hadoop2.0 QJM方式的HA的配置
1 准备
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namenode1
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namenode2
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journalnode1
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journalnode2
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journalnode3
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 >
</ 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 >sshfence</ value >
</ property >
< property >
< name >dfs.ha.fencing.ssh.private-key-files</ name >
< value >/root/.ssh/id_rsa</ value >
</ property >
< property >
< name >dfs.ha.fencing.ssh.connect-timeout</ name >
< value >6000</ value >
</ property >
< property >
< name >dfs.ha.automatic-failover.enabled</ name >
< value >false</ value >
</ property >
</ configuration >
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dfs.ha.automatic-failover.enabled
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fs.ha.namenodes.mycluster
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dfs.namenode.shared.edits.dir
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dfs.journalnode.edits.dir
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dfs.ha.fencing.methods
3 启动
3.1 先在journalnode机器上启动journalnode
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$HADOOP_HOME /sbin/hadoop-daemon .sh
start journalnode
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3.2 在namenode机器上启动namenode
3.2.1
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$HADOOP_HOME /bin/hadoop namenode
- format
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$HADOOP_HOME /bin/hdfs namenode
-initializeSharedEdits
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3.2.2
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$HADOOP_HOME /sbin/hadoop-daemon .sh
start namenode
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3.2.3
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$HADOOP_HOME /sbin/hadoop-daemon .sh
start namenode -bootstrapStandby
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3.2.4
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$HADOOP_HOME /sbin/hadoop-daemon .sh
start namenode
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3.2.5
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$HADOOP_HOME /bin/hdfs haadmin
-transitionToActive nn1
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3.3 在datanode机器上启动datanode
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$HADOOP_HOME /sbin/hadoop-daemon .sh
start datanode
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3.4 检查
4 测试
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$HADOOP_HOME /bin/hdfs haadmin
-transitionToActive nn2
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$HADOOP_HOME /bin/hdfs haadmin
-failover nn1 nn2
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5 QJM方式HA的结构图
6 实战tips
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在namenode1做的一些配置和操作,在namenode2上也要做一次,保持2台机器一致。
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注意首次启动(第一次启动的时候就是HA)和非首次启动(运行一段时间后加入HA特性)的区别。
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因为HA的自动切换容易出现ssh登陆和权限的问题,而且网上也有资料测试自动切换有时候会不成功,所以在生产环境还是建议采用手工切换的方式,这样更加可靠,有问题也可以及时查。