[VOL-5486] Fix deprecated versions
Change-Id: I3e03ea246020547ae75fa92ce8cf5cbba7e8f3bb
Signed-off-by: Abhay Kumar <abhay.kumar@radisys.com>
diff --git a/vendor/google.golang.org/grpc/balancer/pickfirst/internal/internal.go b/vendor/google.golang.org/grpc/balancer/pickfirst/internal/internal.go
new file mode 100644
index 0000000..7d66cb4
--- /dev/null
+++ b/vendor/google.golang.org/grpc/balancer/pickfirst/internal/internal.go
@@ -0,0 +1,35 @@
+/*
+ * Copyright 2024 gRPC authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+
+// Package internal contains code internal to the pickfirst package.
+package internal
+
+import (
+ rand "math/rand/v2"
+ "time"
+)
+
+var (
+ // RandShuffle pseudo-randomizes the order of addresses.
+ RandShuffle = rand.Shuffle
+ // TimeAfterFunc allows mocking the timer for testing connection delay
+ // related functionality.
+ TimeAfterFunc = func(d time.Duration, f func()) func() {
+ timer := time.AfterFunc(d, f)
+ return func() { timer.Stop() }
+ }
+)
diff --git a/vendor/google.golang.org/grpc/balancer/pickfirst/pickfirst.go b/vendor/google.golang.org/grpc/balancer/pickfirst/pickfirst.go
new file mode 100644
index 0000000..b15c10e
--- /dev/null
+++ b/vendor/google.golang.org/grpc/balancer/pickfirst/pickfirst.go
@@ -0,0 +1,291 @@
+/*
+ *
+ * Copyright 2017 gRPC authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+
+// Package pickfirst contains the pick_first load balancing policy.
+package pickfirst
+
+import (
+ "encoding/json"
+ "errors"
+ "fmt"
+ rand "math/rand/v2"
+
+ "google.golang.org/grpc/balancer"
+ "google.golang.org/grpc/balancer/pickfirst/internal"
+ "google.golang.org/grpc/connectivity"
+ "google.golang.org/grpc/grpclog"
+ "google.golang.org/grpc/internal/envconfig"
+ internalgrpclog "google.golang.org/grpc/internal/grpclog"
+ "google.golang.org/grpc/internal/pretty"
+ "google.golang.org/grpc/resolver"
+ "google.golang.org/grpc/serviceconfig"
+
+ _ "google.golang.org/grpc/balancer/pickfirst/pickfirstleaf" // For automatically registering the new pickfirst if required.
+)
+
+func init() {
+ if envconfig.NewPickFirstEnabled {
+ return
+ }
+ balancer.Register(pickfirstBuilder{})
+}
+
+var logger = grpclog.Component("pick-first-lb")
+
+const (
+ // Name is the name of the pick_first balancer.
+ Name = "pick_first"
+ logPrefix = "[pick-first-lb %p] "
+)
+
+type pickfirstBuilder struct{}
+
+func (pickfirstBuilder) Build(cc balancer.ClientConn, _ balancer.BuildOptions) balancer.Balancer {
+ b := &pickfirstBalancer{cc: cc}
+ b.logger = internalgrpclog.NewPrefixLogger(logger, fmt.Sprintf(logPrefix, b))
+ return b
+}
+
+func (pickfirstBuilder) Name() string {
+ return Name
+}
+
+type pfConfig struct {
+ serviceconfig.LoadBalancingConfig `json:"-"`
+
+ // If set to true, instructs the LB policy to shuffle the order of the list
+ // of endpoints received from the name resolver before attempting to
+ // connect to them.
+ ShuffleAddressList bool `json:"shuffleAddressList"`
+}
+
+func (pickfirstBuilder) ParseConfig(js json.RawMessage) (serviceconfig.LoadBalancingConfig, error) {
+ var cfg pfConfig
+ if err := json.Unmarshal(js, &cfg); err != nil {
+ return nil, fmt.Errorf("pickfirst: unable to unmarshal LB policy config: %s, error: %v", string(js), err)
+ }
+ return cfg, nil
+}
+
+type pickfirstBalancer struct {
+ logger *internalgrpclog.PrefixLogger
+ state connectivity.State
+ cc balancer.ClientConn
+ subConn balancer.SubConn
+}
+
+func (b *pickfirstBalancer) ResolverError(err error) {
+ if b.logger.V(2) {
+ b.logger.Infof("Received error from the name resolver: %v", err)
+ }
+ if b.subConn == nil {
+ b.state = connectivity.TransientFailure
+ }
+
+ if b.state != connectivity.TransientFailure {
+ // The picker will not change since the balancer does not currently
+ // report an error.
+ return
+ }
+ b.cc.UpdateState(balancer.State{
+ ConnectivityState: connectivity.TransientFailure,
+ Picker: &picker{err: fmt.Errorf("name resolver error: %v", err)},
+ })
+}
+
+// Shuffler is an interface for shuffling an address list.
+type Shuffler interface {
+ ShuffleAddressListForTesting(n int, swap func(i, j int))
+}
+
+// ShuffleAddressListForTesting pseudo-randomizes the order of addresses. n
+// is the number of elements. swap swaps the elements with indexes i and j.
+func ShuffleAddressListForTesting(n int, swap func(i, j int)) { rand.Shuffle(n, swap) }
+
+func (b *pickfirstBalancer) UpdateClientConnState(state balancer.ClientConnState) error {
+ if len(state.ResolverState.Addresses) == 0 && len(state.ResolverState.Endpoints) == 0 {
+ // The resolver reported an empty address list. Treat it like an error by
+ // calling b.ResolverError.
+ if b.subConn != nil {
+ // Shut down the old subConn. All addresses were removed, so it is
+ // no longer valid.
+ b.subConn.Shutdown()
+ b.subConn = nil
+ }
+ b.ResolverError(errors.New("produced zero addresses"))
+ return balancer.ErrBadResolverState
+ }
+ // We don't have to guard this block with the env var because ParseConfig
+ // already does so.
+ cfg, ok := state.BalancerConfig.(pfConfig)
+ if state.BalancerConfig != nil && !ok {
+ return fmt.Errorf("pickfirst: received illegal BalancerConfig (type %T): %v", state.BalancerConfig, state.BalancerConfig)
+ }
+
+ if b.logger.V(2) {
+ b.logger.Infof("Received new config %s, resolver state %s", pretty.ToJSON(cfg), pretty.ToJSON(state.ResolverState))
+ }
+
+ var addrs []resolver.Address
+ if endpoints := state.ResolverState.Endpoints; len(endpoints) != 0 {
+ // Perform the optional shuffling described in gRFC A62. The shuffling will
+ // change the order of endpoints but not touch the order of the addresses
+ // within each endpoint. - A61
+ if cfg.ShuffleAddressList {
+ endpoints = append([]resolver.Endpoint{}, endpoints...)
+ internal.RandShuffle(len(endpoints), func(i, j int) { endpoints[i], endpoints[j] = endpoints[j], endpoints[i] })
+ }
+
+ // "Flatten the list by concatenating the ordered list of addresses for each
+ // of the endpoints, in order." - A61
+ for _, endpoint := range endpoints {
+ // "In the flattened list, interleave addresses from the two address
+ // families, as per RFC-8304 section 4." - A61
+ // TODO: support the above language.
+ addrs = append(addrs, endpoint.Addresses...)
+ }
+ } else {
+ // Endpoints not set, process addresses until we migrate resolver
+ // emissions fully to Endpoints. The top channel does wrap emitted
+ // addresses with endpoints, however some balancers such as weighted
+ // target do not forward the corresponding correct endpoints down/split
+ // endpoints properly. Once all balancers correctly forward endpoints
+ // down, can delete this else conditional.
+ addrs = state.ResolverState.Addresses
+ if cfg.ShuffleAddressList {
+ addrs = append([]resolver.Address{}, addrs...)
+ internal.RandShuffle(len(addrs), func(i, j int) { addrs[i], addrs[j] = addrs[j], addrs[i] })
+ }
+ }
+
+ if b.subConn != nil {
+ b.cc.UpdateAddresses(b.subConn, addrs)
+ return nil
+ }
+
+ var subConn balancer.SubConn
+ subConn, err := b.cc.NewSubConn(addrs, balancer.NewSubConnOptions{
+ StateListener: func(state balancer.SubConnState) {
+ b.updateSubConnState(subConn, state)
+ },
+ })
+ if err != nil {
+ if b.logger.V(2) {
+ b.logger.Infof("Failed to create new SubConn: %v", err)
+ }
+ b.state = connectivity.TransientFailure
+ b.cc.UpdateState(balancer.State{
+ ConnectivityState: connectivity.TransientFailure,
+ Picker: &picker{err: fmt.Errorf("error creating connection: %v", err)},
+ })
+ return balancer.ErrBadResolverState
+ }
+ b.subConn = subConn
+ b.state = connectivity.Idle
+ b.cc.UpdateState(balancer.State{
+ ConnectivityState: connectivity.Connecting,
+ Picker: &picker{err: balancer.ErrNoSubConnAvailable},
+ })
+ b.subConn.Connect()
+ return nil
+}
+
+// UpdateSubConnState is unused as a StateListener is always registered when
+// creating SubConns.
+func (b *pickfirstBalancer) UpdateSubConnState(subConn balancer.SubConn, state balancer.SubConnState) {
+ b.logger.Errorf("UpdateSubConnState(%v, %+v) called unexpectedly", subConn, state)
+}
+
+func (b *pickfirstBalancer) updateSubConnState(subConn balancer.SubConn, state balancer.SubConnState) {
+ if b.logger.V(2) {
+ b.logger.Infof("Received SubConn state update: %p, %+v", subConn, state)
+ }
+ if b.subConn != subConn {
+ if b.logger.V(2) {
+ b.logger.Infof("Ignored state change because subConn is not recognized")
+ }
+ return
+ }
+ if state.ConnectivityState == connectivity.Shutdown {
+ b.subConn = nil
+ return
+ }
+
+ switch state.ConnectivityState {
+ case connectivity.Ready:
+ b.cc.UpdateState(balancer.State{
+ ConnectivityState: state.ConnectivityState,
+ Picker: &picker{result: balancer.PickResult{SubConn: subConn}},
+ })
+ case connectivity.Connecting:
+ if b.state == connectivity.TransientFailure {
+ // We stay in TransientFailure until we are Ready. See A62.
+ return
+ }
+ b.cc.UpdateState(balancer.State{
+ ConnectivityState: state.ConnectivityState,
+ Picker: &picker{err: balancer.ErrNoSubConnAvailable},
+ })
+ case connectivity.Idle:
+ if b.state == connectivity.TransientFailure {
+ // We stay in TransientFailure until we are Ready. Also kick the
+ // subConn out of Idle into Connecting. See A62.
+ b.subConn.Connect()
+ return
+ }
+ b.cc.UpdateState(balancer.State{
+ ConnectivityState: state.ConnectivityState,
+ Picker: &idlePicker{subConn: subConn},
+ })
+ case connectivity.TransientFailure:
+ b.cc.UpdateState(balancer.State{
+ ConnectivityState: state.ConnectivityState,
+ Picker: &picker{err: state.ConnectionError},
+ })
+ }
+ b.state = state.ConnectivityState
+}
+
+func (b *pickfirstBalancer) Close() {
+}
+
+func (b *pickfirstBalancer) ExitIdle() {
+ if b.subConn != nil && b.state == connectivity.Idle {
+ b.subConn.Connect()
+ }
+}
+
+type picker struct {
+ result balancer.PickResult
+ err error
+}
+
+func (p *picker) Pick(balancer.PickInfo) (balancer.PickResult, error) {
+ return p.result, p.err
+}
+
+// idlePicker is used when the SubConn is IDLE and kicks the SubConn into
+// CONNECTING when Pick is called.
+type idlePicker struct {
+ subConn balancer.SubConn
+}
+
+func (i *idlePicker) Pick(balancer.PickInfo) (balancer.PickResult, error) {
+ i.subConn.Connect()
+ return balancer.PickResult{}, balancer.ErrNoSubConnAvailable
+}
diff --git a/vendor/google.golang.org/grpc/balancer/pickfirst/pickfirstleaf/pickfirstleaf.go b/vendor/google.golang.org/grpc/balancer/pickfirst/pickfirstleaf/pickfirstleaf.go
new file mode 100644
index 0000000..9ffdd28
--- /dev/null
+++ b/vendor/google.golang.org/grpc/balancer/pickfirst/pickfirstleaf/pickfirstleaf.go
@@ -0,0 +1,913 @@
+/*
+ *
+ * Copyright 2024 gRPC authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+
+// Package pickfirstleaf contains the pick_first load balancing policy which
+// will be the universal leaf policy after dualstack changes are implemented.
+//
+// # Experimental
+//
+// Notice: This package is EXPERIMENTAL and may be changed or removed in a
+// later release.
+package pickfirstleaf
+
+import (
+ "encoding/json"
+ "errors"
+ "fmt"
+ "net"
+ "net/netip"
+ "sync"
+ "time"
+
+ "google.golang.org/grpc/balancer"
+ "google.golang.org/grpc/balancer/pickfirst/internal"
+ "google.golang.org/grpc/connectivity"
+ expstats "google.golang.org/grpc/experimental/stats"
+ "google.golang.org/grpc/grpclog"
+ "google.golang.org/grpc/internal/envconfig"
+ internalgrpclog "google.golang.org/grpc/internal/grpclog"
+ "google.golang.org/grpc/internal/pretty"
+ "google.golang.org/grpc/resolver"
+ "google.golang.org/grpc/serviceconfig"
+)
+
+func init() {
+ if envconfig.NewPickFirstEnabled {
+ // Register as the default pick_first balancer.
+ Name = "pick_first"
+ }
+ balancer.Register(pickfirstBuilder{})
+}
+
+// enableHealthListenerKeyType is a unique key type used in resolver
+// attributes to indicate whether the health listener usage is enabled.
+type enableHealthListenerKeyType struct{}
+
+var (
+ logger = grpclog.Component("pick-first-leaf-lb")
+ // Name is the name of the pick_first_leaf balancer.
+ // It is changed to "pick_first" in init() if this balancer is to be
+ // registered as the default pickfirst.
+ Name = "pick_first_leaf"
+ disconnectionsMetric = expstats.RegisterInt64Count(expstats.MetricDescriptor{
+ Name: "grpc.lb.pick_first.disconnections",
+ Description: "EXPERIMENTAL. Number of times the selected subchannel becomes disconnected.",
+ Unit: "{disconnection}",
+ Labels: []string{"grpc.target"},
+ Default: false,
+ })
+ connectionAttemptsSucceededMetric = expstats.RegisterInt64Count(expstats.MetricDescriptor{
+ Name: "grpc.lb.pick_first.connection_attempts_succeeded",
+ Description: "EXPERIMENTAL. Number of successful connection attempts.",
+ Unit: "{attempt}",
+ Labels: []string{"grpc.target"},
+ Default: false,
+ })
+ connectionAttemptsFailedMetric = expstats.RegisterInt64Count(expstats.MetricDescriptor{
+ Name: "grpc.lb.pick_first.connection_attempts_failed",
+ Description: "EXPERIMENTAL. Number of failed connection attempts.",
+ Unit: "{attempt}",
+ Labels: []string{"grpc.target"},
+ Default: false,
+ })
+)
+
+const (
+ // TODO: change to pick-first when this becomes the default pick_first policy.
+ logPrefix = "[pick-first-leaf-lb %p] "
+ // connectionDelayInterval is the time to wait for during the happy eyeballs
+ // pass before starting the next connection attempt.
+ connectionDelayInterval = 250 * time.Millisecond
+)
+
+type ipAddrFamily int
+
+const (
+ // ipAddrFamilyUnknown represents strings that can't be parsed as an IP
+ // address.
+ ipAddrFamilyUnknown ipAddrFamily = iota
+ ipAddrFamilyV4
+ ipAddrFamilyV6
+)
+
+type pickfirstBuilder struct{}
+
+func (pickfirstBuilder) Build(cc balancer.ClientConn, bo balancer.BuildOptions) balancer.Balancer {
+ b := &pickfirstBalancer{
+ cc: cc,
+ target: bo.Target.String(),
+ metricsRecorder: cc.MetricsRecorder(),
+
+ subConns: resolver.NewAddressMapV2[*scData](),
+ state: connectivity.Connecting,
+ cancelConnectionTimer: func() {},
+ }
+ b.logger = internalgrpclog.NewPrefixLogger(logger, fmt.Sprintf(logPrefix, b))
+ return b
+}
+
+func (b pickfirstBuilder) Name() string {
+ return Name
+}
+
+func (pickfirstBuilder) ParseConfig(js json.RawMessage) (serviceconfig.LoadBalancingConfig, error) {
+ var cfg pfConfig
+ if err := json.Unmarshal(js, &cfg); err != nil {
+ return nil, fmt.Errorf("pickfirst: unable to unmarshal LB policy config: %s, error: %v", string(js), err)
+ }
+ return cfg, nil
+}
+
+// EnableHealthListener updates the state to configure pickfirst for using a
+// generic health listener.
+func EnableHealthListener(state resolver.State) resolver.State {
+ state.Attributes = state.Attributes.WithValue(enableHealthListenerKeyType{}, true)
+ return state
+}
+
+type pfConfig struct {
+ serviceconfig.LoadBalancingConfig `json:"-"`
+
+ // If set to true, instructs the LB policy to shuffle the order of the list
+ // of endpoints received from the name resolver before attempting to
+ // connect to them.
+ ShuffleAddressList bool `json:"shuffleAddressList"`
+}
+
+// scData keeps track of the current state of the subConn.
+// It is not safe for concurrent access.
+type scData struct {
+ // The following fields are initialized at build time and read-only after
+ // that.
+ subConn balancer.SubConn
+ addr resolver.Address
+
+ rawConnectivityState connectivity.State
+ // The effective connectivity state based on raw connectivity, health state
+ // and after following sticky TransientFailure behaviour defined in A62.
+ effectiveState connectivity.State
+ lastErr error
+ connectionFailedInFirstPass bool
+}
+
+func (b *pickfirstBalancer) newSCData(addr resolver.Address) (*scData, error) {
+ sd := &scData{
+ rawConnectivityState: connectivity.Idle,
+ effectiveState: connectivity.Idle,
+ addr: addr,
+ }
+ sc, err := b.cc.NewSubConn([]resolver.Address{addr}, balancer.NewSubConnOptions{
+ StateListener: func(state balancer.SubConnState) {
+ b.updateSubConnState(sd, state)
+ },
+ })
+ if err != nil {
+ return nil, err
+ }
+ sd.subConn = sc
+ return sd, nil
+}
+
+type pickfirstBalancer struct {
+ // The following fields are initialized at build time and read-only after
+ // that and therefore do not need to be guarded by a mutex.
+ logger *internalgrpclog.PrefixLogger
+ cc balancer.ClientConn
+ target string
+ metricsRecorder expstats.MetricsRecorder // guaranteed to be non nil
+
+ // The mutex is used to ensure synchronization of updates triggered
+ // from the idle picker and the already serialized resolver,
+ // SubConn state updates.
+ mu sync.Mutex
+ // State reported to the channel based on SubConn states and resolver
+ // updates.
+ state connectivity.State
+ // scData for active subonns mapped by address.
+ subConns *resolver.AddressMapV2[*scData]
+ addressList addressList
+ firstPass bool
+ numTF int
+ cancelConnectionTimer func()
+ healthCheckingEnabled bool
+}
+
+// ResolverError is called by the ClientConn when the name resolver produces
+// an error or when pickfirst determined the resolver update to be invalid.
+func (b *pickfirstBalancer) ResolverError(err error) {
+ b.mu.Lock()
+ defer b.mu.Unlock()
+ b.resolverErrorLocked(err)
+}
+
+func (b *pickfirstBalancer) resolverErrorLocked(err error) {
+ if b.logger.V(2) {
+ b.logger.Infof("Received error from the name resolver: %v", err)
+ }
+
+ // The picker will not change since the balancer does not currently
+ // report an error. If the balancer hasn't received a single good resolver
+ // update yet, transition to TRANSIENT_FAILURE.
+ if b.state != connectivity.TransientFailure && b.addressList.size() > 0 {
+ if b.logger.V(2) {
+ b.logger.Infof("Ignoring resolver error because balancer is using a previous good update.")
+ }
+ return
+ }
+
+ b.updateBalancerState(balancer.State{
+ ConnectivityState: connectivity.TransientFailure,
+ Picker: &picker{err: fmt.Errorf("name resolver error: %v", err)},
+ })
+}
+
+func (b *pickfirstBalancer) UpdateClientConnState(state balancer.ClientConnState) error {
+ b.mu.Lock()
+ defer b.mu.Unlock()
+ b.cancelConnectionTimer()
+ if len(state.ResolverState.Addresses) == 0 && len(state.ResolverState.Endpoints) == 0 {
+ // Cleanup state pertaining to the previous resolver state.
+ // Treat an empty address list like an error by calling b.ResolverError.
+ b.closeSubConnsLocked()
+ b.addressList.updateAddrs(nil)
+ b.resolverErrorLocked(errors.New("produced zero addresses"))
+ return balancer.ErrBadResolverState
+ }
+ b.healthCheckingEnabled = state.ResolverState.Attributes.Value(enableHealthListenerKeyType{}) != nil
+ cfg, ok := state.BalancerConfig.(pfConfig)
+ if state.BalancerConfig != nil && !ok {
+ return fmt.Errorf("pickfirst: received illegal BalancerConfig (type %T): %v: %w", state.BalancerConfig, state.BalancerConfig, balancer.ErrBadResolverState)
+ }
+
+ if b.logger.V(2) {
+ b.logger.Infof("Received new config %s, resolver state %s", pretty.ToJSON(cfg), pretty.ToJSON(state.ResolverState))
+ }
+
+ var newAddrs []resolver.Address
+ if endpoints := state.ResolverState.Endpoints; len(endpoints) != 0 {
+ // Perform the optional shuffling described in gRFC A62. The shuffling
+ // will change the order of endpoints but not touch the order of the
+ // addresses within each endpoint. - A61
+ if cfg.ShuffleAddressList {
+ endpoints = append([]resolver.Endpoint{}, endpoints...)
+ internal.RandShuffle(len(endpoints), func(i, j int) { endpoints[i], endpoints[j] = endpoints[j], endpoints[i] })
+ }
+
+ // "Flatten the list by concatenating the ordered list of addresses for
+ // each of the endpoints, in order." - A61
+ for _, endpoint := range endpoints {
+ newAddrs = append(newAddrs, endpoint.Addresses...)
+ }
+ } else {
+ // Endpoints not set, process addresses until we migrate resolver
+ // emissions fully to Endpoints. The top channel does wrap emitted
+ // addresses with endpoints, however some balancers such as weighted
+ // target do not forward the corresponding correct endpoints down/split
+ // endpoints properly. Once all balancers correctly forward endpoints
+ // down, can delete this else conditional.
+ newAddrs = state.ResolverState.Addresses
+ if cfg.ShuffleAddressList {
+ newAddrs = append([]resolver.Address{}, newAddrs...)
+ internal.RandShuffle(len(newAddrs), func(i, j int) { newAddrs[i], newAddrs[j] = newAddrs[j], newAddrs[i] })
+ }
+ }
+
+ // If an address appears in multiple endpoints or in the same endpoint
+ // multiple times, we keep it only once. We will create only one SubConn
+ // for the address because an AddressMap is used to store SubConns.
+ // Not de-duplicating would result in attempting to connect to the same
+ // SubConn multiple times in the same pass. We don't want this.
+ newAddrs = deDupAddresses(newAddrs)
+ newAddrs = interleaveAddresses(newAddrs)
+
+ prevAddr := b.addressList.currentAddress()
+ prevSCData, found := b.subConns.Get(prevAddr)
+ prevAddrsCount := b.addressList.size()
+ isPrevRawConnectivityStateReady := found && prevSCData.rawConnectivityState == connectivity.Ready
+ b.addressList.updateAddrs(newAddrs)
+
+ // If the previous ready SubConn exists in new address list,
+ // keep this connection and don't create new SubConns.
+ if isPrevRawConnectivityStateReady && b.addressList.seekTo(prevAddr) {
+ return nil
+ }
+
+ b.reconcileSubConnsLocked(newAddrs)
+ // If it's the first resolver update or the balancer was already READY
+ // (but the new address list does not contain the ready SubConn) or
+ // CONNECTING, enter CONNECTING.
+ // We may be in TRANSIENT_FAILURE due to a previous empty address list,
+ // we should still enter CONNECTING because the sticky TF behaviour
+ // mentioned in A62 applies only when the TRANSIENT_FAILURE is reported
+ // due to connectivity failures.
+ if isPrevRawConnectivityStateReady || b.state == connectivity.Connecting || prevAddrsCount == 0 {
+ // Start connection attempt at first address.
+ b.forceUpdateConcludedStateLocked(balancer.State{
+ ConnectivityState: connectivity.Connecting,
+ Picker: &picker{err: balancer.ErrNoSubConnAvailable},
+ })
+ b.startFirstPassLocked()
+ } else if b.state == connectivity.TransientFailure {
+ // If we're in TRANSIENT_FAILURE, we stay in TRANSIENT_FAILURE until
+ // we're READY. See A62.
+ b.startFirstPassLocked()
+ }
+ return nil
+}
+
+// UpdateSubConnState is unused as a StateListener is always registered when
+// creating SubConns.
+func (b *pickfirstBalancer) UpdateSubConnState(subConn balancer.SubConn, state balancer.SubConnState) {
+ b.logger.Errorf("UpdateSubConnState(%v, %+v) called unexpectedly", subConn, state)
+}
+
+func (b *pickfirstBalancer) Close() {
+ b.mu.Lock()
+ defer b.mu.Unlock()
+ b.closeSubConnsLocked()
+ b.cancelConnectionTimer()
+ b.state = connectivity.Shutdown
+}
+
+// ExitIdle moves the balancer out of idle state. It can be called concurrently
+// by the idlePicker and clientConn so access to variables should be
+// synchronized.
+func (b *pickfirstBalancer) ExitIdle() {
+ b.mu.Lock()
+ defer b.mu.Unlock()
+ if b.state == connectivity.Idle {
+ // Move the balancer into CONNECTING state immediately. This is done to
+ // avoid staying in IDLE if a resolver update arrives before the first
+ // SubConn reports CONNECTING.
+ b.updateBalancerState(balancer.State{
+ ConnectivityState: connectivity.Connecting,
+ Picker: &picker{err: balancer.ErrNoSubConnAvailable},
+ })
+ b.startFirstPassLocked()
+ }
+}
+
+func (b *pickfirstBalancer) startFirstPassLocked() {
+ b.firstPass = true
+ b.numTF = 0
+ // Reset the connection attempt record for existing SubConns.
+ for _, sd := range b.subConns.Values() {
+ sd.connectionFailedInFirstPass = false
+ }
+ b.requestConnectionLocked()
+}
+
+func (b *pickfirstBalancer) closeSubConnsLocked() {
+ for _, sd := range b.subConns.Values() {
+ sd.subConn.Shutdown()
+ }
+ b.subConns = resolver.NewAddressMapV2[*scData]()
+}
+
+// deDupAddresses ensures that each address appears only once in the slice.
+func deDupAddresses(addrs []resolver.Address) []resolver.Address {
+ seenAddrs := resolver.NewAddressMapV2[*scData]()
+ retAddrs := []resolver.Address{}
+
+ for _, addr := range addrs {
+ if _, ok := seenAddrs.Get(addr); ok {
+ continue
+ }
+ retAddrs = append(retAddrs, addr)
+ }
+ return retAddrs
+}
+
+// interleaveAddresses interleaves addresses of both families (IPv4 and IPv6)
+// as per RFC-8305 section 4.
+// Whichever address family is first in the list is followed by an address of
+// the other address family; that is, if the first address in the list is IPv6,
+// then the first IPv4 address should be moved up in the list to be second in
+// the list. It doesn't support configuring "First Address Family Count", i.e.
+// there will always be a single member of the first address family at the
+// beginning of the interleaved list.
+// Addresses that are neither IPv4 nor IPv6 are treated as part of a third
+// "unknown" family for interleaving.
+// See: https://datatracker.ietf.org/doc/html/rfc8305#autoid-6
+func interleaveAddresses(addrs []resolver.Address) []resolver.Address {
+ familyAddrsMap := map[ipAddrFamily][]resolver.Address{}
+ interleavingOrder := []ipAddrFamily{}
+ for _, addr := range addrs {
+ family := addressFamily(addr.Addr)
+ if _, found := familyAddrsMap[family]; !found {
+ interleavingOrder = append(interleavingOrder, family)
+ }
+ familyAddrsMap[family] = append(familyAddrsMap[family], addr)
+ }
+
+ interleavedAddrs := make([]resolver.Address, 0, len(addrs))
+
+ for curFamilyIdx := 0; len(interleavedAddrs) < len(addrs); curFamilyIdx = (curFamilyIdx + 1) % len(interleavingOrder) {
+ // Some IP types may have fewer addresses than others, so we look for
+ // the next type that has a remaining member to add to the interleaved
+ // list.
+ family := interleavingOrder[curFamilyIdx]
+ remainingMembers := familyAddrsMap[family]
+ if len(remainingMembers) > 0 {
+ interleavedAddrs = append(interleavedAddrs, remainingMembers[0])
+ familyAddrsMap[family] = remainingMembers[1:]
+ }
+ }
+
+ return interleavedAddrs
+}
+
+// addressFamily returns the ipAddrFamily after parsing the address string.
+// If the address isn't of the format "ip-address:port", it returns
+// ipAddrFamilyUnknown. The address may be valid even if it's not an IP when
+// using a resolver like passthrough where the address may be a hostname in
+// some format that the dialer can resolve.
+func addressFamily(address string) ipAddrFamily {
+ // Parse the IP after removing the port.
+ host, _, err := net.SplitHostPort(address)
+ if err != nil {
+ return ipAddrFamilyUnknown
+ }
+ ip, err := netip.ParseAddr(host)
+ if err != nil {
+ return ipAddrFamilyUnknown
+ }
+ switch {
+ case ip.Is4() || ip.Is4In6():
+ return ipAddrFamilyV4
+ case ip.Is6():
+ return ipAddrFamilyV6
+ default:
+ return ipAddrFamilyUnknown
+ }
+}
+
+// reconcileSubConnsLocked updates the active subchannels based on a new address
+// list from the resolver. It does this by:
+// - closing subchannels: any existing subchannels associated with addresses
+// that are no longer in the updated list are shut down.
+// - removing subchannels: entries for these closed subchannels are removed
+// from the subchannel map.
+//
+// This ensures that the subchannel map accurately reflects the current set of
+// addresses received from the name resolver.
+func (b *pickfirstBalancer) reconcileSubConnsLocked(newAddrs []resolver.Address) {
+ newAddrsMap := resolver.NewAddressMapV2[bool]()
+ for _, addr := range newAddrs {
+ newAddrsMap.Set(addr, true)
+ }
+
+ for _, oldAddr := range b.subConns.Keys() {
+ if _, ok := newAddrsMap.Get(oldAddr); ok {
+ continue
+ }
+ val, _ := b.subConns.Get(oldAddr)
+ val.subConn.Shutdown()
+ b.subConns.Delete(oldAddr)
+ }
+}
+
+// shutdownRemainingLocked shuts down remaining subConns. Called when a subConn
+// becomes ready, which means that all other subConn must be shutdown.
+func (b *pickfirstBalancer) shutdownRemainingLocked(selected *scData) {
+ b.cancelConnectionTimer()
+ for _, sd := range b.subConns.Values() {
+ if sd.subConn != selected.subConn {
+ sd.subConn.Shutdown()
+ }
+ }
+ b.subConns = resolver.NewAddressMapV2[*scData]()
+ b.subConns.Set(selected.addr, selected)
+}
+
+// requestConnectionLocked starts connecting on the subchannel corresponding to
+// the current address. If no subchannel exists, one is created. If the current
+// subchannel is in TransientFailure, a connection to the next address is
+// attempted until a subchannel is found.
+func (b *pickfirstBalancer) requestConnectionLocked() {
+ if !b.addressList.isValid() {
+ return
+ }
+ var lastErr error
+ for valid := true; valid; valid = b.addressList.increment() {
+ curAddr := b.addressList.currentAddress()
+ sd, ok := b.subConns.Get(curAddr)
+ if !ok {
+ var err error
+ // We want to assign the new scData to sd from the outer scope,
+ // hence we can't use := below.
+ sd, err = b.newSCData(curAddr)
+ if err != nil {
+ // This should never happen, unless the clientConn is being shut
+ // down.
+ if b.logger.V(2) {
+ b.logger.Infof("Failed to create a subConn for address %v: %v", curAddr.String(), err)
+ }
+ // Do nothing, the LB policy will be closed soon.
+ return
+ }
+ b.subConns.Set(curAddr, sd)
+ }
+
+ switch sd.rawConnectivityState {
+ case connectivity.Idle:
+ sd.subConn.Connect()
+ b.scheduleNextConnectionLocked()
+ return
+ case connectivity.TransientFailure:
+ // The SubConn is being re-used and failed during a previous pass
+ // over the addressList. It has not completed backoff yet.
+ // Mark it as having failed and try the next address.
+ sd.connectionFailedInFirstPass = true
+ lastErr = sd.lastErr
+ continue
+ case connectivity.Connecting:
+ // Wait for the connection attempt to complete or the timer to fire
+ // before attempting the next address.
+ b.scheduleNextConnectionLocked()
+ return
+ default:
+ b.logger.Errorf("SubConn with unexpected state %v present in SubConns map.", sd.rawConnectivityState)
+ return
+
+ }
+ }
+
+ // All the remaining addresses in the list are in TRANSIENT_FAILURE, end the
+ // first pass if possible.
+ b.endFirstPassIfPossibleLocked(lastErr)
+}
+
+func (b *pickfirstBalancer) scheduleNextConnectionLocked() {
+ b.cancelConnectionTimer()
+ if !b.addressList.hasNext() {
+ return
+ }
+ curAddr := b.addressList.currentAddress()
+ cancelled := false // Access to this is protected by the balancer's mutex.
+ closeFn := internal.TimeAfterFunc(connectionDelayInterval, func() {
+ b.mu.Lock()
+ defer b.mu.Unlock()
+ // If the scheduled task is cancelled while acquiring the mutex, return.
+ if cancelled {
+ return
+ }
+ if b.logger.V(2) {
+ b.logger.Infof("Happy Eyeballs timer expired while waiting for connection to %q.", curAddr.Addr)
+ }
+ if b.addressList.increment() {
+ b.requestConnectionLocked()
+ }
+ })
+ // Access to the cancellation callback held by the balancer is guarded by
+ // the balancer's mutex, so it's safe to set the boolean from the callback.
+ b.cancelConnectionTimer = sync.OnceFunc(func() {
+ cancelled = true
+ closeFn()
+ })
+}
+
+func (b *pickfirstBalancer) updateSubConnState(sd *scData, newState balancer.SubConnState) {
+ b.mu.Lock()
+ defer b.mu.Unlock()
+ oldState := sd.rawConnectivityState
+ sd.rawConnectivityState = newState.ConnectivityState
+ // Previously relevant SubConns can still callback with state updates.
+ // To prevent pickers from returning these obsolete SubConns, this logic
+ // is included to check if the current list of active SubConns includes this
+ // SubConn.
+ if !b.isActiveSCData(sd) {
+ return
+ }
+ if newState.ConnectivityState == connectivity.Shutdown {
+ sd.effectiveState = connectivity.Shutdown
+ return
+ }
+
+ // Record a connection attempt when exiting CONNECTING.
+ if newState.ConnectivityState == connectivity.TransientFailure {
+ sd.connectionFailedInFirstPass = true
+ connectionAttemptsFailedMetric.Record(b.metricsRecorder, 1, b.target)
+ }
+
+ if newState.ConnectivityState == connectivity.Ready {
+ connectionAttemptsSucceededMetric.Record(b.metricsRecorder, 1, b.target)
+ b.shutdownRemainingLocked(sd)
+ if !b.addressList.seekTo(sd.addr) {
+ // This should not fail as we should have only one SubConn after
+ // entering READY. The SubConn should be present in the addressList.
+ b.logger.Errorf("Address %q not found address list in %v", sd.addr, b.addressList.addresses)
+ return
+ }
+ if !b.healthCheckingEnabled {
+ if b.logger.V(2) {
+ b.logger.Infof("SubConn %p reported connectivity state READY and the health listener is disabled. Transitioning SubConn to READY.", sd.subConn)
+ }
+
+ sd.effectiveState = connectivity.Ready
+ b.updateBalancerState(balancer.State{
+ ConnectivityState: connectivity.Ready,
+ Picker: &picker{result: balancer.PickResult{SubConn: sd.subConn}},
+ })
+ return
+ }
+ if b.logger.V(2) {
+ b.logger.Infof("SubConn %p reported connectivity state READY. Registering health listener.", sd.subConn)
+ }
+ // Send a CONNECTING update to take the SubConn out of sticky-TF if
+ // required.
+ sd.effectiveState = connectivity.Connecting
+ b.updateBalancerState(balancer.State{
+ ConnectivityState: connectivity.Connecting,
+ Picker: &picker{err: balancer.ErrNoSubConnAvailable},
+ })
+ sd.subConn.RegisterHealthListener(func(scs balancer.SubConnState) {
+ b.updateSubConnHealthState(sd, scs)
+ })
+ return
+ }
+
+ // If the LB policy is READY, and it receives a subchannel state change,
+ // it means that the READY subchannel has failed.
+ // A SubConn can also transition from CONNECTING directly to IDLE when
+ // a transport is successfully created, but the connection fails
+ // before the SubConn can send the notification for READY. We treat
+ // this as a successful connection and transition to IDLE.
+ // TODO: https://github.com/grpc/grpc-go/issues/7862 - Remove the second
+ // part of the if condition below once the issue is fixed.
+ if oldState == connectivity.Ready || (oldState == connectivity.Connecting && newState.ConnectivityState == connectivity.Idle) {
+ // Once a transport fails, the balancer enters IDLE and starts from
+ // the first address when the picker is used.
+ b.shutdownRemainingLocked(sd)
+ sd.effectiveState = newState.ConnectivityState
+ // READY SubConn interspliced in between CONNECTING and IDLE, need to
+ // account for that.
+ if oldState == connectivity.Connecting {
+ // A known issue (https://github.com/grpc/grpc-go/issues/7862)
+ // causes a race that prevents the READY state change notification.
+ // This works around it.
+ connectionAttemptsSucceededMetric.Record(b.metricsRecorder, 1, b.target)
+ }
+ disconnectionsMetric.Record(b.metricsRecorder, 1, b.target)
+ b.addressList.reset()
+ b.updateBalancerState(balancer.State{
+ ConnectivityState: connectivity.Idle,
+ Picker: &idlePicker{exitIdle: sync.OnceFunc(b.ExitIdle)},
+ })
+ return
+ }
+
+ if b.firstPass {
+ switch newState.ConnectivityState {
+ case connectivity.Connecting:
+ // The effective state can be in either IDLE, CONNECTING or
+ // TRANSIENT_FAILURE. If it's TRANSIENT_FAILURE, stay in
+ // TRANSIENT_FAILURE until it's READY. See A62.
+ if sd.effectiveState != connectivity.TransientFailure {
+ sd.effectiveState = connectivity.Connecting
+ b.updateBalancerState(balancer.State{
+ ConnectivityState: connectivity.Connecting,
+ Picker: &picker{err: balancer.ErrNoSubConnAvailable},
+ })
+ }
+ case connectivity.TransientFailure:
+ sd.lastErr = newState.ConnectionError
+ sd.effectiveState = connectivity.TransientFailure
+ // Since we're re-using common SubConns while handling resolver
+ // updates, we could receive an out of turn TRANSIENT_FAILURE from
+ // a pass over the previous address list. Happy Eyeballs will also
+ // cause out of order updates to arrive.
+
+ if curAddr := b.addressList.currentAddress(); equalAddressIgnoringBalAttributes(&curAddr, &sd.addr) {
+ b.cancelConnectionTimer()
+ if b.addressList.increment() {
+ b.requestConnectionLocked()
+ return
+ }
+ }
+
+ // End the first pass if we've seen a TRANSIENT_FAILURE from all
+ // SubConns once.
+ b.endFirstPassIfPossibleLocked(newState.ConnectionError)
+ }
+ return
+ }
+
+ // We have finished the first pass, keep re-connecting failing SubConns.
+ switch newState.ConnectivityState {
+ case connectivity.TransientFailure:
+ b.numTF = (b.numTF + 1) % b.subConns.Len()
+ sd.lastErr = newState.ConnectionError
+ if b.numTF%b.subConns.Len() == 0 {
+ b.updateBalancerState(balancer.State{
+ ConnectivityState: connectivity.TransientFailure,
+ Picker: &picker{err: newState.ConnectionError},
+ })
+ }
+ // We don't need to request re-resolution since the SubConn already
+ // does that before reporting TRANSIENT_FAILURE.
+ // TODO: #7534 - Move re-resolution requests from SubConn into
+ // pick_first.
+ case connectivity.Idle:
+ sd.subConn.Connect()
+ }
+}
+
+// endFirstPassIfPossibleLocked ends the first happy-eyeballs pass if all the
+// addresses are tried and their SubConns have reported a failure.
+func (b *pickfirstBalancer) endFirstPassIfPossibleLocked(lastErr error) {
+ // An optimization to avoid iterating over the entire SubConn map.
+ if b.addressList.isValid() {
+ return
+ }
+ // Connect() has been called on all the SubConns. The first pass can be
+ // ended if all the SubConns have reported a failure.
+ for _, sd := range b.subConns.Values() {
+ if !sd.connectionFailedInFirstPass {
+ return
+ }
+ }
+ b.firstPass = false
+ b.updateBalancerState(balancer.State{
+ ConnectivityState: connectivity.TransientFailure,
+ Picker: &picker{err: lastErr},
+ })
+ // Start re-connecting all the SubConns that are already in IDLE.
+ for _, sd := range b.subConns.Values() {
+ if sd.rawConnectivityState == connectivity.Idle {
+ sd.subConn.Connect()
+ }
+ }
+}
+
+func (b *pickfirstBalancer) isActiveSCData(sd *scData) bool {
+ activeSD, found := b.subConns.Get(sd.addr)
+ return found && activeSD == sd
+}
+
+func (b *pickfirstBalancer) updateSubConnHealthState(sd *scData, state balancer.SubConnState) {
+ b.mu.Lock()
+ defer b.mu.Unlock()
+ // Previously relevant SubConns can still callback with state updates.
+ // To prevent pickers from returning these obsolete SubConns, this logic
+ // is included to check if the current list of active SubConns includes
+ // this SubConn.
+ if !b.isActiveSCData(sd) {
+ return
+ }
+ sd.effectiveState = state.ConnectivityState
+ switch state.ConnectivityState {
+ case connectivity.Ready:
+ b.updateBalancerState(balancer.State{
+ ConnectivityState: connectivity.Ready,
+ Picker: &picker{result: balancer.PickResult{SubConn: sd.subConn}},
+ })
+ case connectivity.TransientFailure:
+ b.updateBalancerState(balancer.State{
+ ConnectivityState: connectivity.TransientFailure,
+ Picker: &picker{err: fmt.Errorf("pickfirst: health check failure: %v", state.ConnectionError)},
+ })
+ case connectivity.Connecting:
+ b.updateBalancerState(balancer.State{
+ ConnectivityState: connectivity.Connecting,
+ Picker: &picker{err: balancer.ErrNoSubConnAvailable},
+ })
+ default:
+ b.logger.Errorf("Got unexpected health update for SubConn %p: %v", state)
+ }
+}
+
+// updateBalancerState stores the state reported to the channel and calls
+// ClientConn.UpdateState(). As an optimization, it avoids sending duplicate
+// updates to the channel.
+func (b *pickfirstBalancer) updateBalancerState(newState balancer.State) {
+ // In case of TransientFailures allow the picker to be updated to update
+ // the connectivity error, in all other cases don't send duplicate state
+ // updates.
+ if newState.ConnectivityState == b.state && b.state != connectivity.TransientFailure {
+ return
+ }
+ b.forceUpdateConcludedStateLocked(newState)
+}
+
+// forceUpdateConcludedStateLocked stores the state reported to the channel and
+// calls ClientConn.UpdateState().
+// A separate function is defined to force update the ClientConn state since the
+// channel doesn't correctly assume that LB policies start in CONNECTING and
+// relies on LB policy to send an initial CONNECTING update.
+func (b *pickfirstBalancer) forceUpdateConcludedStateLocked(newState balancer.State) {
+ b.state = newState.ConnectivityState
+ b.cc.UpdateState(newState)
+}
+
+type picker struct {
+ result balancer.PickResult
+ err error
+}
+
+func (p *picker) Pick(balancer.PickInfo) (balancer.PickResult, error) {
+ return p.result, p.err
+}
+
+// idlePicker is used when the SubConn is IDLE and kicks the SubConn into
+// CONNECTING when Pick is called.
+type idlePicker struct {
+ exitIdle func()
+}
+
+func (i *idlePicker) Pick(balancer.PickInfo) (balancer.PickResult, error) {
+ i.exitIdle()
+ return balancer.PickResult{}, balancer.ErrNoSubConnAvailable
+}
+
+// addressList manages sequentially iterating over addresses present in a list
+// of endpoints. It provides a 1 dimensional view of the addresses present in
+// the endpoints.
+// This type is not safe for concurrent access.
+type addressList struct {
+ addresses []resolver.Address
+ idx int
+}
+
+func (al *addressList) isValid() bool {
+ return al.idx < len(al.addresses)
+}
+
+func (al *addressList) size() int {
+ return len(al.addresses)
+}
+
+// increment moves to the next index in the address list.
+// This method returns false if it went off the list, true otherwise.
+func (al *addressList) increment() bool {
+ if !al.isValid() {
+ return false
+ }
+ al.idx++
+ return al.idx < len(al.addresses)
+}
+
+// currentAddress returns the current address pointed to in the addressList.
+// If the list is in an invalid state, it returns an empty address instead.
+func (al *addressList) currentAddress() resolver.Address {
+ if !al.isValid() {
+ return resolver.Address{}
+ }
+ return al.addresses[al.idx]
+}
+
+func (al *addressList) reset() {
+ al.idx = 0
+}
+
+func (al *addressList) updateAddrs(addrs []resolver.Address) {
+ al.addresses = addrs
+ al.reset()
+}
+
+// seekTo returns false if the needle was not found and the current index was
+// left unchanged.
+func (al *addressList) seekTo(needle resolver.Address) bool {
+ for ai, addr := range al.addresses {
+ if !equalAddressIgnoringBalAttributes(&addr, &needle) {
+ continue
+ }
+ al.idx = ai
+ return true
+ }
+ return false
+}
+
+// hasNext returns whether incrementing the addressList will result in moving
+// past the end of the list. If the list has already moved past the end, it
+// returns false.
+func (al *addressList) hasNext() bool {
+ if !al.isValid() {
+ return false
+ }
+ return al.idx+1 < len(al.addresses)
+}
+
+// equalAddressIgnoringBalAttributes returns true is a and b are considered
+// equal. This is different from the Equal method on the resolver.Address type
+// which considers all fields to determine equality. Here, we only consider
+// fields that are meaningful to the SubConn.
+func equalAddressIgnoringBalAttributes(a, b *resolver.Address) bool {
+ return a.Addr == b.Addr && a.ServerName == b.ServerName &&
+ a.Attributes.Equal(b.Attributes)
+}