示例#1
0
 def tearDown(self):
     # each test should wait for the wal sender to disappear
     for i in walrepl.polling(30, 0.5):
         with PGconn("") as conn:
             cnt = self.count_walsender(conn)
             if cnt <= 0:
                 break
示例#2
0
文件: __init__.py 项目: 50wu/gpdb
 def tearDown(self):
     # each test should wait for the wal sender to disappear
     for i in walrepl.polling(30, 0.5):
         with PGconn("") as conn:
             cnt = self.count_walsender(conn)
             if cnt <= 0:
                 break
示例#3
0
    def wait_triggered(self, fault_name):

        search = "fault injection state:'triggered'"
        for i in walrepl.polling(10, 3):
            result = self.fault_status(fault_name)
            stdout = result.stdout
            if stdout.find(search) > 0:
                return True

        return False
示例#4
0
    def wait_triggered(self, fault_name):

        search = "fault injection state:'triggered'"
        for i in walrepl.polling(10, 3):
            result = self.fault_status(fault_name)
            stdout = result.stdout
            if stdout.find(search) > 0:
                return True

        return False
示例#5
0
    def wait_for_walsender(self, nretry=30, interval=0.5):
        """
        Wait for walsender to be active for a while, and returns when it
        is.  Finally the wait loop ends, in which case it returns 0.
        """

        num_walsender = 0
        for i in walrepl.polling(nretry, interval):
            num_walsender = self.count_walsender()
            if num_walsender > 0:
                break
        return num_walsender
示例#6
0
    def wait_for_walsender(self, nretry=30, interval=0.5):
        """
        Wait for walsender to be active for a while, and returns when it
        is.  Finally the wait loop ends, in which case it returns 0.
        """

        num_walsender = 0
        for i in walrepl.polling(nretry, interval):
            num_walsender = self.count_walsender()
            if num_walsender > 0:
                break
        return num_walsender
示例#7
0
文件: verify.py 项目: 50wu/gpdb
 def check_pg_stat_replication(self):
     '''Check the state and sync_state from pg_stat_replication '''
     for i in walrepl.polling(max_try=20, interval=0.5):
         res = self.get_pg_stat_replication()
         if len(res) == 0:
             continue
         elif res[0].state == 'streaming' and res[0].sync_state == 'sync':
             tinctest.logger.info('pg_stat_replication is updated with the information')
             return True
         else:
             continue 
     return False
示例#8
0
文件: verify.py 项目: kevinwangl/gpdb
 def check_pg_stat_replication(self):
     '''Check the state and sync_state from pg_stat_replication '''
     for i in walrepl.polling(max_try=20, interval=0.5):
         res = self.get_pg_stat_replication()
         if len(res) == 0:
             continue
         elif res[0].state == 'streaming' and res[0].sync_state == 'sync':
             tinctest.logger.info(
                 'pg_stat_replication is updated with the information')
             return True
         else:
             continue
     return False
    def test_unixsocket(self):
        """
        Connect via unit socket to walsender.

        @tags sanity
        """

        with PGconn("") as conn:
            # gp_libpq_fe doesn't use PGHOST env var, so without giving
            # explicit hostname, it should use unix domain socket.
            res = conn.execute("SELECT test_connect('')")
            self.assertEqual(res.status(), PGRES_TUPLES_OK)

            res = conn.execute("SELECT * FROM pg_stat_replication")
            tup = res.pyobjects().pop(0)

            # client_addr will be NULL in unix socket case
            self.assertIsNone(tup.client_addr)
            # client_port will be -1 in unix socket case
            self.assertEqual(tup.client_port, -1)
            self.assertIsNotNone(tup.sent_location)

            # catch up to the primary
            for i in walrepl.polling(100, 0.5):
                res = conn.execute("SELECT test_receive()")
                if not res.getpyvalue(0, 0):
                    break

            res = conn.execute("SELECT pg_current_xlog_location()")
            current_xlog_location = res.getvalue(0, 0)

            res = conn.execute("SELECT * FROM pg_stat_replication")
            tup = res.pyobjects().pop(0)

            # sent_location follows current_xlog_location.
            # They don't necessarily match, as there should be some
            # window between write and send.
            self.assertTrue(tup.sent_location <= current_xlog_location)
示例#10
0
    def test_unixsocket(self):
        """
        Connect via unit socket to walsender.

        @tags sanity
        """

        with PGconn("") as conn:
            # gp_libpq_fe doesn't use PGHOST env var, so without giving
            # explicit hostname, it should use unix domain socket.
            res = conn.execute("SELECT test_connect('')")
            self.assertEqual(res.status(), PGRES_TUPLES_OK)

            res = conn.execute("SELECT * FROM pg_stat_replication")
            tup = res.pyobjects().pop(0)

            # client_addr will be NULL in unix socket case
            self.assertIsNone(tup.client_addr)
            # client_port will be -1 in unix socket case
            self.assertEqual(tup.client_port, -1)
            self.assertIsNotNone(tup.sent_location)

            # catch up to the primary
            for i in walrepl.polling(100, 0.5):
                res = conn.execute("SELECT test_receive()")
                if not res.getpyvalue(0, 0):
                    break

            res = conn.execute("SELECT pg_current_xlog_location()")
            current_xlog_location = res.getvalue(0, 0)

            res = conn.execute("SELECT * FROM pg_stat_replication")
            tup = res.pyobjects().pop(0)

            # sent_location follows current_xlog_location.
            # They don't necessarily match, as there should be some
            # window between write and send.
            self.assertTrue(tup.sent_location <= current_xlog_location)
示例#11
0
    def test_async(self):
        """
        Run sendtest in async mode.

        @tags sanity
        """

        PSQL.run_sql_command('DROP TABLE IF EXISTS foo')
        with WalClient("replication=true") as client:
            self.assertEqual(client.status(), CONNECTION_OK)
            (sysid, tli, xpos) = client.identify_system()

            xpos_ptr = XLogRecPtr.from_string(xpos)
            client.start_replication(xpos_ptr, sync=False)

            # wouldn't block since it's async connection.
            PSQL.run_sql_command('CREATE TABLE foo(a int, b int)')

            # it may take time to get complete message
            for i in walrepl.polling(10, 0.5):
                msg = client.receive(1000)
                if isinstance(msg, WalMessageData):
                    break
            self.assertIsInstance(msg, WalMessageData)
示例#12
0
文件: test_basic.py 项目: 50wu/gpdb
    def test_disconnect(self):
        """
        @tags sanity
        """

        with PGconn("") as conn:
            # check disconnect does not fail even before connect
            res = conn.execute("SELECT test_disconnect()")
            self.assertEqual(res.status(), PGRES_TUPLES_OK)
            self.assertTrue(res.getvalue(0, 0, convert=True))

            # check if disconnect clears the walsender
            res = conn.execute("SELECT test_connect('')")
            self.assertEqual(res.status(), PGRES_TUPLES_OK)
            res = conn.execute("SELECT test_disconnect()")
            self.assertEqual(res.status(), PGRES_TUPLES_OK)

            # wait for the backend terminates...
            for i in walrepl.polling(10, 0.5):
                cnt = self.count_walsender(conn)
                if cnt == 0:
                    break

            self.assertEqual(cnt, 0)
示例#13
0
    def test_disconnect(self):
        """
        @tags sanity
        """

        with PGconn("") as conn:
            # check disconnect does not fail even before connect
            res = conn.execute("SELECT test_disconnect()")
            self.assertEqual(res.status(), PGRES_TUPLES_OK)
            self.assertTrue(res.getvalue(0, 0, convert=True))

            # check if disconnect clears the walsender
            res = conn.execute("SELECT test_connect('')")
            self.assertEqual(res.status(), PGRES_TUPLES_OK)
            res = conn.execute("SELECT test_disconnect()")
            self.assertEqual(res.status(), PGRES_TUPLES_OK)

            # wait for the backend terminates...
            for i in walrepl.polling(10, 0.5):
                cnt = self.count_walsender(conn)
                if cnt == 0:
                    break

            self.assertEqual(cnt, 0)
示例#14
0
    def test_async(self):
        """
        Run sendtest in async mode.

        @tags sanity
        """

        PSQL.run_sql_command('DROP TABLE IF EXISTS foo')
        with WalClient("replication=true") as client:
            self.assertEqual(client.status(), CONNECTION_OK)
            (sysid, tli, xpos) = client.identify_system()

            xpos_ptr = XLogRecPtr.from_string(xpos)
            client.start_replication(xpos_ptr, sync=False)

            # wouldn't block since it's async connection.
            PSQL.run_sql_command('CREATE TABLE foo(a int, b int)')

            # it may take time to get complete message
            for i in walrepl.polling(10, 0.5):
                msg = client.receive(1000)
                if isinstance(msg, WalMessageData):
                    break
            self.assertIsInstance(msg, WalMessageData)
示例#15
0
文件: test_basic.py 项目: 50wu/gpdb
    def test_smart_shutdown(self):
        # 1. Verify if the system is UP and there is no WAL Receiver running
        # 2. Perform basebackup and deploy it into some dest. directory
        # 3. Copy recover.conf into the dest. directory to be used by Standby
        # 4. Initiate the Standby using the Master (primary) postmaster
        #    paramerters
        # 5. Perform some transaction to generate xlog. Then do a smart shutdown
        # 6. Once the primary DB is down, find the last checkpoint  from pg_control
        #    on primary. Check the last modified xlog seg from the standby and find
        #    if the last checkpoint from primary exists
        # 7. It should be present there!

        # 0. Stop standby if it's running
        PSQL.run_sql_command('DROP table if exists foo')
        standby = Standby('base', 5433)
        standby.stop()

        # 1. Verify if the system is UP and there is no WAL sender running
        self.assertEqual(self.count_walsender(), 0)
        logger.info('No active WAL Receiver found')

        # 2. Perform basebackup and deploy it into some dest.
        #    (currenttly hardcoded 'base') directory
        shutil.rmtree('base', True)

        logger.info('Performing and deploying base backup ...')
        standby.create()

        # 3.Copy recover.conf into the dest. directory to be used by StandBy
        logger.info('Deploying recovery.conf...')

        # 4. Initiate the StandBy using the Master (primary) postmaster
        #    paramerters
        logger.info('Initiating Standby...')
        res = standby.start()
        self.assertTrue(res.wasSuccessful())

        num_walsender = 0
        for i in polling(10, 0.5):
            num_walsender = self.count_walsender()
            if num_walsender > 0:
                break
        self.assertEqual(num_walsender, 1)

        logger.info('Activated WAL Receiver...')

        # 5. Perform some transaction to generate xlog. Then do a smart shutdown
        logger.info('Perform some transaction to generate some XLOG')
        PSQL.run_sql_command('Create table foo (a int)')

        logger.info('Now perform smart shutdown (gpstop -a)')
        cmd = Command(name="gpstop smart",
                      cmdStr="source %s/greenplum_path.sh;\
                      gpstop -a" % os.environ["GPHOME"])
        cmd.run(validateAfter=True)

        # 6. Once the primary DB is down, find the last checkpoint  from pg_control
        #    on primary. Check the last modified xlog seg from the standby and find
        #    if the last checkpoint from primary exists
        logger.info('Read the pg_control from primary, find the last checkpoint & see if it made to standby')

        standby_xlog_path = os.path.join('base','pg_xlog')

        cmd= Command(name = 'pg_controldata ' + os.environ.get('MASTER_DATA_DIRECTORY'),
                     cmdStr = 'pg_controldata ' + os.environ.get('MASTER_DATA_DIRECTORY'))
        cmd.run(validateAfter=True);

        primary_last_ckpt_lsn = self.last_ckpt_lsn((cmd.get_results()).stdout)

        logger.info ("Primary last checkpoint LSN = " + primary_last_ckpt_lsn)

        standby_last_mod_xlog = self.last_mod_file(standby_xlog_path)
        logger.info ("Last mod standby XLOG = " + standby_last_mod_xlog )

        cmd= Command(name = 'xlogdump standby last modifiled xlog',
                     cmdStr="xlogdump " + standby_last_mod_xlog)
        cmd.run(validateAfter=True);

        logger.info('See if we find the shutdown LSN in the XLOG seg file')
        lines  = (cmd.get_results()).stdout.splitlines()
        flag = False
        for line in range(0, len(lines) - 1):
            if ((lines[line]).find(primary_last_ckpt_lsn) > -1):
                self.assertTrue((lines[line]).find("checkpoint") > -1)
                self.assertTrue((lines[line]).find("shutdown") > -1)
                flag = True
                break

        self.assertTrue(flag)
        logger.info('PASS')

        # Re-start the database
        logger.info('Now restart the DB (gpstart -a)')
        cmd = Command(name="gpstop smart",
                      cmdStr="source %s/greenplum_path.sh;\
                      gpstart -a" % os.environ["GPHOME"])
        cmd.run(validateAfter=True)

        # Cleanup. Currently we dont have a clean way of WAL rcv dying
        logger.info('Kill the standby processes as clean standby killing is not supported')
        cmd = Command(name="kill standby",
                      cmdStr="kill -9 `ps -ef | grep 5433 | grep -v grep | awk '{print $2}'`")
        cmd.run(validateAfter=True)
示例#16
0
    def test_icg(self):

        # 1. Verify if the system is UP and there is no WAL Receiver running
        # 2. Perform basebackup and deploy it into some dest. directory
        # 3. Copy recover.conf into the dest. directory to be used by Standby
        # 4. Initiate the Standby using the Master (primary) postmaster
        #    paramerters
        # 5. Once the WAL receiver waits for the next record to arrive, perform
        #    installCheck-good

        # 0. Stop standby if it's running
        standby = Standby('base', 5433)
        standby.stop()

        # 1. Verify if the system is UP and there is no WAL sender running
        self.assertEqual(self.count_wal_sender(), 0)
        logger.info('No active WAL Receiver found')

        # Set environmental variable GPSRC for now for make installcheck purpose
        source_file = sys.modules[self.__class__.__module__].__file__
        source_dir = os.path.dirname(source_file)
        os.environ['GPSRC'] = os.path.join(source_dir, '../../../../')

        # 2. Perform basebackup and deploy it into some dest.
        #    (currenttly hardcoded 'base') directory
        shutil.rmtree('base', True)

        logger.info('Performing and deploying base backup ...')
        standby.create()

        # 3.Copy recover.conf into the dest. directory to be used by StandBy
        logger.info('Deploying recovery.conf...')

        # 4. Initiate the StandBy using the Master (primary) postmaster
        #    paramerters
        logger.info('Initiating Standby...')
        res = standby.start()
        self.assertTrue(res.wasSuccessful())

        num_walsender = 0
        for i in polling(10, 0.5):
            num_walsender = self.count_wal_sender()
            if num_walsender > 0:
                break
        self.assertEqual(num_walsender, 1)

        logger.info('Activated WAL Receiver...')

        # 6. Run installcheck-good
        self.assertTrue(os.environ["GPSRC"])

        installCheckGoodPath = os.path.join(os.environ.get('GPSRC'), 'test',
                                            'regress')

        self.assertTrue(os.path.exists(installCheckGoodPath))
        os.chdir(installCheckGoodPath)

        regression_diffs = os.path.join(installCheckGoodPath,
                                        'regression.diffs')
        if os.path.exists(regression_diffs):
            os.remove(regression_diffs)

        logger.info('Perform InstallCheck-Good...')
        subprocess.check_call('make installcheck-good', shell=True)

        # Verify installcheck result by checking if regression.diff is present.
        self.assertTrue(not os.path.exists(regression_diffs))
示例#17
0
    def test_icg(self):

        # 1. Verify if the system is UP and there is no WAL Receiver running
        # 2. Perform basebackup and deploy it into some dest. directory
        # 3. Copy recover.conf into the dest. directory to be used by Standby
        # 4. Initiate the Standby using the Master (primary) postmaster
        #    paramerters
        # 5. Once the WAL receiver waits for the next record to arrive, perform
        #    installCheck-good

        # 0. Stop standby if it's running
        standby = Standby('base', 5433)
        standby.stop()

        # 1. Verify if the system is UP and there is no WAL sender running
        self.assertEqual(self.count_wal_sender(), 0)
        logger.info('No active WAL Receiver found')

        # Set environmental variable GPSRC for now for make installcheck purpose
        source_file = sys.modules[self.__class__.__module__].__file__
        source_dir = os.path.dirname(source_file)
        os.environ['GPSRC'] = os.path.join(source_dir, '../../../../')

        # 2. Perform basebackup and deploy it into some dest.
        #    (currenttly hardcoded 'base') directory
        shutil.rmtree('base', True)

        logger.info('Performing and deploying base backup ...')
        standby.create()

        # 3.Copy recover.conf into the dest. directory to be used by StandBy
        logger.info('Deploying recovery.conf...')

        # 4. Initiate the StandBy using the Master (primary) postmaster
        #    paramerters
        logger.info('Initiating Standby...')
        res = standby.start()
        self.assertTrue(res.wasSuccessful())

        num_walsender = 0
        for i in polling(10, 0.5):
            num_walsender = self.count_wal_sender()
            if num_walsender > 0:
                break
        self.assertEqual(num_walsender, 1)

        logger.info('Activated WAL Receiver...')

        # 6. Run installcheck-good
        self.assertTrue(os.environ["GPSRC"])

        installCheckGoodPath = os.path.join(os.environ.get('GPSRC'),
                                                           'test',
                                                           'regress')

        self.assertTrue(os.path.exists(installCheckGoodPath))
        os.chdir(installCheckGoodPath)

        regression_diffs = os.path.join(installCheckGoodPath, 'regression.diffs')
        if os.path.exists(regression_diffs):
            os.remove(regression_diffs)

        logger.info('Perform InstallCheck-Good...')
        subprocess.check_call('make installcheck-good', shell=True)

        # Verify installcheck result by checking if regression.diff is present.
        self.assertTrue(not os.path.exists(regression_diffs))
示例#18
0
    def test_negative(self):
        """
            This test verifies that if the WAL sender dies due to
            to any reason ,it should not keep backends blocked on
            replication waiting forever in sync-rep queue
        """

        # Verify if the database is up. Run some sql.
        logger.info('Verify the DB is up...')
        PSQL.run_sql_command('DROP table if exists foo',
                             dbname=os.environ.get('PGDATABASE'))
        Command('remove standby', 'gpinitstandby -ra').run()
        self.assertEqual(self.standby.create(), 0)

        # Trigger file cleanup
        if (os.path.exists(os.path.join(self.standby.datadir,
                                        'wal_rcv_test'))):
            os.remove(os.path.join(self.standby.datadir, 'wal_rcv_test'))

        # Setup a standby
        logger.info('Setting up standby...')
        res = self.standby.start()
        self.assertTrue(res.wasSuccessful())

        # Wait for the walreceiver to start
        num_walsender = self.wait_for_walsender()
        self.assertEqual(num_walsender, 1)
        logger.info('Activated WAL Receiver...')

        # Once the WAL receiver starts, signal it to suspend
        wal_rcv_pid = self.get_pid_having_keyword('wal receiver process')
        trigger_content = 'wait_before_send'
        logger.info('Suspending WAL Receiver(' + str(wal_rcv_pid) + ') ' +
                    'with ' + trigger_content + '...')

        self.generate_trigger_file(trigger_content)
        os.kill(wal_rcv_pid, signal.SIGUSR2)

        # Once suspended, spawn a new backend so that it gets blocked
        # Confirm that its blocked

        result = False
        for i in walrepl.polling(20, 1):
            sql = 'CREATE TABLE foo%s(a int, b int)' % str(i)
            subprocess.Popen(['psql', '-c', sql],
                             stdout=subprocess.PIPE,
                             stderr=subprocess.PIPE)
            num_blocked = self.count_blocked()
            if num_blocked >= 1:
                result = True
                break

        self.assertTrue(result, "no backend blocked")

        logger.info(
            'The backend is blocked for replication (referred pg_stat_activity)...'
        )

        logger.info(
            'Shutdown the standby to break the connection with Master...')

        # Stop the standby as its of no use anymore
        self.standby.stop()

        # Verify that the wal sender died
        num_walsender = self.count_walsender()
        self.assertEqual(num_walsender, 0, "WAL sender has not gone")

        logger.info('Wal sender is now dead...')

        # Confirm that the there are no more replication waiting backends
        # Thats the test
        num_blocked = self.count_blocked()
        self.assertEqual(num_blocked, 0,
                         str(num_blocked) + " backends still blocked")
        logger.info('The backend is no more blocked...')
示例#19
0
    def test_negative(self):

        """
            This test verifies that if the WAL sender dies due to
            to any reason ,it should not keep backends blocked on
            replication waiting forever in sync-rep queue
        """

        # Verify if the database is up. Run some sql.
        logger.info ('Verify the DB is up...')
        PSQL.run_sql_command('DROP table if exists foo',dbname=os.environ.get('PGDATABASE'))
        Command('remove standby', 'gpinitstandby -ra').run()
        self.assertEqual(self.standby.create(), 0)

        # Trigger file cleanup
        if (os.path.exists(os.path.join(self.standby.datadir,
                                        'wal_rcv_test'))):
            os.remove(os.path.join(self.standby.datadir, 'wal_rcv_test'))

        # Setup a standby
        logger.info ('Setting up standby...')
        res = self.standby.start()
        self.assertTrue(res.wasSuccessful())

        # Wait for the walreceiver to start
        num_walsender = self.wait_for_walsender()
        self.assertEqual(num_walsender, 1)
        logger.info('Activated WAL Receiver...')

        # Once the WAL receiver starts, signal it to suspend
        wal_rcv_pid = self.get_pid_having_keyword('wal receiver process')
        trigger_content = 'wait_before_send'
        logger.info('Suspending WAL Receiver(' + str(wal_rcv_pid) +') ' +
              'with ' + trigger_content + '...')

        self.generate_trigger_file(trigger_content)
        os.kill(wal_rcv_pid, signal.SIGUSR2)

        # Once suspended, spawn a new backend so that it gets blocked
        # Confirm that its blocked

        result = False
        for i in walrepl.polling(20, 1):
            sql = 'CREATE TABLE foo%s(a int, b int)' % str(i)
            subprocess.Popen(['psql', '-c', sql],
                             stdout=subprocess.PIPE, stderr=subprocess.PIPE)
            num_blocked = self.count_blocked()
            if num_blocked >= 1:
                result = True
                break

        self.assertTrue(result, "no backend blocked")

        logger.info('The backend is blocked for replication (referred pg_stat_activity)...')

        logger.info('Shutdown the standby to break the connection with Master...')

        # Stop the standby as its of no use anymore
        self.standby.stop()

        # Verify that the wal sender died, max within 1 min
        for retry in range(1,30):
            num_walsender = self.count_walsender()
            if num_walsender == 0:
                break;
            logger.info('Wal sender still exists, retrying ...' + str(retry))
            time.sleep(2);

        self.assertEqual(num_walsender, 0, "WAL sender has not gone")

        logger.info('Wal sender is now dead...')

        # Confirm that the there are no more replication waiting backends
        # Thats the test
        num_blocked = self.count_blocked()
        self.assertEqual(num_blocked, 0,
                         str(num_blocked) + " backends still blocked")
        logger.info('The backend is no more blocked...')
示例#20
0
    def test_smart_shutdown(self):
        # 1. Verify if the system is UP and there is no WAL Receiver running
        # 2. Perform basebackup and deploy it into some dest. directory
        # 3. Copy recover.conf into the dest. directory to be used by Standby
        # 4. Initiate the Standby using the Master (primary) postmaster
        #    paramerters
        # 5. Perform some transaction to generate xlog. Then do a smart shutdown
        # 6. Once the primary DB is down, find the last checkpoint  from pg_control
        #    on primary. Check the last modified xlog seg from the standby and find
        #    if the last checkpoint from primary exists
        # 7. It should be present there!

        # 0. Stop standby if it's running
        PSQL.run_sql_command('DROP table if exists foo')
        standby = Standby('base', 5433)
        standby.stop()

        # 1. Verify if the system is UP and there is no WAL sender running
        self.assertEqual(self.count_walsender(), 0)
        logger.info('No active WAL Receiver found')

        # 2. Perform basebackup and deploy it into some dest.
        #    (currenttly hardcoded 'base') directory
        shutil.rmtree('base', True)

        logger.info('Performing and deploying base backup ...')
        standby.create()

        # 3.Copy recover.conf into the dest. directory to be used by StandBy
        logger.info('Deploying recovery.conf...')

        # 4. Initiate the StandBy using the Master (primary) postmaster
        #    paramerters
        logger.info('Initiating Standby...')
        res = standby.start()
        self.assertTrue(res.wasSuccessful())

        num_walsender = 0
        for i in polling(10, 0.5):
            num_walsender = self.count_walsender()
            if num_walsender > 0:
                break
        self.assertEqual(num_walsender, 1)

        logger.info('Activated WAL Receiver...')

        # 5. Perform some transaction to generate xlog. Then do a smart shutdown
        logger.info('Perform some transaction to generate some XLOG')
        PSQL.run_sql_command('Create table foo (a int)')

        logger.info('Now perform smart shutdown (gpstop -a)')
        cmd = Command(name="gpstop smart",
                      cmdStr="source %s/greenplum_path.sh;\
                      gpstop -a" % os.environ["GPHOME"])
        cmd.run(validateAfter=True)

        # 6. Once the primary DB is down, find the last checkpoint  from pg_control
        #    on primary. Check the last modified xlog seg from the standby and find
        #    if the last checkpoint from primary exists
        logger.info(
            'Read the pg_control from primary, find the last checkpoint & see if it made to standby'
        )

        standby_xlog_path = os.path.join('base', 'pg_xlog')

        cmd = Command(
            name='pg_controldata ' + os.environ.get('MASTER_DATA_DIRECTORY'),
            cmdStr='pg_controldata ' + os.environ.get('MASTER_DATA_DIRECTORY'))
        cmd.run(validateAfter=True)

        primary_last_ckpt_lsn = self.last_ckpt_lsn((cmd.get_results()).stdout)

        logger.info("Primary last checkpoint LSN = " + primary_last_ckpt_lsn)

        standby_last_mod_xlog = self.last_mod_file(standby_xlog_path)
        logger.info("Last mod standby XLOG = " + standby_last_mod_xlog)

        cmd = Command(name='xlogdump standby last modifiled xlog',
                      cmdStr="xlogdump " + standby_last_mod_xlog)
        cmd.run(validateAfter=True)

        logger.info('See if we find the shutdown LSN in the XLOG seg file')
        lines = (cmd.get_results()).stdout.splitlines()
        flag = False
        for line in range(0, len(lines) - 1):
            if ((lines[line]).find(primary_last_ckpt_lsn) > -1):
                self.assertTrue((lines[line]).find("checkpoint") > -1)
                self.assertTrue((lines[line]).find("shutdown") > -1)
                flag = True
                break

        self.assertTrue(flag)
        logger.info('PASS')

        # Re-start the database
        logger.info('Now restart the DB (gpstart -a)')
        cmd = Command(name="gpstop smart",
                      cmdStr="source %s/greenplum_path.sh;\
                      gpstart -a" % os.environ["GPHOME"])
        cmd.run(validateAfter=True)

        # Cleanup. Currently we dont have a clean way of WAL rcv dying
        logger.info(
            'Kill the standby processes as clean standby killing is not supported'
        )
        cmd = Command(
            name="kill standby",
            cmdStr=
            "kill -9 `ps -ef | grep 5433 | grep -v grep | awk '{print $2}'`")
        cmd.run(validateAfter=True)