MySQL-Cluster重启时两个数据节点启动速度慢，耗费时间特别长的问题

config.ini的参数配置情况：

[ndbd default]
NoOfReplicas= 2
MaxNoOfConcurrentOperations= 100000
MaxNoOfLocalOperations=500000
MaxNoOfConcurrentTransactions=50000
MaxNoOfConcurrentIndexOperations=50000
# Amount of memory required=(SizeofDatabase * NumberOfReplicas * 1.1 ) / NumberOfDataNodes
DataMemory= 25600M
IndexMemory= 3072M
TimeBetweenWatchDogCheck= 30000
DataDir=/var/lib/mysql/data
MaxNoOfAttributes=500000
MaxNoOfTables=1000
MaxNoOfOrderedIndexes= 512
StartPartialTimeout=100
StartPartitionedTimeout=100
ArbitrationTimeout=5000
MaxNoOfFiredTriggers=8000
TransactionBufferMemory=5M
TransactionDeadlockDetectionTimeout=90000
HeartbeatIntervalDbDb=5000
StopOnError=0

[ndb_mgmd default]
DataDir=/var/lib/mysql/data
[ndb_mgmd]
NodeId=1
HostName= 172.16.1.74
[ndb_mgmd]
NodeId=2
HostName= 172.16.1.75
[ndbd]
NodeId= 3
HostName= 172.16.1.74
[ndbd]
NodeId= 4
HostName= 172.16.1.75
[mysqld]
ArbitrationRank=2
[mysqld]
ArbitrationRank=2
[mysqld]
[mysqld]
[tcp default]
portnumber=2279

my.cnf中的配置参数：

[mysqld]
datadir=/var/lib/mysql/data/
socket=/var/lib/mysql/mysql.sock
lower_case_table_names=1
ndb_cluster_connection_pool=2
tmp_table_size=512M
max_heap_table_size=512M
thread_stack=1M
# Default to using old password format for compatibility with mysql 3.x
# clients (those using the mysqlclient10 compatibility package).
old_passwords=1
default-storage-engine=ndbcluster
ndbcluster
ndb-connectstring=172.16.1.74,172.16.1.75
[ndbd]
connect-string=172.16.1.74,172.16.1.75
[ndb_mgm]
connect-string=172.16.1.74,172.16.1.75
[ndb_mgmd]
config-file=/var/lib/mysql-cluster/config.ini
[mysql_cluster]
ndb-connectstring=172.16.1.74,172.16.1.75
[mysql.server]
user=mysql
basedir=/usr
[mysqld_safe]
log-error=/var/log/mysqld.log
#pid-file=/var/run/mysqld/mysqld.pid

[mysql]
#socket=/usr/local/var/mysql.sock
[mysqladmin]
#socket=/usr/local/var/mysql.sock
[ndb_restore default]

--在服务器上使用磁盘I/O监控分析工具收集了数据节点启动过程中的存储I/O的读写速度，发现读写速度只有10M/s左右，这就导致数据几点启动时需要把磁盘表中的数据加载到内存中耗费时间较长。这种情况的解决办法就是讲存储换成I/O性能更好的磁盘。使用固态硬盘将会大大提高大数据量情况下数据节点的启动速度。