正如上一篇記錄的那樣，採用sqoop1.99.4 + hadoop2.2.0來將mysql的表資料匯入到HDFS的時候，死活沒有找到如何制定欄位分隔符號，這才有了試用sqoop1.4.5這番折騰。從架構上來將，Sqoop2確實在安全性等方面有很好的提升，但是Sqoop2目前還不推薦在生產環境中使用，它很多功能還缺失，不夠完善，不過，對我們小規模的使用Hadoop的公司來講，Sqoop1.4.X足夠用了，畢竟我等跨部門、多人員來使用的情況還是比較少的，命令列好用的很啊！
（1）安裝環境
         作業系統：Linux（centos6.5）
         JDK版本：1.7.0_45
         Hadoop版本：hadoop2.2.0
         Sqoop版本：sqoop-1.4.5.bin__hadoop-2.0.4-alpha.tar.gz
         hadoop安裝目錄：/home/hadoop/hadoop-2.2.0
         Sqoop2安裝目錄：/home/hadoop/sqoop-1.4.5
         Hadoop和Sqoop都是同一個使用者hadoop下面，hadoop使用者的的家目錄：/home/hadoop
2）修改Sqoop配置檔案 
         cd  /home/hadoop/sqoop-1.4.5/conf  
         cp sqoop-env-template.sh  sqoop-env.sh  
      在檔案sqoop-env.sh的末尾追加如下幾個環境變數設定：
         #add by zhanzk  
         export HADOOP_COMMON_HOME=/home/hadoop/hadoop-2.2.0  
         export HADOOP_MAPRED_HOME=/home/hadoop/hadoop-2.2.0/share/hadoop/mapreduce  
         export HIVE_HOME=/home/hadoop/hive-0.12.0            
（3）修改hadoop使用者的環境變數
      編輯檔案：/home/hadoop/.bash_profile，追加如下內容：
         export SQOOP_HOME=/home/hadoop/sqoop-1.4.5  
         export PATH=$PATH:$SQOOP_HOME/bin  
         export LOGDIR=$SQOOP_HOME/logs  
（4）將mysql的jdbc驅動程式放到$SQOOP_HOME/lib目錄下
         將 mysql-connector-java-5.1.15.jar 複製到 ：/home/hadoop/sqoop-1.4.5/lib目錄下
（5）試用sqoop
         1 、用Sqoop來列出192.168.0.1下的資料庫
                進入$SQOOP_HOME/bin目錄下執行如下命令：
                ./sqoop list-databases --connect jdbc:mysql://192.168.0.1:3306/mydb?characterEncoding=UTF-8 --username test --password 'test'
         2、將表book下的資料匯入到HDFS中去
               進入$SQOOP_HOME/bin目錄下執行如下命令：
              ./sqoop import  --connect jdbc:mysql://192.168.0.1:3306/mydb?characterEncoding=UTF-8 --username test --password 'test' --target-dir '/user/hive/warehouse/book' --table book ;  

注意：我麼這裡也出現問題了:

15/03/15 22:30:33 ERROR manager.SqlManager: Error reading from database: java.sql.SQLException: Streaming result set [email protected] is still active. No statements may be issued when any streaming result sets are open and in use on a given connection. Ensure that you have called .close() on any active streaming result sets before attempting more queries.  
java.sql.SQLException: Streaming result set

[email protected] is still active. No statements may be issued when any streaming result sets are open and in use on a given connection. Ensure that you have called .close() on any active streaming result sets before attempting more queries.  
        at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:930)  
        at com.mysql.jdbc.MysqlIO.checkForOutstandingStreamingData(MysqlIO.java:2694)  
        at com.mysql.jdbc.MysqlIO.sendCommand(MysqlIO.java:1868)  
        at com.mysql.jdbc.MysqlIO.sqlQueryDirect(MysqlIO.java:2109)  
        at com.mysql.jdbc.ConnectionImpl.execSQL(ConnectionImpl.java:2642)  
        at com.mysql.jdbc.ConnectionImpl.execSQL(ConnectionImpl.java:2571)  
        at com.mysql.jdbc.StatementImpl.executeQuery(StatementImpl.java:1464)  
        at com.mysql.jdbc.ConnectionImpl.getMaxBytesPerChar(ConnectionImpl.java:3030)  
        at com.mysql.jdbc.Field.getMaxBytesPerCharacter(Field.java:592)  
        at com.mysql.jdbc.ResultSetMetaData.getPrecision(ResultSetMetaData.java:444)  
        at org.apache.sqoop.manager.SqlManager.getColumnInfoForRawQuery(SqlManager.java:285)  
        at org.apache.sqoop.manager.SqlManager.getColumnTypesForRawQuery(SqlManager.java:240)  
        at org.apache.sqoop.manager.SqlManager.getColumnTypes(SqlManager.java:226)  
        at org.apache.sqoop.manager.ConnManager.getColumnTypes(ConnManager.java:295)  
        at org.apache.sqoop.orm.ClassWriter.getColumnTypes(ClassWriter.java:1773)  
        at org.apache.sqoop.orm.ClassWriter.generate(ClassWriter.java:1578)  
        at org.apache.sqoop.tool.CodeGenTool.generateORM(CodeGenTool.java:96)  
        at org.apache.sqoop.tool.ImportTool.importTable(ImportTool.java:478)  
        at org.apache.sqoop.tool.ImportTool.run(ImportTool.java:601)  
        at org.apache.sqoop.Sqoop.run(Sqoop.java:143)  
        at org.apache.hadoop.util.ToolRunner.run(ToolRunner.java:65)  
        at org.apache.sqoop.Sqoop.runSqoop(Sqoop.java:179)  
        at org.apache.sqoop.Sqoop.runTool(Sqoop.java:218)  
        at org.apache.sqoop.Sqoop.runTool(Sqoop.java:227)  
        at org.apache.sqoop.Sqoop.main(Sqoop.java:236)  
15/03/15 22:30:33 ERROR tool.ImportTool: Encountered IOException running import job: java.io.IOException: No columns to generate for ClassWriter  
        at org.apache.sqoop.orm.ClassWriter.generate(ClassWriter.java:1584)  
        at org.apache.sqoop.tool.CodeGenTool.generateORM(CodeGenTool.java:96)  
        at org.apache.sqoop.tool.ImportTool.importTable(ImportTool.java:478)  
        at org.apache.sqoop.tool.ImportTool.run(ImportTool.java:601)  
        at org.apache.sqoop.Sqoop.run(Sqoop.java:143)  
        at org.apache.hadoop.util.ToolRunner.run(ToolRunner.java:65)  
        at org.apache.sqoop.Sqoop.runSqoop(Sqoop.java:179)  
        at org.apache.sqoop.Sqoop.runTool(Sqoop.java:218)  
        at org.apache.sqoop.Sqoop.runTool(Sqoop.java:227)  
        at org.apache.sqoop.Sqoop.main(Sqoop.java:236)  

不過幸運的是找到這篇文章：

http://my.oschina.net/u/1169607/blog/352225，將 mysql-connector-java-5.1.15.jar 更換為mysql-connector-java-5.1.32-bin.jar 即可消除上述錯誤。

至此還是沒有成功，又出現如下錯誤了：

[[email protected] bin]$  ./sqoop import  --connect jdbc:mysql://192.168.0.1:3306/mydb?characterEncoding=UTF-8 --username test --password 'test' --target-dir '/user/hive/warehouse/book' --table t_book  ;  
Warning: /home/hadoop/sqoop-1.4.5/../hbase does not exist! HBase imports will fail.  
Please set $HBASE_HOME to the root of your HBase installation.  
Warning: /home/hadoop/sqoop-1.4.5/../hcatalog does not exist! HCatalog jobs will fail.  
Please set $HCAT_HOME to the root of your HCatalog installation.  
Warning: /home/hadoop/sqoop-1.4.5/../accumulo does not exist! Accumulo imports will fail.  
Please set $ACCUMULO_HOME to the root of your Accumulo installation.  
Warning: /home/hadoop/sqoop-1.4.5/../zookeeper does not exist! Accumulo imports will fail.  
Please set $ZOOKEEPER_HOME to the root of your Zookeeper installation.  
15/03/15 23:10:55 INFO sqoop.Sqoop: Running Sqoop version: 1.4.5  
15/03/15 23:10:55 WARN tool.BaseSqoopTool: Setting your password on the command-line is insecure. Consider using -P instead.  
15/03/15 23:10:56 INFO manager.MySQLManager: Preparing to use a MySQL streaming resultset.  
15/03/15 23:10:56 INFO tool.CodeGenTool: Beginning code generation  
15/03/15 23:10:56 INFO manager.SqlManager: Executing SQL statement: SELECT t.* FROM `t_book` AS t LIMIT 1  
15/03/15 23:10:56 INFO manager.SqlManager: Executing SQL statement: SELECT t.* FROM `t_book` AS t LIMIT 1  
15/03/15 23:10:56 INFO orm.CompilationManager: HADOOP_MAPRED_HOME is /home/hadoop/hadoop-2.2.0/share/hadoop/mapreduce  
Note: /tmp/sqoop-hadoop/compile/c798c2a151fc7c3baed090b15aa6e2cb/book.java uses or overrides a deprecated API.  
Note: Recompile with -Xlint:deprecation for details.  
15/03/15 23:10:59 INFO orm.CompilationManager: Writing jar file: /tmp/sqoop-hadoop/compile/c798c2a151fc7c3baed090b15aa6e2cb/book.jar  
Exception in thread "main" java.lang.NoClassDefFoundError: org/apache/hadoop/mapreduce/InputFormat  
        at java.lang.ClassLoader.defineClass1(Native Method)  
        at java.lang.ClassLoader.defineClass(ClassLoader.java:800)  
        at java.security.SecureClassLoader.defineClass(SecureClassLoader.java:142)  
        at java.net.URLClassLoader.defineClass(URLClassLoader.java:449)  
        at java.net.URLClassLoader.access$100(URLClassLoader.java:71)  
        at java.net.URLClassLoader$1.run(URLClassLoader.java:361)  
        at java.net.URLClassLoader$1.run(URLClassLoader.java:355)  
        at java.security.AccessController.doPrivileged(Native Method)  
        at java.net.URLClassLoader.findClass(URLClassLoader.java:354)  
        at java.lang.ClassLoader.loadClass(ClassLoader.java:425)  
        at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:308)  
        at java.lang.ClassLoader.loadClass(ClassLoader.java:358)  
        at java.lang.ClassLoader.defineClass1(Native Method)  
        at java.lang.ClassLoader.defineClass(ClassLoader.java:800)  
        at java.security.SecureClassLoader.defineClass(SecureClassLoader.java:142)  
        at java.net.URLClassLoader.defineClass(URLClassLoader.java:449)  
        at java.net.URLClassLoader.access$100(URLClassLoader.java:71)  
        at java.net.URLClassLoader$1.run(URLClassLoader.java:361)  
        at java.net.URLClassLoader$1.run(URLClassLoader.java:355)  
        at java.security.AccessController.doPrivileged(Native Method)  
        at java.net.URLClassLoader.findClass(URLClassLoader.java:354)  
        at java.lang.ClassLoader.loadClass(ClassLoader.java:425)  
        at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:308)  
        at java.lang.ClassLoader.loadClass(ClassLoader.java:358)  
        at java.lang.ClassLoader.defineClass1(Native Method)  
        at java.lang.ClassLoader.defineClass(ClassLoader.java:800)  
        at java.security.SecureClassLoader.defineClass(SecureClassLoader.java:142)  
        at java.net.URLClassLoader.defineClass(URLClassLoader.java:449)  
        at java.net.URLClassLoader.access$100(URLClassLoader.java:71)  
        at java.net.URLClassLoader$1.run(URLClassLoader.java:361)  
        at java.net.URLClassLoader$1.run(URLClassLoader.java:355)  
        at java.security.AccessController.doPrivileged(Native Method)  
        at java.net.URLClassLoader.findClass(URLClassLoader.java:354)  
        at java.lang.ClassLoader.loadClass(ClassLoader.java:425)  
        at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:308)  
        at java.lang.ClassLoader.loadClass(ClassLoader.java:358)  
        at java.lang.ClassLoader.defineClass1(Native Method)  
        at java.lang.ClassLoader.defineClass(ClassLoader.java:800)  
        at java.security.SecureClassLoader.defineClass(SecureClassLoader.java:142)  
        at java.net.URLClassLoader.defineClass(URLClassLoader.java:449)  
        at java.net.URLClassLoader.access$100(URLClassLoader.java:71)  
        at java.net.URLClassLoader$1.run(URLClassLoader.java:361)  
        at java.net.URLClassLoader$1.run(URLClassLoader.java:355)  
        at java.security.AccessController.doPrivileged(Native Method)  
        at java.net.URLClassLoader.findClass(URLClassLoader.java:354)  
        at java.lang.ClassLoader.loadClass(ClassLoader.java:425)  
        at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:308)  
        at java.lang.ClassLoader.loadClass(ClassLoader.java:358)  
        at org.apache.sqoop.manager.ImportJobContext.<init>(ImportJobContext.java:51)  
        at com.cloudera.sqoop.manager.ImportJobContext.<init>(ImportJobContext.java:33)  
        at org.apache.sqoop.tool.ImportTool.importTable(ImportTool.java:483)  
        at org.apache.sqoop.tool.ImportTool.run(ImportTool.java:601)  
        at org.apache.sqoop.Sqoop.run(Sqoop.java:143)  
        at org.apache.hadoop.util.ToolRunner.run(ToolRunner.java:70)  
        at org.apache.sqoop.Sqoop.runSqoop(Sqoop.java:179)  
        at org.apache.sqoop.Sqoop.runTool(Sqoop.java:218)  
        at org.apache.sqoop.Sqoop.runTool(Sqoop.java:227)  
        at org.apache.sqoop.Sqoop.main(Sqoop.java:236)  
Caused by: java.lang.ClassNotFoundException: org.apache.hadoop.mapreduce.InputFormat  
        at java.net.URLClassLoader$1.run(URLClassLoader.java:366)  
        at java.net.URLClassLoader$1.run(URLClassLoader.java:355)  
        at java.security.AccessController.doPrivileged(Native Method)  
        at java.net.URLClassLoader.findClass(URLClassLoader.java:354)  
        at java.lang.ClassLoader.loadClass(ClassLoader.java:425)  
        at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:308)  
        at java.lang.ClassLoader.loadClass(ClassLoader.java:358)  
        ... 58 more  


至此百思不得其解，怎麼會找不到mapred的類呢，琢磨之後馬上意識到問題了，在我的Hadoop環境中配置瞭如下的環境變數：
export HADOOP_PREFIX="/home/hadoop/hadoop-2.2.0"    
export HADOOP_MAPRED_HOME=${HADOOP_PREFIX} 
這個與sqoop-env.sh中配置的環境變數衝突啊:
#add by zhanzk  
export HADOOP_COMMON_HOME=/home/hadoop/hadoop-2.2.0  
export HADOOP_MAPRED_HOME=/home/hadoop/hadoop-2.2.0/share/hadoop/mapreduce
export HIVE_HOME=/home/hadoop/hive-0.12.0        
這才導致找不到mapreduce的包，所以現在有個簡單辦法，即是把mapreduce相關的jar包複製到$SQOOP_HOME/lib下面來，就什麼事情也沒有了。
cp /home/hadoop/hadoop-2.2.0/share/hadoop/mapreduce/*.jar /home/hadoop/sqoop-1.4.5/lib 


至此問題才算真正解決了，再次匯出mysql的資料到hdfs中的時候，終於在HDFS的/user/hive/warehouse/book這個目錄下找到了輸出的檔案資料了。
雖說是匯入資料到HDFS中成功了，但是系統中依然有如下錯誤：
15/03/16 13:07:12 INFO mapreduce.Job: Task Id : attempt_1426431271248_0007_m_000003_0, Status : FAILED  
Error: java.lang.RuntimeException: java.lang.RuntimeException: java.sql.SQLException: Access denied for user 'test'@'192.168.0.2' (using password: YES)  
        at org.apache.sqoop.mapreduce.db.DBInputFormat.setConf(DBInputFormat.java:167)  
        at org.apache.hadoop.util.ReflectionUtils.setConf(ReflectionUtils.java:73)  
        at org.apache.hadoop.util.ReflectionUtils.newInstance(ReflectionUtils.java:133)  
        at org.apache.hadoop.mapred.MapTask.runNewMapper(MapTask.java:725)  
        at org.apache.hadoop.mapred.MapTask.run(MapTask.java:339)  
        at org.apache.hadoop.mapred.YarnChild$2.run(YarnChild.java:162)  
        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:1491)    
        at org.apache.hadoop.mapred.YarnChild.main(YarnChild.java:157)  
Caused by: java.lang.RuntimeException: java.sql.SQLException: Access denied for user 'test'@'192.168.0.1' (using password: YES)  
        at org.apache.sqoop.mapreduce.db.DBInputFormat.getConnection(DBInputFormat.java:220)  
        at org.apache.sqoop.mapreduce.db.DBInputFormat.setConf(DBInputFormat.java:165)  
        ... 9 more  
Caused by: java.sql.SQLException: Access denied for user ''test'@'192.168.0.2' (using password: YES)  
        at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:1094)  
        at com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:4208)  
        at com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:4140)  
        at com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:925)  
        at com.mysql.jdbc.MysqlIO.proceedHandshakeWithPluggableAuthentication(MysqlIO.java:1747)  
        at com.mysql.jdbc.MysqlIO.doHandshake(MysqlIO.java:1287)  
        at com.mysql.jdbc.ConnectionImpl.coreConnect(ConnectionImpl.java:2494)  
        at com.mysql.jdbc.ConnectionImpl.connectOneTryOnly(ConnectionImpl.java:2527)  
        at com.mysql.jdbc.ConnectionImpl.createNewIO(ConnectionImpl.java:2309)  
        at com.mysql.jdbc.ConnectionImpl.<init>(ConnectionImpl.java:834)  
        at com.mysql.jdbc.JDBC4Connection.<init>(JDBC4Connection.java:46)  
        at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)  
        at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:57)  
        at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45)  
        at java.lang.reflect.Constructor.newInstance(Constructor.java:526)  
        at com.mysql.jdbc.Util.handleNewInstance(Util.java:408)  
        at com.mysql.jdbc.ConnectionImpl.getInstance(ConnectionImpl.java:419)  
        at com.mysql.jdbc.NonRegisteringDriver.connect(NonRegisteringDriver.java:344)  
        at java.sql.DriverManager.getConnection(DriverManager.java:571)  
        at java.sql.DriverManager.getConnection(DriverManager.java:215)  
        at org.apache.sqoop.mapreduce.db.DBConfiguration.getConnection(DBConfiguration.java:302)  
        at org.apache.sqoop.mapreduce.db.DBInputFormat.getConnection(DBInputFormat.java:213)  
        ... 10 more  


這個錯誤就簡單了，我的資料庫mydb並沒有對192.168.0.1這個節點授權，完成授權後，問題自然就消失了。