diff --git a/tests/auto_crash_gen_script/auto_crash_gen_script.py b/tests/auto_crash_gen_script/auto_crash_gen_script.py
new file mode 100644
index 0000000000000000000000000000000000000000..547526c8ccaa710f88d4ad2d64bd1d1cd6d31e9b
--- /dev/null
+++ b/tests/auto_crash_gen_script/auto_crash_gen_script.py
@@ -0,0 +1,273 @@
+###################################################################
+#           Copyright (c) 2020 by TAOS Technologies, Inc.
+#                     All rights reserved.
+#
+#  This file is proprietary and confidential to TAOS Technologies.
+#  No part of this file may be reproduced, stored, transmitted,
+#  disclosed or used in any form or by any means other than as
+#  expressly provided by the written permission from Jianhui Tao
+#
+###################################################################
+
+# -*- coding: utf-8 -*-
+import os ,sys
+import random
+import argparse
+import subprocess
+import time
+
+# set path about run instance
+
+core_path = '/home/coredump/'
+base_dir = os.path.dirname(os.path.realpath(__file__))
+if base_dir.find("community")>0:
+    repo = "community"
+elif base_dir.find("TDengine")>0:
+    repo = "TDengine"
+else:
+    repo ="TDengine"
+print("base_dir:",base_dir)
+home_dir = base_dir[:base_dir.find(repo)]
+print("home_dir:",home_dir)
+run_dir = os.path.join(home_dir,'run_dir')
+run_dir = os.path.abspath(run_dir)
+print("run dir is set at :",run_dir)
+if not os.path.exists(run_dir):
+    os.mkdir(run_dir)
+run_log_file = run_dir+'/crash_gen_run.log'
+crash_gen_cmds_file = os.path.join(run_dir, 'crash_gen_cmds.sh')
+exit_status_logs =  os.path.join(run_dir, 'crash_exit.log')
+
+def get_path():
+    buildPath=''
+    selfPath = os.path.dirname(os.path.realpath(__file__))
+    if ("community" in selfPath):
+        projPath = selfPath[:selfPath.find("community")]
+    else:
+        projPath = selfPath[:selfPath.find("tests")]
+
+    for root, dirs, files in os.walk(projPath):
+        if ("taosd" in files):
+            rootRealPath = os.path.dirname(os.path.realpath(root))
+            if ("packaging" not in rootRealPath):
+                buildPath = root[:len(root) - len("/build/bin")]
+                break
+    return buildPath
+
+  
+def random_args(args_list):
+    nums_args_list = ["--max-dbs","--num-replicas","--num-dnodes","--max-steps","--num-threads",] # record int type arguments
+    bools_args_list = ["--auto-start-service" , "--debug","--run-tdengine","--ignore-errors","--track-memory-leaks","--larger-data","--mix-oos-data","--dynamic-db-table-names",
+    "--per-thread-db-connection","--record-ops","--verify-data","--use-shadow-db","--continue-on-exception"
+    ]  # record bool type arguments
+    strs_args_list = ["--connector-type"]  # record str type arguments
+
+    args_list["--auto-start-service"]= True
+    args_list["--continue-on-exception"]=True
+    # connect_types=['native','rest','mixed'] # restful interface has change ,we should trans dbnames to connection or change sql such as "db.test"
+    connect_types=['native']
+    # args_list["--connector-type"]=connect_types[random.randint(0,2)]
+    args_list["--connector-type"]= connect_types[0]
+    args_list["--max-dbs"]= random.randint(1,10)
+    
+    dnodes = [1,3] # set single dnodes;
+    
+    args_list["--num-dnodes"]= random.sample(dnodes,1)[0]
+    args_list["--num-replicas"]= random.randint(1,args_list["--num-dnodes"])
+    args_list["--debug"]=False
+    args_list["--per-thread-db-connection"]=True
+    args_list["--track-memory-leaks"]=False
+
+    num = random.randint(1, 10)   # set --track-memory-leaks randomly
+    if num > 8 :
+        args_list["--track-memory-leaks"]=True
+    
+
+    args_list["--max-steps"]=random.randint(300,500)
+    
+    threads = [32,64,128]
+    args_list["--num-threads"]=random.sample(threads,1)[0] #$ debug
+    args_list["--ignore-errors"]=[]   ## can add error codes for detail
+
+    
+    args_list["--run-tdengine"]= False
+    args_list["--use-shadow-db"]= False
+    args_list["--dynamic-db-table-names"]= False
+    args_list["--verify-data"]= False
+    args_list["--record-ops"] = False
+
+    for key in bools_args_list:
+        set_bool_value = [True,False]
+        if key == "--auto-start-service" :
+            continue
+        elif key =="--run-tdengine":
+            continue
+        elif key == "--ignore-errors":
+            continue
+        elif key == "--debug":
+            continue
+        elif key == "--per-thread-db-connection":
+            continue
+        elif key == "--continue-on-exception":
+            continue
+        elif key == "--use-shadow-db":
+            continue
+        elif key =="--track-memory-leaks":
+            continue
+        elif key == "--dynamic-db-table-names":
+            continue
+        elif key == "--verify-data":
+            continue
+        elif key == "--record-ops":
+            continue
+        else:
+            args_list[key]=set_bool_value[random.randint(0,1)]
+    return args_list
+
+def limits(args_list):
+    if args_list["--use-shadow-db"]==True:
+        if args_list["--max-dbs"] > 1:
+            print("Cannot combine use-shadow-db with max-dbs of more than 1 ,set max-dbs=1")
+            args_list["--max-dbs"]=1
+        else:
+            pass
+
+    elif args_list["--num-replicas"]==0:
+        print(" make sure num-replicas is at least 1 ")
+        args_list["--num-replicas"]=1
+    elif args_list["--num-replicas"]==1:
+        pass
+
+    elif args_list["--num-replicas"]>1:
+        if not args_list["--auto-start-service"]:
+            print("it should be deployed by crash_gen auto-start-service for multi replicas")
+            
+    else:
+        pass
+         
+    return  args_list
+
+def get_cmds(args_list):
+    build_path = get_path()
+    if repo == "community":
+        crash_gen_path = build_path[:-5]+"community/tests/pytest/"
+    elif repo == "TDengine":
+        crash_gen_path = build_path[:-5]+"/tests/pytest/"
+    else:
+        pass
+
+    bools_args_list = ["--auto-start-service" , "--debug","--run-tdengine","--ignore-errors","--track-memory-leaks","--larger-data","--mix-oos-data","--dynamic-db-table-names",
+    "--per-thread-db-connection","--record-ops","--verify-data","--use-shadow-db","--continue-on-exception"]
+    arguments = ""
+    for k ,v in args_list.items():
+        if k == "--ignore-errors":
+            if v:
+                arguments+=(k+"="+str(v)+" ")
+            else:
+                arguments+=""
+        elif  k in bools_args_list and v==True:
+            arguments+=(k+" ")
+        elif k in bools_args_list and v==False:
+            arguments+=""
+        else:
+            arguments+=(k+"="+str(v)+" ")
+    crash_gen_cmd = 'cd %s && ./crash_gen.sh %s '%(crash_gen_path ,arguments)
+    return crash_gen_cmd
+
+def run_crash_gen(crash_cmds,result_file):
+    os.system('echo "%s">>%s'%(crash_cmds,crash_gen_cmds_file))
+    os.system("cp %s %s"%(crash_gen_cmds_file, core_path))
+    os.system("%s>>%s"%(crash_cmds,result_file))
+
+def check_status(result_file):
+    run_code = subprocess.Popen("tail -n 50 %s"%result_file, shell=True, stdout=subprocess.PIPE,stderr=subprocess.STDOUT).stdout.read().decode("utf-8")
+    os.system("tail -n 50 %s>>%s"%(result_file,exit_status_logs))
+    mem_status = check_memory(run_dir)
+    if mem_status >0:
+        return mem_status
+    if "Crash_Gen is now exiting with status code: 1" in run_code:
+        return 1
+    elif "Crash_Gen is now exiting with status code: 0" in run_code:
+        return 0
+    else:
+        return 2 
+
+def check_memory(run_dir):
+    '''
+    invalid read, invalid write
+    '''
+    mem_report_path = os.path.join(run_dir , "reporter")
+    if not os.path.exists(mem_report_path):
+        os.mkdir(mem_report_path)
+    status = 0
+    stderr_files = subprocess.Popen("find %s -name \"stderr.log\" "%run_dir , shell=True, stdout=subprocess.PIPE,stderr=subprocess.STDOUT).stdout.read().decode("utf-8")
+    stderr_list = stderr_files.split("\n")[:-1]
+    for stderr_file in stderr_list:
+        print(stderr_file)
+        grep_res = subprocess.Popen("grep -i 'Invalid read' %s "%stderr_file , shell=True, stdout=subprocess.PIPE,stderr=subprocess.STDOUT).stdout.read().decode("utf-8")
+        dnode_name = stderr_file.split("/")[-3]
+        back_path = os.path.join(core_path,"reporter",dnode_name)
+        if not os.path.exists(back_path):
+            os.system("mkdir -p %s"%back_path)
+
+        if grep_res:
+            os.system("cp %s %s"%(stderr_file , back_path))
+            status = 4
+            break
+        
+        grep_res = subprocess.Popen("grep -i 'Invalid write' %s "%stderr_file , shell=True, stdout=subprocess.PIPE,stderr=subprocess.STDOUT).stdout.read().decode("utf-8")
+        if grep_res:
+            status = 4
+            os.system("cp %s %s"%(stderr_file , back_path))
+            break
+    return status
+
+def main():
+    args_list = {"--auto-start-service":False ,"--max-dbs":0,"--connector-type":"native","--debug":False,"--run-tdengine":False,"--ignore-errors":[],
+        "--num-replicas":1 ,"--track-memory-leaks":False , "--larger-data":False, "--mix-oos-data":False, "--dynamic-db-table-names":False,"--num-dnodes":1,
+        "--per-thread-db-connection":False , "--record-ops":False , "--max-steps":100, "--num-threads":10, "--verify-data":False,"--use-shadow-db":False , 
+        "--continue-on-exception":False }
+
+    build_path = get_path()
+    os.system("pip3 install taospy")
+    if repo =="community":
+        crash_gen_path = build_path[:-5]+"community/tests/pytest/"
+    elif repo =="TDengine":
+        crash_gen_path = build_path[:-5]+"/tests/pytest/"
+    else:
+        pass
+    print(crash_gen_path)
+    if os.path.exists(crash_gen_path+"crash_gen.sh"):
+        print(" make sure crash_gen.sh is ready")
+    else:
+        print( " crash_gen.sh is not exists ")
+        sys.exit(1)
+    
+    # set value args
+
+    args = random_args(args_list)
+    args = limits(args)
+    crash_cmds = get_cmds(args)
+    crash_cmds= crash_cmds+"--set-path="+"%s"%run_dir
+    # clean run_dir
+    os.system('rm -rf %s'%run_dir )
+    if not os.path.exists(run_dir):
+        os.mkdir(run_dir)
+    print(crash_cmds)
+    run_crash_gen(crash_cmds,run_log_file)
+    status = check_status(run_log_file)
+    
+    print("exit status : ", status)
+    if status ==4:
+        print('======== crash_gen found memory bugs at reporter ========')
+    if status >0:
+        print('======== crash_gen run failed and not exit as expected ========')
+    else:
+        print('======== crash_gen run sucess and exit as expected ========')
+    exit(status)
+    
+
+if __name__ == '__main__':
+    main()
+
+
diff --git a/tests/system-test/abnormal/Always_alter_schema.py b/tests/system-test/abnormal/Always_alter_schema.py
deleted file mode 100644
index 175204a791b0504fa7db3f47c15ade77a113e9ae..0000000000000000000000000000000000000000
--- a/tests/system-test/abnormal/Always_alter_schema.py
+++ /dev/null
@@ -1,162 +0,0 @@
-###################################################################
-#           Copyright (c) 2020 by TAOS Technologies, Inc.
-#                     All rights reserved.
-#
-#  This file is proprietary and confidential to TAOS Technologies.
-#  No part of this file may be reproduced, stored, transmitted,
-#  disclosed or used in any form or by any means other than as
-#  expressly provided by the written permission from Jianhui Tao
-#
-###################################################################
-
-# -*- coding: utf-8 -*-
-
-from http import client
-import taos
-import time
-
-from util.log import *
-from util.cases import *
-from util.sql import *
-from util.dnodes import *
-import random
-
-class TDTestCase:
-    def __init__(self):
-        self.ts = 1420041600000 # 2015-01-01 00:00:00  this is begin time for first record
-        self.num = 10
-        self.Loop = 10
-        self.loop_alter = 100
-
-    def caseDescription(self):
-
-        '''
-        case1 <wenzhouwww>: this is an abnormal case for always change schema
-        '''
-        return
-
-    def init(self, conn, logSql):
-        tdLog.debug("start to execute %s" % __file__)
-        tdSql.init(conn.cursor(), logSql)
-
- 
-    def run(self):
-        
-        # Loop 
-        tdSql.execute("drop database if exists testdb")
-        tdSql.execute("create database testdb")
-        tdSql.execute("use testdb")
-        tdSql.execute("create stable testdb.st (ts timestamp ,  value int) tags (ind int)")
-        tdSql.query("describe testdb.st")
-        
-        # insert data
-        for cur in range(self.num):
-            tdSql.execute("insert into tb_%d using st tags(%d) values(%d, %d)"%(cur,cur, self.ts+1000*cur,cur))
-            tdSql.execute("insert into tb_set using st tags(%d) values(%d, %d)"%(cur,self.ts+1000*cur,cur))
-
-        client_0 = taos.connect().cursor()  # global conn
-        
-        client_1 = taos.connect().cursor()
-        client_2 = taos.connect().cursor() 
-
-        add_tag_list = []
-        for i in range(self.loop_alter):
-            sql= "alter stable testdb.st add tag new_tag%d int"%i
-            add_tag_list.append(sql)
-
-        change_tag_list = []
-        for i in range(self.loop_alter+1):
-            sql =   " alter stable testdb.st  change tag new_tag%d new_tag_%d"%(i,i)  
-            change_tag_list.append(sql)
-
-        set_tag_list = []
-        for i in range(self.loop_alter):
-            sql = "alter table testdb.tb_set set tag new_tag_%d=%d"%(i,i*10)
-            set_tag_list.append(sql)
-
-        drop_tag_list = []
-        for i in range(self.loop_alter):
-            sql = "alter stable testdb.st drop tag new_tag_%d"%(i)
-            drop_tag_list.append(sql)
-
-        for i in range(self.loop_alter):
-            add_sql = add_tag_list[i]
-            change_sql = change_tag_list[i]
-            set_sql = set_tag_list[i]
-            drop_sql = drop_tag_list[i]
-
-            execute_list= [add_sql,change_sql,set_sql,drop_sql]
-
-            for ind,sql in enumerate(execute_list):
-                if sql ==drop_sql:
-                    if i%5 !=0:
-                        continue
-                    else:
-                        pass
-
-                if ind%3==0:
-                    # client_0.execute("reset query cache")
-                    client_0.execute(sql)
-                    print(" client_0 runing sqls : %s" %sql )
-                elif ind%3==1:
-                    # client_1.execute("reset query cache")
-                    client_1.execute(sql)
-                    print(" client_1 runing sqls : %s" %sql )
-                elif ind%3==2:
-                    # client_2.execute("reset query cache")
-                    client_2.execute(sql)
-                    print(" client_2 runing sqls : %s" %sql )
-                else:
-                    client_0.execute(sql)
-                    print(" client_0 runing sqls : %s" %sql )
-            
-            query_sqls  = ["select count(*) from testdb.st group by ind",
-                           "describe testdb.st",
-                           "select count(*) from testdb.st group by tbname"]
-            reset_sql = "reset query cache"
-
-            if i%10 ==0:
-                tdSql.execute(reset_sql) 
-                client_0.execute(reset_sql)
-                client_1.execute(reset_sql)
-                client_2.execute(reset_sql)
-
-            for sql in query_sqls:
-                if sql =="describe testdb.st":
-                    print("==========================\n")
-                    print("==========describe=======\n")
-                    print("==========================\n")
-                    client_0.execute(sql)
-                    res = client_0.fetchall()
-                    print("client 0 res :", res) if res  else print("empty")
-
-                    client_1.execute(sql)
-                    res = client_0.fetchall()
-                    print("client 1 res :", res) if res  else print("empty")
-
-                    client_2.execute(sql)
-                    res = client_2.fetchall()
-                    print("client 2 res :", res) if res  else print("empty")
-                else:
-                    client_0.execute(sql)
-                    client_1.execute(sql)
-                    client_2.execute(sql)
-                             
-            tdLog.notice("===== this is the %d_th loop alter tags is going now ===="%i )
-        
-
-
-
-
-        client_1.close()
-        client_2.close()
-
-        client_0.close()
-
-    def stop(self):
-        tdSql.close()
-        tdLog.success("%s successfully executed" % __file__)
-
-
-tdCases.addWindows(__file__, TDTestCase())
-tdCases.addLinux(__file__, TDTestCase())
diff --git a/tests/system-test/abnormal/Loop_restart_and_kill.py b/tests/system-test/abnormal/Loop_restart_and_kill.py
deleted file mode 100644
index 8ac1f7c8f1f7e7b8bb15ffb7549370ec61438165..0000000000000000000000000000000000000000
--- a/tests/system-test/abnormal/Loop_restart_and_kill.py
+++ /dev/null
@@ -1,89 +0,0 @@
-###################################################################
-#           Copyright (c) 2020 by TAOS Technologies, Inc.
-#                     All rights reserved.
-#
-#  This file is proprietary and confidential to TAOS Technologies.
-#  No part of this file may be reproduced, stored, transmitted,
-#  disclosed or used in any form or by any means other than as
-#  expressly provided by the written permission from Jianhui Tao
-#
-###################################################################
-
-# -*- coding: utf-8 -*-
-import taos
-import time
-
-from util.log import *
-from util.cases import *
-from util.sql import *
-from util.dnodes import *
-
-
-class TDTestCase:
-    def __init__(self):
-        self.ts = 1420041600000 # 2015-01-01 00:00:00  this is begin time for first record
-        self.num = 10
-        self.Loop = 100
-
-    def caseDescription(self):
-
-        '''
-        case1 <wenzhouwww>: this is an abnormal case for loop restart taosd
-        and basic this query ,it will run 4 client to change schema ,run always ;
-        '''
-        return
-
-    def init(self, conn, logSql):
-        tdLog.debug("start to execute %s" % __file__)
-        tdSql.init(conn.cursor(), logSql)
-
-    def basic_insert(self):
-        tdSql.execute("create database if not exists testdb")
-        tdSql.execute("use testdb")
-        tdSql.execute("create stable st (ts timestamp ,  value int) tags (ind int)")
-        for i in range(self.num):
-            tdSql.execute("insert into sub_%s using st tags(%d) values (%d , %d );"%(str(i),i,self.ts+10000*i,i))
-
-    def basic_query(self):
-        for i in range(self.num):
-            tdSql.query("select count(*) from testdb.sub_%s"%str(i))
-            tdSql.checkData(0,0,1)
-        tdSql.query("select count(*) from testdb.st")
-        tdSql.checkRows(1)
-
-    
-    def run(self):
-        
-        # Loop 
-
-        for loop_step in range(self.Loop):
-
-            # run basic query and insert
-            # kill all 
-            os.system("ps -aux |grep 'taosd'  |awk '{print $2}'|xargs kill -9 >/dev/null 2>&1")
-            tdDnodes.start(1)
-            if loop_step ==0:
-                self.basic_insert()
-            else:
-                tdSql.execute("insert into sub_10 using st tags(10) values(now ,10)")
-            
-            # another client 
-            os.system('taos -s "insert into testdb.sub_100 using testdb.st tags(100) values(now ,100);"')
-            os.system('taos -s "select count(*) from testdb.sub_100;"')
-            
-            self.basic_query()
-            sleep(2)
-            tdDnodes.stopAll()
-            
-
-            tdLog.info(" this is the %s_th loop restart taosd going " % loop_step)
-
-
-
-    def stop(self):
-        tdSql.close()
-        tdLog.success("%s successfully executed" % __file__)
-
-
-tdCases.addWindows(__file__, TDTestCase())
-tdCases.addLinux(__file__, TDTestCase())
diff --git a/tests/system-test/abnormal/Loop_restart_database_alter.py b/tests/system-test/abnormal/Loop_restart_database_alter.py
deleted file mode 100644
index d2721fa15d3f309bc91d764356e3f1fb3b1d354a..0000000000000000000000000000000000000000
--- a/tests/system-test/abnormal/Loop_restart_database_alter.py
+++ /dev/null
@@ -1,160 +0,0 @@
-###################################################################
-#           Copyright (c) 2020 by TAOS Technologies, Inc.
-#                     All rights reserved.
-#
-#  This file is proprietary and confidential to TAOS Technologies.
-#  No part of this file may be reproduced, stored, transmitted,
-#  disclosed or used in any form or by any means other than as
-#  expressly provided by the written permission from Jianhui Tao
-#
-###################################################################
-
-# -*- coding: utf-8 -*-
-
-from http import client
-import taos
-import time
-
-from util.log import *
-from util.cases import *
-from util.sql import *
-from util.dnodes import *
-import random
-
-class TDTestCase:
-    def __init__(self):
-        self.ts = 1420041600000 # 2015-01-01 00:00:00  this is begin time for first record
-        self.num = 10
-        self.Loop = 100
-        global client
-
-    def caseDescription(self):
-
-        '''
-        case1 <wenzhouwww>: this is an abnormal case for loop restart taosd
-        between restart taosd ,there is an query and is insert is going on 
-        '''
-        return
-
-    def init(self, conn, logSql):
-        tdLog.debug("start to execute %s" % __file__)
-        tdSql.init(conn.cursor(), logSql)
-
- 
-    def run(self):
-        
-        # Loop 
-        tdSql.execute("drop database if exists testdb")
-        client = taos.connect().cursor()  # global conn
-
-        # tdSql.execute("create database testdb")
-        # tdSql.execute("create stable testdb.st (ts timestamp ,  value int) tags (ind int)")
-        # tdSql.query("describe testdb.st")
-        # result = tdSql.getResult("describe testdb.st")
-        # print(result)
-        # tdSql.execute("alter stable testdb.st add tag new_tags int")
-        # result = tdSql.getResult("describe testdb.st")
-        # print(result)
-        # tdSql.execute("alter stable testdb.st change tag new_tags alter_tag")
-        # result = tdSql.getResult("describe testdb.st")
-        # print(result)
-        
-        
-        for loop_step in range(self.Loop):
-
-            # run basic query and insert
-            # kill all 
-            os.system("ps -aux |grep 'taosd'  |awk '{print $2}'|xargs kill -9 >/dev/null 2>&1")
-            tdDnodes.start(1)
-            
-            tdSql.execute("create database if not exists testdb")
-            tdSql.execute("use testdb")
-
-            if loop_step <1:
-                tdSql.execute("create stable st (ts timestamp ,  value int) tags (ind int)")
-
-            tdSql.execute("create stable st%d (ts timestamp ,  value int) tags (ind int)"%loop_step)
-            for cur in range(self.num):
-                tdSql.execute("insert into tb_%d using st%d tags(%d) values(now, %d)"%(loop_step,loop_step,loop_step, cur))
-            
-            os.system('taos -s "insert into testdb.sub_100 using testdb.st tags(100) values(now ,100);"')
-            os.system('taos -s "select count(*) from testdb.sub_100;"')
-            os.system('taos -s "describe testdb.sub_100;"')
-            os.system('show databases\G')
-            # another client 
-            client_1 = taos.connect().cursor()
-            client_2 = taos.connect().cursor() 
-
-            alter_dict = {"days" : int(random.randint(1,5)) , 
-            "keep":int(random.randint(10,20)) ,
-            "precision":"ns",
-            "blocks" : int(random.randint(1,6)*2),
-            "quorum": int(random.randint(0,3)),
-            "comp":int(random.randint(0,3)),
-            "minrows":int(random.randint(1,3)*100),
-            "replica":int(random.randint(1,3))
-            }
-            alter_list = ['days', 'keep', 'precision', 'blocks', 'quorum', 'comp', 'minrows', 'replica']
-            random_key = random.sample(alter_list, 1)[0]
-            
-            sql =  "alter database {} {} {}".format("testdb", random_key, alter_dict[random_key])
-
-            for alter_db in range(100):
-                alter_list = ['days', 'keep', 'precision', 'blocks', 'quorum', 'comp', 'minrows', 'replica']
-                random_key = random.sample(alter_list, 1)[0]
-                sql =  "alter database {} {} {}".format("testdb", random_key, alter_dict[random_key])
-         
-                if alter_db%3==0:
-                    # client_0.execute("reset query cache")
-                    try:
-                        client.execute(sql)
-                        client.fetchall()
-                        os.system('taos -s "insert into testdb.sub_100 using testdb.st tags(100) values(now ,100);"')
-                    except  :
-                        pass
-                    print(" client runing sqls : %s" %sql )
-                elif alter_db%3==1:
-                    # client_1.execute("reset query cache")
-                    try:
-                        client_1.execute(sql)
-                        client_1.fetchall()
-                        os.system('taos -s "insert into testdb.sub_100 using testdb.st tags(100) values(now ,100);"')
-                    except :
-                        pass
-                    print(" client_1 runing sqls : %s" %sql )
-                elif alter_db%3==2:
-                    try:
-                        # client_2.execute("reset query cache")
-                        client_2.execute(sql)
-                        client_2.fetchall()
-                        os.system('taos -s "insert into testdb.sub_100 using testdb.st tags(100) values(now ,100);"')
-                    except:
-                        pass
-                    print(" client_2 runing sqls : %s" %sql )
-                else:
-                    try:
-                        client.execute(sql)
-                        client.fetchall()
-                        os.system('taos -s "insert into testdb.sub_100 using testdb.st tags(100) values(now ,100);"')
-                    except:
-                        pass
-                    print(" client runing sqls : %s" %sql )
-            os.system("taos -s 'show databases;'")
-
-            sleep(2)
-            tdDnodes.stopAll()
-            
-            tdLog.notice(" this is the %s_th loop restart taosd going " % loop_step)
-        
-            client_1.close()
-            client_2.close()
-        
-        client.close()
-
-    def stop(self):
-        tdSql.close()
-        tdLog.success("%s successfully executed" % __file__)
-
-
-tdCases.addWindows(__file__, TDTestCase())
-tdCases.addLinux(__file__, TDTestCase())
diff --git a/tests/system-test/abnormal/Loop_restart_schema_alter.py b/tests/system-test/abnormal/Loop_restart_schema_alter.py
deleted file mode 100644
index 63b4b645af4b73ab7056a07b4566ccdc682f986f..0000000000000000000000000000000000000000
--- a/tests/system-test/abnormal/Loop_restart_schema_alter.py
+++ /dev/null
@@ -1,139 +0,0 @@
-###################################################################
-#           Copyright (c) 2020 by TAOS Technologies, Inc.
-#                     All rights reserved.
-#
-#  This file is proprietary and confidential to TAOS Technologies.
-#  No part of this file may be reproduced, stored, transmitted,
-#  disclosed or used in any form or by any means other than as
-#  expressly provided by the written permission from Jianhui Tao
-#
-###################################################################
-
-# -*- coding: utf-8 -*-
-
-from http import client
-import taos
-import time
-
-from util.log import *
-from util.cases import *
-from util.sql import *
-from util.dnodes import *
-import random
-
-class TDTestCase:
-    def __init__(self):
-        self.ts = 1420041600000 # 2015-01-01 00:00:00  this is begin time for first record
-        self.num = 10
-        self.Loop = 100
-        global client
-
-    def caseDescription(self):
-
-        '''
-        case1 <wenzhouwww>: this is an abnormal case for loop restart taosd
-        between restart taosd ,there is an query and is insert is going on 
-        '''
-        return
-
-    def init(self, conn, logSql):
-        tdLog.debug("start to execute %s" % __file__)
-        tdSql.init(conn.cursor(), logSql)
-
- 
-    def run(self):
-        
-        # Loop 
-        tdSql.execute("drop database if exists testdb")
-        client = taos.connect().cursor()  # global conn
-
-        # tdSql.execute("create database testdb")
-        # tdSql.execute("create stable testdb.st (ts timestamp ,  value int) tags (ind int)")
-        # tdSql.query("describe testdb.st")
-        # result = tdSql.getResult("describe testdb.st")
-        # print(result)
-        # tdSql.execute("alter stable testdb.st add tag new_tags int")
-        # result = tdSql.getResult("describe testdb.st")
-        # print(result)
-        # tdSql.execute("alter stable testdb.st change tag new_tags alter_tag")
-        # result = tdSql.getResult("describe testdb.st")
-        # print(result)
-        
-        
-        for loop_step in range(self.Loop):
-
-            # run basic query and insert
-            # kill all 
-            os.system("ps -aux |grep 'taosd'  |awk '{print $2}'|xargs kill -9 >/dev/null 2>&1")
-            tdDnodes.start(1)
-            
-            tdSql.execute("create database if not exists testdb")
-            tdSql.execute("use testdb")
-
-            if loop_step <1:
-                tdSql.execute("create stable st (ts timestamp ,  value int) tags (ind int)")
-
-            tdSql.execute("create stable st%d (ts timestamp ,  value int) tags (ind int)"%loop_step)
-            for cur in range(self.num):
-                tdSql.execute("insert into tb_%d using st%d tags(%d) values(%d, %d)"%(loop_step,loop_step,loop_step, self.ts+1000*cur,cur))
-            
-            os.system('taos -s "insert into testdb.sub_100 using testdb.st tags(100) values(now ,100);"')
-            os.system('taos -s "select count(*) from testdb.sub_100;"')
-            os.system('taos -s "describe testdb.sub_100;"')
-            # another client 
-            client_1 = taos.connect().cursor()
-            client_2 = taos.connect().cursor() 
-            
-            alter_tag =  [
-                " alter stable testdb.st%d  add tag new_tags int "%loop_step,
-                " alter stable testdb.st%d  change tag new_tags alter_tag"%loop_step,
-                " alter stable testdb.st%d  drop tag alter_tag"%loop_step,
-                "ALTER TABLE testdb.sub_100 SET TAG ind=%d"%(loop_step*10)
-            ]
-            print(alter_tag[0])
-            client_1.execute(alter_tag[0])
-            os.system('taos -s "%s; describe testdb.sub_100;select ind from testdb.sub_100;"'% alter_tag[3] )
-
-            # clinet1
-            os.system('taos -s "%s; describe testdb.sub_100;select ind from testdb.sub_100;"'% alter_tag[3] )
-            # client_1.execute("reset query cache;")
-            client_1.execute(" describe testdb.st%d"%loop_step)
-            res = client_1.fetchall()
-
-            # clinet2 
-            os.system('taos -s "%s; describe testdb.sub_100;select ind from testdb.sub_100;"'% alter_tag[3] )
-
-            print(alter_tag[1])
-            client_2.execute(alter_tag[1])
-            # client_2.execute("reset query cache")
-            client_2.execute("describe testdb.st%d"%loop_step)
-            res = client_2.fetchall()
-
-            client_2.execute("select * from testdb.st%d"%loop_step)
-            res = client_2.fetchall()
-
-            client.execute("show databases;")
-            # client.execute("reset query cache")
-            client.execute("describe testdb.st%d"%loop_step)
-            print(alter_tag[2])
-            client.execute(alter_tag[2])
-            res = client.fetchall_row()
-            
-
-            sleep(2)
-            tdDnodes.stopAll()
-            
-            tdLog.notice(" this is the %s_th loop restart taosd going " % loop_step)
-        
-            client_1.close()
-            client_2.close()
-        
-        client.close()
-
-    def stop(self):
-        tdSql.close()
-        tdLog.success("%s successfully executed" % __file__)
-
-
-tdCases.addWindows(__file__, TDTestCase())
-tdCases.addLinux(__file__, TDTestCase())