POSITIONAL ARGUMENTS

BACKEND_SERVICE_NAME

Name of the backend service to operate on.

REQUIRED FLAGS

--instance-group=INSTANCE_GROUP

Name of the instance group to update the backend service.

OPTIONAL FLAGS

--balancing-mode=BALANCING_MODE

Defines the strategy for balancing load. BALANCING_MODE must be one of:

CONNECTION

Spreads load based on how many concurrent connections the backend can handle. This balancing mode is only available to backend services that use SSL, TCP, or UDP protocols. For backend services with --load-balancing-scheme EXTERNAL, you must specify exactly one of these additional parameters: --max-connections, --max-connections-per-instance, or --max-connections-per-endpoint. For backend services with --load-balancing-scheme INTERNAL, you must omit all of these parameters.

RATE

Spreads load based on how many HTTP requests per second (RPS) the backend can handle. This balancing mode is only available to backend services that use HTTP, HTTPS, or HTTP/2 protocols. You must specify exactly one of these additional parameters: --max-rate, --max-rate-per-instance, or--max-rate-per-endpoint.

UTILIZATION

Spreads load based on the CPU utilization of instances in a backend instance group. This balancing mode is only available to backend services with --load-balancing-scheme EXTERNAL and instance group backends. There is no restriction on the backend service protocol. 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 below.

--capacity-scaler=CAPACITY_SCALER

A setting that applies to all balancing modes. This value is multiplied by the balancing mode value to set the current max usage of the instance group. Acceptable values are 0.0 (0%) through 1.0 (100%). Setting this value to 0.0 (0%) drains the backend service. Note that draining a backend service only prevents new connections to instances in the group. All existing connections are allowed to continue until they close by normal means.

--description=DESCRIPTION

An optional, textual description for the backend.

--max-utilization=MAX_UTILIZATION

Defines the maximum target for average CPU utilization of the backend instance in the backend instance group. Acceptable values are 0.0 (0%) through 1.0 (100%). Available for all backend service protocols, with --balancing-mode=UTILIZATION.
For backend services that use SSL, TCP, or UDP protocols, you may specify either --max-connections or --max-connections-per-instance, either by themselves or one in conjunction with --max-utilization. In other words, the following configuration options are supported:

---

no additional parameter

---

just --max-utilization

---

just --max-connections

---

just --max-connections-per-instance

---

both --max-utilization and --max-connections

---

both --max-utilization and --max-connections-per-instance

The meanings for --max-connections and --max-connections-per-instance are the same as for --balancing-mode=CONNECTION. If one is used in conjunction with --max-utilization, instances are considered at capacity when either maximum utilization or maximum connections is reached.
For backend services that use HTTP, HTTPS, or HTTP/2 protocols, you may specify either --max-rate or --max-rate-per-instance, either by themselves or one in conjunction with --max-utilization. In other words, the following configuration options are supported:

*

no additional parameter

*

just --max-utilization

*

just --max-rate

*

just --max-rate-per-instance

*

both --max-utilization and --max-rate

*

both --max-utilization and --max-rate-per-instance

The meanings for --max-rate and --max-rate-per-instance are the same as for --balancing-mode=RATE. If one is used in conjunction with --max-utilization, instances are considered at capacity when either maximum utilization or the maximum rate is reached.

At most one of these may be specified:

--global

If set, the backend service is global.

--region=REGION

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

At most one of these may be specified:

--instance-group-region=INSTANCE_GROUP_REGION

Region of the instance group to update the backend service. If not specified, you may be prompted to select a region.
To avoid prompting when this flag is omitted, you can set the compute/region property:

$ gcloud config set compute/region REGION

A list of regions can be fetched by running:

$ gcloud compute regions list

To unset the property, run:

$ gcloud config unset compute/region

Alternatively, the region can be stored in the environment variable CLOUDSDK_COMPUTE_REGION.

--instance-group-zone=INSTANCE_GROUP_ZONE

Zone of the instance group to update the backend service. If not specified and the compute/zone property isn't set, you may be prompted to select a zone.
To avoid prompting when this flag is omitted, you can set the compute/zone property:

$ gcloud config set compute/zone ZONE

A list of zones can be fetched by running:

$ gcloud compute zones list

To unset the property, run:

$ gcloud config unset compute/zone

Alternatively, the zone can be stored in the environment variable CLOUDSDK_COMPUTE_ZONE.

At most one of these may be specified:

--max-connections=MAX_CONNECTIONS

Maximum concurrent connections that the backend can handle. Valid for instance group and network endpoint group backends.

--max-connections-per-instance=MAX_CONNECTIONS_PER_INSTANCE

Only valid for instance group backends. Defines a maximum number of concurrent connections per instance if all instances in the instance group are healthy. When one or more instances are unhealthy, an effective maximum number of connections per healthy instance is calculated by multiplying MAX_CONNECTIONS_PER_INSTANCE by the number of instances in the instance group, 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 instance group and network endpoint group backends. Must not be defined if the backend is a managed instance group using autoscaling based on load balancing.

--max-rate-per-instance=MAX_RATE_PER_INSTANCE

Only valid for instance group backends. Defines a maximum number of HTTP requests per second (RPS) per instance if all instances in the instance group are healthy. When one or more instances are unhealthy, an effective maximum RPS per healthy instance is calculated by multiplying MAX_RATE_PER_INSTANCE by the number of instances in the instance group, then dividing by the number of healthy instances. This parameter is compatible with managed instance group backends that use autoscaling based on load balancing.

GCLOUD WIDE FLAGS

NOTES

$ gcloud alpha compute backend-services update-backend $ gcloud beta compute backend-services update-backend