1、当时初学Sqoop的时候，mysql导入到hdfs导入命令执行以后，在hdfs上面没有找到对应的数据，今天根据这个bug，顺便解决这个问题吧，之前写的http://www.cnblogs.com/biehongli/p/8039128.html。
1 [hadoop@slaver1 sqoop-1.4.5-cdh5.3.6]$ bin/sqoop import \
2 > --connect jdbc:mysql://slaver1:3306/test \
3 > --username root \
4 > --password 123456 \
5 > --table tb_user \
6 > --m 1
7 Warning: /home/hadoop/soft/sqoop-1.4.5-cdh5.3.6/../hcatalog does not exist! HCatalog jobs will fail.
8 Please set $HCAT_HOME to the root of your HCatalog installation.
9 Warning: /home/hadoop/soft/sqoop-1.4.5-cdh5.3.6/../accumulo does not exist! Accumulo imports will fail.
10 Please set $ACCUMULO_HOME to the root of your Accumulo installation.
11 18/05/18 19:32:51 INFO sqoop.Sqoop: Running Sqoop version: 1.4.5-cdh5.3.6
12 18/05/18 19:32:51 WARN tool.BaseSqoopTool: Setting your password on the command-line is insecure. Consider using -P instead.
13 18/05/18 19:32:51 INFO manager.MySQLManager: Preparing to use a MySQL streaming resultset.
14 18/05/18 19:32:51 INFO tool.CodeGenTool: Beginning code generation
15 18/05/18 19:32:52 INFO manager.SqlManager: Executing SQL statement: SELECT t.* FROM `tb_user` AS t LIMIT 1
16 18/05/18 19:32:52 INFO manager.SqlManager: Executing SQL statement: SELECT t.* FROM `tb_user` AS t LIMIT 1
17 18/05/18 19:32:52 INFO orm.CompilationManager: HADOOP_MAPRED_HOME is /home/hadoop/soft/hadoop-2.5.0-cdh5.3.6
18 Note: /tmp/sqoop-hadoop/compile/cb147e9deb144db0034d6f38cb47ad68/tb_user.java uses or overrides a deprecated API.
19 Note: Recompile with -Xlint:deprecation for details.
20 18/05/18 19:33:03 INFO orm.CompilationManager: Writing jar file: /tmp/sqoop-hadoop/compile/cb147e9deb144db0034d6f38cb47ad68/tb_user.jar
21 18/05/18 19:33:03 WARN manager.MySQLManager: It looks like you are importing from mysql.
22 18/05/18 19:33:03 WARN manager.MySQLManager: This transfer can be faster! Use the --direct
23 18/05/18 19:33:03 WARN manager.MySQLManager: option to exercise a MySQL-specific fast path.
24 18/05/18 19:33:03 INFO manager.MySQLManager: Setting zero DATETIME behavior to convertToNull (mysql)
25 18/05/18 19:33:03 INFO mapreduce.ImportJobBase: Beginning import of tb_user
26 18/05/18 19:33:04 WARN util.NativeCodeLoader: Unable to load native-hadoop library for your platform... using builtin-java classes where applicable
27 18/05/18 19:33:04 INFO Configuration.deprecation: mapred.jar is deprecated. Instead, use mapreduce.job.jar
28 18/05/18 19:33:07 INFO Configuration.deprecation: mapred.map.tasks is deprecated. Instead, use mapreduce.job.maps
29 18/05/18 19:33:07 INFO client.RMProxy: Connecting to ResourceManager at slaver1/192.168.19.131:8032
30 18/05/18 19:33:08 WARN security.UserGroupInformation: PriviledgedActionException as:hadoop (auth:SIMPLE) cause:org.apache.hadoop.mapred.FileAlreadyExistsException: Output directory hdfs://slaver1:9000/user/hadoop/tb_user already exists
31 18/05/18 19:33:08 ERROR tool.ImportTool: Encountered IOException running import job: org.apache.hadoop.mapred.FileAlreadyExistsException: Output directory hdfs://slaver1:9000/user/hadoop/tb_user already exists
32 at org.apache.hadoop.mapreduce.lib.output.FileOutputFormat.checkOutputSpecs(FileOutputFormat.java:146)
33 at org.apache.hadoop.mapreduce.JobSubmitter.checkSpecs(JobSubmitter.java:554)
34 at org.apache.hadoop.mapreduce.JobSubmitter.submitJobInternal(JobSubmitter.java:430)
35 at org.apache.hadoop.mapreduce.Job$10.run(Job.java:1295)
36 at org.apache.hadoop.mapreduce.Job$10.run(Job.java:1292)
37 at java.security.AccessController.doPrivileged(Native Method)
38 at javax.security.auth.Subject.doAs(Subject.java:415)
39 at org.apache.hadoop.security.UserGroupInformation.doAs(UserGroupInformation.java:1642)
40 at org.apache.hadoop.mapreduce.Job.submit(Job.java:1292)
41 at org.apache.hadoop.mapreduce.Job.waitForCompletion(Job.java:1313)
42 at org.apache.sqoop.mapreduce.ImportJobBase.doSubmitJob(ImportJobBase.java:198)
43 at org.apache.sqoop.mapreduce.ImportJobBase.runJob(ImportJobBase.java:171)
44 at org.apache.sqoop.mapreduce.ImportJobBase.runImport(ImportJobBase.java:268)
45 at org.apache.sqoop.manager.SqlManager.importTable(SqlManager.java:665)
46 at org.apache.sqoop.manager.MySQLManager.importTable(MySQLManager.java:118)
47 at org.apache.sqoop.tool.ImportTool.importTable(ImportTool.java:497)
48 at org.apache.sqoop.tool.ImportTool.run(ImportTool.java:605)
49 at org.apache.sqoop.Sqoop.run(Sqoop.java:143)
50 at org.apache.hadoop.util.ToolRunner.run(ToolRunner.java:70)
51 at org.apache.sqoop.Sqoop.runSqoop(Sqoop.java:179)
52 at org.apache.sqoop.Sqoop.runTool(Sqoop.java:218)
53 at org.apache.sqoop.Sqoop.runTool(Sqoop.java:227)
54 at org.apache.sqoop.Sqoop.main(Sqoop.java:236)
55
56 [hadoop@slaver1 sqoop-1.4.5-cdh5.3.6]$
2、报错说以及存在了，hdfs://slaver1:9000/user/hadoop/tb_user already exists，首先根据路径找到了问题，先将这个路径上面的删除了，然后再执行的时候发现将mysql的数据表数据可以导入到hdfs分布式文件系统上面。
1 [hadoop@slaver1 ~]$ hdfs dfs -rm -r /user/hadoop/tb_user
2 18/05/18 19:34:06 WARN util.NativeCodeLoader: Unable to load native-hadoop library for your platform... using builtin-java classes where applicable
3 18/05/18 19:34:07 INFO fs.TrashPolicyDefault: Namenode trash configuration: Deletion interval = 0 minutes, Emptier interval = 0 minutes.
4 Deleted /user/hadoop/tb_user
5 [hadoop@slaver1 ~]$
3、执行如下所示：
[hadoop@slaver1 sqoop-1.4.5-cdh5.3.6]$ bin/sqoop import \
> --connect jdbc:mysql://slaver1:3306/test \
> --username root \
> --password 123456 \
> --table tb_user \
> --m 1
Warning: /home/hadoop/soft/sqoop-1.4.5-cdh5.3.6/../hcatalog does not exist! HCatalog jobs will fail.
Please set $HCAT_HOME to the root of your HCatalog installation.
Warning: /home/hadoop/soft/sqoop-1.4.5-cdh5.3.6/../accumulo does not exist! Accumulo imports will fail.
Please set $ACCUMULO_HOME to the root of your Accumulo installation.
18/05/18 19:39:26 INFO sqoop.Sqoop: Running Sqoop version: 1.4.5-cdh5.3.6
18/05/18 19:39:26 WARN tool.BaseSqoopTool: Setting your password on the command-line is insecure. Consider using -P instead.
18/05/18 19:39:26 INFO manager.MySQLManager: Preparing to use a MySQL streaming resultset.
18/05/18 19:39:26 INFO tool.CodeGenTool: Beginning code generation
18/05/18 19:39:27 INFO manager.SqlManager: Executing SQL statement: SELECT t.* FROM `tb_user` AS t LIMIT 1
18/05/18 19:39:27 INFO manager.SqlManager: Executing SQL statement: SELECT t.* FROM `tb_user` AS t LIMIT 1
18/05/18 19:39:27 INFO orm.CompilationManager: HADOOP_MAPRED_HOME is /home/hadoop/soft/hadoop-2.5.0-cdh5.3.6
Note: /tmp/sqoop-hadoop/compile/464d9aff412a6285fd9f6f4c6d16b4e6/tb_user.java uses or overrides a deprecated API.
Note: Recompile with -Xlint:deprecation for details.
18/05/18 19:39:29 INFO orm.CompilationManager: Writing jar file: /tmp/sqoop-hadoop/compile/464d9aff412a6285fd9f6f4c6d16b4e6/tb_user.jar
18/05/18 19:39:29 WARN manager.MySQLManager: It looks like you are importing from mysql.
18/05/18 19:39:29 WARN manager.MySQLManager: This transfer can be faster! Use the --direct
18/05/18 19:39:29 WARN manager.MySQLManager: option to exercise a MySQL-specific fast path.
18/05/18 19:39:29 INFO manager.MySQLManager: Setting zero DATETIME behavior to convertToNull (mysql)
18/05/18 19:39:29 INFO mapreduce.ImportJobBase: Beginning import of tb_user
18/05/18 19:39:30 WARN util.NativeCodeLoader: Unable to load native-hadoop library for your platform... using builtin-java classes where applicable
18/05/18 19:39:30 INFO Configuration.deprecation: mapred.jar is deprecated. Instead, use mapreduce.job.jar
18/05/18 19:39:31 INFO Configuration.deprecation: mapred.map.tasks is deprecated. Instead, use mapreduce.job.maps
18/05/18 19:39:31 INFO client.RMProxy: Connecting to ResourceManager at slaver1/192.168.19.131:8032
18/05/18 19:39:37 INFO db.DBInputFormat: Using read commited transaction isolation
18/05/18 19:39:37 INFO mapreduce.JobSubmitter: number of splits:1
18/05/18 19:39:38 INFO mapreduce.JobSubmitter: Submitting tokens for job: job_1526642793183_0001
18/05/18 19:39:39 INFO impl.YarnClientImpl: Submitted application application_1526642793183_0001
18/05/18 19:39:39 INFO mapreduce.Job: The url to track the job: http://slaver1:8088/proxy/application_1526642793183_0001/
18/05/18 19:39:39 INFO mapreduce.Job: Running job: job_1526642793183_0001
18/05/18 19:39:58 INFO mapreduce.Job: Job job_1526642793183_0001 running in uber mode : false
18/05/18 19:39:58 INFO mapreduce.Job: map 0% reduce 0%
18/05/18 19:40:09 INFO mapreduce.Job: map 100% reduce 0%
18/05/18 19:40:09 INFO mapreduce.Job: Job job_1526642793183_0001 completed successfully
18/05/18 19:40:09 INFO mapreduce.Job: Counters: 30
File System Counters
FILE: Number of bytes read=0
FILE: Number of bytes written=132974
FILE: Number of read operations=0
FILE: Number of large read operations=0
FILE: Number of write operations=0
HDFS: Number of bytes read=87
HDFS: Number of bytes written=153
HDFS: Number of read operations=4
HDFS: Number of large read operations=0
HDFS: Number of write operations=2
Job Counters
Launched map tasks=1
Other local map tasks=1
Total time spent by all maps in occupied slots (ms)=8377
Total time spent by all reduces in occupied slots (ms)=0
Total time spent by all map tasks (ms)=8377
Total vcore-seconds taken by all map tasks=8377
Total megabyte-seconds taken by all map tasks=8578048
Map-Reduce Framework
Map input records=10
Map output records=10
Input split bytes=87
Spilled Records=0
Failed Shuffles=0
Merged Map outputs=0
GC time elapsed (ms)=102
CPU time spent (ms)=1310
Physical memory (bytes) snapshot=102690816
Virtual memory (bytes) snapshot=841768960
Total committed heap usage (bytes)=15794176
File Input Format Counters
Bytes Read=0
File Output Format Counters
Bytes Written=153
18/05/18 19:40:09 INFO mapreduce.ImportJobBase: Transferred 153 bytes in 38.0904 seconds (4.0168 bytes/sec)
18/05/18 19:40:09 INFO mapreduce.ImportJobBase: Retrieved 10 records.
[hadoop@slaver1 sqoop-1.4.5-cdh5.3.6]$
4、数据如下所示：
[hadoop@slaver1 ~]$ hdfs dfs -cat /user/hadoop/tb_user/part-m-00000
18/05/18 19:41:25 WARN util.NativeCodeLoader: Unable to load native-hadoop library for your platform... using builtin-java classes where applicable
1,张三,15236083001
2,李四,15236083001
3,王五,15236083001
4,小明,15236083001
5,小红,15236083001
6,小别,15236083001
7,7,7
8,8,8
9,9,9
10,10,10
[hadoop@slaver1 ~]$