feat: add adaptive service

cluster/cluster/adaptivesvc/cluster.go

@@ -0,0 +1,55 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You 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 adaptivesvc
+
+import (
+	"sync"
+)
+
+import (
+	clusterpkg "dubbo.apache.org/dubbo-go/v3/cluster/cluster"
+	"dubbo.apache.org/dubbo-go/v3/cluster/directory"
+	"dubbo.apache.org/dubbo-go/v3/common/constant"
+	"dubbo.apache.org/dubbo-go/v3/common/extension"
+	"dubbo.apache.org/dubbo-go/v3/protocol"
+)
+
+var (
+	once     sync.Once
+	instance clusterpkg.Cluster
+)
+
+func init() {
+	extension.SetCluster(constant.ClusterKeyAdaptiveService, newAdaptiveServiceCluster)
+}
+
+// adaptiveServiceCluster is a cluster for adaptive service.
+type adaptiveServiceCluster struct{}
+
+func newAdaptiveServiceCluster() clusterpkg.Cluster {
+	if instance == nil {
+		once.Do(func() {
+			instance = &adaptiveServiceCluster{}
+		})
+	}
+	return instance
+}
+
+func (c *adaptiveServiceCluster) Join(directory directory.Directory) protocol.Invoker {
+	return clusterpkg.BuildInterceptorChain(newAdaptiveServiceClusterInvoker(directory))
+}

cluster/cluster/adaptivesvc/cluster_invoker.go

@@ -0,0 +1,85 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You 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 adaptivesvc
+
+import (
+	"context"
+	"strconv"
+)
+
+import (
+	perrors "github.com/pkg/errors"
+)
+
+import (
+	"dubbo.apache.org/dubbo-go/v3/cluster/cluster/base"
+	"dubbo.apache.org/dubbo-go/v3/cluster/directory"
+	"dubbo.apache.org/dubbo-go/v3/cluster/metrics"
+	"dubbo.apache.org/dubbo-go/v3/common/constant"
+	"dubbo.apache.org/dubbo-go/v3/common/extension"
+	"dubbo.apache.org/dubbo-go/v3/common/logger"
+	"dubbo.apache.org/dubbo-go/v3/protocol"
+)
+
+type adaptiveServiceClusterInvoker struct {
+	base.ClusterInvoker
+}
+
+func newAdaptiveServiceClusterInvoker(directory directory.Directory) protocol.Invoker {
+	return &adaptiveServiceClusterInvoker{
+		ClusterInvoker: base.NewClusterInvoker(directory),
+	}
+}
+
+func (ivk *adaptiveServiceClusterInvoker) Invoke(ctx context.Context, invocation protocol.Invocation) protocol.Result {
+	invokers := ivk.Directory.List(invocation)
+	if err := ivk.CheckInvokers(invokers, invocation); err != nil {
+		return protocol.NewRPCResult(nil, err)
+	}
+
+	// get loadBalance
+	lbKey := invokers[0].GetURL().GetParam(constant.LoadbalanceKey, constant.LoadBalanceKeyP2C)
+	if lbKey != constant.LoadBalanceKeyP2C {
+		return protocol.NewRPCResult(nil, perrors.Errorf("adaptive service not supports %s load balance", lbKey))
+	}
+	lb := extension.GetLoadbalance(lbKey)
+
+	// select a node by the loadBalance
+	invoker := lb.Select(invokers, invocation)
+
+	// invoke
+	result := invoker.Invoke(ctx, invocation)
+
+	// update metrics
+	remainingStr := result.Attachment(constant.AdaptiveServiceRemainingKey, "").(string)
+	remaining, err := strconv.Atoi(remainingStr)
+	if err != nil {
+		logger.Warnf("the remaining is unexpected, we need a int type, but we got %s, err: %v.", remainingStr, err)
+		return result
+	}
+	logger.Debugf("[adasvc cluster] The server status was received successfully, %s: %#v",
+		constant.AdaptiveServiceRemainingKey, remainingStr)
+	err = metrics.LocalMetrics.SetMethodMetrics(invoker.GetURL(),
+		invocation.MethodName(), metrics.HillClimbing, uint64(remaining))
+	if err != nil {
+		logger.Warnf("adaptive service metrics update is failed, err: %v", err)
+		return protocol.NewRPCResult(nil, err)
+	}
+
+	return result
+}

cluster/cluster/available/cluster_invoker.go

@@ -47,18 +47,18 @@ func (invoker *clusterInvoker) Invoke(ctx context.Context, invocation protocol.I
 	invokers := invoker.Directory.List(invocation)
 	err := invoker.CheckInvokers(invokers, invocation)
 	if err != nil {
-		return &protocol.RPCResult{Err: err}
+		return protocol.NewRPCResult(nil, err)
 	}
 
 	err = invoker.CheckWhetherDestroyed()
 	if err != nil {
-		return &protocol.RPCResult{Err: err}
+		return protocol.NewRPCResult(nil, err)
 	}
 
 	for _, ivk := range invokers {
 		if ivk.IsAvailable() {
 			return ivk.Invoke(ctx, invocation)
 		}
 	}
-	return &protocol.RPCResult{Err: errors.New(fmt.Sprintf("no provider available in %v", invokers))}
+	return protocol.NewRPCResult(nil, errors.New(fmt.Sprintf("no provider available in %v", invokers)))
 }

cluster/cluster/available/cluster_invoker_test.go

@@ -65,7 +65,7 @@ func TestAvailableClusterInvokerSuccess(t *testing.T) {
 	invoker := mock.NewMockInvoker(ctrl)
 	clusterInvoker := registerAvailable(invoker)
 
-	mockResult := &protocol.RPCResult{Rest: clusterpkg.Rest{Tried: 0, Success: true}}
+	mockResult := protocol.NewRPCResult(clusterpkg.Rest{Tried: 0, Success: true}, nil)
 	invoker.EXPECT().IsAvailable().Return(true)
 	invoker.EXPECT().Invoke(gomock.Any()).Return(mockResult)
 

cluster/cluster_impl/import.go

@@ -21,6 +21,7 @@ package cluster_impl
 // This package may be DEPRECATED OR REMOVED in the future.
 
 import (
+	_ "dubbo.apache.org/dubbo-go/v3/cluster/cluster/adaptivesvc"
 	_ "dubbo.apache.org/dubbo-go/v3/cluster/cluster/available"
 	_ "dubbo.apache.org/dubbo-go/v3/cluster/cluster/broadcast"
 	_ "dubbo.apache.org/dubbo-go/v3/cluster/cluster/failback"

cluster/loadbalance/p2c/loadbalance.go

@@ -0,0 +1,129 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You 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 p2c
+
+import (
+	"errors"
+	"fmt"
+	"math/rand"
+	"sync"
+	"time"
+)
+
+import (
+	"dubbo.apache.org/dubbo-go/v3/cluster/loadbalance"
+	"dubbo.apache.org/dubbo-go/v3/cluster/metrics"
+	"dubbo.apache.org/dubbo-go/v3/common/constant"
+	"dubbo.apache.org/dubbo-go/v3/common/extension"
+	"dubbo.apache.org/dubbo-go/v3/common/logger"
+	"dubbo.apache.org/dubbo-go/v3/protocol"
+)
+
+func init() {
+	extension.SetLoadbalance(constant.LoadBalanceKeyP2C, newLoadBalance)
+}
+
+var (
+	once     sync.Once
+	instance loadbalance.LoadBalance
+)
+
+type loadBalance struct{}
+
+func newLoadBalance() loadbalance.LoadBalance {
+	if instance == nil {
+		once.Do(func() {
+			instance = &loadBalance{}
+		})
+	}
+	return instance
+}
+
+func (l *loadBalance) Select(invokers []protocol.Invoker, invocation protocol.Invocation) protocol.Invoker {
+	if len(invokers) == 0 {
+		return nil
+	}
+	if len(invokers) == 1 {
+		return invokers[0]
+	}
+	// m is the Metrics, which saves the metrics of instance, invokers and methods
+	// The local metrics is available only for the earlier version.
+	m := metrics.LocalMetrics
+	// picks two nodes randomly
+	var i, j int
+	if len(invokers) == 2 {
+		i, j = 0, 1
+	} else {
+		rand.Seed(time.Now().Unix())
+		i = rand.Intn(len(invokers))
+		j = i
+		for i == j {
+			j = rand.Intn(len(invokers))
+		}
+	}
+	logger.Debugf("[P2C select] Two invokers were selected, i: %d, j: %d, invoker[i]: %s, invoker[j]: %s.",
+		i, j, invokers[i], invokers[j])
+
+	// TODO(justxuewei): please consider how to get the real method name from $invoke,
+	// 	see also [#1511](https://github.com/apache/dubbo-go/issues/1511)
+	methodName := invocation.MethodName()
+	// remainingIIface, remainingJIface means remaining capacity of node i and node j.
+	// If one of the metrics is empty, invoke the invocation to that node directly.
+	remainingIIface, err := m.GetMethodMetrics(invokers[i].GetURL(), methodName, metrics.HillClimbing)
+	if err != nil {
+		if errors.Is(err, metrics.ErrMetricsNotFound) {
+			logger.Debugf("[P2C select] The invoker[i] was selected, because it hasn't been selected before.")
+			return invokers[i]
+		}
+		logger.Warnf("get method metrics err: %v", err)
+		return nil
+	}
+
+	remainingJIface, err := m.GetMethodMetrics(invokers[j].GetURL(), methodName, metrics.HillClimbing)
+	if err != nil {
+		if errors.Is(err, metrics.ErrMetricsNotFound) {
+			logger.Debugf("[P2C select] The invoker[j] was selected, because it hasn't been selected before.")
+			return invokers[j]
+		}
+		logger.Warnf("get method metrics err: %v", err)
+		return nil
+	}
+
+	// Convert interface to int, if the type is unexpected, panic immediately
+	remainingI, ok := remainingIIface.(uint64)
+	if !ok {
+		panic(fmt.Sprintf("[P2C select] the type of %s expects to be uint64, but gets %T",
+			metrics.HillClimbing, remainingIIface))
+	}
+
+	remainingJ, ok := remainingJIface.(uint64)
+	if !ok {
+		panic(fmt.Sprintf("the type of %s expects to be uint64, but gets %T", metrics.HillClimbing, remainingJIface))
+	}
+
+	logger.Debugf("[P2C select] The invoker[i] remaining is %d, and the invoker[j] is %d.", remainingI, remainingJ)
+
+	// For the remaining capacity, the bigger, the better.
+	if remainingI > remainingJ {
+		logger.Debugf("[P2C select] The invoker[i] was selected.")
+		return invokers[i]
+	}
+
+	logger.Debugf("[P2C select] The invoker[j] was selected.")
+	return invokers[j]
+}

cluster/metrics/constants.go

@@ -0,0 +1,22 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You 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 metrics
+
+const (
+	HillClimbing = "hill-climbing"
+)