diff --git a/internal/msgstream/pulsarms/pulsar_msgstream.go b/internal/msgstream/pulsarms/pulsar_msgstream.go
index 34b7084aba..c93cbf479a 100644
--- a/internal/msgstream/pulsarms/pulsar_msgstream.go
+++ b/internal/msgstream/pulsarms/pulsar_msgstream.go
@@ -128,7 +128,7 @@ func (ms *PulsarMsgStream) AsConsumer(channels []string,
 				Topic:                       channels[i],
 				SubscriptionName:            subName,
 				Type:                        pulsar.KeyShared,
-				SubscriptionInitialPosition: pulsar.SubscriptionPositionEarliest,
+				SubscriptionInitialPosition: pulsar.SubscriptionPositionLatest,
 				MessageChannel:              receiveChannel,
 			})
 			if err != nil {
@@ -521,7 +521,7 @@ func (ms *PulsarTtMsgStream) AsConsumer(channels []string,
 				Topic:                       channels[i],
 				SubscriptionName:            subName,
 				Type:                        pulsar.KeyShared,
-				SubscriptionInitialPosition: pulsar.SubscriptionPositionEarliest,
+				SubscriptionInitialPosition: pulsar.SubscriptionPositionLatest,
 				MessageChannel:              receiveChannel,
 			})
 			if err != nil {
diff --git a/internal/util/flowgraph/node.go b/internal/util/flowgraph/node.go
index a3750461e5..c12da812fd 100644
--- a/internal/util/flowgraph/node.go
+++ b/internal/util/flowgraph/node.go
@@ -4,10 +4,8 @@ import (
 	"context"
 	"fmt"
 	"log"
-	"strconv"
 	"sync"
-
-	"github.com/zilliztech/milvus-distributed/internal/errors"
+	"time"
 )
 
 type Node interface {
@@ -115,14 +113,32 @@ func (nodeCtx *nodeCtx) collectInputMessages() {
 
 	// timeTick alignment check
 	if len(nodeCtx.inputMessages) > 1 {
-		time := (*nodeCtx.inputMessages[0]).TimeTick()
+		t := (*nodeCtx.inputMessages[0]).TimeTick()
+		latestTime := t
 		for i := 1; i < len(nodeCtx.inputMessages); i++ {
-			if time != (*nodeCtx.inputMessages[i]).TimeTick() {
-				err := errors.New("Fatal, misaligned time tick," +
-					"t1=" + strconv.FormatUint(time, 10) +
-					", t2=" + strconv.FormatUint((*nodeCtx.inputMessages[i]).TimeTick(), 10) +
-					", please restart pulsar")
-				panic(err)
+			if t < (*nodeCtx.inputMessages[i]).TimeTick() {
+				latestTime = (*nodeCtx.inputMessages[i]).TimeTick()
+				//err := errors.New("Fatal, misaligned time tick," +
+				//	"t1=" + strconv.FormatUint(time, 10) +
+				//	", t2=" + strconv.FormatUint((*nodeCtx.inputMessages[i]).TimeTick(), 10) +
+				//	", please restart pulsar")
+				//panic(err)
+			}
+		}
+		// wait for time tick
+		for i := 0; i < len(nodeCtx.inputMessages); i++ {
+			for (*nodeCtx.inputMessages[i]).TimeTick() != latestTime {
+				channel := nodeCtx.inputChannels[i]
+				select {
+				case <-time.After(10 * time.Second):
+					panic("cannot find time tick in flow graph")
+				case msg, ok := <-channel:
+					if !ok {
+						log.Println("input channel closed")
+						return
+					}
+					nodeCtx.inputMessages[i] = msg
+				}
 			}
 		}
 	}
diff --git a/tests/python/conftest.py b/tests/python/conftest.py
index 75328740dc..7f1fafb582 100644
--- a/tests/python/conftest.py
+++ b/tests/python/conftest.py
@@ -181,6 +181,22 @@ def collection(request, connect):
     assert connect.has_collection(collection_name)
     return collection_name
 
+@pytest.fixture(scope="function")
+def collection_without_loading(request, connect):
+    ori_collection_name = getattr(request.module, "collection_id", "test")
+    collection_name = gen_unique_str(ori_collection_name)
+    try:
+        default_fields = gen_default_fields()
+        connect.create_collection(collection_name, default_fields)
+    except Exception as e:
+        pytest.exit(str(e))
+    def teardown():
+        if connect.has_collection(collection_name):
+            connect.drop_collection(collection_name, timeout=delete_timeout)
+    request.addfinalizer(teardown)
+    assert connect.has_collection(collection_name)
+    return collection_name
+
 
 # customised id
 @pytest.fixture(scope="function")
diff --git a/tests/python/test_load_collection.py b/tests/python/test_load_collection.py
index 2d5e638595..97f07ba054 100644
--- a/tests/python/test_load_collection.py
+++ b/tests/python/test_load_collection.py
@@ -9,12 +9,13 @@ class TestLoadCollection:
       The following cases are used to test `load_collection` function
     ******************************************************************
     """
-    def test_load_collection(self, connect, collection):
+    def test_load_collection(self, connect, collection_without_loading):
         '''
         target: test load collection and wait for loading collection
         method: insert then flush, when flushed, try load collection
         expected: no errors
         '''
+        collection = collection_without_loading
         ids = connect.insert(collection, default_entities)
         ids = connect.insert(collection, default_entity)
         connect.flush([collection])