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。