转自:http://www.2cto.com/os/201605/510489.html
hadoop1的核心组成是两部分,即HDFS和MapReduce。在hadoop2中变为HDFS和Yarn。新的HDFS中的NameNode不再是只有一个了,可以有多个(目前只支持2个)。每一个都有相同的职能。
两个NameNode
当集群运行时,只有active状态的NameNode是正常工作的,standby状态的NameNode是处于待命状态的,时刻同步active状态NameNode的数据。一旦active状态的NameNode不能工作,通过手工或者自动切换,standby状态的NameNode就可以转变为active状态的,就可以继续工作了。这就是高可靠。
NameNode发生故障时
2个NameNode的数据其实是实时共享的。新HDFS采用了一种共享机制,JournalNode集群或者NFS进行共享。NFS是操作系统层面的,JournalNode是hadoop层面的,我们这里使用JournalNode集群进行数据共享。
实现NameNode的自动切换
需要使用ZooKeeper集群进行选择了。HDFS集群中的两个NameNode都在ZooKeeper中注册,当active状态的NameNode出故障时,ZooKeeper能检测到这种情况,它就会自动把standby状态的NameNode切换为active状态。
HDFS Federation
NameNode是核心节点,维护着整个HDFS中的元数据信息,那么其容量是有限的,受制于服务器的内存空间。当NameNode服务器的内存装不下数据后,那么HDFS集群就装不下数据了,寿命也就到头了。因此其扩展性是受限的。HDFS联盟指的是有多个HDFS集群同时工作,那么其容量理论上就不受限了,夸张点说就是无限扩展。
配置过程详述
配置文件一共包括6个,分别是hadoop-env.sh、core-site.xml、hdfs-site.xml、mapred-site.xml、yarn-site.xml和slaves。除了hdfs-site.xml文件在不同集群配置不同外,其余文件在四个节点的配置是完全一样的,可以复制。
hadoop-env.sh
默认的HDFS路径。当有多个HDFS集群同时工作时,用户如果不写集群名称,那么默认使用哪个哪就在这里指定!该值来自于hdfs-site.xml中的配置
默认是NameNode、DataNode、JournalNode等存放数据的公共目录
ZooKeeper集群的地址和端口。注意,数量一定是奇数
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<configuration> <property>
<name>fs.defaultFS</name>
<value>hdfs://cluster1</value>
</property>
<property>
<name>hadoop.tmp.dir</name>
<value>/opt/ha/hadoop-2.7.2/data/tmp</value>
</property>
<property>
<name>io.file.buffer.size</name>
<value>131072</value>
</property>
<property>
<name>ha.zookeeper.quorum</name>
<value>hadoop:2181,hadoop1:2181,hadoop2:2181;slave1:2181;slave2:2181</value>
</property>
</configuration> |
hdfs-site.xml
这里dfs.namenode.shared.edits.dir的只在hadoop1,hadoop2中最后路径为cluster1,在slave1,slave2中最后路径为cluster2,区分开就行,可以是别的名称,还有一个core-site.xml中的fs.defaultFS在slave1和slave2中可以更改为cluster2
yarn-site.xml
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<property> <name>yarn.nodemanager.aux-services</name>
<value>mapreduce_shuffle</value>
</property><property> <name>yarn.nodemanager.aux-services.mapreduce.shuffle.class</name>
<value>org.apache.hadoop.mapred.ShuffleHandler</value>
</property><property> <name>yarn.resourcemanager.hostname</name>
<value>hadoop</value>
</property><property> <name>yarn.log-aggregation-enable</name>
<value>true</value>
</property><property> <name>yarn.log-aggregation.retain-seconds</name>
<value>604800</value>
</property> |
mapred-site.xml
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<property> <name>mapreduce.framework.name</name>
<value>yarn</value>
</property><property> <name>mapreduce.job.tracker</name>
<value>hdfs://hadoop:9001</value>
<final>true</final>
</property><property> <name>mapreduce.jobhistory.address</name>
<value>hadoop:10020</value>
</property><property> <name>mapreduce.jobhistory.webapp.address</name>
<value>hadoop:19888</value>
</property> |
slaves
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hadoophadoop1hadoop2slave1slave2 |
启动过程
在所有zk节点启动zookeeper
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hadoop@hadoop:hadoop-2.7.2$ zkServer.sh start |
格式化zookeeper集群
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[hadoop@hadoop1 hadoop-2.7.2]$ bin/hdfs zkfc -formatZK[hadoop@slave1 hadoop-2.7.2]$ bin/hdfs zkfc -formatZK[hadoop@slave1 hadoop-2.7.2]$ zkCli.sh[zk: localhost:2181(CONNECTED) 5] ls /hadoop-ha/clustercluster2 cluster1 |
在所有节点启动journalnode
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hadoop@hadoop:hadoop-2.7.2$ sbin/hadoop-daemon.sh start journalnodestarting journalnode, logging to /opt/ha/hadoop-2.7.2/logs/hadoop-hadoop-journalnode-hadoop.out
hadoop@hadoop:hadoop-2.7.2$ |
在cluster1中的nn1格式化namenode,验证并启动
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[hadoop@hadoop1 hadoop-2.7.2]$ bin/hdfs namenode -format -clusterId hadoop116/05/19 15:43:01 INFO common.Storage: Storage directory /opt/ha/hadoop-2.7.2/data/dfs/name has been successfully formatted.
16/05/19 15:43:01 INFO namenode.NNStorageRetentionManager: Going to retain 1 images with txid >= 0
16/05/19 15:43:01 INFO util.ExitUtil: Exiting with status 0
16/05/19 15:43:01 INFO namenode.NameNode: SHUTDOWN_MSG: /************************************************************SHUTDOWN_MSG: Shutting down NameNode at hadoop1/192.168.2.10
************************************************************/[hadoop@hadoop1 hadoop-2.7.2]$ ls data/dfs/name/current/
fsimage_0000000000000000000 seen_txidfsimage_0000000000000000000.md5 VERSION[hadoop@hadoop1 hadoop-2.7.2]$ sbin/hadoop-daemon.sh start namenodestarting namenode, logging to /opt/ha/hadoop-2.7.2/logs/hadoop-hadoop-namenode-hadoop1.out
[hadoop@hadoop1 hadoop-2.7.2]$ jps9551 NameNode9423 JournalNode9627 Jps9039 QuorumPeerMain |
http://hadoop1:50070查看
cluster1中另一个节点同步数据格式化,并启动
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[hadoop@hadoop2 hadoop-2.7.2]$ bin/hdfs namenode -bootstrapStandby......16/05/19 15:48:27 INFO common.Storage: Storage directory /opt/ha/hadoop-2.7.2/data/dfs/name has been successfully formatted.
16/05/19 15:48:27 INFO namenode.TransferFsImage: Opening connection to http://hadoop1:50070/imagetransfer?getimage=1&txid=0&storageInfo=-63:1280767544:0:hadoop1
16/05/19 15:48:28 INFO namenode.TransferFsImage: Image Transfer timeout configured to 60000 milliseconds
16/05/19 15:48:28 INFO namenode.TransferFsImage: Transfer took 0.00s at 0.00 KB/s
16/05/19 15:48:28 INFO namenode.TransferFsImage: Downloaded file fsimage.ckpt_0000000000000000000 size 353 bytes.
16/05/19 15:48:28 INFO util.ExitUtil: Exiting with status 0
16/05/19 15:48:28 INFO namenode.NameNode: SHUTDOWN_MSG: /************************************************************SHUTDOWN_MSG: Shutting down NameNode at hadoop2/192.168.2.11
************************************************************/[hadoop@hadoop2 hadoop-2.7.2]$ ls data/dfs/name/current/
fsimage_0000000000000000000 seen_txidfsimage_0000000000000000000.md5 VERSION[hadoop@hadoop2 hadoop-2.7.2]$ [hadoop@hadoop2 hadoop-2.7.2]$ sbin/hadoop-daemon.sh start namenodestarting namenode, logging to /opt/ha/hadoop-2.7.2/logs/hadoop-hadoop-namenode-hadoop2.out
[hadoop@hadoop2 hadoop-2.7.2]$ jps7196 Jps6980 JournalNode7120 NameNode6854 QuorumPeerMain |
http://hadoop2:50070查看如下
使用以上步骤同是启动cluster2的两个namenode;这里省略
然后启动所有的datanode和(必须也在hadoop节点上启动)yarn
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[hadoop@hadoop1 hadoop-2.7.2]$ sbin/hadoop-daemons.sh start datanodehadoop1: starting datanode, logging to /opt/ha/hadoop-2.7.2/logs/hadoop-hadoop-datanode-hadoop1.out
slave2: starting datanode, logging to /opt/ha/hadoop-2.7.2/logs/hadoop-hadoop-datanode-slave2.out
hadoop2: starting datanode, logging to /opt/ha/hadoop-2.7.2/logs/hadoop-hadoop-datanode-hadoop2.out
slave1: starting datanode, logging to /opt/ha/hadoop-2.7.2/logs/hadoop-hadoop-datanode-slave1.out
hadoop: starting datanode, logging to /opt/ha/hadoop-2.7.2/logs/hadoop-hadoop-datanode-hadoop.out
hadoop@hadoop:hadoop-2.7.2$ sbin/start-yarn.sh starting yarn daemonsstarting resourcemanager, logging to /opt/ha/hadoop-2.7.2/logs/yarn-hadoop-resourcemanager-hadoop.out
hadoop2: starting nodemanager, logging to /opt/ha/hadoop-2.7.2/logs/yarn-hadoop-nodemanager-hadoop2.out
hadoop1: starting nodemanager, logging to /opt/ha/hadoop-2.7.2/logs/yarn-hadoop-nodemanager-hadoop1.out
slave2: starting nodemanager, logging to /opt/ha/hadoop-2.7.2/logs/yarn-hadoop-nodemanager-slave2.out
hadoop: starting nodemanager, logging to /opt/ha/hadoop-2.7.2/logs/yarn-hadoop-nodemanager-hadoop.out
slave1: starting nodemanager, logging to /opt/ha/hadoop-2.7.2/logs/yarn-hadoop-nodemanager-slave1.out
hadoop@hadoop:hadoop-2.7.2$ jps19384 JournalNode19013 QuorumPeerMain20649 Jps20241 ResourceManager20396 NodeManager19815 DataNode[hadoop@hadoop1 hadoop-2.7.2]$ jps10091 NodeManager9551 NameNode9822 DataNode9423 JournalNode10232 Jps9039 QuorumPeerMain[hadoop@hadoop2 hadoop-2.7.2]$ jps7450 NodeManager7295 DataNode6980 JournalNode7120 NameNode6854 QuorumPeerMain7580 Jps[hadoop@slave1 hadoop-2.7.2]$ jps3706 DataNode3988 Jps3374 JournalNode3591 NameNode3860 NodeManager3184 QuorumPeerMain[hadoop@slave2 hadoop-2.7.2]$ jps3023 QuorumPeerMain3643 NodeManager3782 Jps3177 JournalNode3497 DataNode3383 NameNod |
http://hadoop:8088/cluster/nodes/
所有namenode节点启动zkfc
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[hadoop@hadoop1 hadoop-2.7.2]$ sbin/hadoop-daemon.sh start zkfcstarting zkfc, logging to /opt/ha/hadoop-2.7.2/logs/hadoop-hadoop-zkfc-hadoop1.out
[hadoop@hadoop1 hadoop-2.7.2]$ jps10665 DFSZKFailoverController9551 NameNode9822 DataNode9423 JournalNode10739 Jps9039 QuorumPeerMain10483 NodeManager |
上传文件测试
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[hadoop@hadoop1 hadoop-2.7.2]$ bin/hdfs dfs -mkdir /test16/05/19 16:09:19 WARN util.NativeCodeLoader: Unable to load native-hadoop library for your platform... using builtin-java classes where applicable
[hadoop@hadoop1 hadoop-2.7.2]$ bin/hdfs dfs -put etc/hadoop/*.xml /test16/05/19 16:09:36 WARN util.NativeCodeLoader: Unable to load native-hadoop library for your platform... using builtin-java classes where applicable
#在slave1中查看[hadoop@slave1 hadoop-2.7.2]$ bin/hdfs dfs -ls -R /16/05/19 16:11:32 WARN util.NativeCodeLoader: Unable to load native-hadoop library for your platform... using builtin-java classes where applicable
drwxr-xr-x - hadoop supergroup 0 2016-05-19 16:09 /test-rw-r--r-- 2 hadoop supergroup 4436 2016-05-19 16:09 /test/capacity-scheduler.xml
-rw-r--r-- 2 hadoop supergroup 1185 2016-05-19 16:09 /test/core-site.xml
-rw-r--r-- 2 hadoop supergroup 9683 2016-05-19 16:09 /test/hadoop-policy.xml
-rw-r--r-- 2 hadoop supergroup 3814 2016-05-19 16:09 /test/hdfs-site.xml
-rw-r--r-- 2 hadoop supergroup 620 2016-05-19 16:09 /test/httpfs-site.xml
-rw-r--r-- 2 hadoop supergroup 3518 2016-05-19 16:09 /test/kms-acls.xml
-rw-r--r-- 2 hadoop supergroup 5511 2016-05-19 16:09 /test/kms-site.xml
-rw-r--r-- 2 hadoop supergroup 1170 2016-05-19 16:09 /test/mapred-site.xml
-rw-r--r-- 2 hadoop supergroup 1777 2016-05-19 16:09 /test/yarn-site.xml
[hadoop@slave1 hadoop-2.7.2]$ |
验证yarn
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[hadoop@hadoop1 hadoop-2.7.2]$ bin/hadoop jar share/hadoop/mapreduce/hadoop-mapreduce-examples-2.7.2.jar wordcount /test /out
16/05/19 16:15:25 WARN util.NativeCodeLoader: Unable to load native-hadoop library for your platform... using builtin-java classes where applicable
16/05/19 16:15:26 INFO client.RMProxy: Connecting to ResourceManager at hadoop/192.168.2.3:8032
16/05/19 16:15:27 INFO input.FileInputFormat: Total input paths to process : 9
16/05/19 16:15:27 INFO mapreduce.JobSubmitter: number of splits:9
16/05/19 16:15:27 INFO mapreduce.JobSubmitter: Submitting tokens for job: job_1463644924165_0001
16/05/19 16:15:27 INFO impl.YarnClientImpl: Submitted application application_1463644924165_000116/05/19 16:15:27 INFO mapreduce.Job: The url to track the job: http://hadoop:8088/proxy/application_1463644924165_0001/
16/05/19 16:15:27 INFO mapreduce.Job: Running job: job_1463644924165_000116/05/19 16:15:35 INFO mapreduce.Job: Job job_1463644924165_0001 running in uber mode : false
16/05/19 16:15:35 INFO mapreduce.Job: map 0% reduce 0%16/05/19 16:15:44 INFO mapreduce.Job: map 11% reduce 0%16/05/19 16:15:59 INFO mapreduce.Job: map 11% reduce 4%16/05/19 16:16:08 INFO mapreduce.Job: map 22% reduce 4%16/05/19 16:16:10 INFO mapreduce.Job: map 22% reduce 7%16/05/19 16:16:22 INFO mapreduce.Job: map 56% reduce 7%16/05/19 16:16:26 INFO mapreduce.Job: map 100% reduce 67%16/05/19 16:16:29 INFO mapreduce.Job: map 100% reduce 100%16/05/19 16:16:29 INFO mapreduce.Job: Job job_1463644924165_0001 completed successfully16/05/19 16:16:31 INFO mapreduce.Job: Counters: 51 File System Counters
FILE: Number of bytes read=25164
FILE: Number of bytes written=1258111
FILE: Number of read operations=0
FILE: Number of large read operations=0
FILE: Number of write operations=0
HDFS: Number of bytes read=32620
HDFS: Number of bytes written=13523
HDFS: Number of read operations=30
HDFS: Number of large read operations=0
HDFS: Number of write operations=2
Job Counters
Killed map tasks=2
Launched map tasks=10
Launched reduce tasks=1
Data-local map tasks=8
Rack-local map tasks=2
Total time spent by all maps in occupied slots (ms)=381816
Total time spent by all reduces in occupied slots (ms)=42021
Total time spent by all map tasks (ms)=381816
Total time spent by all reduce tasks (ms)=42021
Total vcore-milliseconds taken by all map tasks=381816
Total vcore-milliseconds taken by all reduce tasks=42021
Total megabyte-milliseconds taken by all map tasks=390979584
Total megabyte-milliseconds taken by all reduce tasks=43029504
Map-Reduce Framework
Map input records=963
Map output records=3041
Map output bytes=41311
Map output materialized bytes=25212
Input split bytes=906
Combine input records=3041
Combine output records=1335
Reduce input groups=673
Reduce shuffle bytes=25212
Reduce input records=1335
Reduce output records=673
Spilled Records=2670
Shuffled Maps =9
Failed Shuffles=0
Merged Map outputs=9
GC time elapsed (ms)=43432
CPU time spent (ms)=30760
Physical memory (bytes) snapshot=1813704704
Virtual memory (bytes) snapshot=8836780032
Total committed heap usage (bytes)=1722810368
Shuffle Errors
BAD_ID=0
CONNECTION=0
IO_ERROR=0
WRONG_LENGTH=0
WRONG_MAP=0
WRONG_REDUCE=0
File Input Format Counters
Bytes Read=31714
File Output Format Counters
Bytes Written=13523
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http://hadoop:8088/查看
结果
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[hadoop@slave1 hadoop-2.7.2]$ bin/hdfs dfs -lsr /out
lsr: DEPRECATED: Please use 'ls -R' instead.
16/05/19 16:22:14 WARN util.NativeCodeLoader: Unable to load native-hadoop library for your platform... using builtin-java classes where applicable
-rw-r--r-- 2 hadoop supergroup 0 2016-05-19 16:16 /out/_SUCCESS
-rw-r--r-- 2 hadoop supergroup 13523 2016-05-19 16:16 /out/part-r-00000
[hadoop@slave1 hadoop-2.7.2]$ |
测试故障自动转移
当前情况在网页查看hadoop1和slave1为Active状态,
那把这两个namenode关闭,再查看
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[hadoop@hadoop1 hadoop-2.7.2]$ jps10665 DFSZKFailoverController9551 NameNode12166 Jps9822 DataNode9423 JournalNode9039 QuorumPeerMain10483 NodeManager[hadoop@hadoop1 hadoop-2.7.2]$ sbin/hadoop-daemon.sh stop namenodestopping namenode[hadoop@hadoop1 hadoop-2.7.2]$ jps10665 DFSZKFailoverController9822 DataNode9423 JournalNode12221 Jps9039 QuorumPeerMain10483 NodeManager |
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[hadoop@slave1 hadoop-2.7.2]$ sbin/hadoop-daemon.sh stop namenodestopping namenode[hadoop@slave1 hadoop-2.7.2]$ jps3706 DataNode3374 JournalNode4121 NodeManager5460 Jps4324 DFSZKFailoverController3184 QuorumPeerMain |
此时Active NN已经分别转移到hadoop2和slave2上了
以上是hadoop2.2.0的HDFS集群HA配置和自动切换、HDFS federation配置、Yarn配置的基本过程,其中大家可以添加其他配置,zookeeper和journalnode也不一定所有节点都启动,只要是奇数个就ok,如果集群数量多,这些及节点均可以单独配置在一个host上