diff --git a/internal/proxynode/insert_channels.go b/internal/proxynode/insert_channels.go
index deda7ef03c..90451614bd 100644
--- a/internal/proxynode/insert_channels.go
+++ b/internal/proxynode/insert_channels.go
@@ -134,12 +134,10 @@ func (m *InsertChannelsMap) closeInsertMsgStream(collID UniqueID) error {
 	m.usageHistogram[loc]--
 	if m.usageHistogram[loc] <= 0 {
 		m.insertMsgStreams[loc].Close()
+		m.droppedBitMap[loc] = 1
+		delete(m.collectionID2InsertChannels, collID)
+		log.Print("close insert message stream ...")
 	}
-	log.Print("close insert message stream ...")
-
-	m.droppedBitMap[loc] = 1
-	delete(m.collectionID2InsertChannels, collID)
-
 	return nil
 }
 
diff --git a/tests/python/requirements.txt b/tests/python/requirements.txt
index fcf08cf5d0..a4136e23e7 100644
--- a/tests/python/requirements.txt
+++ b/tests/python/requirements.txt
@@ -2,7 +2,7 @@ grpcio==1.26.0
 grpcio-tools==1.26.0
 numpy==1.18.1
 pytest-cov==2.8.1
-pymilvus-distributed==0.0.19
+pymilvus-distributed==0.0.17
 sklearn==0.0
 pytest==4.5.0
 pytest-timeout==1.3.3