Package io.grpc.internal
Class PickFirstLoadBalancer
java.lang.Object
io.grpc.LoadBalancer
io.grpc.internal.PickFirstLoadBalancer
A
LoadBalancer
that provides no load-balancing over the addresses from the NameResolver
. The channel's default behavior is used, which is walking down the address
list and sticking to the first that works.-
Nested Class Summary
Nested ClassesModifier and TypeClassDescriptionprivate static final class
No-op picker which doesn't add any custom picking logic.static final class
private final class
Picker that requests connection during the first pick, and returns noResult.Nested classes/interfaces inherited from class io.grpc.LoadBalancer
LoadBalancer.CreateSubchannelArgs, LoadBalancer.ErrorPicker, LoadBalancer.Factory, LoadBalancer.FixedResultPicker, LoadBalancer.Helper, LoadBalancer.PickDetailsConsumer, LoadBalancer.PickResult, LoadBalancer.PickSubchannelArgs, LoadBalancer.ResolvedAddresses, LoadBalancer.Subchannel, LoadBalancer.SubchannelPicker, LoadBalancer.SubchannelStateListener
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Field Summary
FieldsModifier and TypeFieldDescriptionprivate ConnectivityState
private final LoadBalancer.Helper
private LoadBalancer.Subchannel
Fields inherited from class io.grpc.LoadBalancer
ATTR_HEALTH_CHECKING_CONFIG, DISABLE_SUBCHANNEL_RECONNECT_KEY, EMPTY_PICKER, HAS_HEALTH_PRODUCER_LISTENER_KEY, HEALTH_CONSUMER_LISTENER_ARG_KEY, IS_PETIOLE_POLICY
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Constructor Summary
Constructors -
Method Summary
Modifier and TypeMethodDescriptionacceptResolvedAddresses
(LoadBalancer.ResolvedAddresses resolvedAddresses) Accepts newly resolved addresses from the name resolution system.void
handleNameResolutionError
(Status error) Handles an error from the name resolution system.private void
processSubchannelState
(LoadBalancer.Subchannel subchannel, ConnectivityStateInfo stateInfo) void
The channel asks the LoadBalancer to establish connections now (if applicable) so that the upcoming RPC may then just pick a ready connection without waiting for connections.void
shutdown()
The channel asks the load-balancer to shutdown.private void
updateBalancingState
(ConnectivityState state, LoadBalancer.SubchannelPicker picker) Methods inherited from class io.grpc.LoadBalancer
canHandleEmptyAddressListFromNameResolution, handleResolvedAddresses, handleSubchannelState
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Field Details
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helper
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subchannel
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currentState
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Constructor Details
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PickFirstLoadBalancer
PickFirstLoadBalancer(LoadBalancer.Helper helper)
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Method Details
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acceptResolvedAddresses
Description copied from class:LoadBalancer
Accepts newly resolved addresses from the name resolution system. TheEquivalentAddressGroup
addresses should be considered equivalent but may be flattened into a single list if needed.Implementations can choose to reject the given addresses by returning
false
.Implementations should not modify the given
addresses
.- Overrides:
acceptResolvedAddresses
in classLoadBalancer
- Parameters:
resolvedAddresses
- the resolved server addresses, attributes, and config.- Returns:
true
if the resolved addresses were accepted.false
if rejected.
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handleNameResolutionError
Description copied from class:LoadBalancer
Handles an error from the name resolution system.- Specified by:
handleNameResolutionError
in classLoadBalancer
- Parameters:
error
- a non-OK status
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processSubchannelState
private void processSubchannelState(LoadBalancer.Subchannel subchannel, ConnectivityStateInfo stateInfo) -
updateBalancingState
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shutdown
public void shutdown()Description copied from class:LoadBalancer
The channel asks the load-balancer to shutdown. No more methods on this class will be called after this method. The implementation should shutdown all Subchannels and OOB channels, and do any other cleanup as necessary.- Specified by:
shutdown
in classLoadBalancer
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requestConnection
public void requestConnection()Description copied from class:LoadBalancer
The channel asks the LoadBalancer to establish connections now (if applicable) so that the upcoming RPC may then just pick a ready connection without waiting for connections. This is triggered byManagedChannel.getState(true)
.If LoadBalancer doesn't override it, this is no-op. If it infeasible to create connections given the current state, e.g. no Subchannel has been created yet, LoadBalancer can ignore this request.
- Overrides:
requestConnection
in classLoadBalancer
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