diff --git a/internal/distributed/proxy/service.go b/internal/distributed/proxy/service.go
index e70f5e24e4c1f831c49e5a7d62603305e0c8e876..1f0d01a8e9fa924ad74ec52f656896077b842db0 100644
--- a/internal/distributed/proxy/service.go
+++ b/internal/distributed/proxy/service.go
@@ -138,8 +138,11 @@ func (s *Server) init() error {
 
 	proxy.Params.Init()
 	log.Debug("init params done ...")
+
+	// NetworkPort & IP don't matter here, NetworkAddress matters
 	proxy.Params.NetworkPort = Params.Port
 	proxy.Params.IP = Params.IP
+
 	proxy.Params.NetworkAddress = Params.Address
 	// for purpose of ID Allocator
 	proxy.Params.RootCoordAddress = Params.RootCoordAddress
diff --git a/internal/proxy/channels_mgr.go b/internal/proxy/channels_mgr.go
index 99609d79e336130f68974eb19913cd347f54d4f6..ab4b7fefe1612d24929f8307d2579475bc0f3dc1 100644
--- a/internal/proxy/channels_mgr.go
+++ b/internal/proxy/channels_mgr.go
@@ -24,9 +24,6 @@ import (
 	"go.uber.org/zap"
 )
 
-type vChan = string
-type pChan = string
-
 type channelsMgr interface {
 	getChannels(collectionID UniqueID) ([]pChan, error)
 	getVChannels(collectionID UniqueID) ([]vChan, error)
@@ -179,7 +176,12 @@ func (mgr *singleTypeChannelsMgr) getAllVIDs(collectionID UniqueID) ([]int, erro
 	mgr.collMtx.RLock()
 	defer mgr.collMtx.RUnlock()
 
-	return mgr.collectionID2VIDs[collectionID], nil
+	ids, exist := mgr.collectionID2VIDs[collectionID]
+	if !exist {
+		return nil, fmt.Errorf("collection %d not found", collectionID)
+	}
+
+	return ids, nil
 }
 
 func (mgr *singleTypeChannelsMgr) getVChansByVID(vid int) ([]vChan, error) {
@@ -339,10 +341,15 @@ func (mgr *singleTypeChannelsMgr) getVChannels(collectionID UniqueID) ([]vChan,
 
 func (mgr *singleTypeChannelsMgr) createMsgStream(collectionID UniqueID) error {
 	channels, err := mgr.getChannelsFunc(collectionID)
-	log.Debug("singleTypeChannelsMgr", zap.Any("createMsgStream.getChannels", channels))
 	if err != nil {
+		log.Warn("failed to create message stream",
+			zap.Int64("collection_id", collectionID),
+			zap.Error(err))
 		return err
 	}
+	log.Debug("singleTypeChannelsMgr",
+		zap.Int64("collection_id", collectionID),
+		zap.Any("createMsgStream.getChannels", channels))
 
 	mgr.updateChannels(channels)
 
@@ -480,13 +487,13 @@ func (mgr *channelsMgrImpl) removeAllDMLStream() error {
 	return mgr.dmlChannelsMgr.removeAllStream()
 }
 
-func newChannelsMgr(
+func newChannelsMgrImpl(
 	getDmlChannelsFunc getChannelsFuncType,
 	dmlRepackFunc repackFuncType,
 	getDqlChannelsFunc getChannelsFuncType,
 	dqlRepackFunc repackFuncType,
 	msgStreamFactory msgstream.Factory,
-) channelsMgr {
+) *channelsMgrImpl {
 	return &channelsMgrImpl{
 		dmlChannelsMgr: newSingleTypeChannelsMgr(getDmlChannelsFunc, msgStreamFactory, dmlRepackFunc, dmlStreamType),
 		dqlChannelsMgr: newSingleTypeChannelsMgr(getDqlChannelsFunc, msgStreamFactory, dqlRepackFunc, dqlStreamType),
diff --git a/internal/proxy/channels_mgr_test.go b/internal/proxy/channels_mgr_test.go
index 66e98e4076ad72a1d5ac75d16f547f9401cc70dc..2a82207ad5372324e6a2a5b23375484314743f3d 100644
--- a/internal/proxy/channels_mgr_test.go
+++ b/internal/proxy/channels_mgr_test.go
@@ -11,7 +11,6 @@
 
 package proxy
 
-/*
 import (
 	"testing"
 
@@ -38,7 +37,7 @@ func TestChannelsMgrImpl_getChannels(t *testing.T) {
 	master := newMockGetChannelsService()
 	query := newMockGetChannelsService()
 	factory := msgstream.NewSimpleMsgStreamFactory()
-	mgr := newChannelsMgr(master.GetChannels, nil, query.GetChannels, nil, factory)
+	mgr := newChannelsMgrImpl(master.GetChannels, nil, query.GetChannels, nil, factory)
 	defer mgr.removeAllDMLStream()
 
 	collID := UniqueID(getUniqueIntGeneratorIns().get())
@@ -56,7 +55,7 @@ func TestChannelsMgrImpl_getVChannels(t *testing.T) {
 	master := newMockGetChannelsService()
 	query := newMockGetChannelsService()
 	factory := msgstream.NewSimpleMsgStreamFactory()
-	mgr := newChannelsMgr(master.GetChannels, nil, query.GetChannels, nil, factory)
+	mgr := newChannelsMgrImpl(master.GetChannels, nil, query.GetChannels, nil, factory)
 	defer mgr.removeAllDMLStream()
 
 	collID := UniqueID(getUniqueIntGeneratorIns().get())
@@ -74,7 +73,7 @@ func TestChannelsMgrImpl_createDMLMsgStream(t *testing.T) {
 	master := newMockGetChannelsService()
 	query := newMockGetChannelsService()
 	factory := msgstream.NewSimpleMsgStreamFactory()
-	mgr := newChannelsMgr(master.GetChannels, nil, query.GetChannels, nil, factory)
+	mgr := newChannelsMgrImpl(master.GetChannels, nil, query.GetChannels, nil, factory)
 	defer mgr.removeAllDMLStream()
 
 	collID := UniqueID(getUniqueIntGeneratorIns().get())
@@ -96,7 +95,7 @@ func TestChannelsMgrImpl_getDMLMsgStream(t *testing.T) {
 	master := newMockGetChannelsService()
 	query := newMockGetChannelsService()
 	factory := msgstream.NewSimpleMsgStreamFactory()
-	mgr := newChannelsMgr(master.GetChannels, nil, query.GetChannels, nil, factory)
+	mgr := newChannelsMgrImpl(master.GetChannels, nil, query.GetChannels, nil, factory)
 	defer mgr.removeAllDMLStream()
 
 	collID := UniqueID(getUniqueIntGeneratorIns().get())
@@ -114,7 +113,7 @@ func TestChannelsMgrImpl_removeDMLMsgStream(t *testing.T) {
 	master := newMockGetChannelsService()
 	query := newMockGetChannelsService()
 	factory := msgstream.NewSimpleMsgStreamFactory()
-	mgr := newChannelsMgr(master.GetChannels, nil, query.GetChannels, nil, factory)
+	mgr := newChannelsMgrImpl(master.GetChannels, nil, query.GetChannels, nil, factory)
 	defer mgr.removeAllDMLStream()
 
 	collID := UniqueID(getUniqueIntGeneratorIns().get())
@@ -141,7 +140,7 @@ func TestChannelsMgrImpl_removeAllDMLMsgStream(t *testing.T) {
 	master := newMockGetChannelsService()
 	query := newMockGetChannelsService()
 	factory := msgstream.NewSimpleMsgStreamFactory()
-	mgr := newChannelsMgr(master.GetChannels, nil, query.GetChannels, nil, factory)
+	mgr := newChannelsMgrImpl(master.GetChannels, nil, query.GetChannels, nil, factory)
 	defer mgr.removeAllDMLStream()
 
 	num := 10
@@ -156,21 +155,12 @@ func TestChannelsMgrImpl_createDQLMsgStream(t *testing.T) {
 	master := newMockGetChannelsService()
 	query := newMockGetChannelsService()
 	factory := msgstream.NewSimpleMsgStreamFactory()
-	mgr := newChannelsMgr(master.GetChannels, nil, query.GetChannels, nil, factory)
+	mgr := newChannelsMgrImpl(master.GetChannels, nil, query.GetChannels, nil, factory)
 	defer mgr.removeAllDMLStream()
 
 	collID := UniqueID(getUniqueIntGeneratorIns().get())
-	_, err := mgr.getChannels(collID)
-	assert.NotEqual(t, nil, err)
-	_, err = mgr.getVChannels(collID)
-	assert.NotEqual(t, nil, err)
-
-	err = mgr.createDQLStream(collID)
-	assert.Equal(t, nil, err)
 
-	_, err = mgr.getChannels(collID)
-	assert.Equal(t, nil, err)
-	_, err = mgr.getVChannels(collID)
+	err := mgr.createDQLStream(collID)
 	assert.Equal(t, nil, err)
 }
 
@@ -178,7 +168,7 @@ func TestChannelsMgrImpl_getDQLMsgStream(t *testing.T) {
 	master := newMockGetChannelsService()
 	query := newMockGetChannelsService()
 	factory := msgstream.NewSimpleMsgStreamFactory()
-	mgr := newChannelsMgr(master.GetChannels, nil, query.GetChannels, nil, factory)
+	mgr := newChannelsMgrImpl(master.GetChannels, nil, query.GetChannels, nil, factory)
 	defer mgr.removeAllDMLStream()
 
 	collID := UniqueID(getUniqueIntGeneratorIns().get())
@@ -196,7 +186,7 @@ func TestChannelsMgrImpl_removeDQLMsgStream(t *testing.T) {
 	master := newMockGetChannelsService()
 	query := newMockGetChannelsService()
 	factory := msgstream.NewSimpleMsgStreamFactory()
-	mgr := newChannelsMgr(master.GetChannels, nil, query.GetChannels, nil, factory)
+	mgr := newChannelsMgrImpl(master.GetChannels, nil, query.GetChannels, nil, factory)
 	defer mgr.removeAllDMLStream()
 
 	collID := UniqueID(getUniqueIntGeneratorIns().get())
@@ -223,7 +213,7 @@ func TestChannelsMgrImpl_removeAllDQLMsgStream(t *testing.T) {
 	master := newMockGetChannelsService()
 	query := newMockGetChannelsService()
 	factory := msgstream.NewSimpleMsgStreamFactory()
-	mgr := newChannelsMgr(master.GetChannels, nil, query.GetChannels, nil, factory)
+	mgr := newChannelsMgrImpl(master.GetChannels, nil, query.GetChannels, nil, factory)
 	defer mgr.removeAllDMLStream()
 
 	num := 10
@@ -233,4 +223,3 @@ func TestChannelsMgrImpl_removeAllDQLMsgStream(t *testing.T) {
 		assert.Equal(t, nil, err)
 	}
 }
-*/
diff --git a/internal/proxy/channels_time_ticker.go b/internal/proxy/channels_time_ticker.go
index 99cd79b1603f037ad4aaecdc2c74af2d16e1a968..2765f928752052257bd770ec61fe444466dce65e 100644
--- a/internal/proxy/channels_time_ticker.go
+++ b/internal/proxy/channels_time_ticker.go
@@ -21,11 +21,6 @@ import (
 	"go.uber.org/zap"
 )
 
-type pChanStatistics struct {
-	minTs Timestamp
-	maxTs Timestamp
-}
-
 // ticker can update ts only when the minTs greater than the ts of ticker, we can use maxTs to update current later
 type getPChanStatisticsFuncType func() (map[pChan]*pChanStatistics, error)
 
diff --git a/internal/proxy/dummyreq_test.go b/internal/proxy/dummyreq_test.go
index c807ddfe8c98761bb0203aa3e32eed312aa6b52f..e1e0b941085230a7399176fc03e0c24d740b3be9 100644
--- a/internal/proxy/dummyreq_test.go
+++ b/internal/proxy/dummyreq_test.go
@@ -11,6 +11,181 @@
 
 package proxy
 
+import (
+	"encoding/json"
+	"testing"
+
+	"github.com/milvus-io/milvus/internal/log"
+	"go.uber.org/zap"
+
+	"github.com/stretchr/testify/assert"
+)
+
+func Test_parseDummyRequestType(t *testing.T) {
+	var err error
+
+	// not in json format
+	notInJSONFormatStr := "not in json format string"
+	_, err = parseDummyRequestType(notInJSONFormatStr)
+	assert.NotNil(t, err)
+
+	// only contain other field, in json format
+	otherField := "other_field"
+	otherFieldValue := "not important"
+	m1 := make(map[string]string)
+	m1[otherField] = otherFieldValue
+	bs1, err := json.Marshal(m1)
+	assert.Nil(t, err)
+	log.Info("Test_parseDummyRequestType",
+		zap.String("json", string(bs1)))
+	ret1, err := parseDummyRequestType(string(bs1))
+	assert.Nil(t, err)
+	assert.Equal(t, 0, len(ret1.RequestType))
+
+	// normal case
+	key := "request_type"
+	value := "value"
+	m2 := make(map[string]string)
+	m2[key] = value
+	bs2, err := json.Marshal(m2)
+	assert.Nil(t, err)
+	log.Info("Test_parseDummyRequestType",
+		zap.String("json", string(bs2)))
+	ret2, err := parseDummyRequestType(string(bs2))
+	assert.Nil(t, err)
+	assert.Equal(t, value, ret2.RequestType)
+
+	// contain other field and request_type
+	m3 := make(map[string]string)
+	m3[key] = value
+	m3[otherField] = otherFieldValue
+	bs3, err := json.Marshal(m3)
+	assert.Nil(t, err)
+	log.Info("Test_parseDummyRequestType",
+		zap.String("json", string(bs3)))
+	ret3, err := parseDummyRequestType(string(bs3))
+	assert.Nil(t, err)
+	assert.Equal(t, value, ret3.RequestType)
+}
+
+func Test_parseDummyQueryRequest(t *testing.T) {
+	var err error
+
+	// not in json format
+	notInJSONFormatStr := "not in json format string"
+	_, err = parseDummyQueryRequest(notInJSONFormatStr)
+	assert.NotNil(t, err)
+
+	// only contain other field, in json format
+	otherField := "other_field"
+	otherFieldValue := "not important"
+	m1 := make(map[string]interface{})
+	m1[otherField] = otherFieldValue
+	bs1, err := json.Marshal(m1)
+	log.Info("Test_parseDummyQueryRequest",
+		zap.String("json", string(bs1)))
+	assert.Nil(t, err)
+	ret1, err := parseDummyQueryRequest(string(bs1))
+	assert.Nil(t, err)
+	assert.Equal(t, 0, len(ret1.RequestType))
+	assert.Equal(t, 0, len(ret1.DbName))
+	assert.Equal(t, 0, len(ret1.CollectionName))
+	assert.Equal(t, 0, len(ret1.PartitionNames))
+	assert.Equal(t, 0, len(ret1.Expr))
+	assert.Equal(t, 0, len(ret1.OutputFields))
+
+	requestTypeKey := "request_type"
+	requestTypeValue := "request_type"
+	dbNameKey := "dbname"
+	dbNameValue := "dbname"
+	collectionNameKey := "collection_name"
+	collectionNameValue := "collection_name"
+	partitionNamesKey := "partition_names"
+	partitionNamesValue := []string{"partition_names"}
+	exprKey := "expr"
+	exprValue := "expr"
+	outputFieldsKey := "output_fields"
+	outputFieldsValue := []string{"output_fields"}
+
+	// all fields
+	m2 := make(map[string]interface{})
+	m2[requestTypeKey] = requestTypeValue
+	m2[dbNameKey] = dbNameValue
+	m2[collectionNameKey] = collectionNameValue
+	m2[partitionNamesKey] = partitionNamesValue
+	m2[exprKey] = exprValue
+	m2[outputFieldsKey] = outputFieldsValue
+	bs2, err := json.Marshal(m2)
+	log.Info("Test_parseDummyQueryRequest",
+		zap.String("json", string(bs2)))
+	assert.Nil(t, err)
+	ret2, err := parseDummyQueryRequest(string(bs2))
+	assert.Nil(t, err)
+	assert.Equal(t, requestTypeValue, ret2.RequestType)
+	assert.Equal(t, dbNameValue, ret2.DbName)
+	assert.Equal(t, collectionNameValue, ret2.CollectionName)
+	assert.Equal(t, partitionNamesValue, ret2.PartitionNames)
+	assert.Equal(t, exprValue, ret2.Expr)
+	assert.Equal(t, outputFieldsValue, ret2.OutputFields)
+
+	// all fields and other field
+	m3 := make(map[string]interface{})
+	m3[otherField] = otherFieldValue
+	m3[requestTypeKey] = requestTypeValue
+	m3[dbNameKey] = dbNameValue
+	m3[collectionNameKey] = collectionNameValue
+	m3[partitionNamesKey] = partitionNamesValue
+	m3[exprKey] = exprValue
+	m3[outputFieldsKey] = outputFieldsValue
+	bs3, err := json.Marshal(m3)
+	log.Info("Test_parseDummyQueryRequest",
+		zap.String("json", string(bs3)))
+	assert.Nil(t, err)
+	ret3, err := parseDummyQueryRequest(string(bs3))
+	assert.Nil(t, err)
+	assert.Equal(t, requestTypeValue, ret3.RequestType)
+	assert.Equal(t, dbNameValue, ret3.DbName)
+	assert.Equal(t, collectionNameValue, ret3.CollectionName)
+	assert.Equal(t, partitionNamesValue, ret3.PartitionNames)
+	assert.Equal(t, exprValue, ret3.Expr)
+	assert.Equal(t, outputFieldsValue, ret3.OutputFields)
+
+	// partial fields
+	m4 := make(map[string]interface{})
+	m4[requestTypeKey] = requestTypeValue
+	m4[dbNameKey] = dbNameValue
+	bs4, err := json.Marshal(m4)
+	log.Info("Test_parseDummyQueryRequest",
+		zap.String("json", string(bs4)))
+	assert.Nil(t, err)
+	ret4, err := parseDummyQueryRequest(string(bs4))
+	assert.Nil(t, err)
+	assert.Equal(t, requestTypeValue, ret4.RequestType)
+	assert.Equal(t, dbNameValue, ret4.DbName)
+	assert.Equal(t, collectionNameValue, ret2.CollectionName)
+	assert.Equal(t, partitionNamesValue, ret2.PartitionNames)
+	assert.Equal(t, exprValue, ret2.Expr)
+	assert.Equal(t, outputFieldsValue, ret2.OutputFields)
+
+	// partial fields and other field
+	m5 := make(map[string]interface{})
+	m5[otherField] = otherFieldValue
+	m5[requestTypeKey] = requestTypeValue
+	m5[dbNameKey] = dbNameValue
+	bs5, err := json.Marshal(m5)
+	log.Info("Test_parseDummyQueryRequest",
+		zap.String("json", string(bs5)))
+	assert.Nil(t, err)
+	ret5, err := parseDummyQueryRequest(string(bs5))
+	assert.Nil(t, err)
+	assert.Equal(t, requestTypeValue, ret5.RequestType)
+	assert.Equal(t, dbNameValue, ret5.DbName)
+	assert.Equal(t, collectionNameValue, ret2.CollectionName)
+	assert.Equal(t, partitionNamesValue, ret2.PartitionNames)
+	assert.Equal(t, exprValue, ret2.Expr)
+	assert.Equal(t, outputFieldsValue, ret2.OutputFields)
+}
+
 // func TestParseDummyQueryRequest(t *testing.T) {
 // 	invalidStr := `{"request_type":"query"`
 // 	_, err := parseDummyQueryRequest(invalidStr)
diff --git a/internal/proxy/error_test.go b/internal/proxy/error_test.go
index 626dae926cb1d8dca8dabfe53b3702bb5360615f..5975e58b7f824f29ea4a4eceba80c97f69549721 100644
--- a/internal/proxy/error_test.go
+++ b/internal/proxy/error_test.go
@@ -14,28 +14,134 @@ package proxy
 import (
 	"testing"
 
+	"github.com/milvus-io/milvus/internal/proto/schemapb"
+
 	"github.com/milvus-io/milvus/internal/log"
 	"go.uber.org/zap"
 )
 
-func TestMsgProxyIsUnhealthy(t *testing.T) {
+func Test_errInvalidNumRows(t *testing.T) {
+	invalidNumRowsList := []uint32{
+		0,
+		16384,
+	}
+
+	for _, invalidNumRows := range invalidNumRowsList {
+		log.Info("Test_errInvalidNumRows",
+			zap.Error(errInvalidNumRows(invalidNumRows)))
+	}
+}
+
+func Test_errNumRowsLessThanOrEqualToZero(t *testing.T) {
+	invalidNumRowsList := []uint32{
+		0,
+		16384,
+	}
+
+	for _, invalidNumRows := range invalidNumRowsList {
+		log.Info("Test_errNumRowsLessThanOrEqualToZero",
+			zap.Error(errNumRowsLessThanOrEqualToZero(invalidNumRows)))
+	}
+}
+
+func Test_errEmptyFieldData(t *testing.T) {
+	log.Info("Test_errEmptyFieldData",
+		zap.Error(errEmptyFieldData))
+}
+
+func Test_errFieldsLessThanNeeded(t *testing.T) {
+	cases := []struct {
+		fieldsNum int
+		neededNum int
+	}{
+		{0, 1},
+		{1, 2},
+	}
+
+	for _, test := range cases {
+		log.Info("Test_errFieldsLessThanNeeded",
+			zap.Error(errFieldsLessThanNeeded(test.fieldsNum, test.neededNum)))
+	}
+}
+
+func Test_errUnsupportedDataType(t *testing.T) {
+	unsupportedDTypes := []schemapb.DataType{
+		schemapb.DataType_None,
+	}
+
+	for _, dType := range unsupportedDTypes {
+		log.Info("Test_errUnsupportedDataType",
+			zap.Error(errUnsupportedDataType(dType)))
+	}
+}
+
+func Test_errUnsupportedDType(t *testing.T) {
+	unsupportedDTypes := []string{
+		"bytes",
+		"None",
+	}
+
+	for _, dType := range unsupportedDTypes {
+		log.Info("Test_errUnsupportedDType",
+			zap.Error(errUnsupportedDType(dType)))
+	}
+}
+
+func Test_errInvalidDim(t *testing.T) {
+	invalidDimList := []int{
+		0,
+		-1,
+	}
+
+	for _, invalidDim := range invalidDimList {
+		log.Info("Test_errInvalidDim",
+			zap.Error(errInvalidDim(invalidDim)))
+	}
+}
+
+func Test_errDimLessThanOrEqualToZero(t *testing.T) {
+	invalidDimList := []int{
+		0,
+		-1,
+	}
+
+	for _, invalidDim := range invalidDimList {
+		log.Info("Test_errDimLessThanOrEqualToZero",
+			zap.Error(errDimLessThanOrEqualToZero(invalidDim)))
+	}
+}
+
+func Test_errDimShouldDivide8(t *testing.T) {
+	invalidDimList := []int{
+		0,
+		1,
+		7,
+	}
+
+	for _, invalidDim := range invalidDimList {
+		log.Info("Test_errDimShouldDivide8",
+			zap.Error(errDimShouldDivide8(invalidDim)))
+	}
+}
+
+func Test_msgProxyIsUnhealthy(t *testing.T) {
 	ids := []UniqueID{
 		1,
 	}
 
 	for _, id := range ids {
-		log.Info("TestMsgProxyIsUnhealthy",
+		log.Info("Test_msgProxyIsUnhealthy",
 			zap.String("msg", msgProxyIsUnhealthy(id)))
 	}
 }
 
-func TestErrProxyIsUnhealthy(t *testing.T) {
+func Test_errProxyIsUnhealthy(t *testing.T) {
 	ids := []UniqueID{
 		1,
 	}
 
 	for _, id := range ids {
-		log.Info("TestErrProxyIsUnhealthy",
+		log.Info("Test_errProxyIsUnhealthy",
 			zap.Error(errProxyIsUnhealthy(id)))
 	}
 }
diff --git a/internal/proxy/insert_channels.go b/internal/proxy/insert_channels.go
deleted file mode 100644
index 39e075ee25fe34476b42f91393b361f340a23095..0000000000000000000000000000000000000000
--- a/internal/proxy/insert_channels.go
+++ /dev/null
@@ -1,169 +0,0 @@
-// Copyright (C) 2019-2020 Zilliz. All rights reserved.
-//
-// 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 proxy
-
-import (
-	"context"
-	"errors"
-	"fmt"
-	"sort"
-	"sync"
-
-	"github.com/milvus-io/milvus/internal/util/funcutil"
-
-	"github.com/milvus-io/milvus/internal/log"
-	"github.com/milvus-io/milvus/internal/msgstream"
-	"go.uber.org/zap"
-)
-
-type insertChannelsMap struct {
-	collectionID2InsertChannels map[UniqueID]int      // the value of map is the location of insertChannels & insertMsgStreams
-	insertChannels              [][]string            // it's a little confusing to use []string as the key of map
-	insertMsgStreams            []msgstream.MsgStream // maybe there's a better way to implement Set, just agilely now
-	droppedBitMap               []int                 // 0 -> normal, 1 -> dropped
-	usageHistogram              []int                 // message stream can be closed only when the use count is zero
-	// TODO: use fine grained lock
-	mtx          sync.RWMutex
-	nodeInstance *Proxy
-	msFactory    msgstream.Factory
-}
-
-func (m *insertChannelsMap) CreateInsertMsgStream(collID UniqueID, channels []string) error {
-	m.mtx.Lock()
-	defer m.mtx.Unlock()
-
-	_, ok := m.collectionID2InsertChannels[collID]
-	if ok {
-		return errors.New("impossible and forbidden to create message stream twice")
-	}
-	sort.Slice(channels, func(i, j int) bool {
-		return channels[i] <= channels[j]
-	})
-	for loc, existedChannels := range m.insertChannels {
-		if m.droppedBitMap[loc] == 0 && funcutil.SortedSliceEqual(existedChannels, channels) {
-			m.collectionID2InsertChannels[collID] = loc
-			m.usageHistogram[loc]++
-			return nil
-		}
-	}
-	m.insertChannels = append(m.insertChannels, channels)
-	m.collectionID2InsertChannels[collID] = len(m.insertChannels) - 1
-
-	stream, _ := m.msFactory.NewMsgStream(context.Background())
-	stream.AsProducer(channels)
-	log.Debug("proxy", zap.Strings("proxy AsProducer: ", channels))
-	stream.SetRepackFunc(insertRepackFunc)
-	stream.Start()
-	m.insertMsgStreams = append(m.insertMsgStreams, stream)
-	m.droppedBitMap = append(m.droppedBitMap, 0)
-	m.usageHistogram = append(m.usageHistogram, 1)
-
-	return nil
-}
-
-func (m *insertChannelsMap) CloseInsertMsgStream(collID UniqueID) error {
-	m.mtx.Lock()
-	defer m.mtx.Unlock()
-
-	loc, ok := m.collectionID2InsertChannels[collID]
-	if !ok {
-		return fmt.Errorf("cannot find collection with id %d", collID)
-	}
-	if m.droppedBitMap[loc] != 0 {
-		return errors.New("insert message stream already closed")
-	}
-	if m.usageHistogram[loc] <= 0 {
-		return errors.New("insert message stream already closed")
-	}
-
-	m.usageHistogram[loc]--
-	if m.usageHistogram[loc] <= 0 {
-		m.insertMsgStreams[loc].Close()
-		m.droppedBitMap[loc] = 1
-		log.Warn("close insert message stream ...")
-	}
-
-	delete(m.collectionID2InsertChannels, collID)
-
-	return nil
-}
-
-func (m *insertChannelsMap) GetInsertChannels(collID UniqueID) ([]string, error) {
-	m.mtx.RLock()
-	defer m.mtx.RUnlock()
-
-	loc, ok := m.collectionID2InsertChannels[collID]
-	if !ok {
-		return nil, fmt.Errorf("cannot find collection with id: %d", collID)
-	}
-
-	if m.droppedBitMap[loc] != 0 {
-		return nil, errors.New("insert message stream already closed")
-	}
-	ret := append([]string(nil), m.insertChannels[loc]...)
-	return ret, nil
-}
-
-func (m *insertChannelsMap) GetInsertMsgStream(collID UniqueID) (msgstream.MsgStream, error) {
-	m.mtx.RLock()
-	defer m.mtx.RUnlock()
-
-	loc, ok := m.collectionID2InsertChannels[collID]
-	if !ok {
-		return nil, fmt.Errorf("cannot find collection with id: %d", collID)
-	}
-
-	if m.droppedBitMap[loc] != 0 {
-		return nil, errors.New("insert message stream already closed")
-	}
-
-	return m.insertMsgStreams[loc], nil
-}
-
-func (m *insertChannelsMap) CloseAllMsgStream() {
-	m.mtx.Lock()
-	defer m.mtx.Unlock()
-
-	for loc, stream := range m.insertMsgStreams {
-		if m.droppedBitMap[loc] == 0 && m.usageHistogram[loc] >= 1 {
-			stream.Close()
-		}
-	}
-
-	m.collectionID2InsertChannels = make(map[UniqueID]int)
-	m.insertChannels = make([][]string, 0)
-	m.insertMsgStreams = make([]msgstream.MsgStream, 0)
-	m.droppedBitMap = make([]int, 0)
-	m.usageHistogram = make([]int, 0)
-}
-
-func newInsertChannelsMap(node *Proxy) *insertChannelsMap {
-	return &insertChannelsMap{
-		collectionID2InsertChannels: make(map[UniqueID]int),
-		insertChannels:              make([][]string, 0),
-		insertMsgStreams:            make([]msgstream.MsgStream, 0),
-		droppedBitMap:               make([]int, 0),
-		usageHistogram:              make([]int, 0),
-		nodeInstance:                node,
-		msFactory:                   node.msFactory,
-	}
-}
-
-var globalInsertChannelsMap *insertChannelsMap
-var initGlobalInsertChannelsMapOnce sync.Once
-
-// change to singleton mode later? Such as GetInsertChannelsMapInstance like GetConfAdapterMgrInstance.
-func initGlobalInsertChannelsMap(node *Proxy) {
-	initGlobalInsertChannelsMapOnce.Do(func() {
-		globalInsertChannelsMap = newInsertChannelsMap(node)
-	})
-}
diff --git a/internal/proxy/insert_channels_test.go b/internal/proxy/insert_channels_test.go
deleted file mode 100644
index 62ad3157a496fc0249838fb192f4dac2a0422e0c..0000000000000000000000000000000000000000
--- a/internal/proxy/insert_channels_test.go
+++ /dev/null
@@ -1,239 +0,0 @@
-// Copyright (C) 2019-2020 Zilliz. All rights reserved.
-//
-// 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 proxy
-
-import (
-	"testing"
-
-	"github.com/milvus-io/milvus/internal/util/funcutil"
-
-	"github.com/stretchr/testify/assert"
-
-	"github.com/milvus-io/milvus/internal/msgstream"
-)
-
-func TestInsertChannelsMap_CreateInsertMsgStream(t *testing.T) {
-	msFactory := msgstream.NewSimpleMsgStreamFactory()
-	node := &Proxy{
-		segAssigner: nil,
-		msFactory:   msFactory,
-	}
-	m := newInsertChannelsMap(node)
-
-	var err error
-
-	err = m.CreateInsertMsgStream(1, []string{"1"})
-	assert.Equal(t, nil, err)
-
-	// duplicated
-	err = m.CreateInsertMsgStream(1, []string{"1"})
-	assert.NotEqual(t, nil, err)
-
-	// duplicated
-	err = m.CreateInsertMsgStream(1, []string{"1", "2"})
-	assert.NotEqual(t, nil, err)
-
-	// use same channels
-	err = m.CreateInsertMsgStream(2, []string{"1"})
-	assert.Equal(t, nil, err)
-
-	err = m.CreateInsertMsgStream(3, []string{"3"})
-	assert.Equal(t, nil, err)
-}
-
-func TestInsertChannelsMap_CloseInsertMsgStream(t *testing.T) {
-	msFactory := msgstream.NewSimpleMsgStreamFactory()
-	node := &Proxy{
-		segAssigner: nil,
-		msFactory:   msFactory,
-	}
-	m := newInsertChannelsMap(node)
-
-	var err error
-
-	_ = m.CreateInsertMsgStream(1, []string{"1"})
-	_ = m.CreateInsertMsgStream(2, []string{"1"})
-	_ = m.CreateInsertMsgStream(3, []string{"3"})
-
-	// don't exist
-	err = m.CloseInsertMsgStream(0)
-	assert.NotEqual(t, nil, err)
-
-	err = m.CloseInsertMsgStream(1)
-	assert.Equal(t, nil, err)
-
-	// close twice
-	err = m.CloseInsertMsgStream(1)
-	assert.NotEqual(t, nil, err)
-
-	err = m.CloseInsertMsgStream(2)
-	assert.Equal(t, nil, err)
-
-	// close twice
-	err = m.CloseInsertMsgStream(2)
-	assert.NotEqual(t, nil, err)
-
-	err = m.CloseInsertMsgStream(3)
-	assert.Equal(t, nil, err)
-
-	// close twice
-	err = m.CloseInsertMsgStream(3)
-	assert.NotEqual(t, nil, err)
-}
-
-func TestInsertChannelsMap_GetInsertChannels(t *testing.T) {
-	msFactory := msgstream.NewSimpleMsgStreamFactory()
-	node := &Proxy{
-		segAssigner: nil,
-		msFactory:   msFactory,
-	}
-	m := newInsertChannelsMap(node)
-
-	var err error
-	var channels []string
-
-	_ = m.CreateInsertMsgStream(1, []string{"1"})
-	_ = m.CreateInsertMsgStream(2, []string{"1"})
-	_ = m.CreateInsertMsgStream(3, []string{"3"})
-
-	// don't exist
-	channels, err = m.GetInsertChannels(0)
-	assert.NotEqual(t, nil, err)
-	assert.Equal(t, 0, len(channels))
-
-	channels, err = m.GetInsertChannels(1)
-	assert.Equal(t, nil, err)
-	assert.Equal(t, true, funcutil.SortedSliceEqual(channels, []string{"1"}))
-
-	channels, err = m.GetInsertChannels(2)
-	assert.Equal(t, nil, err)
-	assert.Equal(t, true, funcutil.SortedSliceEqual(channels, []string{"1"}))
-
-	channels, err = m.GetInsertChannels(3)
-	assert.Equal(t, nil, err)
-	assert.Equal(t, true, funcutil.SortedSliceEqual(channels, []string{"3"}))
-
-	_ = m.CloseInsertMsgStream(1)
-	channels, err = m.GetInsertChannels(1)
-	assert.NotEqual(t, nil, err)
-	assert.Equal(t, 0, len(channels))
-
-	_ = m.CloseInsertMsgStream(2)
-	channels, err = m.GetInsertChannels(2)
-	assert.NotEqual(t, nil, err)
-	assert.Equal(t, 0, len(channels))
-
-	_ = m.CloseInsertMsgStream(3)
-	channels, err = m.GetInsertChannels(3)
-	assert.NotEqual(t, nil, err)
-	assert.Equal(t, 0, len(channels))
-}
-
-func TestInsertChannelsMap_GetInsertMsgStream(t *testing.T) {
-	msFactory := msgstream.NewSimpleMsgStreamFactory()
-	node := &Proxy{
-		segAssigner: nil,
-		msFactory:   msFactory,
-	}
-	m := newInsertChannelsMap(node)
-
-	var err error
-	var stream msgstream.MsgStream
-
-	_ = m.CreateInsertMsgStream(1, []string{"1"})
-	_ = m.CreateInsertMsgStream(2, []string{"1"})
-	_ = m.CreateInsertMsgStream(3, []string{"3"})
-
-	// don't exist
-	stream, err = m.GetInsertMsgStream(0)
-	assert.NotEqual(t, nil, err)
-	assert.Equal(t, nil, stream)
-
-	stream, err = m.GetInsertMsgStream(1)
-	assert.Equal(t, nil, err)
-	assert.NotEqual(t, nil, stream)
-
-	stream, err = m.GetInsertMsgStream(2)
-	assert.Equal(t, nil, err)
-	assert.NotEqual(t, nil, stream)
-
-	stream, err = m.GetInsertMsgStream(3)
-	assert.Equal(t, nil, err)
-	assert.NotEqual(t, nil, stream)
-
-	_ = m.CloseInsertMsgStream(1)
-	stream, err = m.GetInsertMsgStream(1)
-	assert.NotEqual(t, nil, err)
-	assert.Equal(t, nil, stream)
-
-	_ = m.CloseInsertMsgStream(2)
-	stream, err = m.GetInsertMsgStream(2)
-	assert.NotEqual(t, nil, err)
-	assert.Equal(t, nil, stream)
-
-	_ = m.CloseInsertMsgStream(3)
-	stream, err = m.GetInsertMsgStream(3)
-	assert.NotEqual(t, nil, err)
-	assert.Equal(t, nil, stream)
-}
-
-func TestInsertChannelsMap_CloseAllMsgStream(t *testing.T) {
-	msFactory := msgstream.NewSimpleMsgStreamFactory()
-	node := &Proxy{
-		segAssigner: nil,
-		msFactory:   msFactory,
-	}
-	m := newInsertChannelsMap(node)
-
-	var err error
-	var stream msgstream.MsgStream
-	var channels []string
-
-	_ = m.CreateInsertMsgStream(1, []string{"1"})
-	_ = m.CreateInsertMsgStream(2, []string{"1"})
-	_ = m.CreateInsertMsgStream(3, []string{"3"})
-
-	m.CloseAllMsgStream()
-
-	err = m.CloseInsertMsgStream(1)
-	assert.NotEqual(t, nil, err)
-
-	err = m.CloseInsertMsgStream(2)
-	assert.NotEqual(t, nil, err)
-
-	err = m.CloseInsertMsgStream(3)
-	assert.NotEqual(t, nil, err)
-
-	channels, err = m.GetInsertChannels(1)
-	assert.NotEqual(t, nil, err)
-	assert.Equal(t, 0, len(channels))
-
-	channels, err = m.GetInsertChannels(2)
-	assert.NotEqual(t, nil, err)
-	assert.Equal(t, 0, len(channels))
-
-	channels, err = m.GetInsertChannels(3)
-	assert.NotEqual(t, nil, err)
-	assert.Equal(t, 0, len(channels))
-
-	stream, err = m.GetInsertMsgStream(1)
-	assert.NotEqual(t, nil, err)
-	assert.Equal(t, nil, stream)
-
-	stream, err = m.GetInsertMsgStream(2)
-	assert.NotEqual(t, nil, err)
-	assert.Equal(t, nil, stream)
-
-	stream, err = m.GetInsertMsgStream(3)
-	assert.NotEqual(t, nil, err)
-	assert.Equal(t, nil, stream)
-}
diff --git a/internal/proxy/paramtable.go b/internal/proxy/paramtable.go
index 8800f994755b749f8101349460c035c5163e8e6a..185f30359929a870d3ec6b46fc2990eb503dbdfc 100644
--- a/internal/proxy/paramtable.go
+++ b/internal/proxy/paramtable.go
@@ -31,16 +31,21 @@ const (
 type ParamTable struct {
 	paramtable.BaseTable
 
-	NetworkPort    int
-	IP             string
+	// NetworkPort & IP are not used
+	NetworkPort int
+	IP          string
+
 	NetworkAddress string
-	Alias          string
+
+	// TODO(dragondriver): maybe using the Proxy + ProxyID as the alias is more reasonable
+	Alias string
 
 	EtcdEndpoints    []string
 	MetaRootPath     string
 	RootCoordAddress string
 	PulsarAddress    string
-	RocksmqPath      string
+
+	RocksmqPath string // not used in Proxy
 
 	ProxyID                    UniqueID
 	TimeTickInterval           time.Duration
diff --git a/internal/proxy/paramtable_test.go b/internal/proxy/paramtable_test.go
new file mode 100644
index 0000000000000000000000000000000000000000..a244ec9b8cb2aaef6ba6ee10f60a3831e94deb82
--- /dev/null
+++ b/internal/proxy/paramtable_test.go
@@ -0,0 +1,78 @@
+// Copyright (C) 2019-2020 Zilliz. All rights reserved.
+//
+// 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 proxy
+
+import "testing"
+
+func TestParamTable(t *testing.T) {
+	Params.Init()
+
+	t.Run("EtcdEndPoints", func(t *testing.T) {
+		t.Logf("EtcdEndPoints: %v", Params.EtcdEndpoints)
+	})
+
+	t.Run("MetaRootPath", func(t *testing.T) {
+		t.Logf("MetaRootPath: %s", Params.MetaRootPath)
+	})
+
+	t.Run("PulsarAddress", func(t *testing.T) {
+		t.Logf("PulsarAddress: %s", Params.PulsarAddress)
+	})
+
+	t.Run("RocksmqPath", func(t *testing.T) {
+		t.Logf("RocksmqPath: %s", Params.RocksmqPath)
+	})
+
+	t.Run("TimeTickInterval", func(t *testing.T) {
+		t.Logf("TimeTickInterval: %v", Params.TimeTickInterval)
+	})
+
+	t.Run("ProxySubName", func(t *testing.T) {
+		t.Logf("ProxySubName: %s", Params.ProxySubName)
+	})
+
+	t.Run("ProxyTimeTickChannelNames", func(t *testing.T) {
+		t.Logf("ProxyTimeTickChannelNames: %v", Params.ProxyTimeTickChannelNames)
+	})
+
+	t.Run("MsgStreamTimeTickBufSize", func(t *testing.T) {
+		t.Logf("MsgStreamTimeTickBufSize: %d", Params.MsgStreamTimeTickBufSize)
+	})
+
+	t.Run("MaxNameLength", func(t *testing.T) {
+		t.Logf("MaxNameLength: %d", Params.MaxNameLength)
+	})
+
+	t.Run("MaxFieldNum", func(t *testing.T) {
+		t.Logf("MaxFieldNum: %d", Params.MaxFieldNum)
+	})
+
+	t.Run("MaxDimension", func(t *testing.T) {
+		t.Logf("MaxDimension: %d", Params.MaxDimension)
+	})
+
+	t.Run("DefaultPartitionName", func(t *testing.T) {
+		t.Logf("DefaultPartitionName: %s", Params.DefaultPartitionName)
+	})
+
+	t.Run("DefaultIndexName", func(t *testing.T) {
+		t.Logf("DefaultIndexName: %s", Params.DefaultIndexName)
+	})
+
+	t.Run("PulsarMaxMessageSize", func(t *testing.T) {
+		t.Logf("PulsarMaxMessageSize: %d", Params.PulsarMaxMessageSize)
+	})
+
+	t.Run("RoleName", func(t *testing.T) {
+		t.Logf("RoleName: %s", Params.RoleName)
+	})
+}
diff --git a/internal/proxy/proxy.go b/internal/proxy/proxy.go
index a6c32b86508f5d1ad72ba662a8492a2a36743c39..d952af7527cf66a80aad6c25d3b80ec4679010d1 100644
--- a/internal/proxy/proxy.go
+++ b/internal/proxy/proxy.go
@@ -250,7 +250,7 @@ func (node *Proxy) Init() error {
 		return m, nil
 	}
 
-	chMgr := newChannelsMgr(getDmlChannelsFunc, defaultInsertRepackFunc, getDqlChannelsFunc, nil, node.msFactory)
+	chMgr := newChannelsMgrImpl(getDmlChannelsFunc, defaultInsertRepackFunc, getDqlChannelsFunc, nil, node.msFactory)
 	node.chMgr = chMgr
 
 	node.sched, err = NewTaskScheduler(node.ctx, node.idAllocator, node.tsoAllocator, node.msFactory)
diff --git a/internal/proxy/repack_func.go b/internal/proxy/repack_func.go
index 07df195db08cda035132153693dc3f94ede88e0f..9ce74e12d09dcf86698ceb7b145d4c888dbc9cd8 100644
--- a/internal/proxy/repack_func.go
+++ b/internal/proxy/repack_func.go
@@ -12,11 +12,23 @@
 package proxy
 
 import (
+	"fmt"
+
 	"github.com/milvus-io/milvus/internal/msgstream"
 )
 
-func insertRepackFunc(tsMsgs []msgstream.TsMsg,
-	hashKeys [][]int32) (map[int32]*msgstream.MsgPack, error) {
+func insertRepackFunc(
+	tsMsgs []msgstream.TsMsg,
+	hashKeys [][]int32,
+) (map[int32]*msgstream.MsgPack, error) {
+
+	if len(hashKeys) < len(tsMsgs) {
+		return nil, fmt.Errorf(
+			"the length of hash keys (%d) is less than the length of messages (%d)",
+			len(hashKeys),
+			len(tsMsgs),
+		)
+	}
 
 	result := make(map[int32]*msgstream.MsgPack)
 	for i, request := range tsMsgs {
@@ -28,17 +40,32 @@ func insertRepackFunc(tsMsgs []msgstream.TsMsg,
 				result[key] = &msgstream.MsgPack{}
 			}
 			result[key].Msgs = append(result[key].Msgs, request)
+		} else {
+			return nil, fmt.Errorf("no hash key for %dth message", i)
 		}
 	}
+
 	return result, nil
 }
 
-func defaultInsertRepackFunc(tsMsgs []msgstream.TsMsg, hashKeys [][]int32) (map[int32]*msgstream.MsgPack, error) {
+func defaultInsertRepackFunc(
+	tsMsgs []msgstream.TsMsg,
+	hashKeys [][]int32,
+) (map[int32]*msgstream.MsgPack, error) {
+
+	if len(hashKeys) < len(tsMsgs) {
+		return nil, fmt.Errorf(
+			"the length of hash keys (%d) is less than the length of messages (%d)",
+			len(hashKeys),
+			len(tsMsgs),
+		)
+	}
+
 	// after assigning segment id to msg, tsMsgs was already re-bucketed
 	pack := make(map[int32]*msgstream.MsgPack)
 	for idx, msg := range tsMsgs {
 		if len(hashKeys[idx]) <= 0 {
-			continue
+			return nil, fmt.Errorf("no hash key for %dth message", idx)
 		}
 		key := hashKeys[idx][0]
 		_, ok := pack[key]
diff --git a/internal/proxy/repack_func_test.go b/internal/proxy/repack_func_test.go
new file mode 100644
index 0000000000000000000000000000000000000000..f95f8c4c50cf10f95618116e2db050768becf026
--- /dev/null
+++ b/internal/proxy/repack_func_test.go
@@ -0,0 +1,191 @@
+// Copyright (C) 2019-2020 Zilliz. All rights reserved.
+//
+// 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 proxy
+
+import (
+	"math/rand"
+	"testing"
+
+	"github.com/milvus-io/milvus/internal/msgstream"
+
+	"github.com/stretchr/testify/assert"
+)
+
+func Test_insertRepackFunc(t *testing.T) {
+	var err error
+
+	// tsMsgs is empty
+	ret1, err := insertRepackFunc(nil, [][]int32{{1, 2}})
+	assert.Nil(t, err)
+	assert.Equal(t, 0, len(ret1))
+
+	// hashKeys is empty
+	tsMsgs2 := []msgstream.TsMsg{
+		&msgstream.InsertMsg{}, // not important
+		&msgstream.InsertMsg{}, // not important
+	}
+	ret2, err := insertRepackFunc(tsMsgs2, nil)
+	assert.NotNil(t, err)
+	assert.Nil(t, ret2)
+
+	// len(hashKeys) < len(tsMsgs), 1 < 2
+	ret2, err = insertRepackFunc(tsMsgs2, [][]int32{{1, 2}})
+	assert.NotNil(t, err)
+	assert.Nil(t, ret2)
+
+	// both tsMsgs & hashKeys are empty
+	ret3, err := insertRepackFunc(nil, nil)
+	assert.Nil(t, err)
+	assert.Equal(t, 0, len(ret3))
+
+	num := rand.Int()%100 + 1
+	tsMsgs4 := make([]msgstream.TsMsg, 0)
+	for i := 0; i < num; i++ {
+		tsMsgs4 = append(tsMsgs4, &msgstream.InsertMsg{
+			// not important
+		})
+	}
+
+	// len(hashKeys) = len(tsMsgs), but no hash key
+	hashKeys1 := make([][]int32, num)
+	ret4, err := insertRepackFunc(tsMsgs4, hashKeys1)
+	assert.NotNil(t, err)
+	assert.Nil(t, ret4)
+
+	// all messages are shuffled to same bucket
+	hashKeys2 := make([][]int32, num)
+	key := int32(0)
+	for i := 0; i < num; i++ {
+		hashKeys2[i] = []int32{key}
+	}
+	ret5, err := insertRepackFunc(tsMsgs4, hashKeys2)
+	assert.Nil(t, err)
+	assert.Equal(t, 1, len(ret5))
+	assert.Equal(t, num, len(ret5[key].Msgs))
+
+	// evenly shuffle
+	hashKeys3 := make([][]int32, num)
+	for i := 0; i < num; i++ {
+		hashKeys3[i] = []int32{int32(i)}
+	}
+	ret6, err := insertRepackFunc(tsMsgs4, hashKeys3)
+	assert.Nil(t, err)
+	assert.Equal(t, num, len(ret6))
+	for key := range ret6 {
+		assert.Equal(t, 1, len(ret6[key].Msgs))
+	}
+
+	// randomly shuffle
+	histogram := make(map[int32]int) // key -> key num
+	hashKeys4 := make([][]int32, num)
+	for i := 0; i < num; i++ {
+		k := int32(rand.Uint32())
+		hashKeys4[i] = []int32{k}
+		_, exist := histogram[k]
+		if exist {
+			histogram[k]++
+		} else {
+			histogram[k] = 1
+		}
+	}
+	ret7, err := insertRepackFunc(tsMsgs4, hashKeys4)
+	assert.Nil(t, err)
+	assert.Equal(t, len(histogram), len(ret7))
+	for key := range ret7 {
+		assert.Equal(t, histogram[key], len(ret7[key].Msgs))
+	}
+}
+
+func Test_defaultInsertRepackFunc(t *testing.T) {
+	var err error
+
+	// tsMsgs is empty
+	ret1, err := defaultInsertRepackFunc(nil, [][]int32{{1, 2}})
+	assert.Nil(t, err)
+	assert.Equal(t, 0, len(ret1))
+
+	// hashKeys is empty
+	tsMsgs2 := []msgstream.TsMsg{
+		&msgstream.InsertMsg{}, // not important
+		&msgstream.InsertMsg{}, // not important
+	}
+	ret2, err := defaultInsertRepackFunc(tsMsgs2, nil)
+	assert.NotNil(t, err)
+	assert.Nil(t, ret2)
+
+	// len(hashKeys) < len(tsMsgs), 1 < 2
+	ret2, err = defaultInsertRepackFunc(tsMsgs2, [][]int32{{1, 2}})
+	assert.NotNil(t, err)
+	assert.Nil(t, ret2)
+
+	// both tsMsgs & hashKeys are empty
+	ret3, err := defaultInsertRepackFunc(nil, nil)
+	assert.Nil(t, err)
+	assert.Equal(t, 0, len(ret3))
+
+	num := rand.Int()%100 + 1
+	tsMsgs4 := make([]msgstream.TsMsg, 0)
+	for i := 0; i < num; i++ {
+		tsMsgs4 = append(tsMsgs4, &msgstream.InsertMsg{
+			// not important
+		})
+	}
+
+	// len(hashKeys) = len(tsMsgs), but no hash key
+	hashKeys1 := make([][]int32, num)
+	ret4, err := defaultInsertRepackFunc(tsMsgs4, hashKeys1)
+	assert.NotNil(t, err)
+	assert.Nil(t, ret4)
+
+	// all messages are shuffled to same bucket
+	hashKeys2 := make([][]int32, num)
+	key := int32(0)
+	for i := 0; i < num; i++ {
+		hashKeys2[i] = []int32{key}
+	}
+	ret5, err := defaultInsertRepackFunc(tsMsgs4, hashKeys2)
+	assert.Nil(t, err)
+	assert.Equal(t, 1, len(ret5))
+	assert.Equal(t, num, len(ret5[key].Msgs))
+
+	// evenly shuffle
+	hashKeys3 := make([][]int32, num)
+	for i := 0; i < num; i++ {
+		hashKeys3[i] = []int32{int32(i)}
+	}
+	ret6, err := defaultInsertRepackFunc(tsMsgs4, hashKeys3)
+	assert.Nil(t, err)
+	assert.Equal(t, num, len(ret6))
+	for key := range ret6 {
+		assert.Equal(t, 1, len(ret6[key].Msgs))
+	}
+
+	// randomly shuffle
+	histogram := make(map[int32]int) // key -> key num
+	hashKeys4 := make([][]int32, num)
+	for i := 0; i < num; i++ {
+		k := int32(rand.Uint32())
+		hashKeys4[i] = []int32{k}
+		_, exist := histogram[k]
+		if exist {
+			histogram[k]++
+		} else {
+			histogram[k] = 1
+		}
+	}
+	ret7, err := defaultInsertRepackFunc(tsMsgs4, hashKeys4)
+	assert.Nil(t, err)
+	assert.Equal(t, len(histogram), len(ret7))
+	for key := range ret7 {
+		assert.Equal(t, histogram[key], len(ret7[key].Msgs))
+	}
+}
diff --git a/internal/proxy/type_def.go b/internal/proxy/type_def.go
new file mode 100644
index 0000000000000000000000000000000000000000..efadda8e6d648b043e8a523755d091c471e5516a
--- /dev/null
+++ b/internal/proxy/type_def.go
@@ -0,0 +1,20 @@
+// Copyright (C) 2019-2020 Zilliz. All rights reserved.
+//
+// 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 proxy
+
+type vChan = string
+type pChan = string
+
+type pChanStatistics struct {
+	minTs Timestamp
+	maxTs Timestamp
+}