Package io.grpc.internal

Class PickFirstLoadBalancerProvider

java.lang.Object

io.grpc.LoadBalancer.Factory

io.grpc.LoadBalancerProvider

io.grpc.internal.PickFirstLoadBalancerProvider

public final class PickFirstLoadBalancerProvider
extends LoadBalancerProvider

Provider for the "pick_first" balancing policy.

This provides no load-balancing over the addresses from the NameResolver. It walks down the address list and sticks to the first that works.

Field Summary

Fields

Modifier and Type	Field	Description
static final String	GRPC_PF_USE_HAPPY_EYEBALLS

Constructor Summary

Constructors

Constructor	Description
PickFirstLoadBalancerProvider()

Method Summary

Modifier and Type	Method	Description
String	getPolicyName()	Returns the load-balancing policy name associated with this provider, which makes it selectable via LoadBalancerRegistry.getProvider(java.lang.String).
int	getPriority()	A priority, from 0 to 10 that this provider should be used, taking the current environment into consideration.
boolean	isAvailable()	Whether this provider is available for use, taking the current environment into consideration.
static boolean	isEnabledHappyEyeballs()
static boolean	isEnabledNewPickFirst()
LoadBalancer	newLoadBalancer(LoadBalancer.Helper helper)	Creates a LoadBalancer that will be used inside a channel.
NameResolver.ConfigOrError	parseLoadBalancingPolicyConfig(Map<String,?> rawLbPolicyConfig)	Parses the config for the Load Balancing policy unpacked from the service config.

Methods inherited from class io.grpc.LoadBalancerProvider

equals, hashCode, toString

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Field Details

GRPC_PF_USE_HAPPY_EYEBALLS

public static final String GRPC_PF_USE_HAPPY_EYEBALLS

See Also:

• Constant Field Values

Constructor Details

PickFirstLoadBalancerProvider

public PickFirstLoadBalancerProvider()

Method Details

isEnabledHappyEyeballs

public static boolean isEnabledHappyEyeballs()

isAvailable

public boolean isAvailable()

Description copied from class: LoadBalancerProvider

Whether this provider is available for use, taking the current environment into consideration. If false, LoadBalancer.Factory.newLoadBalancer(io.grpc.LoadBalancer.Helper) is not safe to be called.

Specified by:

isAvailable in class LoadBalancerProvider

getPriority

public int getPriority()

Description copied from class: LoadBalancerProvider

A priority, from 0 to 10 that this provider should be used, taking the current environment into consideration. 5 should be considered the default, and then tweaked based on environment detection. A priority of 0 does not imply that the provider wouldn't work; just that it should be last in line.

Specified by:

getPriority in class LoadBalancerProvider

getPolicyName

public String getPolicyName()

Description copied from class: LoadBalancerProvider

Returns the load-balancing policy name associated with this provider, which makes it selectable via LoadBalancerRegistry.getProvider(java.lang.String). This is called only when the class is loaded. It shouldn't change, and there is no point doing so.

The policy name should consist of only lower case letters letters, underscore and digits, and can only start with letters.

Specified by:

getPolicyName in class LoadBalancerProvider

newLoadBalancer

public LoadBalancer newLoadBalancer(LoadBalancer.Helper helper)

Description copied from class: LoadBalancer.Factory

Creates a LoadBalancer that will be used inside a channel.

Specified by:

newLoadBalancer in class LoadBalancer.Factory

parseLoadBalancingPolicyConfig

public NameResolver.ConfigOrError parseLoadBalancingPolicyConfig(Map<String,?> rawLbPolicyConfig)

Description copied from class: LoadBalancerProvider

Parses the config for the Load Balancing policy unpacked from the service config. This will return a NameResolver.ConfigOrError which contains either the successfully parsed config, or the Status representing the failure to parse. Implementations are expected to not throw exceptions but return a Status representing the failure. If successful, the load balancing policy config should be immutable.

Overrides:

parseLoadBalancingPolicyConfig in class LoadBalancerProvider

Parameters:

rawLbPolicyConfig - The Map representation of the load balancing policy choice.

Returns:

a tuple of the fully parsed and validated balancer configuration, else the Status.

See Also:

• A24-lb-policy-config.md

isEnabledNewPickFirst

public static boolean isEnabledNewPickFirst()