hadoop+hive使用中遇到的有關問題彙總

1.datanode沒法正常啓動
添加datanode後，datanode沒法正常啓動，進程一會莫名其妙掛掉，查看namenode日誌顯示以下：

2013-06-21 18:53:39,182 FATAL org.apache.hadoop.hdfs.StateChange: BLOCK* NameSystem.getDatanode: Data node x.x.x.x:50010 is attempting to report storage ID DS-1357535176-x.x.x.x-50010-1371808472808. Node y.y.y.y:50010 is expected to serve this storage.

緣由分析：
    拷貝hadoop安裝包時，包含data與tmp文件夾（見本人《hadoop安裝》一文），未成功格式化datanode
解決辦法：

rm -rf /data/hadoop/hadoop-1.1.2/datarm -rf /data/hadoop/hadoop-1.1.2/tmphadoop datanode -format

2. safe mode

2013-06-20 10:35:43,758 ERROR org.apache.hadoop.security.UserGroupInformation: PriviledgedActionException as:hadoop cause:org.apache.hadoop.hdfs.server.namenode.SafeModeException: Cannot renew lease for DFSClient_hb_rs_wdev1.corp.qihoo.net,60020,1371631589073. Name node is in safe mode.

解決方案：

hadoop dfsadmin -safemode leave

3.鏈接異常

2013-06-21 19:55:05,801 WARN org.apache.hadoop.hdfs.server.datanode.DataNode: java.io.IOException: Call to homename/x.x.x.x:9000 failed on local exception: java.io.EOFException

可能緣由：
namenode監聽127.0.0.1:9000，而非0.0.0.0:9000或外網IP:9000 iptables限制
解決方案：
檢查/etc/hosts配置，使得hostname綁定到非127.0.0.1的IP上 iptables放開端口

4. namenode id

ERROR org.apache.hadoop.hdfs.server.datanode.DataNode: java.io.IOException: Incompatible namespaceIDs in /var/lib/hadoop-0.20/cache/hdfs/dfs/data: namenode namespaceID = 240012870; datanode namespaceID = 1462711424 .

問題：Namenode上namespaceID與datanode上namespaceID不一致。 

　　問題產生緣由：每次namenode format會從新建立一個namenodeId,而tmp/dfs/data下包含了上次format下的id,namenode format清空了namenode下的數據,可是沒有清空datanode下的數據,因此形成namenode節點上的namespaceID與datanode節點上的namespaceID不一致。啓動失敗。 

　　解決辦法：參考該網址 http://blog.csdn.net/wh62592855/archive/2010/07/21/5752199.aspx 給出兩種解決方法，咱們使用的是第一種解決方法：即: 

　　(1)停掉集羣服務 

　　(2)在出問題的datanode節點上刪除data目錄，data目錄便是在hdfs-site.xml文件中配置的dfs.data.dir目錄，本機器上那個是/var/lib/hadoop-0.20/cache/hdfs/dfs/data/ (注：咱們當時在全部的datanode和namenode節點上均執行了該步驟。以防刪掉後不成功，能夠先把data目錄保存一個副本). 

　　(3)格式化namenode. 

　　(4)從新啓動集羣。 

　　問題解決。 
    這種方法帶來的一個反作用便是，hdfs上的全部數據丟失。若是hdfs上存放有重要數據的時候，不建議採用該方法，能夠嘗試提供的網址中的第二種方法。

5. 目錄權限
start-dfs.sh執行無錯，顯示啓動datanode，執行完後無datanode。查看datanode機器上的日誌，顯示因dfs.data.dir目錄權限不正確致使：

expected: drwxr-xr-x,current:drwxrwxr-x

解決辦法：
    查看dfs.data.dir的目錄配置，修改權限便可。

hive錯誤
1.NoClassDefFoundError
Could not initialize class java.lang.NoClassDefFoundError: Could not initialize class org.apache.hadoop.hbase.io.HbaseObjectWritable
將protobuf-***.jar添加到jars路徑

//$HIVE_HOME/conf/hive-site.xml<property>   <name>hive.aux.jars.path</name>   <value>file:///data/hadoop/hive-0.10.0/lib/hive-hbase-handler-0.10.0.jar,file:///data/hadoop/hive-0.10.0/lib/hbase-0.94.8.jar,file:///data/hadoop/hive-0.10.0/lib/zookeeper-3.4.5.jar,file:///data/hadoop/hive-0.10.0/lib/guava-r09.jar,file:///data/hadoop/hive-0.10.0/lib/hive-contrib-0.10.0.jar,file:///data/hadoop/hive-0.10.0/lib/protobuf-java-2.4.0a.jar</value></property>

2.hive動態分區異常
[Fatal Error] Operator FS_2 (id=2): Number of dynamic partitions exceeded hive.exec.max.dynamic.partitions.pernode

hive> set hive.exec.max.dynamic.partitions.pernode = 10000;

3.mapreduce進程超內存限制——hadoop Java heap space
vim mapred-site.xml添加：

//mapred-site.xml<property><name>mapred.child.java.opts</name><value>-Xmx2048m</value></property>

#$HADOOP_HOME/conf/hadoop_env.shexport HADOOP_HEAPSIZE=5000

4.hive文件數限制
[Fatal Error] total number of created files now is 100086, which exceeds 100000

hive> set hive.exec.max.created.files=655350;

5.metastore鏈接超時

FAILED: SemanticException org.apache.thrift.transport.TTransportException: java.net.SocketTimeoutException: Read timed out

解決方案：

hive> set hive.metastore.client.socket.timeout=500;

6. java.io.IOException: error=7, Argument list too long

Task with the most failures(5): -----Task ID:  task_201306241630_0189_r_000009URL:  http://namenode.godlovesdog.com:50030/taskdetails.jsp?jobid=job_201306241630_0189&tipid=task_201306241630_0189_r_000009-----Diagnostic Messages for this Task:java.lang.RuntimeException: org.apache.hadoop.hive.ql.metadata.HiveException: Hive Runtime Error while processing row (tag=0) {"key":{"reducesinkkey0":"164058872","reducesinkkey1":"djh,S1","reducesinkkey2":"20130117170703","reducesinkkey3":"xxx"},"value":{"_col0":"1","_col1":"xxx","_col2":"20130117170703","_col3":"164058872","_col4":"xxx,S1"},"alias":0}at org.apache.hadoop.hive.ql.exec.ExecReducer.reduce(ExecReducer.java:270)at org.apache.hadoop.mapred.ReduceTask.runOldReducer(ReduceTask.java:520)at org.apache.hadoop.mapred.ReduceTask.run(ReduceTask.java:421)at org.apache.hadoop.mapred.Child$4.run(Child.java:255)at java.security.AccessController.doPrivileged(Native Method)at javax.security.auth.Subject.doAs(Subject.java:415)at org.apache.hadoop.security.UserGroupInformation.doAs(UserGroupInformation.java:1149)at org.apache.hadoop.mapred.Child.main(Child.java:249)Caused by: org.apache.hadoop.hive.ql.metadata.HiveException: Hive Runtime Error while processing row (tag=0) {"key":{"reducesinkkey0":"164058872","reducesinkkey1":"xxx,S1","reducesinkkey2":"20130117170703","reducesinkkey3":"xxx"},"value":{"_col0":"1","_col1":"xxx","_col2":"20130117170703","_col3":"164058872","_col4":"djh,S1"},"alias":0}at org.apache.hadoop.hive.ql.exec.ExecReducer.reduce(ExecReducer.java:258)... 7 moreCaused by: org.apache.hadoop.hive.ql.metadata.HiveException: [Error 20000]: Unable to initialize custom script.at org.apache.hadoop.hive.ql.exec.ScriptOperator.processOp(ScriptOperator.java:354)at org.apache.hadoop.hive.ql.exec.Operator.process(Operator.java:474)at org.apache.hadoop.hive.ql.exec.Operator.forward(Operator.java:800)at org.apache.hadoop.hive.ql.exec.SelectOperator.processOp(SelectOperator.java:84)at org.apache.hadoop.hive.ql.exec.Operator.process(Operator.java:474)at org.apache.hadoop.hive.ql.exec.Operator.forward(Operator.java:800)at org.apache.hadoop.hive.ql.exec.ExtractOperator.processOp(ExtractOperator.java:45)at org.apache.hadoop.hive.ql.exec.Operator.process(Operator.java:474)at org.apache.hadoop.hive.ql.exec.ExecReducer.reduce(ExecReducer.java:249)... 7 moreCaused by: java.io.IOException: Cannot run program "/usr/bin/python2.7": error=7, 參數列表過長at java.lang.ProcessBuilder.start(ProcessBuilder.java:1042)at org.apache.hadoop.hive.ql.exec.ScriptOperator.processOp(ScriptOperator.java:313)... 15 moreCaused by: java.io.IOException: error=7, 參數列表過長at java.lang.UNIXProcess.forkAndExec(Native Method)at java.lang.UNIXProcess.<init>(UNIXProcess.java:135)at java.lang.ProcessImpl.start(ProcessImpl.java:130)at java.lang.ProcessBuilder.start(ProcessBuilder.java:1023)... 16 moreFAILED: Execution Error, return code 20000 from org.apache.hadoop.hive.ql.exec.MapRedTask. Unable to initialize custom script.

解決方案：
升級內核或減小分區數https://issues.apache.org/jira/browse/HIVE-2372