NDB7.5.4: start/stop/restart nodes in ndb_mgm client got Permanent error: Application error (no replies)

I installed MySQL Cluster CGE edition version 7.5.4 downloaded from Oracle edilivery site. And what I used is the binary tar.gz file, followed by officail instruction documents. Required by our use case, I installed all MGM node, SQL node and Data node on one system.

When I use ndb_mgm client to manage the cluster, only show information commands and shutdown command work. start/stop/restart can not work.

Could someone help to look at my problems? Thanks very much in advance.

Errors like below:
==================
ndb_mgm> show
Connected to Management Server at: localhost:1186
Cluster Configuration
---------------------
[ndbd(NDB)] 1 node(s)
id=2 @127.0.0.1 (mysql-5.7.16 ndb-7.5.4, Nodegroup: 0, *)

[ndb_mgmd(MGM)] 1 node(s)
id=1 @127.0.0.1 (mysql-5.7.16 ndb-7.5.4)

[mysqld(API)] 1 node(s)
id=3 @127.0.0.1 (mysql-5.7.16 ndb-7.5.4)

ndb_mgm> 2 stop
Node 2: Node shutdown aborted
Shutdown failed.
* 2002: Stop failed
* Node shutdown would cause system crash: Permanent error: Application error

ndb_mgm> 2 restart
Node 2: Node shutdown aborted
Restart failed.
* 2003: Restart failed
* 5028-Node shutdown would cause system crash: Permanent error: Application error


Here is how I start up three nodes:
===================================
# ps -ef | grep mysql
root 6583 1 0 Dec19 ? 00:21:57 /u03/app/oracle/mysqlcluster/mgm_node/bin/ndb_mgmd --initial -f /u03/app/oracle/mysqlcluster/mgm_node/config.ini --config-cache=0
root 6595 1 0 Dec19 ? 00:01:10 /u03/app/oracle/mysqlcluster/data_node/bin/ndbd --defaults-file=/u03/app/oracle/mysqlcluster/data_node/my.cnf
root 6596 6595 0 Dec19 ? 00:22:03 /u03/app/oracle/mysqlcluster/data_node/bin/ndbd --defaults-file=/u03/app/oracle/mysqlcluster/data_node/my.cnf
oracle 6668 1 0 Dec19 ? 00:37:08 /u03/app/oracle/mysqlcluster/sql_node/bin/mysqld --defaults-file=/u03/app/oracle/mysqlcluster/sql_node/my.cnf
root 31605 31076 0 14:04 pts/1 00:00:00 grep mysql


Here is configuration for MGM node:
===================================
# cat config.ini
[ndbd default]
# If there is only one data node, NoOfReplicas should be set to 1, default value is 2
NoOfReplicas=1
DataMemory=1G
IndexMemory=200M

[tcp default]
# It is recommended not to specify the port
# portnumber=2202

[ndb_mgmd]
hostname=localhost
datadir=/u03/app/oracle/mysqlcluster/mgm_node/data
portnumber=1186

[ndbd]
hostname=localhost
datadir=/u03/app/oracle/mysqlcluster/data_node/data

[mysqld]
hostname=localhost

Configuration for Data node:
============================
# cat my.cnf
[mysqld]
datadir=/u03/app/oracle/mysqlcluster/data_node/data
ndbcluster

[mysql_cluster]
# location of management server
ndb-connectstring=localhost


Configuration for SQL node:
===========================
# cat my.cnf
[mysqld]
ndbcluster
datadir=/u03/app/oracle/mysqlcluster/sql_node/data
socket=/u03/app/oracle/mysqlcluster/sql_node/data/mysqld.sock
port=49500
user=oracle

pid-file=/u03/app/oracle/mysqlcluster/sql_node/data/mysqld.pid
log-error=/u03/app/oracle/mysqlcluster/sql_node/data/mysqld.err

[mysql_cluster]
# location of management server
ndb-connectstring=localhost