle.

You must specify exactly one of these additional parameters:--max-rate,--max-rate-per-instance, or--max-rate-per-endpoint.

UTILIZATION

Available if the backend service's load balancing scheme isINTERNAL_MANAGED,INTERNAL_SELF_MANAGED, orEXTERNAL. Available only for managed or unmanaged instance groupbackends.

Spreads load based on the backend utilization of instances in a backend instancegroup.

The following additional parameters may be specified:--max-utilization,--max-rate,--max-rate-per-instance,--max-connections,--max-connections-per-instance. For valid combinations, see--max-utilization.

--capacity-scaler=CAPACITY_SCALER

Scales down the target capacity (max utilization, max rate, or max connections)without changing the target capacity. For usage guidelines and examples, seeCapacityscaler.

--description=DESCRIPTION

An optional, textual description for the backend.

--failover

Designates whether this is a failover backend. More than one failover backendcan be configured for a given BackendService. Not compatible with the --globalflag

--max-utilization=MAX_UTILIZATION

Defines the maximum target for average utilization of the backend instancegroup. Supported values are0.0 (0%) through1.0(100%). This is an optional parameter for theUTILIZATION balancingmode.

You can use this parameter with other parameters for defining target capacity.For usage guidelines, seeBalancingmode combinations.

--preference=PREFERENCE

This parameter specifies whether a backend should be fully utilized beforesending traffic to backends with the default preference. This parameter cannotbe used with regional managed instance groups and when the endpoint type of anattached network endpoint group is INTERNET_IP_PORT, INTERNET_FQDN_PORT, orSERVERLESS.PREFERENCE must be one of:

DEFAULT

This is the default setting. If the designated preferred backends don't haveenough capacity, backends in the default category are used. Traffic isdistributed between default backends based on the load balancing algorithm used.

PREFERRED

Backends with this preference setting are used up to their capacity limitsfirst, while optimizing overall network latency.

At most one of these can be specified:

--clear-custom-metrics

Clears current list of CUSTOM_METRICS.

--custom-metrics=[CUSTOM_METRICS,…]

List of custom metrics that are used for CUSTOM_METRICS balancing mode andWEIGHTED_ROUND_ROBIN locality load balancing policy.

Example:

gcloudcomputebackend-servicesupdate-backend--custom-metrics='name=my-signal,maxUtilization=0.8,dryRun=true'gcloudcomputebackend-servicesupdate-backend--custom-metrics='name=my-signal,maxUtilization=0.8,dryRun=true'--custom-metrics='name=my-signal2,maxUtilization=0.2'gcloudcomputebackend-servicesupdate-backend--custom-metrics='[{"name" : "my-signal", "maxUtilization" : 0.8, "dryRun" : true}, {"name" : "my-signal2", "maxUtilization" : 0.1}]'

Setscustom_metrics value.

dryRun

SetsdryRun value.

maxUtilization

SetsmaxUtilization value.

name

Required, setsname value.

Shorthand Example:

--custom-metrics=dryRun=boolean,maxUtilization=float,name=string--custom-metrics=dryRun=boolean,maxUtilization=float,name=string

JSON Example:

--custom-metrics='[{"dryRun": boolean, "maxUtilization": float, "name": "string"}]'

File Example:

--custom-metrics=path_to_file.(yaml|json)

--custom-metrics-file=[CUSTOM_METRICS,…]

File path to json file with custom metrics that are used for CUSTOM_METRICSbalancing mode and WEIGHTED_ROUND_ROBIN locality load balancing policy.

Example:

gcloudcomputebackend-servicesupdate-backend--custom-metrics-file='customMetric.json'

Setscustom_metrics_file value.

dryRun

SetsdryRun value.

maxUtilization

SetsmaxUtilization value.

name

Required, setsname value.

Shorthand Example:

--custom-metrics-file=dryRun=boolean,maxUtilization=float,name=string--custom-metrics-file=dryRun=boolean,maxUtilization=float,name=string

JSON Example:

--custom-metrics-file='[{"dryRun": boolean, "maxUtilization": float, "name": "string"}]'

File Example:

--custom-metrics-file=path_to_file.(yaml|json)

At most one of these can be specified:

--global

If set, the backend service is global.

--region=REGION

Region of the backend service to operate on. Overrides the defaultcompute/region property value for this command invocation.

At most one of these can be specified:

--max-connections=MAX_CONNECTIONS

Maximum concurrent connections that the backend can handle. Valid for networkendpoint group and instance group backends (except for regional managed instancegroups).

--max-connections-per-endpoint=MAX_CONNECTIONS_PER_ENDPOINT

Only valid for network endpoint group backends. Defines a maximum number ofconnections per endpoint if all endpoints are healthy. When one or moreendpoints are unhealthy, an effective maximum average number of connections perhealthy endpoint is calculated by multiplyingMAX_CONNECTIONS_PER_ENDPOINT by the number of endpoints in thenetwork endpoint group, and then dividing by the number of healthy endpoints.

--max-connections-per-instance=MAX_CONNECTIONS_PER_INSTANCE

Only valid for instance group backends. Defines a maximum number of concurrentconnections per instance if all instances in the instance group are healthy.When one or more instances are unhealthy, an effective average maximum number ofconnections per healthy instance is calculated by multiplyingMAX_CONNECTIONS_PER_INSTANCE by the number of instances in theinstance group, and then dividing by the number of healthy instances.

--max-rate=MAX_RATE

Maximum number of HTTP requests per second (RPS) that the backend can handle.Valid for network endpoint group and instance group backends (except forregional managed instance groups). Must not be defined if the backend is amanaged instance group using load balancing-based autoscaling.

--max-rate-per-endpoint=MAX_RATE_PER_ENDPOINT

Only valid for network endpoint group backends. Defines a maximum number of HTTPrequests per second (RPS) per endpoint if all endpoints are healthy. When one ormore endpoints are unhealthy, an effective maximum rate per healthy endpoint iscalculated by multiplyingMAX_RATE_PER_ENDPOINT by the number ofendpoints in the network endpoint group, and then dividing by the number ofhealthy endpoints.

--max-rate-per-instance=MAX_RATE_PER_INSTANCE

Only valid for instance group backends. Defines a maximum number of HTTPrequests per second (RPS) per instance if all instances in the instance groupare healthy. When one or more instances are unhealthy, an effective maximum RPSper healthy instance is calculated by multiplyingMAX_RATE_PER_INSTANCE by the number of instances in the instancegroup, and then dividing by the number of healthy instances. This parameter iscompatible with managed instance group backends that use autoscaling based onload balancing.

Run$gcloud help for details.