(三)大数据环境准备：Hive安装步骤(依赖Hadoop)
1、解压缩文件[root@hadoop0opt]#tar-zxvfhive-0.9.0.tar.gz
2、改名字[root@hadoop0opt]#mvhive-0.9.0hive
3、配置环境变量，修改etc/profile全局变量文件/opt/hive/bin
JAVA_HOME=/opt/jdk1.6.0_24
HADOOP_HOME=/opt/hadoop
HBASE_HOME=/opt/hbase
HIVE_HOME=/opt/hive
PATH=$JAVA_HOME/bin:$HADOOP_HOME/bin:$HBASE_HOME/bin:$HIVE_HOME/bin:$PATH
exportJAVA_HOMEHADOOP_HOMEHBASE_HOMEHIVE_HOMEPATH
[root@hadoop0bin]#su-
4、测试运行，看看是否安装成功[root@hadoop0~]#hive
WARNING:org.apache.hadoop.metrics.jvm.EventCounterisdeprecated.Pleaseuseorg.apache.hadoop.log.metrics.EventCounterinallthelog4j.propertiesfiles.
Logginginitializedusingconfigurationinjar:file:/opt/hive/lib/hive-common-0.9.0.jar!/hive-log4j.properties
Hivehistoryfile=/tmp/root/hive_job_log_root_201509250619_148272494.txt
hive>showtables;
FAILED:Errorinmetadata:MetaException(message:Gotexception:java.net.ConnectExceptionCalltohadoop0/192.168.46.129:9000failedonconnectionexception:java.net.ConnectException:Connectionrefused)
FAILED:ExecutionError,returncode1fromorg.apache.hadoop.hive.ql.exec.DDLTask
--解决方案：hive依赖于hdfs存储数据，所以确保hadoop启动了
[root@hadoop0~]#start-all.sh
Warning:$HADOOP_HOMEisdeprecated.
startingnamenode,loggingto/opt/hadoop/libexec/../logs/hadoop-root-namenode-hadoop0.out
localhost:startingdatanode,loggingto/opt/hadoop/libexec/../logs/hadoop-root-datanode-hadoop0.out
localhost:startingsecondarynamenode,loggingto/opt/hadoop/libexec/../logs/hadoop-root-secondarynamenode-hadoop0.out
startingjobtracker,loggingto/opt/hadoop/libexec/../logs/hadoop-root-jobtracker-hadoop0.out
localhost:startingtasktracker,loggingto/opt/hadoop/libexec/../logs/hadoop-root-tasktracker-hadoop0.out
--至此最简单的hive环境配置完毕
5、开始创建数据表hive>showtables;
OK
Timetaken:5.619seconds
hive>createtablestu(nameString,ageint);
FAILED:Errorinmetadata:MetaException(message:Gotexception:org.apache.hadoop.ipc.RemoteException
org.apache.hadoop.hdfs.server.namenode.SafeModeException:Cannotcreatedirectory/user/hive/warehouse/stu.
Namenodeisinsafemode.
Thereportedblocks18hasreachedthethreshold0.9990oftotalblocks17.Safemodewillbeturnedoffautomaticallyin15seconds.
atorg.apache.hadoop.hdfs.server.namenode.FSNamesystem.mkdirsInternal(FSNamesystem.java:2204)
atorg.apache.hadoop.hdfs.server.namenode.FSNamesystem.mkdirs(FSNamesystem.java:2178)
atorg.apache.hadoop.hdfs.server.namenode.NameNode.mkdirs(NameNode.java:857)
atsun.reflect.NativeMethodAccessorImpl.invoke0(NativeMethod)
atsun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
atsun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
atjava.lang.reflect.Method.invoke(Method.java:597)
atorg.apache.hadoop.ipc.RPC$Server.call(RPC.java:578)
atorg.apache.hadoop.ipc.Server$Handler$1.run(Server.java:1393)
atorg.apache.hadoop.ipc.Server$Handler$1.run(Server.java:1389)
atjava.security.AccessController.doPrivileged(NativeMethod)
atjavax.security.auth.Subject.doAs(Subject.java:396)
atorg.apache.hadoop.security.UserGroupInformation.doAs(UserGroupInformation.java:1149)
atorg.apache.hadoop.ipc.Server$Handler.run(Server.java:1387)
)
FAILED:ExecutionError,returncode1fromorg.apache.hadoop.hive.ql.exec.DDLTask
--解决方案：由于缺少参数配置，手工建立目录，解决这个问题
[root@hadoop0~]#mkdir-p/user/hive/warehouse/stu
hive>createtablestu(nameString,ageint);
OK
Timetaken:0.229seconds
6、开始插入数据，Hive不支持Insert语句hive>insertintostuvalues('MengMeng',24);
FAILED:ParseError:line1:12mismatchedinput'stu'expectingTABLEnear'into'ininsertclause
hive>showtables;
OK
stu
Timetaken:0.078seconds
hive>descstu;
OK
namestring
ageint
Timetaken:0.255seconds
--解决方案：hive不支持上述操作，可以使用load加载
hive>LOADDATALOCALINPATH'/opt/stu.txt'OVERWRITEINTOTABLEstu;
Copyingdatafromfile:/opt/stu.txt
Copyingfile:file:/opt/stu.txt
Loadingdatatotabledefault.stu
Deletedhdfs://hadoop0:9000/user/hive/warehouse/stu
OK
Timetaken:0.643seconds
7、查询刚才导入的语句hive>selectname,agefromstu;
TotalMapReducejobs=1
LaunchingJob1outof1
Numberofreducetasksissetto0sincethere'snoreduceoperator
StartingJob=job_201509250620_0001,TrackingURL=http://hadoop0:50030/jobdetails.jsp?jobid=job_201509250620_0001
KillCommand=/opt/hadoop/libexec/../bin/hadoopjob-Dmapred.job.tracker=hadoop0:9001-killjob_201509250620_0001
HadoopjobinformationforStage-1:numberofmappers:1;numberofreducers:0
2015-09-2506:37:55,535Stage-1map=0%,reduce=0%
2015-09-2506:37:58,565Stage-1map=100%,reduce=0%,CumulativeCPU0.59sec
2015-09-2506:37:59,595Stage-1map=100%,reduce=0%,CumulativeCPU0.59sec
2015-09-2506:38:00,647Stage-1map=100%,reduce=100%,CumulativeCPU0.59sec
MapReduceTotalcumulativeCPUtime:590msec
EndedJob=job_201509250620_0001
MapReduceJobsLaunched:
Job0:Map:1CumulativeCPU:0.59secHDFSRead:221HDFSWrite:22SUCCESS
TotalMapReduceCPUTimeSpent:590msec
OK
--查询结构显示出来了
JieJie26NULL
MM24NULL
Timetaken:12.812seconds
疑问：为何有个null值呢，切待下次研究