[Err] 1296 - Got error 4008 'Receive from NDB failed' from NDBCLUSTER (no replies)

I used mysql-cluster-advanced-7.4.6-linux-glibc2.5-x86_64.tar.gz on my Linux (OS:redhat 6),There are 2 mgm nodes,4 data nodes and 4 sql nodes. BTY,the sql node and the data node are on the same mechine. every mechine has the same hardware : 32G memory, 16 Cpu , i encounterd a strange problem ,when i query a join sql:
SELECT
I.PARTY_ID,
I.ID_TP_CD,
I.REF_NUM,
I.MATCH_NUM
FROM
PARTY PA
LEFT JOIN PERSON PE ON PE.PARTY_ID = PA.PARTY_ID
LEFT JOIN IDENTIFIER I ON I.PARTY_ID = PA.PARTY_ID
LEFT JOIN PERSON_NAME PN ON PN.PARTY_ID = PA.PARTY_ID
WHERE
PA.INACTIVATED_DT IS NULL
AND PE.GENDER_TP_CODE = 2
AND PE.BIRTH_DT = '2011-12-10'
AND PN.LAST_NAME = 'name-测试111'

it has errors:[Err] 1296 - Got error 4008 'Receive from NDB failed' from NDBCLUSTER

and every table have the primary key party_id,and the sum record is 15000000 , but when i query a simple sql ,ie, select * from party where party_id=123434;
it can return successfully .
mgm configuration:

[ndbd default]

NoOfReplicas=2 # Number of replicas
DataMemory=7000M # How much memory to allocate for data storage
IndexMemory=2000M # How much memory to allocate for index storage
MaxNoOfConcurrentTransactions = 8096
MaxNoOfConcurrentOperations = 20M
NoOfFragmentLogFiles =500
TransactionDeadLockDetectionTimeOut=10000
TotalSendBufferMemory = 256M

[tcp default]
SendBufferMemory=16M
ReceiveBufferMemory=16M

[ndb_mgmd]
NodeId=1
hostname=22.8.129.203 # Hostname or IP address of MGM node
datadir=/hadoop/mysql/mysql_cluster/data # Directory for MGM node log files

[ndb_mgmd]
NodeId=2
hostname=22.8.129.204 # Hostname or IP address of MGM node
datadir=/hadoop/mysql/mysql_cluster/data # Directory for MGM node log files

[ndbd]
NodeId=3
hostname=22.8.129.205 # Hostname or IP address
datadir=/hadoop/mysql/mysql_cluster/data # Directory for this data node's data files

[ndbd]
NodeId=4
hostname=22.8.129.206 # Hostname or IP address
datadir=/hadoop/mysql/mysql_cluster/data # Directory for this data node's data files


[ndbd]
NodeId=7
hostname=22.8.129.207 # Hostname or IP address
datadir=/hadoop/mysql/mysql_cluster/data # Directory for this data node's data files

[ndbd]
NodeId=9
hostname=22.8.129.209 # Hostname or IP address
datadir=/hadoop/mysql/mysql_cluster/data # Directory for this data node's data files

[mysqld]
NodeId=5
hostname=22.8.129.205 # Hostname or IP address

[mysqld]
NodeId=6
hostname=22.8.129.206 # Hostname or IP address

[mysqld]
NodeId=19
hostname=22.8.129.207 # Hostname or IP address

[mysqld]
NodeId=20
hostname=22.8.129.209 # Hostname or IP address


sql node and data node configuration:
[mysqld]
max_connections = 8096
max_connect_errors = 99999999
max_user_connections = 8000
wait_timeout = 28800
interactive_timeout = 28800
thread_concurrency = 16
basedir = /hadoop/mysql/mysql_cluster
datadir = /hadoop/mysql/mysql_cluster/data
log-error=/hadoop/mysql/log/mysqld.log
character_set_server = utf8
sql_mode=NO_ENGINE_SUBSTITUTION
ndbcluster
ndb-connectstring=22.8.129.203,22.8.129.204
[mysql_cluster]
ndb-connectstring=22.8.129.203,22.8.129.204

i want to know if this is a bug?

and i was wondering that i have set the dataMemory and indexMemory in config.ini,why when i start the cluster , i found the sql node and data node has used almost the full memory of the mechine?(31G) even if i restart the cluster..