REST Resource: targetPools

Resource: TargetPool

Represents a Target Pool resource.

Target pools are used with external passthrough Network Load Balancers. A target pool references member instances, an associated legacy HttpHealthCheck resource, and, optionally, a backup target pool. For more information, readUsing target pools.

JSON representation
{"kind":string,"id":string,"creationTimestamp":string,"name":string,"description":string,"region":string,"healthChecks":[string],"instances":[string],"sessionAffinity":enum,"failoverRatio":number,"backupPool":string,"selfLink":string,"securityPolicy":string}
Fields
kind

string

[Output Only] Type of the resource. Alwayscompute#targetPool for target pools.

id

string (uint64 format)

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

creationTimestamp

string

[Output Only] Creation timestamp inRFC3339 text format.

name

string

Name of the resource. Provided by the client when the resource is created. The name must be 1-63 characters long, and comply withRFC1035. Specifically, the name must be 1-63 characters long and match the regular expression[a-z]([-a-z0-9]*[a-z0-9])? which means the first character must be a lowercase letter, and all following characters must be a dash, lowercase letter, or digit, except the last character, which cannot be a dash.

description

string

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

region

string

[Output Only] URL of the region where the target pool resides.

healthChecks[]

string

The URL of the HttpHealthCheck resource. A member instance in this pool is considered healthy if and only if the health checks pass. Only legacy HttpHealthChecks are supported. Only one health check may be specified.

instances[]

string

A list of resource URLs to the virtual machine instances serving this pool. They must live in zones contained in the same region as this pool.

sessionAffinity

enum

Session affinity option, must be one of the following values:
NONE: Connections from the same client IP may go to any instance in the pool.
CLIENT_IP: Connections from the same client IP will go to the same instance in the pool while that instance remains healthy.
CLIENT_IP_PROTO: Connections from the same client IP with the same IP protocol will go to the same instance in the pool while that instance remains healthy.

failoverRatio

number

This field is applicable only when the containing target pool is serving a forwarding rule as the primary pool (i.e., not as a backup pool to some other target pool). The value of the field must be in [0, 1].

If set,backupPool must also be set. They together define the fallback behavior of the primary target pool: if the ratio of the healthy instances in the primary pool is at or below this number, traffic arriving at the load-balanced IP will be directed to the backup pool.

In case wherefailoverRatio is not set or all the instances in the backup pool are unhealthy, the traffic will be directed back to the primary pool in the "force" mode, where traffic will be spread to the healthy instances with the best effort, or to all instances when no instance is healthy.

backupPool

string

The server-defined URL for the resource. This field is applicable only when the containing target pool is serving a forwarding rule as the primary pool, and itsfailoverRatio field is properly set to a value between [0, 1].backupPool andfailoverRatio together define the fallback behavior of the primary target pool: if the ratio of the healthy instances in the primary pool is at or belowfailoverRatio, traffic arriving at the load-balanced IP will be directed to the backup pool.

In case wherefailoverRatio andbackupPool are not set, or all the instances in the backup pool are unhealthy, the traffic will be directed back to the primary pool in the "force" mode, where traffic will be spread to the healthy instances with the best effort, or to all instances when no instance is healthy.

selfLink

string

[Output Only] Server-defined URL for the resource.

securityPolicy

string

[Output Only] The resource URL for the security policy associated with this target pool.

Methods

addHealthCheck

 Adds health check URLs to a target pool.

addInstance

 Adds an instance to a target pool.

aggregatedList

 Retrieves an aggregated list of target pools.

delete

 Deletes the specified target pool.

get

 Returns the specified target pool.

getHealth

 Gets the most recent health check results for each IP for the instance that is referenced by the given target pool.

insert

 Creates a target pool in the specified project and region using the data included in the request.

list

 Retrieves a list of target pools available to the specified project and region.

removeHealthCheck

 Removes health check URL from a target pool.

removeInstance

 Removes instance URL from a target pool.

setBackup

 Changes a backup target pool's configurations.

setSecurityPolicy

 Sets the Google Cloud Armor security policy for the specified target pool.

testIamPermissions

 Returns permissions that a caller has on the specified resource.

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Last updated 2025-09-18 UTC.