在Linux上配置Hadoop分布式文件系统(HDFS)的高可用性(HA)可以确保系统在关键组件出现故障时仍能继续运行,从而保障数据的高可用性和可靠性。以下是一个基本的HDFS高可用性配置方案:
<configuration>
<property>
<name>fs.defaultFS</name>
<value>hdfs://mycluster</value>
</property>
<property>
<name>hadoop.tmp.dir</name>
<value>/path/to/hadoop-tmp</value>
</property>
</configuration>
<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>/path/to/private/key</value>
</property>
<property>
<name>dfs.journalnode.edits.dir</name>
<value>/path/to/journalnode/data</value>
</property>
</configuration>
<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>zookeeper1:2181,zookeeper2:2181,zookeeper3:2181</value>
</property>
</configuration>
在其中一个NameNode上执行以下命令:
hdfs namenode -format
在所有JournalNode节点上启动JournalNode服务:
hdfs --daemon start journalnode
在其中一个NameNode上执行以下命令,将元数据同步到JournalNode:
hdfs namenode -bootstrapStandby
在所有NameNode节点上启动NameNode服务:
hdfs --daemon start namenode
在所有ResourceManager节点上启动ResourceManager服务:
yarn --daemon start resourcemanager
访问HDFS Web界面,确保两个NameNode都显示为Active/Standby状态。运行一些HDFS命令,验证集群是否正常工作。
确保客户端配置文件(如core-site.xml和hdfs-site.xml)包含正确的配置,以便客户端能够正确地进行故障转移。