diff --git a/tests/system-test/7-tmq/tmqDropNtb-snapshot0.py b/tests/system-test/7-tmq/tmqDropNtb-snapshot0.py
new file mode 100644
index 0000000000000000000000000000000000000000..650d9188285580b649fca67cd1971ed9ae9c7041
--- /dev/null
+++ b/tests/system-test/7-tmq/tmqDropNtb-snapshot0.py
@@ -0,0 +1,225 @@
+
+import taos
+import sys
+import time
+import socket
+import os
+import threading
+from enum import Enum
+
+from util.log import *
+from util.sql import *
+from util.cases import *
+from util.dnodes import *
+sys.path.append("./7-tmq")
+from tmqCommon import *
+
+class TDTestCase:
+    def __init__(self):
+        self.snapshot   = 0
+        self.vgroups    = 4
+        self.ctbNum     = 1000
+        self.rowsPerTbl = 10
+        
+    def init(self, conn, logSql):
+        tdLog.debug(f"start to excute {__file__}")
+        tdSql.init(conn.cursor(), False)
+        
+    # drop some ntbs
+    def tmqCase1(self):
+        tdLog.printNoPrefix("======== test case 1: ")
+        paraDict = {'dbName':     'dbt',
+                    'dropFlag':   1,
+                    'event':      '',
+                    'vgroups':    4,
+                    'stbName':    'stb',
+                    'colPrefix':  'c',
+                    'tagPrefix':  't',
+                    'colSchema':   [{'type': 'INT', 'count':1},{'type': 'BIGINT', 'count':1},{'type': 'DOUBLE', 'count':1},{'type': 'TIMESTAMP', 'count':1}],
+                    'tagSchema':   [{'type': 'INT', 'count':1},{'type': 'BIGINT', 'count':1},{'type': 'DOUBLE', 'count':1},{'type': 'BINARY', 'len':32, 'count':1},{'type': 'NCHAR', 'len':32, 'count':1}],
+                    'ctbPrefix':  'ntb',
+                    'ctbStartIdx': 0,
+                    'ctbNum':     1000,
+                    'rowsPerTbl': 100,
+                    'batchNum':   100,
+                    'startTs':    1640966400000,  # 2022-01-01 00:00:00.000
+                    'endTs': 0,
+                    'pollDelay':  5,
+                    'showMsg':    1,
+                    'showRow':    1,
+                    'snapshot':   0}
+        paraDict['snapshot'] = self.snapshot
+        paraDict['vgroups'] = self.vgroups
+        paraDict['ctbNum'] = self.ctbNum
+        paraDict['rowsPerTbl'] = self.rowsPerTbl        
+        
+        tmqCom.initConsumerTable()
+        tdLog.info("start create database....")
+        tdCom.create_database(tdSql, paraDict["dbName"],paraDict["dropFlag"], vgroups=paraDict["vgroups"],replica=1)
+        tdLog.info("start create normal tables....")
+        tmqCom.create_ntable(tsql=tdSql, dbname=paraDict["dbName"], tbname_prefix=paraDict["ctbPrefix"], tbname_index_start_num = 1, column_elm_list=paraDict["colSchema"], colPrefix='c', tblNum=paraDict["ctbNum"])
+        tdLog.info("start insert data into normal tables....")
+        tmqCom.insert_rows_into_ntbl(tsql=tdSql, dbname=paraDict["dbName"], tbname_prefix=paraDict["ctbPrefix"], tbname_index_start_num = 1, column_ele_list=paraDict["colSchema"],startTs=paraDict["startTs"], tblNum=paraDict["ctbNum"], rows=paraDict["rowsPerTbl"])
+                
+        tdLog.info("create topics from database")
+        topicFromDb = 'topic_dbt'                
+        tdSql.execute("create topic %s as database %s" %(topicFromDb, paraDict['dbName']))
+        
+        if self.snapshot == 0:
+            consumerId     = 0
+        elif self.snapshot == 1:
+            consumerId     = 1
+
+        expectrowcnt   = int(paraDict["rowsPerTbl"] * paraDict["ctbNum"])
+        topicList      = topicFromDb
+        ifcheckdata    = 1
+        ifManualCommit = 1
+        keyList        = 'group.id:cgrp1,\
+                        enable.auto.commit:true,\
+                        auto.commit.interval.ms:1000,\
+                        auto.offset.reset:earliest'
+        tmqCom.insertConsumerInfo(consumerId, expectrowcnt,topicList,keyList,ifcheckdata,ifManualCommit)
+
+        tdLog.info("start consume processor")
+        tmqCom.startTmqSimProcess(pollDelay=paraDict['pollDelay'],dbName=paraDict["dbName"],showMsg=paraDict['showMsg'], showRow=paraDict['showRow'],snapshot=paraDict['snapshot'])
+
+        tmqCom.getStartConsumeNotifyFromTmqsim()  
+        tdLog.info("drop some ntables")
+        # drop 1/4 ctbls from half offset
+        paraDict["ctbStartIdx"] = paraDict["ctbStartIdx"] + int(paraDict["ctbNum"] * 1 / 2)
+        paraDict["ctbNum"] = int(paraDict["ctbNum"] / 4)
+        tmqCom.drop_ctable(tdSql, dbname=paraDict['dbName'], count=paraDict["ctbNum"], default_ctbname_prefix=paraDict["ctbPrefix"], ctbStartIdx=paraDict["ctbStartIdx"])
+        
+        tdLog.info("start to check consume result")
+        expectRows = 1
+        resultList = tmqCom.selectConsumeResult(expectRows)
+        totalConsumeRows = 0
+        for i in range(expectRows):
+            totalConsumeRows += resultList[i]
+
+        tdLog.info("act consume rows: %d, expect consume rows: %d"%(totalConsumeRows, expectrowcnt))
+        
+        if not ((totalConsumeRows >= expectrowcnt * 3/4) and (totalConsumeRows < expectrowcnt)):
+            tdLog.exit("tmq consume rows error with snapshot = 0!")
+        
+        tdLog.info("wait subscriptions exit ....")      
+        tmqCom.waitSubscriptionExit(tdSql, topicFromDb)
+            
+        tdSql.query("drop topic %s"%topicFromDb)
+        tdLog.info("success dorp topic: %s"%topicFromDb)
+        tdLog.printNoPrefix("======== test case 1 end ...... ")
+    
+
+    
+    # drop some ntbs and create some new ntbs
+    def tmqCase2(self):
+        tdLog.printNoPrefix("======== test case 2: ")
+        paraDict = {'dbName':     'dbt',
+                    'dropFlag':   1,
+                    'event':      '',
+                    'vgroups':    4,
+                    'stbName':    'stb',
+                    'colPrefix':  'c',
+                    'tagPrefix':  't',
+                    'colSchema':   [{'type': 'INT', 'count':1},{'type': 'BIGINT', 'count':1},{'type': 'DOUBLE', 'count':1},{'type': 'TIMESTAMP', 'count':1}],
+                    'tagSchema':   [{'type': 'INT', 'count':1},{'type': 'BIGINT', 'count':1},{'type': 'DOUBLE', 'count':1},{'type': 'BINARY', 'len':32, 'count':1},{'type': 'NCHAR', 'len':32, 'count':1}],
+                    'ctbPrefix':  'ntb',
+                    'ctbStartIdx': 0,
+                    'ctbNum':     1000,
+                    'rowsPerTbl': 100,
+                    'batchNum':   100,
+                    'startTs':    1640966400000,  # 2022-01-01 00:00:00.000
+                    'endTs': 0,
+                    'pollDelay':  10,
+                    'showMsg':    1,
+                    'showRow':    1,
+                    'snapshot':   0}
+        paraDict['snapshot'] = self.snapshot
+        paraDict['vgroups'] = self.vgroups
+        paraDict['ctbNum'] = self.ctbNum
+        paraDict['rowsPerTbl'] = self.rowsPerTbl        
+        
+        tmqCom.initConsumerTable()
+        tdLog.info("start create database....")
+        tdCom.create_database(tdSql, paraDict["dbName"],paraDict["dropFlag"], vgroups=paraDict["vgroups"],replica=1)
+        tdLog.info("start create normal tables....")
+        tmqCom.create_ntable(tsql=tdSql, dbname=paraDict["dbName"], tbname_prefix=paraDict["ctbPrefix"], tbname_index_start_num = 1, column_elm_list=paraDict["colSchema"], colPrefix='c', tblNum=paraDict["ctbNum"])
+        tdLog.info("start insert data into normal tables....")
+        tmqCom.insert_rows_into_ntbl(tsql=tdSql, dbname=paraDict["dbName"], tbname_prefix=paraDict["ctbPrefix"], tbname_index_start_num = 1, column_ele_list=paraDict["colSchema"],startTs=paraDict["startTs"], tblNum=paraDict["ctbNum"], rows=paraDict["rowsPerTbl"])
+                
+        tdLog.info("create topics from database")
+        topicFromDb = 'topic_dbt'                
+        tdSql.execute("create topic %s as database %s" %(topicFromDb, paraDict['dbName']))
+        
+        if self.snapshot == 0:
+            consumerId     = 2
+        elif self.snapshot == 1:
+            consumerId     = 3
+
+        expectrowcnt   = int(paraDict["rowsPerTbl"] * paraDict["ctbNum"] * 2)
+        topicList      = topicFromDb
+        ifcheckdata    = 1
+        ifManualCommit = 1
+        keyList        = 'group.id:cgrp1,\
+                        enable.auto.commit:true,\
+                        auto.commit.interval.ms:1000,\
+                        auto.offset.reset:earliest'
+        tmqCom.insertConsumerInfo(consumerId, expectrowcnt,topicList,keyList,ifcheckdata,ifManualCommit)
+
+        tdLog.info("start consume processor")
+        tmqCom.startTmqSimProcess(pollDelay=paraDict['pollDelay'],dbName=paraDict["dbName"],showMsg=paraDict['showMsg'], showRow=paraDict['showRow'],snapshot=paraDict['snapshot'])
+
+        tmqCom.getStartConsumeNotifyFromTmqsim()  
+        tdLog.info("drop some ntables")
+        # drop 1/4 ctbls from half offset
+        paraDict["ctbStartIdx"] = paraDict["ctbStartIdx"] + int(paraDict["ctbNum"] * 1 / 2)
+        paraDict["ctbNum"] = int(paraDict["ctbNum"] / 4)
+        tmqCom.drop_ctable(tdSql, dbname=paraDict['dbName'], count=paraDict["ctbNum"], default_ctbname_prefix=paraDict["ctbPrefix"], ctbStartIdx=paraDict["ctbStartIdx"])
+                
+        tdLog.info("start create some new normal tables....")
+        paraDict["ctbPrefix"] = 'newCtb'
+        paraDict["ctbNum"] = self.ctbNum
+        tmqCom.create_ntable(tsql=tdSql, dbname=paraDict["dbName"], tbname_prefix=paraDict["ctbPrefix"], tbname_index_start_num = 1, column_elm_list=paraDict["colSchema"], colPrefix='c', tblNum=paraDict["ctbNum"])
+        tdLog.info("start insert data into these new normal tables....")
+        tmqCom.insert_rows_into_ntbl(tsql=tdSql, dbname=paraDict["dbName"], tbname_prefix=paraDict["ctbPrefix"], tbname_index_start_num = 1, column_ele_list=paraDict["colSchema"],startTs=paraDict["startTs"], tblNum=paraDict["ctbNum"], rows=paraDict["rowsPerTbl"])
+        
+        tdLog.info("start to check consume result")
+        expectRows = 1
+        resultList = tmqCom.selectConsumeResult(expectRows)
+        totalConsumeRows = 0
+        for i in range(expectRows):
+            totalConsumeRows += resultList[i]
+
+        tdLog.info("act consume rows: %d, expect consume rows: %d"%(totalConsumeRows, expectrowcnt))
+        
+        if not ((totalConsumeRows >= expectrowcnt / 2 * (1 + 3/4)) and (totalConsumeRows < expectrowcnt)):
+            tdLog.exit("tmq consume rows error with snapshot = 0!")
+        
+        tdLog.info("wait subscriptions exit ....")      
+        tmqCom.waitSubscriptionExit(tdSql, topicFromDb)
+            
+        tdSql.query("drop topic %s"%topicFromDb)
+        tdLog.info("success dorp topic: %s"%topicFromDb)
+        tdLog.printNoPrefix("======== test case 2 end ...... ")
+        
+    def run(self):        
+        tdLog.printNoPrefix("=============================================")
+        tdLog.printNoPrefix("======== snapshot is 0: only consume from wal")
+        self.snapshot = 0
+        self.tmqCase1()
+        self.tmqCase2()               
+        
+        # tdLog.printNoPrefix("====================================================================")
+        # tdLog.printNoPrefix("======== snapshot is 1: firstly consume from tsbs, and then from wal")
+        # self.snapshot = 1
+        # self.tmqCase1()
+        # self.tmqCase2()
+
+    def stop(self):
+        tdSql.close()
+        tdLog.success(f"{__file__} successfully executed")
+
+event = threading.Event()
+
+tdCases.addLinux(__file__, TDTestCase())
+tdCases.addWindows(__file__, TDTestCase())
diff --git a/tests/system-test/7-tmq/tmqDropNtb-snapshot1.py b/tests/system-test/7-tmq/tmqDropNtb-snapshot1.py
new file mode 100644
index 0000000000000000000000000000000000000000..b23f42258584164b1868eaca4f884cf478bd40b0
--- /dev/null
+++ b/tests/system-test/7-tmq/tmqDropNtb-snapshot1.py
@@ -0,0 +1,225 @@
+
+import taos
+import sys
+import time
+import socket
+import os
+import threading
+from enum import Enum
+
+from util.log import *
+from util.sql import *
+from util.cases import *
+from util.dnodes import *
+sys.path.append("./7-tmq")
+from tmqCommon import *
+
+class TDTestCase:
+    def __init__(self):
+        self.snapshot   = 0
+        self.vgroups    = 4
+        self.ctbNum     = 1000
+        self.rowsPerTbl = 10
+        
+    def init(self, conn, logSql):
+        tdLog.debug(f"start to excute {__file__}")
+        tdSql.init(conn.cursor(), False)
+        
+    # drop some ntbs
+    def tmqCase1(self):
+        tdLog.printNoPrefix("======== test case 1: ")
+        paraDict = {'dbName':     'dbt',
+                    'dropFlag':   1,
+                    'event':      '',
+                    'vgroups':    4,
+                    'stbName':    'stb',
+                    'colPrefix':  'c',
+                    'tagPrefix':  't',
+                    'colSchema':   [{'type': 'INT', 'count':1},{'type': 'BIGINT', 'count':1},{'type': 'DOUBLE', 'count':1},{'type': 'TIMESTAMP', 'count':1}],
+                    'tagSchema':   [{'type': 'INT', 'count':1},{'type': 'BIGINT', 'count':1},{'type': 'DOUBLE', 'count':1},{'type': 'BINARY', 'len':32, 'count':1},{'type': 'NCHAR', 'len':32, 'count':1}],
+                    'ctbPrefix':  'ntb',
+                    'ctbStartIdx': 0,
+                    'ctbNum':     1000,
+                    'rowsPerTbl': 100,
+                    'batchNum':   100,
+                    'startTs':    1640966400000,  # 2022-01-01 00:00:00.000
+                    'endTs': 0,
+                    'pollDelay':  5,
+                    'showMsg':    1,
+                    'showRow':    1,
+                    'snapshot':   0}
+        paraDict['snapshot'] = self.snapshot
+        paraDict['vgroups'] = self.vgroups
+        paraDict['ctbNum'] = self.ctbNum
+        paraDict['rowsPerTbl'] = self.rowsPerTbl        
+        
+        tmqCom.initConsumerTable()
+        tdLog.info("start create database....")
+        tdCom.create_database(tdSql, paraDict["dbName"],paraDict["dropFlag"], vgroups=paraDict["vgroups"],replica=1)
+        tdLog.info("start create normal tables....")
+        tmqCom.create_ntable(tsql=tdSql, dbname=paraDict["dbName"], tbname_prefix=paraDict["ctbPrefix"], tbname_index_start_num = 1, column_elm_list=paraDict["colSchema"], colPrefix='c', tblNum=paraDict["ctbNum"])
+        tdLog.info("start insert data into normal tables....")
+        tmqCom.insert_rows_into_ntbl(tsql=tdSql, dbname=paraDict["dbName"], tbname_prefix=paraDict["ctbPrefix"], tbname_index_start_num = 1, column_ele_list=paraDict["colSchema"],startTs=paraDict["startTs"], tblNum=paraDict["ctbNum"], rows=paraDict["rowsPerTbl"])
+                
+        tdLog.info("create topics from database")
+        topicFromDb = 'topic_dbt'                
+        tdSql.execute("create topic %s as database %s" %(topicFromDb, paraDict['dbName']))
+        
+        if self.snapshot == 0:
+            consumerId     = 0
+        elif self.snapshot == 1:
+            consumerId     = 1
+
+        expectrowcnt   = int(paraDict["rowsPerTbl"] * paraDict["ctbNum"])
+        topicList      = topicFromDb
+        ifcheckdata    = 1
+        ifManualCommit = 1
+        keyList        = 'group.id:cgrp1,\
+                        enable.auto.commit:true,\
+                        auto.commit.interval.ms:1000,\
+                        auto.offset.reset:earliest'
+        tmqCom.insertConsumerInfo(consumerId, expectrowcnt,topicList,keyList,ifcheckdata,ifManualCommit)
+
+        tdLog.info("start consume processor")
+        tmqCom.startTmqSimProcess(pollDelay=paraDict['pollDelay'],dbName=paraDict["dbName"],showMsg=paraDict['showMsg'], showRow=paraDict['showRow'],snapshot=paraDict['snapshot'])
+
+        tmqCom.getStartConsumeNotifyFromTmqsim()  
+        tdLog.info("drop some ntables")
+        # drop 1/4 ctbls from half offset
+        paraDict["ctbStartIdx"] = paraDict["ctbStartIdx"] + int(paraDict["ctbNum"] * 1 / 2)
+        paraDict["ctbNum"] = int(paraDict["ctbNum"] / 4)
+        tmqCom.drop_ctable(tdSql, dbname=paraDict['dbName'], count=paraDict["ctbNum"], default_ctbname_prefix=paraDict["ctbPrefix"], ctbStartIdx=paraDict["ctbStartIdx"])
+        
+        tdLog.info("start to check consume result")
+        expectRows = 1
+        resultList = tmqCom.selectConsumeResult(expectRows)
+        totalConsumeRows = 0
+        for i in range(expectRows):
+            totalConsumeRows += resultList[i]
+
+        tdLog.info("act consume rows: %d, expect consume rows: %d"%(totalConsumeRows, expectrowcnt))
+        
+        if not ((totalConsumeRows >= expectrowcnt * 3/4) and (totalConsumeRows < expectrowcnt)):
+            tdLog.exit("tmq consume rows error with snapshot = 0!")
+        
+        tdLog.info("wait subscriptions exit ....")      
+        tmqCom.waitSubscriptionExit(tdSql, topicFromDb)
+            
+        tdSql.query("drop topic %s"%topicFromDb)
+        tdLog.info("success dorp topic: %s"%topicFromDb)
+        tdLog.printNoPrefix("======== test case 1 end ...... ")
+    
+
+    
+    # drop some ntbs and create some new ntbs
+    def tmqCase2(self):
+        tdLog.printNoPrefix("======== test case 2: ")
+        paraDict = {'dbName':     'dbt',
+                    'dropFlag':   1,
+                    'event':      '',
+                    'vgroups':    4,
+                    'stbName':    'stb',
+                    'colPrefix':  'c',
+                    'tagPrefix':  't',
+                    'colSchema':   [{'type': 'INT', 'count':1},{'type': 'BIGINT', 'count':1},{'type': 'DOUBLE', 'count':1},{'type': 'TIMESTAMP', 'count':1}],
+                    'tagSchema':   [{'type': 'INT', 'count':1},{'type': 'BIGINT', 'count':1},{'type': 'DOUBLE', 'count':1},{'type': 'BINARY', 'len':32, 'count':1},{'type': 'NCHAR', 'len':32, 'count':1}],
+                    'ctbPrefix':  'ntb',
+                    'ctbStartIdx': 0,
+                    'ctbNum':     1000,
+                    'rowsPerTbl': 100,
+                    'batchNum':   100,
+                    'startTs':    1640966400000,  # 2022-01-01 00:00:00.000
+                    'endTs': 0,
+                    'pollDelay':  10,
+                    'showMsg':    1,
+                    'showRow':    1,
+                    'snapshot':   0}
+        paraDict['snapshot'] = self.snapshot
+        paraDict['vgroups'] = self.vgroups
+        paraDict['ctbNum'] = self.ctbNum
+        paraDict['rowsPerTbl'] = self.rowsPerTbl        
+        
+        tmqCom.initConsumerTable()
+        tdLog.info("start create database....")
+        tdCom.create_database(tdSql, paraDict["dbName"],paraDict["dropFlag"], vgroups=paraDict["vgroups"],replica=1)
+        tdLog.info("start create normal tables....")
+        tmqCom.create_ntable(tsql=tdSql, dbname=paraDict["dbName"], tbname_prefix=paraDict["ctbPrefix"], tbname_index_start_num = 1, column_elm_list=paraDict["colSchema"], colPrefix='c', tblNum=paraDict["ctbNum"])
+        tdLog.info("start insert data into normal tables....")
+        tmqCom.insert_rows_into_ntbl(tsql=tdSql, dbname=paraDict["dbName"], tbname_prefix=paraDict["ctbPrefix"], tbname_index_start_num = 1, column_ele_list=paraDict["colSchema"],startTs=paraDict["startTs"], tblNum=paraDict["ctbNum"], rows=paraDict["rowsPerTbl"])
+                
+        tdLog.info("create topics from database")
+        topicFromDb = 'topic_dbt'                
+        tdSql.execute("create topic %s as database %s" %(topicFromDb, paraDict['dbName']))
+        
+        if self.snapshot == 0:
+            consumerId     = 2
+        elif self.snapshot == 1:
+            consumerId     = 3
+
+        expectrowcnt   = int(paraDict["rowsPerTbl"] * paraDict["ctbNum"] * 2)
+        topicList      = topicFromDb
+        ifcheckdata    = 1
+        ifManualCommit = 1
+        keyList        = 'group.id:cgrp1,\
+                        enable.auto.commit:true,\
+                        auto.commit.interval.ms:1000,\
+                        auto.offset.reset:earliest'
+        tmqCom.insertConsumerInfo(consumerId, expectrowcnt,topicList,keyList,ifcheckdata,ifManualCommit)
+
+        tdLog.info("start consume processor")
+        tmqCom.startTmqSimProcess(pollDelay=paraDict['pollDelay'],dbName=paraDict["dbName"],showMsg=paraDict['showMsg'], showRow=paraDict['showRow'],snapshot=paraDict['snapshot'])
+
+        tmqCom.getStartConsumeNotifyFromTmqsim()  
+        tdLog.info("drop some ntables")
+        # drop 1/4 ctbls from half offset
+        paraDict["ctbStartIdx"] = paraDict["ctbStartIdx"] + int(paraDict["ctbNum"] * 1 / 2)
+        paraDict["ctbNum"] = int(paraDict["ctbNum"] / 4)
+        tmqCom.drop_ctable(tdSql, dbname=paraDict['dbName'], count=paraDict["ctbNum"], default_ctbname_prefix=paraDict["ctbPrefix"], ctbStartIdx=paraDict["ctbStartIdx"])
+                
+        tdLog.info("start create some new normal tables....")
+        paraDict["ctbPrefix"] = 'newCtb'
+        paraDict["ctbNum"] = self.ctbNum
+        tmqCom.create_ntable(tsql=tdSql, dbname=paraDict["dbName"], tbname_prefix=paraDict["ctbPrefix"], tbname_index_start_num = 1, column_elm_list=paraDict["colSchema"], colPrefix='c', tblNum=paraDict["ctbNum"])
+        tdLog.info("start insert data into these new normal tables....")
+        tmqCom.insert_rows_into_ntbl(tsql=tdSql, dbname=paraDict["dbName"], tbname_prefix=paraDict["ctbPrefix"], tbname_index_start_num = 1, column_ele_list=paraDict["colSchema"],startTs=paraDict["startTs"], tblNum=paraDict["ctbNum"], rows=paraDict["rowsPerTbl"])
+        
+        tdLog.info("start to check consume result")
+        expectRows = 1
+        resultList = tmqCom.selectConsumeResult(expectRows)
+        totalConsumeRows = 0
+        for i in range(expectRows):
+            totalConsumeRows += resultList[i]
+
+        tdLog.info("act consume rows: %d, expect consume rows: %d"%(totalConsumeRows, expectrowcnt))
+        
+        if not ((totalConsumeRows >= expectrowcnt / 2 * (1 + 3/4)) and (totalConsumeRows < expectrowcnt)):
+            tdLog.exit("tmq consume rows error with snapshot = 0!")
+        
+        tdLog.info("wait subscriptions exit ....")      
+        tmqCom.waitSubscriptionExit(tdSql, topicFromDb)
+            
+        tdSql.query("drop topic %s"%topicFromDb)
+        tdLog.info("success dorp topic: %s"%topicFromDb)
+        tdLog.printNoPrefix("======== test case 2 end ...... ")
+        
+    def run(self):        
+        # tdLog.printNoPrefix("=============================================")
+        # tdLog.printNoPrefix("======== snapshot is 0: only consume from wal")
+        # self.snapshot = 0
+        # self.tmqCase1()
+        # self.tmqCase2()               
+        
+        tdLog.printNoPrefix("====================================================================")
+        tdLog.printNoPrefix("======== snapshot is 1: firstly consume from tsbs, and then from wal")
+        self.snapshot = 1
+        self.tmqCase1()
+        self.tmqCase2()
+
+    def stop(self):
+        tdSql.close()
+        tdLog.success(f"{__file__} successfully executed")
+
+event = threading.Event()
+
+tdCases.addLinux(__file__, TDTestCase())
+tdCases.addWindows(__file__, TDTestCase())
diff --git a/tests/system-test/fulltest.sh b/tests/system-test/fulltest.sh
index ba104ddf22d5779372ef59d54ddca369083765b9..f074bd885045553cbe94029bd128dbc2235aea7a 100755
--- a/tests/system-test/fulltest.sh
+++ b/tests/system-test/fulltest.sh
@@ -219,7 +219,8 @@ python3 ./test.py -f 7-tmq/tmqDelete-1ctb.py
 python3 ./test.py -f 7-tmq/tmqDelete-multiCtb.py
 python3 ./test.py -f 7-tmq/tmqDropStb.py
 python3 ./test.py -f 7-tmq/tmqDropStbCtb.py
-python3 ./test.py -f 7-tmq/tmqDropNtb.py
+python3 ./test.py -f 7-tmq/tmqDropNtb-snapshot0.py
+python3 ./test.py -f 7-tmq/tmqDropNtb-snapshot1.py
 python3 ./test.py -f 7-tmq/tmqUdf.py
 python3 ./test.py -f 7-tmq/tmqUdf-multCtb-snapshot0.py
 python3 ./test.py -f 7-tmq/tmqUdf-multCtb-snapshot1.py