hadoop2.0 HA的主备自动切换
1 准备
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zookeeper1
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zookeeper2
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zookeeper3
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namenode1
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namenode2
2 配置
2.1 core-site.xml
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< configuration >
< property >
< name >fs.defaultFS</ name >
< value >hdfs://mycluster</ value >
</ property >
< property >
< name >hadoop.tmp.dir</ name >
< value >/home/tmp/hadoop2.0</ value >
</ property >
< property >
< name >ha.zookeeper.quorum</ name >
< value >zookeeper1:2181,zookeeper2:2181,zookeeper3:2181</ value >
</ property >
</ configuration >
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2.2 hdfs-site.xml
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< configuration >
< property >
< name >dfs.replication</ name >
< value >1</ value >
</ property >
< property >
< name >dfs.namenode.name.dir</ name >
< value >/home/dfs/name</ value >
</ property >
< property >
< name >dfs.datanode.data.dir</ name >
< value >/home/dfs/data</ value >
</ property >
< property >
< name >dfs.permissions</ name >
< value >false</ value >
</ property >
< 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.journalnode.edits.dir</ name >
< value >/home/dfs/journal</ 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 >shell(/bin/true)</ value >
</ property >
< property >
< name >dfs.ha.automatic-failover.enabled</ name >
< value >true</ value >
</ property >
</ configuration >
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dfs.ha.automatic-failover.enabled
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dfs.ha.fencing.methods
3 在zookeeper中初始化
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$HADOOP_HOME /bin/hdfs zkfc
-formatZK
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4 启动zkfc(zookeeper failover controller)
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$HADOOP_HOME /sbin/hadoop-daemon .sh
start zkfc
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5 启动HDFS
6 测试
7 QJM方式HA automatic failover的结构图
8 实战tips
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zookeeper可以在hadoop集群中选几台机器同时作为zookeeper节点,给HA私用。
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在实践中建议采用手工切换的方式,这样更可靠,也方便查找问题。