Mysql cluster problem.ndbd down !

[NiCK_76]

ndbd down when was started about 1 minute....
Why?

As trace log is following:

--------------- Signal ----------------
r.bn: 253 "NDBFS", r.proc: 2, r.sigId: 1708759 gsn: 264 "FSREADREQ" prio: 0
s.bn: 248 "DBACC", s.proc: 2, s.sigId: 1708758 length: 10 trace: 0 #sec: 0
fragInf: 0
UserPointer: 0
FilePointer: 545
UserReference: H'00f80002 Operation flag: H'00000000 (No sync, Format=List of pairs)
varIndex: 2
numberOfPages: 2
pageData: H'00000000, H'0000003b
H'00000001, H'0000003c


As config.ini is following:
[NDBD DEFAULT]
NoOfReplicas= 2
DataDir= /var/lib/mysql-cluster
DataMemory = 700M
IndexMemory = 196M
MaxNoOfOrderedIndexes = 1024
MaxNoOfUniqueHashIndexes = 512
MaxNoOfConcurrentOperations=250000
UndoIndexBuffer=10M
RedoBuffer=32M
NoOfFragmentLogFiles=16

[NDB_MGMD]
Hostname= 61.129.68.152
DataDir= /var/lib/mysql-cluster

[NDBD]
Hostname= 61.129.68.141

[NDBD]
Hostname= 61.129.68.152

[MYSQLD]
Hostname= 61.129.68.141

[MYSQLD]
Hostname= 61.129.68.152

[NiCK_76]

I solved below problem by mysql maillist.However , another problem cornered me.
"ERROR 1297: Get temporary error 4031 'Node failure caused abort of transaction' from ndbcluster" appear when alter a big table to ndb engine. The big table contain about 800000 rows.

How to solve it?