七台机器部署Hadoop2.6.5高可用集群

1.HA架构注意事项

两个Namenode节点在某个时间只能有一个节点正常响应客户端请求，响应请求的节点状态必须是active
standby状态要能够快速无缝切换成active状态，两个NN节点必须时刻保持元数据一致
将edits文件放到qjournal(一种分布式应用，依赖zookeeper实现，管理edits)，而不存储在两个NN上，如果各个edits放在各个NN上，只能通过网络通信达到同步效果，可用性、安全性大大降低
每个namenode有一个监控进程zkfc，用来监控namenode是否异常
避免状态切换时发生brain split，执行自定义脚本杀死NN进程，确保只有一个NN是active状态
两个NN组成Federation

2.搭建准备

准备七台机器

3.安装过程

在CentOS7One机器上安装jdk、hadoop的过程不再赘述，参考本文

首先配置免密

CentOS7One需要免密连接CentOS7Five,CentOS7Six,CentOS7Seven，用以启动zookeeper,datanode

CentOS7Three需要免密连接CentOS7Five,CentOS7Six,CentOS7Seven，用以启动nodemanager

免密配置过程参考Hadoop免密钥配置

3.1 zookeeper配置

配置CentOS7Five的zoo.cfg

# The number of milliseconds of each tick

tickTime=2000

# The number of ticks that the initial

# synchronization phase can take

initLimit=10

# The number of ticks that can pass between

# sending a request and getting an acknowledgement

syncLimit=5

# the directory where the snapshot is stored.

# do not use /tmp for storage, /tmp here is just

# example sakes.

dataDir=/opt/zkdata

dataLogDir=/opt/zkdatalog

# the port at which the clients will connect

clientPort=2181

# the maximum number of client connections.

# increase this if you need to handle more clients

#maxClientCnxns=60

#

# Be sure to read the maintenance section of the

# administrator guide before turning on autopurge.

#

# http://zookeeper.apache.org/doc/current/zookeeperAdmin.html#sc_maintenance

#

# The number of snapshots to retain in dataDir

#autopurge.snapRetainCount=3

# Purge task interval in hours

# Set to "0" to disable auto purge feature

#autopurge.purgeInterval=1

server.4=192.168.94.142:2888:3888

server.5=192.168.94.143:2888:3888

server.6=192.168.94.144:2888:

将配置好的zookeeper复制到CentOS7Six,CentOS7Seven

scp /opt/zookeeper/zookeeper-3.4.10 CentOS7Six:/opt/zookeeper/zookeeper-3.4.10

scp /opt/zookeeper/zookeeper-3.4.10 CentOS7Seven:/opt/zookeeper/zookeeper-3.4.10

3.2 hadoop配置

编辑CentOS7One的core-site.xml

<?xml version="1.0" encoding="UTF-8"?>

<?xml-stylesheet type="text/xsl" href="configuration.xsl"?>

<!--

  Licensed under the Apache License, Version 2.0 (the "License");

  you may not use this file except in compliance with the License.

  You may obtain a copy of the License at

    http://www.apache.org/licenses/LICENSE-2.0

  Unless required by applicable law or agreed to in writing, software

  distributed under the License is distributed on an "AS IS" BASIS,

  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.

  See the License for the specific language governing permissions and

  limitations under the License. See accompanying LICENSE file.

-->

<!-- Put site-specific property overrides in this file. -->

<configuration>

<property>

<name>fs.defaultFS</name>

<value>hdfs://ns1/</value>

</property>

<property>

<name>hadoop.tmp.dir</name>

<value>/usr/local/hadoop-2.6.5/data</value>

</property>

<property>

        <name>ha.zookeeper.quorum</name>

        <value>CentOS7Five:2181,CentOS7Six:2181,CentOS7Seven:2181</value>

</property>

</configuration>

编辑CentOS7One的hdfs-site.xml

<?xml version="1.0" encoding="UTF-8"?>

<?xml-stylesheet type="text/xsl" href="configuration.xsl"?>

<!--

  Licensed under the Apache License, Version 2.0 (the "License");

  you may not use this file except in compliance with the License.

  You may obtain a copy of the License at

    http://www.apache.org/licenses/LICENSE-2.0

  Unless required by applicable law or agreed to in writing, software

  distributed under the License is distributed on an "AS IS" BASIS,

  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.

  See the License for the specific language governing permissions and

  limitations under the License. See accompanying LICENSE file.

-->

<!-- Put site-specific property overrides in this file. -->

<configuration>

<!--指定hdfs的nameservice为ns1，需要和core-site.xml中的保持一致 -->

<property>

<name>dfs.nameservices</name>

<value>ns1</value>

</property>

<!-- ns1下面有两个NameNode，分别是nn1，nn2 -->

<property>

<name>dfs.ha.namenodes.ns1</name>

<value>nn1,nn2</value>

</property>

<!-- nn1的RPC通信地址 -->

<property>

<name>dfs.namenode.rpc-address.ns1.nn1</name>

<value>CentOS7One:9000</value>

</property>

<!-- nn1的http通信地址 -->

<property>

<name>dfs.namenode.http-address.ns1.nn1</name>

<value>CentOS7One:50070</value>

</property>

<!-- nn2的RPC通信地址 -->

<property>

<name>dfs.namenode.rpc-address.ns1.nn2</name>

<value>CentOS7Two:9000</value>

</property>

<!-- nn2的http通信地址 -->

<property>

<name>dfs.namenode.http-address.ns1.nn2</name>

<value>CentOS7Two:50070</value>

</property>

<!-- 指定NameNode的元数据在JournalNode上的存放位置 -->

<property>

<name>dfs.namenode.shared.edits.dir</name>

<value>qjournal://CentOS7Five:8485;CentoS7Six:8485;CentOS7Seven:8485/ns1</value>

</property>

<!-- 指定JournalNode在本地磁盘存放数据的位置 -->

<property>

<name>dfs.journalnode.edits.dir</name>

<value>/usr/local/hadoop-2.6.5/journaldata</value>

</property>

<!-- 开启NameNode失败自动切换 -->

<property>

<name>dfs.ha.automatic-failover.enabled</name>

<value>true</value>

</property>

<!-- 配置失败自动切换实现方式 -->

<property>

<name>dfs.client.failover.proxy.provider.ns1</name>

<value>org.apache.hadoop.hdfs.server.namenode.ha.ConfiguredFailoverProxyProvider</value>

</property>

<!-- 配置隔离机制方法，多个机制用换行分割，即每个机制暂用一行-->

<property>

<name>dfs.ha.fencing.methods</name>

<value>

sshfence

shell(/bin/true)

</value>

</property>

<!-- 使用sshfence隔离机制时需要ssh免登陆 -->

<property>

<name>dfs.ha.fencing.ssh.private-key-files</name>

<value>/root/.ssh/id_rsa</value>

</property>

<!-- 配置sshfence隔离机制超时时间 -->

<property>

<name>dfs.ha.fencing.ssh.connect-timeout</name>

<value>30000</value>

</property>

</configuration>

编辑CentOS7One的mapred-site.xml

<?xml version="1.0"?>

<?xml-stylesheet type="text/xsl" href="configuration.xsl"?>

<!--

  Licensed under the Apache License, Version 2.0 (the "License");

  you may not use this file except in compliance with the License.

  You may obtain a copy of the License at

    http://www.apache.org/licenses/LICENSE-2.0

  Unless required by applicable law or agreed to in writing, software

  distributed under the License is distributed on an "AS IS" BASIS,

  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.

  See the License for the specific language governing permissions and

  limitations under the License. See accompanying LICENSE file.

-->

<!-- Put site-specific property overrides in this file. -->

<configuration>

<property>

<name>mapreduce.framework.name</name>

<value>yarn</value>

</property>

</configuration>

编辑CentOS7One的yarn-site.xml

<?xml version="1.0"?>

<!--

  Licensed under the Apache License, Version 2.0 (the "License");

  you may not use this file except in compliance with the License.

  You may obtain a copy of the License at

    http://www.apache.org/licenses/LICENSE-2.0

  Unless required by applicable law or agreed to in writing, software

  distributed under the License is distributed on an "AS IS" BASIS,

  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.

  See the License for the specific language governing permissions and

  limitations under the License. See accompanying LICENSE file.

-->

<configuration>

<!-- 开启RM高可用 -->

<property>

<name>yarn.resourcemanager.ha.enabled</name>

<value>true</value>

</property>

<!-- 指定RM的cluster id -->

<property>

<name>yarn.resourcemanager.cluster-id</name>

<value>yrc</value>

</property>

<!-- 指定RM的名字 -->

<property>

<name>yarn.resourcemanager.ha.rm-ids</name>

<value>rm1,rm2</value>

</property>

<!-- 分别指定RM的地址 -->

<property>

<name>yarn.resourcemanager.hostname.rm1</name>

<value>CentOS7Three</value>

</property>

<property>

<name>yarn.resourcemanager.hostname.rm2</name>

<value>CentOS7Four</value>

"yarn-site.xml" 52L, 1479C

<name>yarn.resourcemanager.hostname.rm2</name>

<value>CentOS7Four</value>

</property>

<!-- 指定zk集群地址 -->

<property>

<name>yarn.resourcemanager.zk-address</name>

<value>CentOS7Five:2181,CentOS7Six:2181,CentOS7Seven:2181</value>

</property>

<property>

<name>yarn.nodemanager.aux-services</name>

<value>mapreduce_shuffle</value>

</property>

</configuration>

将配置好的Hadoop发送给所有机器

scp -r /usr/local/hadoop-2.6.5 CentOS7Two:/usr/local/hadoop-2.6.5/

scp -r /usr/local/hadoop-2.6.5 CentOS7Three:/usr/local/hadoop-2.6.5/

scp -r /usr/local/hadoop-2.6.5 CentOS7Four:/usr/local/hadoop-2.6.5/

scp -r /usr/local/hadoop-2.6.5 CentOS7Five:/usr/local/hadoop-2.6.5/

scp -r /usr/local/hadoop-2.6.5 CentOS7Six:/usr/local/hadoop-2.6.5/

scp -r /usr/local/hadoop-2.6.5 CentOS7Seven:/usr/local/hadoop-2.6.5/

至此，配置完毕

4.启动流程

在CentOS7Five,CentOS7Six,CentOS7Seven启动zookeeper

sh zkServer.sh start

在CentOS7Five,CentOS7Six,CentOS7Seven启动journalnode

sh hadoop-daemon.sh start journalnode

在CentOS7One上格式化namenode（以后启动无需格式化）

hdfs namenode -format

在CentOS7One上格式化 ZKFC（以后启动无需格式化）

hdfs zkfc -formatZK

在CentOS7One上启动hdfs

sh start-dfs.sh

在CentOS7Three,CentOS7Four上启动yarn

sh start-yarn.sh

5.结果

CentOS7One启动成功应该有如下进程

[root@CentOS7One ~]# jps

17397 DFSZKFailoverController

17111 NameNode

17480 Jps

CentOS7Two

[root@CentOS7Two ~]# jps

2497 Jps

2398 DFSZKFailoverController

2335 NameNode

CentOS7Three

[root@CentOS7Three ~]# jps

2344 ResourceManager

2619 Jps

CentOS7Four

[root@CentOS7Four ~]# jps

2344 ResourceManager

2619 Jps

CentOS7Five

[root@CentOS7Five logs]# jps

2803 Jps

2310 QuorumPeerMain

2460 JournalNode

2668 NodeManager

2543 DataNode

CentOS7Six

[root@CentOS7Six ~]# jps

2400 JournalNode

2608 NodeManager

2483 DataNode

2743 Jps

2301 QuorumPeerMain

CentOS7Seven

[root@CentOS7Seven ~]# jps

2768 Jps

2313 QuorumPeerMain

2425 JournalNode

2650 NodeManager

2525 DataNode

访问http://centos7one:50070，可以看到我们有三个datanode

访问http://centos7three:8088/

查看集群情况

6.致谢

https://www.cnblogs.com/biehongli/p/7660310.html

https://www.bilibili.com/video/av15390641/?p=44

7.常见问题

7.1 备用Namenode启动失败

原因：主节点格式化后备用节点的data目录还是原来的

解决：主节点格式化之后要将主节点data目录复制给备用

sh /usr/local/hadoop-2.6./hadoop-2.6./bin/hadoop namenode -format

scp -r /usr/local/hadoop-2.6.5/data/ CentOS7Two:/usr/local/hadoop-2.6.5/