在CentOS上实现HDFS(Hadoop分布式文件系统)的自动故障转移,主要依赖于Hadoop的高可用性配置。以下是详细的步骤和配置指南:
首先,确保你已经在CentOS上安装了Hadoop。你可以从Apache Hadoop官方网站下载并按照安装指南进行安装。
core-site.xml
编辑$HADOOP_HOME/etc/hadoop/core-site.xml
文件,添加以下配置:
<configuration>
<property>
<name>fs.defaultFS</name>
<value>hdfs://mycluster</value>
</property>
<property>
<name>ha.zookeeper.quorum</name>
<value>zk1:2181,zk2:2181,zk3:2181</value>
</property>
</configuration>
hdfs-site.xml
编辑$HADOOP_HOME/etc/hadoop/hdfs-site.xml
文件,添加以下配置:
<configuration>
<property>
<name>dfs.nameservices</name>
<value>mycluster</value>
</property>
<property>
<name>dfs.ha.namenodes.mycluster</name>
<value>nn1,nn2</value>
</property>
<property>
<name>dfs.namenode.rpc-address.mycluster.nn1</name>
<value>namenode1:8020</value>
</property>
<property>
<name>dfs.namenode.rpc-address.mycluster.nn2</name>
<value>namenode2:8020</value>
</property>
<property>
<name>dfs.namenode.http-address.mycluster.nn1</name>
<value>namenode1:50070</value>
</property>
<property>
<name>dfs.namenode.http-address.mycluster.nn2</name>
<value>namenode2:50070</value>
</property>
<property>
<name>dfs.namenode.shared.edits.dir</name>
<value>qjournal://journalnode1:8485;journalnode2:8485;journalnode3:8485/mycluster</value>
</property>
<property>
<name>dfs.client.failover.proxy.provider.mycluster</name>
<value>org.apache.hadoop.hdfs.server.namenode.ha.ConfiguredFailoverProxyProvider</value>
</property>
<property>
<name>dfs.ha.fencing.methods</name>
<value>sshfence</value>
</property>
<property>
<name>dfs.ha.fencing.ssh.private-key-files</name>
<value>/home/hadoop/.ssh/id_rsa</value>
</property>
<property>
<name>dfs.journalnode.edits.dir</name>
<value>/path/to/journalnode/data</value>
</property>
</configuration>
yarn-site.xml
编辑$HADOOP_HOME/etc/hadoop/yarn-site.xml
文件,添加以下配置:
<configuration>
<property>
<name>yarn.resourcemanager.ha.enabled</name>
<value>true</value>
</property>
<property>
<name>yarn.resourcemanager.cluster-id</name>
<value>yarn-cluster</value>
</property>
<property>
<name>yarn.resourcemanager.ha.rm-ids</name>
<value>rm1,rm2</value>
</property>
<property>
<name>yarn.resourcemanager.hostname.rm1</name>
<value>resourcemanager1</value>
</property>
<property>
<name>yarn.resourcemanager.hostname.rm2</name>
<value>resourcemanager2</value>
</property>
<property>
<name>yarn.resourcemanager.zk-address</name>
<value>zk1:2181,zk2:2181,zk3:2181</value>
</property>
<property>
<name>yarn.resourcemanager.scheduler.address.rm1</name>
<value>resourcemanager1:8032</value>
</property>
<property>
<name>yarn.resourcemanager.scheduler.address.rm2</name>
<value>resourcemanager2:8032</value>
</property>
<property>
<name>yarn.resourcemanager.webapp.address.rm1</name>
<value>resourcemanager1:8088</value>
</property>
<property>
<name>yarn.resourcemanager.webapp.address.rm2</name>
<value>resourcemanager2:8088</value>
</property>
</configuration>
确保你已经安装并配置了ZooKeeper集群。ZooKeeper用于管理Hadoop的高可用性状态。
在所有JournalNode节点上启动JournalNode服务:
$HADOOP_HOME/sbin/hadoop-daemon.sh start journalnode
在其中一个NameNode节点上格式化NameNode:
$HADOOP_HOME/bin/hdfs namenode -format
在其中一个NameNode节点上启动NameNode:
$HADOOP_HOME/sbin/hadoop-daemon.sh start namenode
在另一个NameNode节点上同步元数据:
$HADOOP_HOME/bin/hdfs namenode -bootstrapStandby
在Secondary NameNode节点上启动Secondary NameNode:
$HADOOP_HOME/sbin/hadoop-daemon.sh start secondarynamenode
在ResourceManager节点上启动ResourceManager:
$HADOOP_HOME/sbin/yarn-daemon.sh start resourcemanager
在所有NodeManager节点上启动NodeManager:
$HADOOP_HOME/sbin/yarn-daemon.sh start nodemanager
使用hdfs dfsadmin -report
命令验证HDFS集群的状态,确保所有NameNode和ResourceManager都正常运行。
通过以上步骤,你可以在CentOS上实现HDFS的自动故障转移。确保所有配置文件正确无误,并且所有服务都已正确启动。