Merge branch 'develop' into read

CHANGE.md

 # Release Notes
 ---
 
+## 1.5.1
+
+### New Features
+- [Add dynamic tag router](https://github.com/apache/dubbo-go/pull/703)
+- [Add TLS support](https://github.com/apache/dubbo-go/pull/685)
+- [Add Nearest first for multiple registry](https://github.com/apache/dubbo-go/pull/659)
+- [Add application and service level router](https://github.com/apache/dubbo-go/pull/662)
+- [Add dynamic tag router](https://github.com/apache/dubbo-go/pull/665)
+
+### Enhancement
+- [Avoid init the log twice](https://github.com/apache/dubbo-go/pull/719)
+- [Correct words and format codes](https://github.com/apache/dubbo-go/pull/704)
+- [Change log stack level from warn to error](https://github.com/apache/dubbo-go/pull/702)
+- [Optimize remotes configuration](https://github.com/apache/dubbo-go/pull/687)
+
+### Bugfixes
+- [Fix register service instance after provider config load](https://github.com/apache/dubbo-go/pull/694)
+- [Fix call subscribe function asynchronously](https://github.com/apache/dubbo-go/pull/721)
+- [Fix tag router rule copy](https://github.com/apache/dubbo-go/pull/721)
+- [Fix nacos unit test failed](https://github.com/apache/dubbo-go/pull/705)
+- [Fix can not inovke nacos destroy when graceful shutdown](https://github.com/apache/dubbo-go/pull/689)
+- [Fix zk lost event](https://github.com/apache/dubbo-go/pull/692)
+- [Fix k8s ut bug](https://github.com/apache/dubbo-go/pull/693)
+
+Milestone: [https://github.com/apache/dubbo-go/milestone/2?closed=1](https://github.com/apache/dubbo-go/milestone/2?closed=1)
+
+Project: [https://github.com/apache/dubbo-go/projects/8](https://github.com/apache/dubbo-go/projects/8)
+
 ## 1.5.0
 
 ### New Features

README.md

@@ -16,6 +16,8 @@ Apache License, Version 2.0
 
 ## Release note ##
 
+[v1.5.1 - Aug 23, 2020](https://github.com/apache/dubbo-go/releases/tag/v1.5.1)
+
 [v1.5.0 - July 24, 2020](https://github.com/apache/dubbo-go/releases/tag/v1.5.0)
 
 [v1.4.0 - Mar 17, 2020](https://github.com/apache/dubbo-go/releases/tag/v1.4.0)

cluster/directory/static_directory.go

@@ -39,10 +39,13 @@ func NewStaticDirectory(invokers []protocol.Invoker) *staticDirectory {
 	if len(invokers) > 0 {
 		url = invokers[0].GetUrl()
 	}
-	return &staticDirectory{
+	dir := &staticDirectory{
 		BaseDirectory: NewBaseDirectory(&url),
 		invokers:      invokers,
 	}
+
+	dir.routerChain.SetInvokers(invokers)
+	return dir
 }
 
 //for-loop invokers ,if all invokers is available ,then it means directory is available
@@ -69,7 +72,7 @@ func (dir *staticDirectory) List(invocation protocol.Invocation) []protocol.Invo
 		return invokers
 	}
 	dirUrl := dir.GetUrl()
-	return routerChain.Route(invokers, &dirUrl, invocation)
+	return routerChain.Route(&dirUrl, invocation)
 }
 
 // Destroy Destroy
@@ -92,6 +95,7 @@ func (dir *staticDirectory) BuildRouterChain(invokers []protocol.Invoker) error
 	if e != nil {
 		return e
 	}
+	routerChain.SetInvokers(dir.invokers)
 	dir.SetRouterChain(routerChain)
 	return nil
 }

cluster/router/chain.go

+/*
+ * 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 router
+
+import (
+	"github.com/apache/dubbo-go/common"
+	"github.com/apache/dubbo-go/protocol"
+)
+
+// Chain
+type Chain interface {
+	Route(*common.URL, protocol.Invocation) []protocol.Invoker
+	// Refresh invokers
+	SetInvokers([]protocol.Invoker)
+	// AddRouters Add routers
+	AddRouters([]PriorityRouter)
+}

cluster/router/chain/chain.go

@@ -18,9 +18,10 @@
 package chain
 
 import (
-	"math"
 	"sort"
 	"sync"
+	"sync/atomic"
+	"time"
 )
 
 import (
@@ -30,11 +31,18 @@ import (
 import (
 	"github.com/apache/dubbo-go/cluster/router"
 	"github.com/apache/dubbo-go/common"
+	"github.com/apache/dubbo-go/common/constant"
 	"github.com/apache/dubbo-go/common/extension"
 	"github.com/apache/dubbo-go/common/logger"
 	"github.com/apache/dubbo-go/protocol"
 )
 
+const (
+	timeInterval   = 5 * time.Second
+	timeThreshold  = 2 * time.Second
+	countThreshold = 5
+)
+
 // RouterChain Router chain
 type RouterChain struct {
 	// Full list of addresses from registry, classified by method name.
@@ -48,30 +56,38 @@ type RouterChain struct {
 	mutex sync.RWMutex
 
 	url common.URL
+
+	// The times of address notification since last update for address cache
+	count int64
+	// The timestamp of last update for address cache
+	last time.Time
+	// Channel for notify to update the address cache
+	notify chan struct{}
+	// Address cache
+	cache atomic.Value
 }
 
 // Route Loop routers in RouterChain and call Route method to determine the target invokers list.
-func (c *RouterChain) Route(invokers []protocol.Invoker, url *common.URL, invocation protocol.Invocation) []protocol.Invoker {
-	finalInvokers := invokers
-	l := len(c.routers)
-	rs := make([]router.PriorityRouter, l, int(math.Ceil(float64(l)*1.2)))
-	c.mutex.RLock()
-	copy(rs, c.routers)
-	c.mutex.RUnlock()
+func (c *RouterChain) Route(url *common.URL, invocation protocol.Invocation) []protocol.Invoker {
+	cache := c.loadCache()
+	if cache == nil {
+		c.mutex.RLock()
+		defer c.mutex.RUnlock()
+		return c.invokers
+	}
 
-	for _, r := range rs {
-		finalInvokers = r.Route(finalInvokers, url, invocation)
+	bitmap := cache.bitmap
+	for _, r := range c.copyRouters() {
+		bitmap = r.Route(bitmap, cache, url, invocation)
 	}
-	return finalInvokers
-}
 
-// SetInvokers notify router chain of the initial addresses from registry at the first time. Notify whenever addresses in registry change.
-func (c *RouterChain) SetInvokers(invokers []protocol.Invoker) {
-	for _, r := range c.routers {
-		if notifyRouter, ok := r.(router.NotifyRouter); ok {
-			notifyRouter.Notify(invokers)
-		}
+	indexes := bitmap.ToArray()
+	finalInvokers := make([]protocol.Invoker, len(indexes))
+	for i, index := range indexes {
+		finalInvokers[i] = cache.invokers[index]
 	}
+
+	return finalInvokers
 }
 
 // AddRouters Add routers to router chain
@@ -88,6 +104,116 @@ func (c *RouterChain) AddRouters(routers []router.PriorityRouter) {
 	c.routers = newRouters
 }
 
+// SetInvokers receives updated invokers from registry center. If the times of notification exceeds countThreshold and
+// time interval exceeds timeThreshold since last cache update, then notify to update the cache.
+func (c *RouterChain) SetInvokers(invokers []protocol.Invoker) {
+	c.mutex.Lock()
+	c.invokers = invokers
+	c.mutex.Unlock()
+
+	c.count++
+	now := time.Now()
+	if c.count >= countThreshold && now.Sub(c.last) >= timeThreshold {
+		c.last = now
+		c.count = 0
+		go func() {
+			c.notify <- struct{}{}
+		}()
+	}
+}
+
+// loop listens on events to update the address cache when it's necessary, either when it receives notification
+// from address update, or when timeInterval exceeds.
+func (c *RouterChain) loop() {
+	for {
+		ticker := time.NewTicker(timeInterval)
+		select {
+		case <-ticker.C:
+			c.buildCache()
+		case <-c.notify:
+			c.buildCache()
+		}
+	}
+}
+
+// copyRouters make a snapshot copy from RouterChain's router list.
+func (c *RouterChain) copyRouters() []router.PriorityRouter {
+	c.mutex.RLock()
+	defer c.mutex.RUnlock()
+	ret := make([]router.PriorityRouter, 0, len(c.routers))
+	ret = append(ret, c.routers...)
+	return ret
+}
+
+// copyInvokers copies a snapshot of the received invokers.
+func (c *RouterChain) copyInvokers() []protocol.Invoker {
+	c.mutex.RLock()
+	defer c.mutex.RUnlock()
+	if c.invokers == nil || len(c.invokers) == 0 {
+		return nil
+	}
+	ret := make([]protocol.Invoker, 0, len(c.invokers))
+	ret = append(ret, c.invokers...)
+	return ret
+}
+
+// loadCache loads cache from sync.Value to guarantee the visibility
+func (c *RouterChain) loadCache() *InvokerCache {
+	v := c.cache.Load()
+	if v == nil {
+		return nil
+	}
+
+	return v.(*InvokerCache)
+}
+
+// copyInvokerIfNecessary compares chain's invokers copy and cache's invokers copy, to avoid copy as much as possible
+func (c *RouterChain) copyInvokerIfNecessary(cache *InvokerCache) []protocol.Invoker {
+	var invokers []protocol.Invoker
+	if cache != nil {
+		invokers = cache.invokers
+	}
+
+	c.mutex.RLock()
+	defer c.mutex.RUnlock()
+	if isInvokersChanged(invokers, c.invokers) {
+		invokers = c.copyInvokers()
+	}
+	return invokers
+}
+
+// buildCache builds address cache with the new invokers for all poolable routers.
+func (c *RouterChain) buildCache() {
+	origin := c.loadCache()
+	invokers := c.copyInvokerIfNecessary(origin)
+	if invokers == nil || len(invokers) == 0 {
+		return
+	}
+
+	var (
+		mutex sync.Mutex
+		wg    sync.WaitGroup
+	)
+
+	cache := BuildCache(invokers)
+	for _, r := range c.copyRouters() {
+		if p, ok := r.(router.Poolable); ok {
+			wg.Add(1)
+			go func(p router.Poolable) {
+				defer wg.Done()
+				pool, info := poolRouter(p, origin, invokers)
+				mutex.Lock()
+				defer mutex.Unlock()
+				cache.pools[p.Name()] = pool
+				cache.metadatas[p.Name()] = info
+			}(p)
+		}
+	}
+	wg.Wait()
+
+	c.cache.Store(cache)
+}
+
 // URL Return URL in RouterChain
 func (c *RouterChain) URL() common.URL {
 	return c.url
@@ -118,14 +244,62 @@ func NewRouterChain(url *common.URL) (*RouterChain, error) {
 	chain := &RouterChain{
 		builtinRouters: routers,
 		routers:        newRouters,
+		last:           time.Now(),
+		notify:         make(chan struct{}),
 	}
 	if url != nil {
 		chain.url = *url
 	}
 
+	go chain.loop()
 	return chain, nil
 }
 
+// poolRouter calls poolable router's Pool() to create new address pool and address metadata if necessary.
+// If the corresponding cache entry exists, and the poolable router answers no need to re-pool (possibly because its
+// rule doesn't change), and the address list doesn't change, then the existing data will be re-used.
+func poolRouter(p router.Poolable, origin *InvokerCache, invokers []protocol.Invoker) (router.AddrPool, router.AddrMetadata) {
+	name := p.Name()
+	if isCacheMiss(origin, name) || p.ShouldPool() || &(origin.invokers) != &invokers {
+		logger.Debugf("build address cache for router %q", name)
+		return p.Pool(invokers)
+	}
+
+	logger.Debugf("reuse existing address cache for router %q", name)
+	return origin.pools[name], origin.metadatas[name]
+}
+
+// isCacheMiss checks if the corresponding cache entry for a poolable router has already existed.
+// False returns when the cache is nil, or cache's pool is nil, or cache's invokers snapshot is nil, or the entry
+// doesn't exist.
+func isCacheMiss(cache *InvokerCache, key string) bool {
+	if cache == nil || cache.pools == nil || cache.invokers == nil || cache.pools[key] == nil {
+		return true
+	}
+	return false
+}
+
+// isInvokersChanged compares new invokers on the right changes, compared with the old invokers on the left.
+func isInvokersChanged(left []protocol.Invoker, right []protocol.Invoker) bool {
+	if len(right) != len(left) {
+		return true
+	}
+
+	for _, r := range right {
+		found := false
+		for _, l := range left {
+			if common.IsEquals(l.GetUrl(), r.GetUrl(), constant.TIMESTAMP_KEY, constant.REMOTE_TIMESTAMP_KEY) {
+				found = true
+				break
+			}
+		}
+		if !found {
+			return true
+		}
+	}
+	return false
+}
+
 // sortRouter Sort router instance by priority with stable algorithm
 func sortRouter(routers []router.PriorityRouter) {
 	sort.Stable(byPriority(routers))

cluster/router/chain/chain_test.go

@@ -172,12 +172,12 @@ func TestRouterChainRoute(t *testing.T) {
 	invokers := []protocol.Invoker{}
 	dubboURL, _ := common.NewURL(fmt.Sprintf(dubboForamt, test1234IP, port20000))
 	invokers = append(invokers, protocol.NewBaseInvoker(dubboURL))
-
 	chain.SetInvokers(invokers)
+	chain.buildCache()
 
 	targetURL, _ := common.NewURL(fmt.Sprintf(consumerFormat, test1111IP))
 	inv := &invocation.RPCInvocation{}
-	finalInvokers := chain.Route(invokers, &targetURL, inv)
+	finalInvokers := chain.Route(&targetURL, inv)
 
 	assert.Equal(t, 1, len(finalInvokers))
 }
@@ -213,10 +213,12 @@ conditions:
 	invokers := []protocol.Invoker{}
 	dubboURL, _ := common.NewURL(fmt.Sprintf(dubboForamt, test1234IP, port20000))
 	invokers = append(invokers, protocol.NewBaseInvoker(dubboURL))
+	chain.SetInvokers(invokers)
+	chain.buildCache()
 
 	targetURL, _ := common.NewURL(fmt.Sprintf(consumerFormat, test1111IP))
 	inv := &invocation.RPCInvocation{}
-	finalInvokers := chain.Route(invokers, &targetURL, inv)
+	finalInvokers := chain.Route(&targetURL, inv)
 
 	assert.Equal(t, 0, len(finalInvokers))
 }
@@ -236,13 +238,16 @@ func TestRouterChainRouteNoRoute(t *testing.T) {
 
 	url := getConditionRouteUrl(applicationKey)
 	assert.NotNil(t, url)
+
 	invokers := []protocol.Invoker{}
 	dubboURL, _ := common.NewURL(fmt.Sprintf(dubboForamt, test1234IP, port20000))
 	invokers = append(invokers, protocol.NewBaseInvoker(dubboURL))
+	chain.SetInvokers(invokers)
+	chain.buildCache()
 
 	targetURL, _ := common.NewURL(fmt.Sprintf(consumerFormat, test1111IP))
 	inv := &invocation.RPCInvocation{}
-	finalInvokers := chain.Route(invokers, &targetURL, inv)
+	finalInvokers := chain.Route(&targetURL, inv)
 
 	assert.Equal(t, 0, len(finalInvokers))
 }

cluster/router/chain/invoker_cache.go

+/*
+ * 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 chain
+
+import (
+	"github.com/RoaringBitmap/roaring"
+)
+
+import (
+	"github.com/apache/dubbo-go/cluster/router"
+	"github.com/apache/dubbo-go/cluster/router/utils"
+	"github.com/apache/dubbo-go/protocol"
+)
+
+// Cache caches all addresses relevant info for a snapshot of received invokers. It keeps a snapshot of the received
+// address list, and also keeps address pools and address metadata from routers based on the same address snapshot, if
+// the router implements Poolable.
+type InvokerCache struct {
+	// The snapshot of invokers
+	invokers []protocol.Invoker
+
+	// The bitmap representation for invokers snapshot
+	bitmap *roaring.Bitmap
+
+	// Address pool from routers which implement Poolable
+	pools map[string]router.AddrPool
+
+	// Address metadata from routers which implement Poolable
+	metadatas map[string]router.AddrMetadata
+}
+
+// BuildCache builds address cache from the given invokers.
+func BuildCache(invokers []protocol.Invoker) *InvokerCache {
+	return &InvokerCache{
+		invokers:  invokers,
+		bitmap:    utils.ToBitmap(invokers),
+		pools:     make(map[string]router.AddrPool, 8),
+		metadatas: make(map[string]router.AddrMetadata, 8),
+	}
+}
+
+// GetInvokers get invokers snapshot.
+func (c *InvokerCache) GetInvokers() []protocol.Invoker {
+	return c.invokers
+}
+
+// FindAddrPool finds address pool for a poolable router.
+func (c *InvokerCache) FindAddrPool(p router.Poolable) router.AddrPool {
+	return c.pools[p.Name()]
+}
+
+// FindAddrMeta finds address metadata for a poolable router.
+func (c *InvokerCache) FindAddrMeta(p router.Poolable) router.AddrMetadata {
+	return c.metadatas[p.Name()]
+}
+
+// SetAddrPool sets address pool for a poolable router, for unit test only
+func (c *InvokerCache) SetAddrPool(name string, pool router.AddrPool) {
+	c.pools[name] = pool
+}
+
+// SetAddrMeta sets address metadata for a poolable router, for unit test only
+func (c *InvokerCache) SetAddrMeta(name string, meta router.AddrMetadata) {
+	c.metadatas[name] = meta
+}

cluster/router/condition/factory_test.go

@@ -32,6 +32,9 @@ import (
 )
 
 import (
+	"github.com/apache/dubbo-go/cluster/router"
+	"github.com/apache/dubbo-go/cluster/router/chain"
+	"github.com/apache/dubbo-go/cluster/router/utils"
 	"github.com/apache/dubbo-go/common"
 	"github.com/apache/dubbo-go/common/constant"
 	"github.com/apache/dubbo-go/common/logger"
@@ -180,30 +183,30 @@ func TestRoute_matchFilter(t *testing.T) {
 	router5, _ := newConditionRouterFactory().NewPriorityRouter(getRouteUrl(rule5))
 	router6, _ := newConditionRouterFactory().NewPriorityRouter(getRouteUrl(rule6))
 	cUrl, _ := common.NewURL(fmt.Sprintf(factoryConsumerFormat, localIP))
-	fileredInvokers1 := router1.Route(invokers, &cUrl, &invocation.RPCInvocation{})
-	fileredInvokers2 := router2.Route(invokers, &cUrl, &invocation.RPCInvocation{})
-	fileredInvokers3 := router3.Route(invokers, &cUrl, &invocation.RPCInvocation{})
-	fileredInvokers4 := router4.Route(invokers, &cUrl, &invocation.RPCInvocation{})
-	fileredInvokers5 := router5.Route(invokers, &cUrl, &invocation.RPCInvocation{})
-	fileredInvokers6 := router6.Route(invokers, &cUrl, &invocation.RPCInvocation{})
-	assert.Equal(t, 1, len(fileredInvokers1))
-	assert.Equal(t, 0, len(fileredInvokers2))
-	assert.Equal(t, 0, len(fileredInvokers3))
-	assert.Equal(t, 1, len(fileredInvokers4))
-	assert.Equal(t, 2, len(fileredInvokers5))
-	assert.Equal(t, 1, len(fileredInvokers6))
+	ret1 := router1.Route(utils.ToBitmap(invokers), setUpAddrCache(invokers), &cUrl, &invocation.RPCInvocation{})
+	ret2 := router2.Route(utils.ToBitmap(invokers), setUpAddrCache(invokers), &cUrl, &invocation.RPCInvocation{})
+	ret3 := router3.Route(utils.ToBitmap(invokers), setUpAddrCache(invokers), &cUrl, &invocation.RPCInvocation{})
+	ret4 := router4.Route(utils.ToBitmap(invokers), setUpAddrCache(invokers), &cUrl, &invocation.RPCInvocation{})
+	ret5 := router5.Route(utils.ToBitmap(invokers), setUpAddrCache(invokers), &cUrl, &invocation.RPCInvocation{})
+	ret6 := router6.Route(utils.ToBitmap(invokers), setUpAddrCache(invokers), &cUrl, &invocation.RPCInvocation{})
+	assert.Equal(t, 1, len(ret1.ToArray()))
+	assert.Equal(t, 0, len(ret2.ToArray()))
+	assert.Equal(t, 0, len(ret3.ToArray()))
+	assert.Equal(t, 1, len(ret4.ToArray()))
+	assert.Equal(t, 2, len(ret5.ToArray()))
+	assert.Equal(t, 1, len(ret6.ToArray()))
 
 }
 
 func TestRoute_methodRoute(t *testing.T) {
 	inv := invocation.NewRPCInvocationWithOptions(invocation.WithMethodName("getFoo"), invocation.WithParameterTypes([]reflect.Type{}), invocation.WithArguments([]interface{}{}))
 	rule := base64.URLEncoding.EncodeToString([]byte("host !=4.4.4.* & host = 2.2.2.2,1.1.1.1,3.3.3.3 => host = 1.2.3.4"))
-	router, _ := newConditionRouterFactory().NewPriorityRouter(getRouteUrl(rule))
+	r, _ := newConditionRouterFactory().NewPriorityRouter(getRouteUrl(rule))
 	url, _ := common.NewURL("consumer://1.1.1.1/com.foo.BarService?methods=setFoo,getFoo,findFoo")
-	matchWhen := router.(*ConditionRouter).MatchWhen(&url, inv)
+	matchWhen := r.(*ConditionRouter).MatchWhen(&url, inv)
 	assert.Equal(t, true, matchWhen)
 	url1, _ := common.NewURL(fmt.Sprintf(factoryConsumerMethodFormat, factory1111Ip))
-	matchWhen = router.(*ConditionRouter).MatchWhen(&url1, inv)
+	matchWhen = r.(*ConditionRouter).MatchWhen(&url1, inv)
 	assert.Equal(t, true, matchWhen)
 	url2, _ := common.NewURL(fmt.Sprintf(factoryConsumerMethodFormat, factory1111Ip))
 	rule2 := base64.URLEncoding.EncodeToString([]byte("methods=getFoo & host!=1.1.1.1 => host = 1.2.3.4"))
@@ -225,9 +228,9 @@ func TestRoute_ReturnFalse(t *testing.T) {
 	inv := &invocation.RPCInvocation{}
 	rule := base64.URLEncoding.EncodeToString([]byte("host = " + localIP + " => false"))
 	curl, _ := common.NewURL(fmt.Sprintf(factoryConsumerFormat, localIP))
-	router, _ := newConditionRouterFactory().NewPriorityRouter(getRouteUrl(rule))
-	fileredInvokers := router.(*ConditionRouter).Route(invokers, &curl, inv)
-	assert.Equal(t, 0, len(fileredInvokers))
+	r, _ := newConditionRouterFactory().NewPriorityRouter(getRouteUrl(rule))
+	ret := r.Route(utils.ToBitmap(invokers), setUpAddrCache(invokers), &curl, inv)
+	assert.Equal(t, 0, len(ret.ToArray()))
 }
 
 func TestRoute_ReturnEmpty(t *testing.T) {
@@ -237,9 +240,9 @@ func TestRoute_ReturnEmpty(t *testing.T) {
 	inv := &invocation.RPCInvocation{}
 	rule := base64.URLEncoding.EncodeToString([]byte("host = " + localIP + " => "))
 	curl, _ := common.NewURL(fmt.Sprintf(factoryConsumerFormat, localIP))
-	router, _ := newConditionRouterFactory().NewPriorityRouter(getRouteUrl(rule))
-	fileredInvokers := router.(*ConditionRouter).Route(invokers, &curl, inv)
-	assert.Equal(t, 0, len(fileredInvokers))
+	r, _ := newConditionRouterFactory().NewPriorityRouter(getRouteUrl(rule))
+	ret := r.Route(utils.ToBitmap(invokers), setUpAddrCache(invokers), &curl, inv)
+	assert.Equal(t, 0, len(ret.ToArray()))
 }
 
 func TestRoute_ReturnAll(t *testing.T) {
@@ -253,9 +256,9 @@ func TestRoute_ReturnAll(t *testing.T) {
 	inv := &invocation.RPCInvocation{}
 	rule := base64.URLEncoding.EncodeToString([]byte("host = " + localIP + " => " + " host = " + localIP))
 	curl, _ := common.NewURL(fmt.Sprintf(factoryConsumerFormat, localIP))
-	router, _ := newConditionRouterFactory().NewPriorityRouter(getRouteUrl(rule))
-	fileredInvokers := router.(*ConditionRouter).Route(invokers, &curl, inv)
-	assert.Equal(t, invokers, fileredInvokers)
+	r, _ := newConditionRouterFactory().NewPriorityRouter(getRouteUrl(rule))
+	ret := r.Route(utils.ToBitmap(invokers), setUpAddrCache(invokers), &curl, inv)
+	assert.Equal(t, len(invokers), len(ret.ToArray()))
 }
 
 func TestRoute_HostFilter(t *testing.T) {
@@ -270,11 +273,11 @@ func TestRoute_HostFilter(t *testing.T) {
 	inv := &invocation.RPCInvocation{}
 	rule := base64.URLEncoding.EncodeToString([]byte("host = " + localIP + " => " + " host = " + localIP))
 	curl, _ := common.NewURL(fmt.Sprintf(factoryConsumerFormat, localIP))
-	router, _ := newConditionRouterFactory().NewPriorityRouter(getRouteUrl(rule))
-	fileredInvokers := router.(*ConditionRouter).Route(invokers, &curl, inv)
-	assert.Equal(t, 2, len(fileredInvokers))
-	assert.Equal(t, invoker2, fileredInvokers[0])
-	assert.Equal(t, invoker3, fileredInvokers[1])
+	r, _ := newConditionRouterFactory().NewPriorityRouter(getRouteUrl(rule))
+	ret := r.Route(utils.ToBitmap(invokers), setUpAddrCache(invokers), &curl, inv)
+	assert.Equal(t, 2, len(ret.ToArray()))
+	assert.Equal(t, invoker2, invokers[ret.ToArray()[0]])
+	assert.Equal(t, invoker3, invokers[ret.ToArray()[1]])
 }
 
 func TestRoute_Empty_HostFilter(t *testing.T) {
@@ -289,11 +292,11 @@ func TestRoute_Empty_HostFilter(t *testing.T) {
 	inv := &invocation.RPCInvocation{}
 	rule := base64.URLEncoding.EncodeToString([]byte(" => " + " host = " + localIP))
 	curl, _ := common.NewURL(fmt.Sprintf(factoryConsumerFormat, localIP))
-	router, _ := newConditionRouterFactory().NewPriorityRouter(getRouteUrl(rule))
-	fileredInvokers := router.(*ConditionRouter).Route(invokers, &curl, inv)
-	assert.Equal(t, 2, len(fileredInvokers))
-	assert.Equal(t, invoker2, fileredInvokers[0])
-	assert.Equal(t, invoker3, fileredInvokers[1])
+	r, _ := newConditionRouterFactory().NewPriorityRouter(getRouteUrl(rule))
+	ret := r.Route(utils.ToBitmap(invokers), setUpAddrCache(invokers), &curl, inv)
+	assert.Equal(t, 2, len(ret.ToArray()))
+	assert.Equal(t, invoker2, invokers[ret.ToArray()[0]])
+	assert.Equal(t, invoker3, invokers[ret.ToArray()[1]])
 }
 
 func TestRoute_False_HostFilter(t *testing.T) {
@@ -308,11 +311,11 @@ func TestRoute_False_HostFilter(t *testing.T) {
 	inv := &invocation.RPCInvocation{}
 	rule := base64.URLEncoding.EncodeToString([]byte("true => " + " host = " + localIP))
 	curl, _ := common.NewURL(fmt.Sprintf(factoryConsumerFormat, localIP))
-	router, _ := newConditionRouterFactory().NewPriorityRouter(getRouteUrl(rule))
-	fileredInvokers := router.(*ConditionRouter).Route(invokers, &curl, inv)
-	assert.Equal(t, 2, len(fileredInvokers))
-	assert.Equal(t, invoker2, fileredInvokers[0])
-	assert.Equal(t, invoker3, fileredInvokers[1])
+	r, _ := newConditionRouterFactory().NewPriorityRouter(getRouteUrl(rule))
+	ret := r.Route(utils.ToBitmap(invokers), setUpAddrCache(invokers), &curl, inv)
+	assert.Equal(t, 2, len(ret.ToArray()))
+	assert.Equal(t, invoker2, invokers[ret.ToArray()[0]])
+	assert.Equal(t, invoker3, invokers[ret.ToArray()[1]])
 }
 
 func TestRoute_Placeholder(t *testing.T) {
@@ -327,11 +330,11 @@ func TestRoute_Placeholder(t *testing.T) {
 	inv := &invocation.RPCInvocation{}
 	rule := base64.URLEncoding.EncodeToString([]byte("host = " + localIP + " => " + " host = $host"))
 	curl, _ := common.NewURL(fmt.Sprintf(factoryConsumerFormat, localIP))
-	router, _ := newConditionRouterFactory().NewPriorityRouter(getRouteUrl(rule))
-	fileredInvokers := router.(*ConditionRouter).Route(invokers, &curl, inv)
-	assert.Equal(t, 2, len(fileredInvokers))
-	assert.Equal(t, invoker2, fileredInvokers[0])
-	assert.Equal(t, invoker3, fileredInvokers[1])
+	r, _ := newConditionRouterFactory().NewPriorityRouter(getRouteUrl(rule))
+	ret := r.Route(utils.ToBitmap(invokers), setUpAddrCache(invokers), &curl, inv)
+	assert.Equal(t, 2, len(ret.ToArray()))
+	assert.Equal(t, invoker2, invokers[ret.ToArray()[0]])
+	assert.Equal(t, invoker3, invokers[ret.ToArray()[1]])
 }
 
 func TestRoute_NoForce(t *testing.T) {
@@ -346,9 +349,9 @@ func TestRoute_NoForce(t *testing.T) {
 	inv := &invocation.RPCInvocation{}
 	rule := base64.URLEncoding.EncodeToString([]byte(fmt.Sprintf(factoryHostIp1234Format, localIP)))
 	curl, _ := common.NewURL(fmt.Sprintf(factoryConsumerFormat, localIP))
-	router, _ := newConditionRouterFactory().NewPriorityRouter(getRouteUrlWithNoForce(rule))
-	fileredInvokers := router.(*ConditionRouter).Route(invokers, &curl, inv)
-	assert.Equal(t, invokers, fileredInvokers)
+	r, _ := newConditionRouterFactory().NewPriorityRouter(getRouteUrlWithNoForce(rule))
+	ret := r.Route(utils.ToBitmap(invokers), setUpAddrCache(invokers), &curl, inv)
+	assert.Equal(t, len(invokers), len(ret.ToArray()))
 }
 
 func TestRoute_Force(t *testing.T) {
@@ -363,9 +366,9 @@ func TestRoute_Force(t *testing.T) {
 	inv := &invocation.RPCInvocation{}
 	rule := base64.URLEncoding.EncodeToString([]byte(fmt.Sprintf(factoryHostIp1234Format, localIP)))
 	curl, _ := common.NewURL(fmt.Sprintf(factoryConsumerFormat, localIP))
-	router, _ := newConditionRouterFactory().NewPriorityRouter(getRouteUrlWithForce(rule, "true"))
-	fileredInvokers := router.(*ConditionRouter).Route(invokers, &curl, inv)
-	assert.Equal(t, 0, len(fileredInvokers))
+	r, _ := newConditionRouterFactory().NewPriorityRouter(getRouteUrlWithForce(rule, "true"))
+	fileredInvokers := r.Route(utils.ToBitmap(invokers), setUpAddrCache(invokers), &curl, inv)
+	assert.Equal(t, 0, len(fileredInvokers.ToArray()))
 }
 
 func TestNewConditionRouterFactory(t *testing.T) {
@@ -377,3 +380,7 @@ func TestNewAppRouterFactory(t *testing.T) {
 	factory := newAppRouterFactory()
 	assert.NotNil(t, factory)
 }
+
+func setUpAddrCache(addrs []protocol.Invoker) router.Cache {
+	return chain.BuildCache(addrs)
+}

cluster/router/condition/listenable_router.go

@@ -22,10 +22,12 @@ import (
 )
 
 import (
+	"github.com/RoaringBitmap/roaring"
 	perrors "github.com/pkg/errors"
 )
 
 import (
+	"github.com/apache/dubbo-go/cluster/router"
 	"github.com/apache/dubbo-go/common"
 	"github.com/apache/dubbo-go/common/config"
 	"github.com/apache/dubbo-go/common/constant"
@@ -64,14 +66,14 @@ func newListenableRouter(url *common.URL, ruleKey string) (*AppRouter, error) {
 	l.priority = listenableRouterDefaultPriority
 
 	routerKey := ruleKey + constant.ConditionRouterRuleSuffix
-	//add listener
+	// add listener
 	dynamicConfiguration := config.GetEnvInstance().GetDynamicConfiguration()
 	if dynamicConfiguration == nil {
 		return nil, perrors.Errorf("Get dynamicConfiguration fail, dynamicConfiguration is nil, init config center plugin please")
 	}
 
 	dynamicConfiguration.AddListener(routerKey, l)
-	//get rule
+	// get rule
 	rule, err := dynamicConfiguration.GetRule(routerKey, config_center.WithGroup(config_center.DEFAULT_GROUP))
 	if len(rule) == 0 || err != nil {
 		return nil, perrors.Errorf("Get rule fail, config rule{%s},  error{%v}", rule, err)
@@ -129,13 +131,13 @@ func (l *listenableRouter) generateConditions(rule *RouterRule) {
 }
 
 // Route Determine the target invokers list.
-func (l *listenableRouter) Route(invokers []protocol.Invoker, url *common.URL, invocation protocol.Invocation) []protocol.Invoker {
-	if len(invokers) == 0 || len(l.conditionRouters) == 0 {
+func (l *listenableRouter) Route(invokers *roaring.Bitmap, cache router.Cache, url *common.URL, invocation protocol.Invocation) *roaring.Bitmap {
+	if invokers.IsEmpty() || len(l.conditionRouters) == 0 {
 		return invokers
 	}
-	//We will check enabled status inside each router.
+	// We will check enabled status inside each router.
 	for _, r := range l.conditionRouters {
-		invokers = r.Route(invokers, url, invocation)
+		invokers = r.Route(invokers, cache, url, invocation)
 	}
 	return invokers
 }

cluster/router/condition/router.go

@@ -23,20 +23,23 @@ import (
 )
 
 import (
+	"github.com/RoaringBitmap/roaring"
+	"github.com/dubbogo/gost/container/set"
+	"github.com/dubbogo/gost/net"
 	perrors "github.com/pkg/errors"
 )
 
 import (
+	"github.com/apache/dubbo-go/cluster/router"
+	"github.com/apache/dubbo-go/cluster/router/utils"
 	"github.com/apache/dubbo-go/common"
 	"github.com/apache/dubbo-go/common/constant"
 	"github.com/apache/dubbo-go/common/logger"
 	"github.com/apache/dubbo-go/protocol"
-	"github.com/dubbogo/gost/container/set"
-	"github.com/dubbogo/gost/net"
 )
 
 const (
-	//pattern route pattern regex
+	// pattern route pattern regex
 	pattern = `([&!=,]*)\\s*([^&!=,\\s]+)`
 )
 
@@ -148,29 +151,36 @@ func (c *ConditionRouter) Enabled() bool {
 }
 
 // Route Determine the target invokers list.
-func (c *ConditionRouter) Route(invokers []protocol.Invoker, url *common.URL, invocation protocol.Invocation) []protocol.Invoker {
+func (c *ConditionRouter) Route(invokers *roaring.Bitmap, cache router.Cache, url *common.URL, invocation protocol.Invocation) *roaring.Bitmap {
 	if !c.Enabled() {
 		return invokers
 	}
-	if len(invokers) == 0 {
+
+	if invokers.IsEmpty() {
 		return invokers
 	}
+
 	isMatchWhen := c.MatchWhen(url, invocation)
 	if !isMatchWhen {
 		return invokers
 	}
-	var result []protocol.Invoker
+
 	if len(c.ThenCondition) == 0 {
-		return result
+		return utils.EmptyAddr
 	}
-	for _, invoker := range invokers {
+
+	result := roaring.NewBitmap()
+	for iter := invokers.Iterator(); iter.HasNext(); {
+		index := iter.Next()
+		invoker := cache.GetInvokers()[index]
 		invokerUrl := invoker.GetUrl()
 		isMatchThen := c.MatchThen(&invokerUrl, url)
 		if isMatchThen {
-			result = append(result, invoker)
+			result.Add(index)
 		}
 	}
-	if len(result) > 0 {
+
+	if !result.IsEmpty() {
 		return result
 	} else if c.Force {
 		rule, _ := url.GetParamAndDecoded(constant.RULE_KEY)
@@ -178,6 +188,7 @@ func (c *ConditionRouter) Route(invokers []protocol.Invoker, url *common.URL, in
 		logger.Warnf("The route result is empty and force execute. consumer: %s, service: %s, router: %s", localIP, url.Service(), rule)
 		return result
 	}
+
 	return invokers
 }
 

cluster/router/healthcheck/health_check_route.go

@@ -17,8 +17,13 @@
 
 package healthcheck
 
+import (
+	"github.com/RoaringBitmap/roaring"
+)
+
 import (
 	"github.com/apache/dubbo-go/cluster/router"
+	"github.com/apache/dubbo-go/cluster/router/utils"
 	"github.com/apache/dubbo-go/common"
 	"github.com/apache/dubbo-go/common/constant"
 	"github.com/apache/dubbo-go/common/extension"
@@ -28,6 +33,8 @@ import (
 
 const (
 	HEALTH_ROUTE_ENABLED_KEY = "health.route.enabled"
+	healthy                  = "healthy"
+	name                     = "health-check-router"
 )
 
 // HealthCheckRouter provides a health-first routing mechanism through HealthChecker
@@ -51,25 +58,48 @@ func NewHealthCheckRouter(url *common.URL) (router.PriorityRouter, error) {
 }
 
 // Route gets a list of healthy invoker
-func (r *HealthCheckRouter) Route(invokers []protocol.Invoker, url *common.URL, invocation protocol.Invocation) []protocol.Invoker {
+func (r *HealthCheckRouter) Route(invokers *roaring.Bitmap, cache router.Cache, url *common.URL, invocation protocol.Invocation) *roaring.Bitmap {
 	if !r.enabled {
 		return invokers
 	}
-	healthyInvokers := make([]protocol.Invoker, 0, len(invokers))
+
+	addrPool := cache.FindAddrPool(r)
 	// Add healthy invoker to the list
-	for _, invoker := range invokers {
-		if r.checker.IsHealthy(invoker) {
-			healthyInvokers = append(healthyInvokers, invoker)
-		}
-	}
-	// If all Invoke are considered unhealthy, downgrade to all inovker
-	if len(healthyInvokers) == 0 {
+	healthyInvokers := utils.JoinIfNotEqual(addrPool[healthy], invokers)
+	// If all invokers are considered unhealthy, downgrade to all invoker
+	if healthyInvokers.IsEmpty() {
 		logger.Warnf(" Now all invokers are unhealthy, so downgraded to all! Service: [%s]", url.ServiceKey())
 		return invokers
 	}
 	return healthyInvokers
 }
 
+// Pool separates healthy invokers from others.
+func (r *HealthCheckRouter) Pool(invokers []protocol.Invoker) (router.AddrPool, router.AddrMetadata) {
+	if !r.enabled {
+		return nil, nil
+	}
+
+	rb := make(router.AddrPool, 8)
+	rb[healthy] = roaring.NewBitmap()
+	for i, invoker := range invokers {
+		if r.checker.IsHealthy(invoker) {
+			rb[healthy].Add(uint32(i))
+		}
+	}
+
+	return rb, nil
+}
+
+// ShouldPool will always return true to make sure healthy check constantly.
+func (r *HealthCheckRouter) ShouldPool() bool {
+	return r.enabled
+}
+
+func (r *HealthCheckRouter) Name() string {
+	return name
+}
+
 // Priority
 func (r *HealthCheckRouter) Priority() int64 {
 	return 0

cluster/router/healthcheck/health_check_route_test.go

@@ -29,6 +29,9 @@ import (
 )
 
 import (
+	"github.com/apache/dubbo-go/cluster/router"
+	"github.com/apache/dubbo-go/cluster/router/chain"
+	"github.com/apache/dubbo-go/cluster/router/utils"
 	"github.com/apache/dubbo-go/common"
 	"github.com/apache/dubbo-go/common/constant"
 	"github.com/apache/dubbo-go/protocol"
@@ -59,25 +62,25 @@ func TestHealthCheckRouterRoute(t *testing.T) {
 	invoker3 := NewMockInvoker(url3)
 	invokers = append(invokers, invoker1, invoker2, invoker3)
 	inv := invocation.NewRPCInvocation(healthCheckRouteMethodNameTest, nil, nil)
-	res := hcr.Route(invokers, &consumerURL, inv)
+	res := hcr.Route(utils.ToBitmap(invokers), setUpAddrCache(hcr.(*HealthCheckRouter), invokers), &consumerURL, inv)
 	// now all invokers are healthy
-	assert.True(t, len(res) == len(invokers))
+	assert.True(t, len(res.ToArray()) == len(invokers))
 
 	for i := 0; i < 10; i++ {
 		request(url1, healthCheckRouteMethodNameTest, 0, false, false)
 	}
-	res = hcr.Route(invokers, &consumerURL, inv)
+	res = hcr.Route(utils.ToBitmap(invokers), setUpAddrCache(hcr.(*HealthCheckRouter), invokers), &consumerURL, inv)
 	// invokers1  is unhealthy now
-	assert.True(t, len(res) == 2 && !contains(res, invoker1))
+	assert.True(t, len(res.ToArray()) == 2 && !res.Contains(0))
 
 	for i := 0; i < 10; i++ {
 		request(url1, healthCheckRouteMethodNameTest, 0, false, false)
 		request(url2, healthCheckRouteMethodNameTest, 0, false, false)
 	}
 
-	res = hcr.Route(invokers, &consumerURL, inv)
+	res = hcr.Route(utils.ToBitmap(invokers), setUpAddrCache(hcr.(*HealthCheckRouter), invokers), &consumerURL, inv)
 	// only invokers3  is healthy now
-	assert.True(t, len(res) == 1 && !contains(res, invoker1) && !contains(res, invoker2))
+	assert.True(t, len(res.ToArray()) == 1 && !res.Contains(0) && !res.Contains(1))
 
 	for i := 0; i < 10; i++ {
 		request(url1, healthCheckRouteMethodNameTest, 0, false, false)
@@ -85,37 +88,28 @@ func TestHealthCheckRouterRoute(t *testing.T) {
 		request(url3, healthCheckRouteMethodNameTest, 0, false, false)
 	}
 
-	res = hcr.Route(invokers, &consumerURL, inv)
+	res = hcr.Route(utils.ToBitmap(invokers), setUpAddrCache(hcr.(*HealthCheckRouter), invokers), &consumerURL, inv)
 	// now all invokers are unhealthy, so downgraded to all
-	assert.True(t, len(res) == 3)
+	assert.True(t, len(res.ToArray()) == 3)
 
 	// reset the invoker1 successive failed count, so invoker1 go to healthy
 	request(url1, healthCheckRouteMethodNameTest, 0, false, true)
-	res = hcr.Route(invokers, &consumerURL, inv)
-	assert.True(t, contains(res, invoker1))
+	res = hcr.Route(utils.ToBitmap(invokers), setUpAddrCache(hcr.(*HealthCheckRouter), invokers), &consumerURL, inv)
+	assert.True(t, res.Contains(0))
 
 	for i := 0; i < 6; i++ {
 		request(url1, healthCheckRouteMethodNameTest, 0, false, false)
 	}
 	// now all invokers are unhealthy, so downgraded to all again
-	res = hcr.Route(invokers, &consumerURL, inv)
-	assert.True(t, len(res) == 3)
+	res = hcr.Route(utils.ToBitmap(invokers), setUpAddrCache(hcr.(*HealthCheckRouter), invokers), &consumerURL, inv)
+	assert.True(t, len(res.ToArray()) == 3)
 	time.Sleep(time.Second * 2)
 	// invoker1 go to healthy again after 2s
-	res = hcr.Route(invokers, &consumerURL, inv)
-	assert.True(t, contains(res, invoker1))
+	res = hcr.Route(utils.ToBitmap(invokers), setUpAddrCache(hcr.(*HealthCheckRouter), invokers), &consumerURL, inv)
+	assert.True(t, res.Contains(0))
 
 }
 
-func contains(invokers []protocol.Invoker, invoker protocol.Invoker) bool {
-	for _, e := range invokers {
-		if e == invoker {
-			return true
-		}
-	}
-	return false
-}
-
 func TestNewHealthCheckRouter(t *testing.T) {
 	defer protocol.CleanAllStatus()
 	url, _ := common.NewURL(fmt.Sprintf(healthCheckDubboUrlFormat, healthCheckDubbo1010IP))
@@ -143,3 +137,11 @@ func TestNewHealthCheckRouter(t *testing.T) {
 	assert.Equal(t, dhc.requestSuccessiveFailureThreshold, int32(10))
 	assert.Equal(t, dhc.circuitTrippedTimeoutFactor, int32(500))
 }
+
+func setUpAddrCache(r router.Poolable, addrs []protocol.Invoker) router.Cache {
+	pool, info := r.Pool(addrs)
+	cache := chain.BuildCache(addrs)
+	cache.SetAddrMeta(r.Name(), info)
+	cache.SetAddrPool(r.Name(), pool)
+	return cache
+}

cluster/router/router.go

@@ -17,6 +17,10 @@
 
 package router
 
+import (
+	"github.com/RoaringBitmap/roaring"
+)
+
 import (
 	"github.com/apache/dubbo-go/common"
 	"github.com/apache/dubbo-go/protocol"
@@ -38,7 +42,8 @@ type FilePriorityRouterFactory interface {
 // Router
 type router interface {
 	// Route Determine the target invokers list.
-	Route([]protocol.Invoker, *common.URL, protocol.Invocation) []protocol.Invoker
+	Route(*roaring.Bitmap, Cache, *common.URL, protocol.Invocation) *roaring.Bitmap
+
 	// URL Return URL in router
 	URL() common.URL
 }
@@ -51,10 +56,38 @@ type PriorityRouter interface {
 	Priority() int64
 }
 
-// NotifyRouter notify router use the invoker list. Invoker list may change from time to time. This method gives the router a
-// chance to prepare before {@link Router#route(List, URL, Invocation)} gets called.
-type NotifyRouter interface {
-	PriorityRouter
-	// Notify notify whenever addresses in registry change
-	Notify([]protocol.Invoker)
+// Poolable caches address pool and address metadata for a router instance which will be used later in Router's Route.
+type Poolable interface {
+	// Pool created address pool and address metadata from the invokers.
+	Pool([]protocol.Invoker) (AddrPool, AddrMetadata)
+
+	// ShouldPool returns if it should pool. One typical scenario is a router rule changes, in this case, a pooling
+	// is necessary, even if the addresses not changed at all.
+	ShouldPool() bool
+
+	// Name return the Poolable's name.
+	Name() string
+}
+
+// AddrPool is an address pool, backed by a snapshot of address list, divided into categories.
+type AddrPool map[string]*roaring.Bitmap
+
+// AddrMetadta is address metadata, collected from a snapshot of address list by a router, if it implements Poolable.
+type AddrMetadata interface {
+	// Source indicates where the metadata comes from.
+	Source() string
+}
+
+// Cache caches all addresses relevant info for a snapshot of received invokers. It keeps a snapshot of the received
+// address list, and also keeps address pools and address metadata from routers based on the same address snapshot, if
+// the router implements Poolable.
+type Cache interface {
+	// GetInvokers returns the snapshot of received invokers.
+	GetInvokers() []protocol.Invoker
+
+	// FindAddrPool returns address pool associated with the given Poolable instance.
+	FindAddrPool(Poolable) AddrPool
+
+	// FindAddrMeta returns address metadata associated with the given Poolable instance.
+	FindAddrMeta(Poolable) AddrMetadata
 }

cluster/router/tag/file.go

@@ -24,10 +24,12 @@ import (
 )
 
 import (
+	"github.com/RoaringBitmap/roaring"
 	perrors "github.com/pkg/errors"
 )
 
 import (
+	"github.com/apache/dubbo-go/cluster/router"
 	"github.com/apache/dubbo-go/common"
 	"github.com/apache/dubbo-go/common/constant"
 	"github.com/apache/dubbo-go/protocol"
@@ -74,9 +76,10 @@ func (f *FileTagRouter) Priority() int64 {
 	return f.router.priority
 }
 
-func (f *FileTagRouter) Route(invokers []protocol.Invoker, url *common.URL, invocation protocol.Invocation) []protocol.Invoker {
-	if len(invokers) == 0 {
+func (f *FileTagRouter) Route(invokers *roaring.Bitmap, cache router.Cache, url *common.URL, invocation protocol.Invocation) *roaring.Bitmap {
+	if invokers.IsEmpty() {
 		return invokers
 	}
-	return f.Route(invokers, url, invocation)
+	// FIXME: I believe this is incorrect.
+	return f.Route(invokers, cache, url, invocation)
 }

cluster/router/tag/router_rule.go

@@ -41,8 +41,8 @@ import (
 type RouterRule struct {
 	router.BaseRouterRule `yaml:",inline"`
 	Tags                  []Tag
-	addressToTagNames     map[string][]string
-	tagNameToAddresses    map[string][]string
+	AddressToTagNames     map[string][]string
+	TagNameToAddresses    map[string][]string
 }
 
 func getRule(rawRule string) (*RouterRule, error) {
@@ -58,13 +58,13 @@ func getRule(rawRule string) (*RouterRule, error) {
 
 // parseTags use for flattening tags data to @addressToTagNames and @tagNameToAddresses
 func (t *RouterRule) parseTags() {
-	t.addressToTagNames = make(map[string][]string, 2*len(t.Tags))
-	t.tagNameToAddresses = make(map[string][]string, len(t.Tags))
+	t.AddressToTagNames = make(map[string][]string, 2*len(t.Tags))
+	t.TagNameToAddresses = make(map[string][]string, len(t.Tags))
 	for _, tag := range t.Tags {
 		for _, address := range tag.Addresses {
-			t.addressToTagNames[address] = append(t.addressToTagNames[address], tag.Name)
+			t.AddressToTagNames[address] = append(t.AddressToTagNames[address], tag.Name)
 		}
-		t.tagNameToAddresses[tag.Name] = tag.Addresses
+		t.TagNameToAddresses[tag.Name] = tag.Addresses
 	}
 }
 
@@ -85,15 +85,15 @@ func (t *RouterRule) getTagNames() []string {
 }
 
 func (t *RouterRule) hasTag(tag string) bool {
-	return len(t.tagNameToAddresses[tag]) > 0
+	return len(t.TagNameToAddresses[tag]) > 0
 }
 
 func (t *RouterRule) getAddressToTagNames() map[string][]string {
-	return t.addressToTagNames
+	return t.AddressToTagNames
 }
 
 func (t *RouterRule) getTagNameToAddresses() map[string][]string {
-	return t.tagNameToAddresses
+	return t.TagNameToAddresses
 }
 
 func (t *RouterRule) getTags() []Tag {

cluster/router/tag/tag_router.go

@@ -18,16 +18,20 @@
 package tag
 
 import (
-	"net"
 	"strconv"
+	"strings"
+	"sync"
 )
 
 import (
+	"github.com/RoaringBitmap/roaring"
 	gxnet "github.com/dubbogo/gost/net"
 	perrors "github.com/pkg/errors"
 )
 
 import (
+	"github.com/apache/dubbo-go/cluster/router"
+	"github.com/apache/dubbo-go/cluster/router/utils"
 	"github.com/apache/dubbo-go/common"
 	"github.com/apache/dubbo-go/common/config"
 	"github.com/apache/dubbo-go/common/constant"
@@ -37,6 +41,32 @@ import (
 	"github.com/apache/dubbo-go/remoting"
 )
 
+const (
+	name          = "tag-router"
+	staticPrefix  = "static-"
+	dynamicPrefix = "dynamic-"
+)
+
+// addrMetadata keeps snapshot data for app name, and some infos extracted from dynamic tag rule in order to make
+// Route() method lock-free.
+type addrMetadata struct {
+	// application name
+	application string
+	// is rule a runtime rule
+	ruleRuntime bool
+	// is rule a force rule
+	ruleForce bool
+	// is rule a valid rule
+	ruleValid bool
+	// is rule an enabled rule
+	ruleEnabled bool
+}
+
+// Source indicates where the metadata comes from.
+func (m *addrMetadata) Source() string {
+	return name
+}
+
 // tagRouter defines url, enable and the priority
 type tagRouter struct {
 	url           *common.URL
@@ -44,6 +74,8 @@ type tagRouter struct {
 	enabled       bool
 	priority      int64
 	application   string
+	ruleChanged   bool
+	mutex         sync.RWMutex
 }
 
 // NewTagRouter returns a tagRouter instance if url is not nil
@@ -63,61 +95,80 @@ func (c *tagRouter) isEnabled() bool {
 	return c.enabled
 }
 
-func (c *tagRouter) tagRouterRuleCopy() RouterRule {
-	routerRule := *c.tagRouterRule
-	return routerRule
-}
-
 // Route gets a list of invoker
-func (c *tagRouter) Route(invokers []protocol.Invoker, url *common.URL, invocation protocol.Invocation) []protocol.Invoker {
-	var (
-		result    []protocol.Invoker
-		addresses []string
-	)
+func (c *tagRouter) Route(invokers *roaring.Bitmap, cache router.Cache, url *common.URL, invocation protocol.Invocation) *roaring.Bitmap {
+	if !c.isEnabled() || invokers.IsEmpty() {
+		return invokers
+	}
+
+	if shouldUseDynamicTag(cache.FindAddrMeta(c)) {
+		return c.routeWithDynamicTag(invokers, cache, url, invocation)
+	}
+	return c.routeWithStaticTag(invokers, cache, url, invocation)
+}
 
-	if !c.isEnabled() || len(invokers) == 0 {
+// routeWithStaticTag routes with static tag rule
+func (c *tagRouter) routeWithStaticTag(invokers *roaring.Bitmap, cache router.Cache, url *common.URL, invocation protocol.Invocation) *roaring.Bitmap {
+	tag := findTag(invocation, url)
+	if tag == "" {
 		return invokers
 	}
 
-	// Use static tags if dynamic tags are not set or invalid
-	if c.tagRouterRule == nil || !c.tagRouterRule.Valid || !c.tagRouterRule.Enabled {
-		return filterUsingStaticTag(invokers, url, invocation)
+	ret, _ := c.filterWithTag(invokers, cache, staticPrefix+tag)
+	if ret.IsEmpty() && !isForceUseTag(url, invocation) {
+		return invokers
 	}
 
-	// since the rule can be changed by config center, we should copy one to use.
-	tagRouterRuleCopy := c.tagRouterRuleCopy()
-	tag, ok := invocation.Attachments()[constant.Tagkey]
-	if !ok {
-		tag = url.GetParam(constant.Tagkey, "")
+	return ret
+}
+
+// routeWithDynamicTag routes with dynamic tag rule
+func (c *tagRouter) routeWithDynamicTag(invokers *roaring.Bitmap, cache router.Cache, url *common.URL, invocation protocol.Invocation) *roaring.Bitmap {
+	tag := findTag(invocation, url)
+	if tag == "" {
+		return c.filterNotInDynamicTag(invokers, cache)
 	}
 
-	// if we are requesting for a Provider with a specific tag
-	if len(tag) > 0 {
-		return filterInvokersWithTag(invokers, url, invocation, tagRouterRuleCopy, tag)
+	ret, ok := c.filterWithTag(invokers, cache, dynamicPrefix+tag)
+	if ok && (!ret.IsEmpty() || isTagRuleForce(cache.FindAddrMeta(c))) {
+		return ret
 	}
 
-	// return all addresses in dynamic tag group.
-	addresses = tagRouterRuleCopy.getAddresses()
-	if len(addresses) > 0 {
-		filterAddressNotMatches := func(invoker protocol.Invoker) bool {
-			url := invoker.GetUrl()
-			return len(addresses) == 0 || !checkAddressMatch(addresses, url.Ip, url.Port)
-		}
-		result = filterInvoker(invokers, filterAddressNotMatches)
-		// 1. all addresses are in dynamic tag group, return empty list.
-		if len(result) == 0 {
-			return result
+	// dynamic tag group doesn't have any item about the requested app OR it's null after filtered by
+	// dynamic tag group but force=false. check static tag
+	if ret.IsEmpty() {
+		ret, _ = c.filterWithTag(invokers, cache, staticPrefix+tag)
+		// If there's no tagged providers that can match the current tagged request. force.tag is set by default
+		// to false, which means it will invoke any providers without a tag unless it's explicitly disallowed.
+		if !ret.IsEmpty() || isForceUseTag(url, invocation) {
+			return ret
 		}
+		return c.filterNotInDynamicTag(invokers, cache)
+	}
+	return ret
+}
+
+// filterWithTag filters incoming invokers with the given tag
+func (c *tagRouter) filterWithTag(invokers *roaring.Bitmap, cache router.Cache, tag string) (*roaring.Bitmap, bool) {
+	if target, ok := cache.FindAddrPool(c)[tag]; ok {
+		return utils.JoinIfNotEqual(target, invokers), true
 	}
-	// 2. if there are some addresses that are not in any dynamic tag group, continue to filter using the
-	// static tag group.
-	filter := func(invoker protocol.Invoker) bool {
-		localTag := invoker.GetUrl().GetParam(constant.Tagkey, "")
-		return len(localTag) == 0 || !(tagRouterRuleCopy.hasTag(localTag))
+	return utils.EmptyAddr, false
+}
+
+// filterNotInDynamicTag filters incoming invokers not applied to dynamic tag rule
+func (c *tagRouter) filterNotInDynamicTag(invokers *roaring.Bitmap, cache router.Cache) *roaring.Bitmap {
+	// FAILOVER: return all Providers without any tags.
+	invokers = invokers.Clone()
+	for k, v := range cache.FindAddrPool(c) {
+		if strings.HasPrefix(k, dynamicPrefix) {
+			invokers.AndNot(v)
+		}
 	}
-	return filterInvoker(result, filter)
+	return invokers
 }
 
+// Process parses dynamic tag rule
 func (c *tagRouter) Process(event *config_center.ConfigChangeEvent) {
 	logger.Infof("Notification of tag rule, change type is:[%s] , raw rule is:[%v]", event.ConfigType, event.Value)
 	if remoting.EventTypeDel == event.ConfigType {
@@ -135,16 +186,52 @@ func (c *tagRouter) Process(event *config_center.ConfigChangeEvent) {
 		logger.Errorf("Parse dynamic tag router rule fail,error:[%s] ", err)
 		return
 	}
+
+	c.mutex.Lock()
+	defer c.mutex.Unlock()
 	c.tagRouterRule = routerRule
-	return
+	c.ruleChanged = true
+}
+
+// URL gets the url of tagRouter
+func (c *tagRouter) URL() common.URL {
+	return *c.url
 }
 
-func (c *tagRouter) Notify(invokers []protocol.Invoker) {
-	if len(invokers) == 0 {
+// Priority gets the priority of tagRouter
+func (c *tagRouter) Priority() int64 {
+	return c.priority
+}
+
+// Pool divided invokers into different address pool by tag.
+func (c *tagRouter) Pool(invokers []protocol.Invoker) (router.AddrPool, router.AddrMetadata) {
+	c.fetchRuleIfNecessary(invokers)
+
+	rb := make(router.AddrPool, 8)
+	poolWithStaticTag(invokers, rb)
+
+	c.mutex.Lock()
+	defer c.mutex.Unlock()
+	poolWithDynamicTag(invokers, c.tagRouterRule, rb)
+	c.ruleChanged = false
+	// create metadata in order to avoid lock in route()
+	meta := addrMetadata{application: c.application}
+	if c.tagRouterRule != nil {
+		meta.ruleForce = c.tagRouterRule.Force
+		meta.ruleEnabled = c.tagRouterRule.Enabled
+		meta.ruleValid = c.tagRouterRule.Valid
+	}
+
+	return rb, &meta
+}
+
+// fetchRuleIfNecessary fetches, parses rule and register listener for the further change
+func (c *tagRouter) fetchRuleIfNecessary(invokers []protocol.Invoker) {
+	if invokers == nil || len(invokers) == 0 {
 		return
 	}
-	invoker := invokers[0]
-	url := invoker.GetUrl()
+
+	url := invokers[0].GetUrl()
 	providerApplication := url.GetParam(constant.RemoteApplicationKey, "")
 	if len(providerApplication) == 0 {
 		logger.Error("TagRouter must getConfig from or subscribe to a specific application, but the application " +
@@ -159,11 +246,15 @@ func (c *tagRouter) Notify(invokers []protocol.Invoker) {
 
 	if providerApplication != c.application {
 		dynamicConfiguration.RemoveListener(c.application+constant.TagRouterRuleSuffix, c)
+	} else {
+		// if app name from URL is as same as the current app name, then it is safe to jump out
+		return
 	}
 
+	c.application = providerApplication
 	routerKey := providerApplication + constant.TagRouterRuleSuffix
 	dynamicConfiguration.AddListener(routerKey, c)
-	//get rule
+	// get rule
 	rule, err := dynamicConfiguration.GetRule(routerKey, config_center.WithGroup(config_center.DEFAULT_GROUP))
 	if len(rule) == 0 || err != nil {
 		logger.Errorf("Get rule fail, config rule{%s},  error{%v}", rule, err)
@@ -177,71 +268,52 @@ func (c *tagRouter) Notify(invokers []protocol.Invoker) {
 	}
 }
 
-// URL gets the url of tagRouter
-func (c *tagRouter) URL() common.URL {
-	return *c.url
+// ShouldPool returns false, to make sure address cache for tag router happens once and only once.
+func (c *tagRouter) ShouldPool() bool {
+	c.mutex.RLock()
+	defer c.mutex.RUnlock()
+	return c.ruleChanged
 }
 
-// Priority gets the priority of tagRouter
-func (c *tagRouter) Priority() int64 {
-	return c.priority
+// Name returns pool's name
+func (c *tagRouter) Name() string {
+	return name
 }
 
-// filterUsingStaticTag gets a list of invoker using static tag
-func filterUsingStaticTag(invokers []protocol.Invoker, url *common.URL, invocation protocol.Invocation) []protocol.Invoker {
-	if tag, ok := invocation.Attachments()[constant.Tagkey]; ok {
-		result := make([]protocol.Invoker, 0, 8)
-		for _, v := range invokers {
-			if v.GetUrl().GetParam(constant.Tagkey, "") == tag {
-				result = append(result, v)
-			}
-		}
-		if len(result) == 0 && !isForceUseTag(url, invocation) {
-			return invokers
-		}
-		return result
+// poolWithDynamicTag pools addresses with the tags defined in dynamic tag rule, all keys have prefix "dynamic-"
+func poolWithDynamicTag(invokers []protocol.Invoker, rule *RouterRule, pool router.AddrPool) {
+	if rule == nil {
+		return
 	}
-	return invokers
-}
 
-// filterInvokersWithTag gets a list of invoker using dynamic route with tag
-func filterInvokersWithTag(invokers []protocol.Invoker, url *common.URL, invocation protocol.Invocation, tagRouterRule RouterRule, tag string) []protocol.Invoker {
-	var (
-		result    []protocol.Invoker
-		addresses []string
-	)
-	addresses, _ = tagRouterRule.getTagNameToAddresses()[tag]
-	// filter by dynamic tag group first
-	if len(addresses) > 0 {
-		filterAddressMatches := func(invoker protocol.Invoker) bool {
-			url := invoker.GetUrl()
-			return len(addresses) > 0 && checkAddressMatch(addresses, url.Ip, url.Port)
-		}
-		result = filterInvoker(invokers, filterAddressMatches)
-		if len(result) > 0 || tagRouterRule.Force {
-			return result
-		}
-	}
-	// dynamic tag group doesn't have any item about the requested app OR it's null after filtered by
-	// dynamic tag group but force=false. check static tag
-	filter := func(invoker protocol.Invoker) bool {
-		return invoker.GetUrl().GetParam(constant.Tagkey, "") == tag
-	}
-	result = filterInvoker(invokers, filter)
-	// If there's no tagged providers that can match the current tagged request. force.tag is set by default
-	// to false, which means it will invoke any providers without a tag unless it's explicitly disallowed.
-	if len(result) > 0 || isForceUseTag(url, invocation) {
-		return result
+	tagNameToAddresses := rule.getTagNameToAddresses()
+	for tag, addrs := range tagNameToAddresses {
+		pool[dynamicPrefix+tag] = addrsToBitmap(addrs, invokers)
 	}
-	// FAILOVER: return all Providers without any tags.
-	filterAddressNotMatches := func(invoker protocol.Invoker) bool {
+}
+
+// poolWithStaticTag pools addresses with tags found from incoming URLs, all keys have prefix "static-"
+func poolWithStaticTag(invokers []protocol.Invoker, pool router.AddrPool) {
+	for i, invoker := range invokers {
 		url := invoker.GetUrl()
-		return len(addresses) == 0 || !checkAddressMatch(tagRouterRule.getAddresses(), url.Ip, url.Port)
-	}
-	filterTagIsEmpty := func(invoker protocol.Invoker) bool {
-		return invoker.GetUrl().GetParam(constant.Tagkey, "") == ""
+		tag := url.GetParam(constant.Tagkey, "")
+		if len(tag) > 0 {
+			if _, ok := pool[staticPrefix+tag]; !ok {
+				pool[staticPrefix+tag] = roaring.NewBitmap()
+			}
+			pool[staticPrefix+tag].AddInt(i)
+		}
 	}
-	return filterInvoker(invokers, filterAddressNotMatches, filterTagIsEmpty)
+}
+
+// shouldUseDynamicTag uses the snapshot data from the parsed rule to decide if dynamic tag rule should be used or not
+func shouldUseDynamicTag(meta router.AddrMetadata) bool {
+	return meta.(*addrMetadata).ruleValid && meta.(*addrMetadata).ruleEnabled
+}
+
+// isTagRuleForce uses the snapshot data from the parsed rule to decide if dynamic tag rule is forced or not
+func isTagRuleForce(meta router.AddrMetadata) bool {
+	return meta.(*addrMetadata).ruleForce
 }
 
 // isForceUseTag returns whether force use tag
@@ -252,31 +324,44 @@ func isForceUseTag(url *common.URL, invocation protocol.Invocation) bool {
 	return false
 }
 
-type filter func(protocol.Invoker) bool
+// addrsToBitmap finds indexes for the given IP addresses in the target URL list, if any '0.0.0.0' IP address is met,
+// then returns back all indexes of the URLs list.
+func addrsToBitmap(addrs []string, invokers []protocol.Invoker) *roaring.Bitmap {
+	ret := roaring.NewBitmap()
+	for _, addr := range addrs {
+		if isAnyHost(addr) {
+			ret.AddRange(0, uint64(len(invokers)))
+			return ret
+		}
 
-func filterInvoker(invokers []protocol.Invoker, filters ...filter) []protocol.Invoker {
-	var res []protocol.Invoker
-OUTER:
-	for _, invoker := range invokers {
-		for _, filter := range filters {
-			if !filter(invoker) {
-				continue OUTER
-			}
+		index := findIndexWithIp(addr, invokers)
+		if index != -1 {
+			ret.AddInt(index)
 		}
-		res = append(res, invoker)
 	}
-	return res
+	return ret
 }
 
-func checkAddressMatch(addresses []string, host, port string) bool {
-	addr := net.JoinHostPort(constant.ANYHOST_VALUE, port)
-	for _, address := range addresses {
-		if gxnet.MatchIP(address, host, port) {
-			return true
-		}
-		if address == addr {
-			return true
+// findIndexWithIp finds index for one particular IP
+func findIndexWithIp(addr string, invokers []protocol.Invoker) int {
+	for i, invoker := range invokers {
+		if gxnet.MatchIP(addr, invoker.GetUrl().Ip, invoker.GetUrl().Port) {
+			return i
 		}
 	}
-	return false
+	return -1
+}
+
+// isAnyHost checks if an IP is '0.0.0.0'
+func isAnyHost(addr string) bool {
+	return strings.HasPrefix(addr, constant.ANYHOST_VALUE)
+}
+
+// findTag finds tag, first from invocation's attachment, then from URL
+func findTag(invocation protocol.Invocation, consumerUrl *common.URL) string {
+	tag, ok := invocation.Attachments()[constant.Tagkey]
+	if !ok {
+		tag = consumerUrl.GetParam(constant.Tagkey, "")
+	}
+	return tag
 }

cluster/router/tag/tag_router_test.go

@@ -25,15 +25,18 @@ import (
 )
 
 import (
+	"github.com/RoaringBitmap/roaring"
 	"github.com/dubbogo/go-zookeeper/zk"
 	"github.com/stretchr/testify/assert"
 	"github.com/stretchr/testify/suite"
 )
 
 import (
+	"github.com/apache/dubbo-go/cluster/router"
+	"github.com/apache/dubbo-go/cluster/router/chain"
+	"github.com/apache/dubbo-go/cluster/router/utils"
 	"github.com/apache/dubbo-go/common"
 	"github.com/apache/dubbo-go/common/config"
-	"github.com/apache/dubbo-go/common/constant"
 	"github.com/apache/dubbo-go/common/extension"
 	"github.com/apache/dubbo-go/config_center"
 	_ "github.com/apache/dubbo-go/config_center/zookeeper"
@@ -143,17 +146,17 @@ func TestTagRouterRouteForce(t *testing.T) {
 	invokers = append(invokers, inv2, inv3, inv4)
 	inv := &invocation.RPCInvocation{}
 	inv.SetAttachments(tagRouterTestDubboTag, tagRouterTestHangZhou)
-	invRst1 := tagRouter.Route(invokers, &u1, inv)
-	assert.Equal(t, 1, len(invRst1))
-	assert.Equal(t, tagRouterTestHangZhou, invRst1[0].GetUrl().GetParam(tagRouterTestDubboTag, ""))
+	invRst1 := tagRouter.Route(utils.ToBitmap(invokers), setUpAddrCache(tagRouter, invokers), &u1, inv)
+	assert.Equal(t, 1, len(invRst1.ToArray()))
+	assert.Equal(t, tagRouterTestHangZhou, invokers[invRst1.ToArray()[0]].GetUrl().GetParam(tagRouterTestDubboTag, ""))
 
 	inv.SetAttachments(tagRouterTestDubboTag, tagRouterTestGuangZhou)
-	invRst2 := tagRouter.Route(invokers, &u1, inv)
-	assert.Equal(t, 0, len(invRst2))
+	invRst2 := tagRouter.Route(utils.ToBitmap(invokers), setUpAddrCache(tagRouter, invokers), &u1, inv)
+	assert.Equal(t, 0, len(invRst2.ToArray()))
 	inv.SetAttachments(tagRouterTestDubboForceTag, tagRouterTestFalse)
 	inv.SetAttachments(tagRouterTestDubboTag, tagRouterTestGuangZhou)
-	invRst3 := tagRouter.Route(invokers, &u1, inv)
-	assert.Equal(t, 3, len(invRst3))
+	invRst3 := tagRouter.Route(utils.ToBitmap(invokers), setUpAddrCache(tagRouter, invokers), &u1, inv)
+	assert.Equal(t, 3, len(invRst3.ToArray()))
 }
 
 func TestTagRouterRouteNoForce(t *testing.T) {
@@ -175,20 +178,37 @@ func TestTagRouterRouteNoForce(t *testing.T) {
 	invokers = append(invokers, inv2, inv3, inv4)
 	inv := &invocation.RPCInvocation{}
 	inv.SetAttachments(tagRouterTestDubboTag, tagRouterTestHangZhou)
-	invRst := tagRouter.Route(invokers, &u1, inv)
-	assert.Equal(t, 1, len(invRst))
-	assert.Equal(t, tagRouterTestHangZhou, invRst[0].GetUrl().GetParam(tagRouterTestDubboTag, ""))
+	invRst := tagRouter.Route(utils.ToBitmap(invokers), setUpAddrCache(tagRouter, invokers), &u1, inv)
+	assert.Equal(t, 1, len(invRst.ToArray()))
+	assert.Equal(t, tagRouterTestHangZhou, invokers[invRst.ToArray()[0]].GetUrl().GetParam(tagRouterTestDubboTag, ""))
 
 	inv.SetAttachments(tagRouterTestDubboTag, tagRouterTestGuangZhou)
 	inv.SetAttachments(tagRouterTestDubboForceTag, tagRouterTestTrue)
-	invRst1 := tagRouter.Route(invokers, &u1, inv)
-	assert.Equal(t, 0, len(invRst1))
+	invRst1 := tagRouter.Route(utils.ToBitmap(invokers), setUpAddrCache(tagRouter, invokers), &u1, inv)
+	assert.Equal(t, 0, len(invRst1.ToArray()))
 	inv.SetAttachments(tagRouterTestDubboForceTag, tagRouterTestFalse)
-	invRst2 := tagRouter.Route(invokers, &u1, inv)
-	assert.Equal(t, 3, len(invRst2))
+	invRst2 := tagRouter.Route(utils.ToBitmap(invokers), setUpAddrCache(tagRouter, invokers), &u1, inv)
+	assert.Equal(t, 3, len(invRst2.ToArray()))
 }
 
-func TestFilterInvoker(t *testing.T) {
+func setUpAddrCache(r router.Poolable, addrs []protocol.Invoker) router.Cache {
+	pool, info := r.Pool(addrs)
+	cache := chain.BuildCache(addrs)
+	cache.SetAddrPool(r.Name(), pool)
+	cache.SetAddrMeta(r.Name(), info)
+	return cache
+}
+
+func setUpAddrCacheWithRuleDisabled(r router.Poolable, addrs []protocol.Invoker) router.Cache {
+	pool, info := r.Pool(addrs)
+	info.(*addrMetadata).ruleEnabled = false
+	cache := chain.BuildCache(addrs)
+	cache.SetAddrPool(r.Name(), pool)
+	cache.SetAddrMeta(r.Name(), info)
+	return cache
+}
+
+func TestRouteBeijingInvoker(t *testing.T) {
 	u2, e2 := common.NewURL(tagRouterTestHangZhouUrl)
 	u3, e3 := common.NewURL(tagRouterTestShangHaiUrl)
 	u4, e4 := common.NewURL(tagRouterTestBeijingUrl)
@@ -203,23 +223,17 @@ func TestFilterInvoker(t *testing.T) {
 	inv5 := NewMockInvoker(u5)
 	var invokers []protocol.Invoker
 	invokers = append(invokers, inv2, inv3, inv4, inv5)
-	filterTag := func(invoker protocol.Invoker) bool {
-		if invoker.GetUrl().GetParam(constant.Tagkey, "") == "beijing" {
-			return true
-		}
-		return false
-	}
-	res := filterInvoker(invokers, filterTag)
-	assert.Equal(t, []protocol.Invoker{inv4, inv5}, res)
-	flag := true
-	filterEnabled := func(invoker protocol.Invoker) bool {
-		if invoker.GetUrl().GetParamBool(constant.RouterEnabled, false) == flag {
-			return true
-		}
-		return false
-	}
-	res2 := filterInvoker(invokers, filterTag, filterEnabled)
-	assert.Equal(t, []protocol.Invoker{inv4}, res2)
+
+	url, _ := common.NewURL(tagRouterTestBeijingUrl)
+	tagRouter, _ := NewTagRouter(&url)
+
+	rb := roaring.NewBitmap()
+	rb.AddRange(0, uint64(len(invokers)))
+	cache := setUpAddrCache(tagRouter, invokers)
+	inv := &invocation.RPCInvocation{}
+	res := tagRouter.Route(rb, cache, &url, inv)
+	// inv4 and inv5
+	assert.Equal(t, []uint32{2, 3}, res.ToArray())
 }
 
 type DynamicTagRouter struct {
@@ -301,44 +315,51 @@ func (suite *DynamicTagRouter) TearDownTest() {
 
 func (suite *DynamicTagRouter) TestDynamicTagRouterSetByIPv4() {
 	invokers := suite.invokers
-	suite.route.Notify(invokers)
+	rb := roaring.NewBitmap()
+	rb.AddRange(0, uint64(len(invokers)))
+	cache := setUpAddrCache(suite.route, invokers)
 	suite.NotNil(suite.route.tagRouterRule)
 
 	consumer := &invocation.RPCInvocation{}
 	consumer.SetAttachments(tagRouterTestDubboTag, "tag1")
-	targetInvokers := suite.route.Route(invokers, suite.url, consumer)
-	suite.Equal(1, len(targetInvokers))
-	suite.Equal(targetInvokers[0], suite.invokers[0])
+	targetInvokers := suite.route.Route(rb, cache, suite.url, consumer)
+	suite.Equal(uint64(1), targetInvokers.GetCardinality())
+	suite.Equal(targetInvokers.ToArray()[0], uint32(0))
 
 	consumer.SetAttachments(tagRouterTestDubboTag, "tag3")
-	targetInvokers = suite.route.Route(invokers, suite.url, consumer)
-	suite.Equal(2, len(targetInvokers))
-	suite.Equal(targetInvokers, []protocol.Invoker{suite.invokers[2], suite.invokers[3]})
+	targetInvokers = suite.route.Route(rb, cache, suite.url, consumer)
+	suite.Equal(uint64(2), targetInvokers.GetCardinality())
+	suite.True(targetInvokers.Contains(2) && targetInvokers.Contains(3))
 }
 
 func (suite *DynamicTagRouter) TestDynamicTagRouterStaticTag() {
 	invokers := suite.invokers
+	rb := roaring.NewBitmap()
+	rb.AddRange(0, uint64(len(invokers)))
+	cache := setUpAddrCacheWithRuleDisabled(suite.route, invokers)
 	consumer := &invocation.RPCInvocation{}
 	consumer.SetAttachments(tagRouterTestDubboTag, "tag4")
-	targetInvokers := suite.route.Route(invokers, suite.url, consumer)
-	suite.Equal(1, len(targetInvokers))
-	suite.Equal(targetInvokers[0], suite.invokers[3])
+	targetInvokers := suite.route.Route(rb, cache, suite.url, consumer)
+	suite.Equal(uint64(1), targetInvokers.GetCardinality())
+	suite.Equal(targetInvokers.ToArray()[0], uint32(3))
 }
 
 // Teas no tag and return a address are not in dynamic tag group
 func (suite *DynamicTagRouter) TestDynamicTagRouterByNoTagAndAddressMatch() {
 	invokers := suite.invokers
-	suite.route.Notify(invokers)
+	rb := roaring.NewBitmap()
+	rb.AddRange(0, uint64(len(invokers)))
+	cache := setUpAddrCache(suite.route, invokers)
 	suite.NotNil(suite.route.tagRouterRule)
 	consumer := &invocation.RPCInvocation{}
-	targetInvokers := suite.route.Route(invokers, suite.url, consumer)
-	suite.Equal(1, len(targetInvokers))
-	suite.Equal(targetInvokers[0], suite.invokers[4])
+	targetInvokers := suite.route.Route(rb, cache, suite.url, consumer)
+	suite.Equal(uint64(1), targetInvokers.GetCardinality())
+	suite.Equal(targetInvokers.ToArray()[0], uint32(4))
 	// test if there are some addresses that are not in any dynamic tag group, continue to filter using the static tag group.
 	consumer.SetAttachments(tagRouterTestDubboTag, "tag5")
-	targetInvokers = suite.route.Route(invokers, suite.url, consumer)
-	suite.Equal(1, len(targetInvokers))
-	suite.Equal(targetInvokers[0], suite.invokers[4])
+	targetInvokers = suite.route.Route(rb, cache, suite.url, consumer)
+	suite.Equal(uint64(1), targetInvokers.GetCardinality())
+	suite.Equal(targetInvokers.ToArray()[0], uint32(4))
 }
 
 func TestProcess(t *testing.T) {

cluster/router/utils/bitmap_util.go

+/*
+ * 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 utils
+
+import (
+	"github.com/RoaringBitmap/roaring"
+)
+
+import (
+	"github.com/apache/dubbo-go/protocol"
+)
+
+var EmptyAddr = roaring.NewBitmap()
+
+func JoinIfNotEqual(left *roaring.Bitmap, right *roaring.Bitmap) *roaring.Bitmap {
+	if !left.Equals(right) {
+		left = left.Clone()
+		left.And(right)
+	}
+	return left
+}
+
+func FallbackIfJoinToEmpty(left *roaring.Bitmap, right *roaring.Bitmap) *roaring.Bitmap {
+	ret := JoinIfNotEqual(left, right)
+	if ret == nil || ret.IsEmpty() {
+		return right
+	}
+	return ret
+}
+
+func ToBitmap(invokers []protocol.Invoker) *roaring.Bitmap {
+	bitmap := roaring.NewBitmap()
+	bitmap.AddRange(0, uint64(len(invokers)))
+	return bitmap
+}

common/extension/metadata_service.go

@@ -21,6 +21,10 @@ import (
 	"fmt"
 )
 
+import (
+	perrors "github.com/pkg/errors"
+)
+
 import (
 	"github.com/apache/dubbo-go/metadata/service"
 )
@@ -36,12 +40,11 @@ func SetMetadataService(msType string, creator func() (service.MetadataService,
 }
 
 // GetMetadataService will create a MetadataService instance
-// it will panic if msType not found
 func GetMetadataService(msType string) (service.MetadataService, error) {
 	if creator, ok := metadataServiceInsMap[msType]; ok {
 		return creator()
 	}
-	panic(fmt.Sprintf("could not find the metadata service creator for metadataType: %s, please check whether you have imported relative packages, \n"+
+	return nil, perrors.New(fmt.Sprintf("could not find the metadata service creator for metadataType: %s, please check whether you have imported relative packages, \n"+
 		"local - github.com/apache/dubbo-go/metadata/service/inmemory, \n"+
 		"remote - github.com/apache/dubbo-go/metadata/service/remote", msType))
 }

common/logger/logger.go

@@ -60,6 +60,10 @@ type Logger interface {
 }
 
 func init() {
+	// forbidden to executing twice.
+	if logger != nil {
+		return
+	}
 	logConfFile := os.Getenv(constant.APP_LOG_CONF_FILE)
 	err := InitLog(logConfFile)
 	if err != nil {