This commit is contained in:
dougbtv
2019-08-29 14:57:28 -04:00
committed by Tomofumi Hayashi
parent 59a267363d
commit 56f42e0b51
97 changed files with 8367 additions and 3388 deletions

View File

@@ -21,14 +21,18 @@
package balancer
import (
"context"
"encoding/json"
"errors"
"net"
"strings"
"golang.org/x/net/context"
"google.golang.org/grpc/connectivity"
"google.golang.org/grpc/credentials"
"google.golang.org/grpc/internal"
"google.golang.org/grpc/metadata"
"google.golang.org/grpc/resolver"
"google.golang.org/grpc/serviceconfig"
)
var (
@@ -37,7 +41,10 @@ var (
)
// Register registers the balancer builder to the balancer map. b.Name
// (lowercased) will be used as the name registered with this builder.
// (lowercased) will be used as the name registered with this builder. If the
// Builder implements ConfigParser, ParseConfig will be called when new service
// configs are received by the resolver, and the result will be provided to the
// Balancer in UpdateClientConnState.
//
// NOTE: this function must only be called during initialization time (i.e. in
// an init() function), and is not thread-safe. If multiple Balancers are
@@ -46,8 +53,20 @@ func Register(b Builder) {
m[strings.ToLower(b.Name())] = b
}
// unregisterForTesting deletes the balancer with the given name from the
// balancer map.
//
// This function is not thread-safe.
func unregisterForTesting(name string) {
delete(m, name)
}
func init() {
internal.BalancerUnregister = unregisterForTesting
}
// Get returns the resolver builder registered with the given name.
// Note that the compare is done in a case-insenstive fashion.
// Note that the compare is done in a case-insensitive fashion.
// If no builder is register with the name, nil will be returned.
func Get(name string) Builder {
if b, ok := m[strings.ToLower(name)]; ok {
@@ -88,7 +107,15 @@ type SubConn interface {
}
// NewSubConnOptions contains options to create new SubConn.
type NewSubConnOptions struct{}
type NewSubConnOptions struct {
// CredsBundle is the credentials bundle that will be used in the created
// SubConn. If it's nil, the original creds from grpc DialOptions will be
// used.
CredsBundle credentials.Bundle
// HealthCheckEnabled indicates whether health check service should be
// enabled on this SubConn
HealthCheckEnabled bool
}
// ClientConn represents a gRPC ClientConn.
//
@@ -105,7 +132,7 @@ type ClientConn interface {
// The SubConn will be shutdown.
RemoveSubConn(SubConn)
// UpdateBalancerState is called by balancer to nofity gRPC that some internal
// UpdateBalancerState is called by balancer to notify gRPC that some internal
// state in balancer has changed.
//
// gRPC will update the connectivity state of the ClientConn, and will call pick
@@ -116,6 +143,8 @@ type ClientConn interface {
ResolveNow(resolver.ResolveNowOption)
// Target returns the dial target for this ClientConn.
//
// Deprecated: Use the Target field in the BuildOptions instead.
Target() string
}
@@ -125,12 +154,18 @@ type BuildOptions struct {
// use to dial to a remote load balancer server. The Balancer implementations
// can ignore this if it does not need to talk to another party securely.
DialCreds credentials.TransportCredentials
// CredsBundle is the credentials bundle that the Balancer can use.
CredsBundle credentials.Bundle
// Dialer is the custom dialer the Balancer implementation can use to dial
// to a remote load balancer server. The Balancer implementations
// can ignore this if it doesn't need to talk to remote balancer.
Dialer func(context.Context, string) (net.Conn, error)
// ChannelzParentID is the entity parent's channelz unique identification number.
ChannelzParentID int64
// Target contains the parsed address info of the dial target. It is the same resolver.Target as
// passed to the resolver.
// See the documentation for the resolver.Target type for details about what it contains.
Target resolver.Target
}
// Builder creates a balancer.
@@ -142,17 +177,36 @@ type Builder interface {
Name() string
}
// ConfigParser parses load balancer configs.
type ConfigParser interface {
// ParseConfig parses the JSON load balancer config provided into an
// internal form or returns an error if the config is invalid. For future
// compatibility reasons, unknown fields in the config should be ignored.
ParseConfig(LoadBalancingConfigJSON json.RawMessage) (serviceconfig.LoadBalancingConfig, error)
}
// PickOptions contains addition information for the Pick operation.
type PickOptions struct{}
type PickOptions struct {
// FullMethodName is the method name that NewClientStream() is called
// with. The canonical format is /service/Method.
FullMethodName string
}
// DoneInfo contains additional information for done.
type DoneInfo struct {
// Err is the rpc error the RPC finished with. It could be nil.
Err error
// Trailer contains the metadata from the RPC's trailer, if present.
Trailer metadata.MD
// BytesSent indicates if any bytes have been sent to the server.
BytesSent bool
// BytesReceived indicates if any byte has been received from the server.
BytesReceived bool
// ServerLoad is the load received from server. It's usually sent as part of
// trailing metadata.
//
// The only supported type now is *orca_v1.LoadReport.
ServerLoad interface{}
}
var (
@@ -182,8 +236,10 @@ type Picker interface {
//
// If a SubConn is returned:
// - If it is READY, gRPC will send the RPC on it;
// - If it is not ready, or becomes not ready after it's returned, gRPC will block
// until UpdateBalancerState() is called and will call pick on the new picker.
// - If it is not ready, or becomes not ready after it's returned, gRPC will
// block until UpdateBalancerState() is called and will call pick on the
// new picker. The done function returned from Pick(), if not nil, will be
// called with nil error, no bytes sent and no bytes received.
//
// If the returned error is not nil:
// - If the error is ErrNoSubConnAvailable, gRPC will block until UpdateBalancerState()
@@ -194,9 +250,10 @@ type Picker interface {
// - Else (error is other non-nil error):
// - The RPC will fail with unavailable error.
//
// The returned done() function will be called once the rpc has finished, with the
// final status of that RPC.
// done may be nil if balancer doesn't care about the RPC status.
// The returned done() function will be called once the rpc has finished,
// with the final status of that RPC. If the SubConn returned is not a
// valid SubConn type, done may not be called. done may be nil if balancer
// doesn't care about the RPC status.
Pick(ctx context.Context, opts PickOptions) (conn SubConn, done func(DoneInfo), err error)
}
@@ -215,18 +272,55 @@ type Balancer interface {
// that back to gRPC.
// Balancer should also generate and update Pickers when its internal state has
// been changed by the new state.
//
// Deprecated: if V2Balancer is implemented by the Balancer,
// UpdateSubConnState will be called instead.
HandleSubConnStateChange(sc SubConn, state connectivity.State)
// HandleResolvedAddrs is called by gRPC to send updated resolved addresses to
// balancers.
// Balancer can create new SubConn or remove SubConn with the addresses.
// An empty address slice and a non-nil error will be passed if the resolver returns
// non-nil error to gRPC.
//
// Deprecated: if V2Balancer is implemented by the Balancer,
// UpdateClientConnState will be called instead.
HandleResolvedAddrs([]resolver.Address, error)
// Close closes the balancer. The balancer is not required to call
// ClientConn.RemoveSubConn for its existing SubConns.
Close()
}
// SubConnState describes the state of a SubConn.
type SubConnState struct {
ConnectivityState connectivity.State
// TODO: add last connection error
}
// ClientConnState describes the state of a ClientConn relevant to the
// balancer.
type ClientConnState struct {
ResolverState resolver.State
// The parsed load balancing configuration returned by the builder's
// ParseConfig method, if implemented.
BalancerConfig serviceconfig.LoadBalancingConfig
}
// V2Balancer is defined for documentation purposes. If a Balancer also
// implements V2Balancer, its UpdateClientConnState method will be called
// instead of HandleResolvedAddrs and its UpdateSubConnState will be called
// instead of HandleSubConnStateChange.
type V2Balancer interface {
// UpdateClientConnState is called by gRPC when the state of the ClientConn
// changes.
UpdateClientConnState(ClientConnState)
// UpdateSubConnState is called by gRPC when the state of a SubConn
// changes.
UpdateSubConnState(SubConn, SubConnState)
// Close closes the balancer. The balancer is not required to call
// ClientConn.RemoveSubConn for its existing SubConns.
Close()
}
// ConnectivityStateEvaluator takes the connectivity states of multiple SubConns
// and returns one aggregated connectivity state.
//