一个sqoop export案例中踩到的坑

Posted 2021-11-11 wang-bing

案例分析：

　　需要将hdfs上的数据导出到mysql里的一张表里。

　　虚拟机集群的为：centos1-centos5

问题1：
在centos1上将hdfs上的数据导出到centos1上的mysql里：

sqoop export 
　　--connect jdbc:mysql://centos1:3306/test \\
　　--username root 　　--password root 　　--table order_uid 　　--export-dir /user/hive/warehouse/test.db/order_uid/ 　　--fields-terminated-by ‘,‘

报错：

Error executing statement: java.sql.SQLException: Access denied for user ‘root‘@‘centos1‘ (using password: YES)

改成：

sqoop export 
　　--connect jdbc:mysql://localhost:3306/test \\
　　--username root \\
　　--password root \\
　　--table order_uid \\
　　--export-dir /user/hive/warehouse/test.db/order_uid/ \\
　　--fields-terminated-by ‘,‘

 报错：

Error: java.io.IOException: com.mysql.jdbc.exceptions.jdbc4.MySQLSyntaxErrorException: Table ‘test.order_uid‘ doesn‘t exist at
org.apache.sqoop.mapreduce.AsyncSqlRecordWriter.close(AsyncSqlRecordWriter.java:205) at 
org.apache.hadoop.mapred.MapTask$NewDirectOutputCollector.close(MapTask.java:670) at
org.apache.hadoop.mapred.MapTask.runNewMapper(MapTask.java:793) at org.apache.hadoop.mapred.MapTask.run(MapTask.java:341) at
org.apache.hadoop.mapred.YarnChild$2.run(YarnChild.java:164) at java.security.AccessController.doPrivileged(Native Method) at 
javax.security.auth.Subject.doAs(Subject.java:422) at
...

问题2：

在centos3上将hdfs上的数据导出到centos1上的mysql里：

sqoop export 
　　--connect jdbc:mysql://centos1:3306/test \\
　　--username root 　　--password root 　　--table order_uid 　　--export-dir /user/hive/warehouse/test.db/order_uid/ 　　--fields-terminated-by ‘,‘

报错： 

19/03/27 17:47:41 ERROR mapreduce.ExportJobBase: Export job failed!
19/03/27 17:47:41 ERROR tool.ExportTool: Error during export: 
Export job failed!
at org.apache.sqoop.mapreduce.ExportJobBase.runExport(ExportJobBase.java:445)
at org.apache.sqoop.manager.SqlManager.exportTable(SqlManager.java:931)
at org.apache.sqoop.tool.ExportTool.exportTable(ExportTool.java:80)
at org.apache.sqoop.tool.ExportTool.run(ExportTool.java:99)
at org.apache.sqoop.Sqoop.run(Sqoop.java:147)
at org.apache.hadoop.util.ToolRunner.run(ToolRunner.java:70)
at org.apache.sqoop.Sqoop.runSqoop(Sqoop.java:183)
at org.apache.sqoop.Sqoop.runTool(Sqoop.java:234)
at org.apache.sqoop.Sqoop.runTool(Sqoop.java:243)
at org.apache.sqoop.Sqoop.main(Sqoop.java:252)

在网上找到两种解决方案：

1.在网上找到有人说在hdfs的路径写到具体文件，而不是写到目录，改成： 

sqoop export 
　　--connect jdbc:mysql://centos1:3306/test \\
　　--username root 　　--password root 　　--table order_uid 　　--export-dir /user/hive/warehouse/test.db/order_uid/t1.dat 　　--fields-terminated-by ‘,‘

还是报相同错误！

2. 更改mysql里表的编码

将cengos1里mysql的表order_uid字符集编码改成：utf-8，重新执行，centos1的mysql表里导入了部分数据， 仍然报错：

Job failed as tasks failed. failedMaps:1 failedReduces:0
19/03/27 17:54:08 INFO mapreduce.Job: Counters: 33
File System Counters
FILE: Number of bytes read=0
FILE: Number of bytes written=290362
FILE: Number of read operations=0
FILE: Number of large read operations=0
FILE: Number of write operations=0
HDFS: Number of bytes read=1130
HDFS: Number of bytes written=0
HDFS: Number of read operations=8
HDFS: Number of large read operations=0
HDFS: Number of write operations=0
Job Counters 
Failed map tasks=1
Killed map tasks=1
Launched map tasks=4
Data-local map tasks=1
Rack-local map tasks=3
Total time spent by all maps in occupied slots (ms)=300866
Total time spent by all reduces in occupied slots (ms)=0
Total time spent by all map tasks (ms)=300866
Total vcore-milliseconds taken by all map tasks=300866
Total megabyte-milliseconds taken by all map tasks=308086784
Map-Reduce Framework
Map input records=5
Map output records=5
Input split bytes=282
Spilled Records=0
Failed Shuffles=0
Merged Map outputs=0
GC time elapsed (ms)=664
CPU time spent (ms)=2460
Physical memory (bytes) snapshot=315748352
Virtual memory (bytes) snapshot=4170031104
Total committed heap usage (bytes)=146800640
File Input Format Counters 
Bytes Read=0
File Output Format Counters 
Bytes Written=0
19/03/27 17:54:08 INFO mapreduce.ExportJobBase: Transferred 1.1035 KB in 223.4219 seconds (5.0577 bytes/sec)
19/03/27 17:54:08 INFO mapreduce.ExportJobBase: Exported 5 records.
19/03/27 17:54:08 ERROR mapreduce.ExportJobBase: Export job failed!
19/03/27 17:54:08 ERROR tool.ExportTool: Error during export: 
Export job failed!
at org.apache.sqoop.mapreduce.ExportJobBase.runExport(ExportJobBase.java:445)
at org.apache.sqoop.manager.SqlManager.exportTable(SqlManager.java:931)
at org.apache.sqoop.tool.ExportTool.exportTable(ExportTool.java:80)
at org.apache.sqoop.tool.ExportTool.run(ExportTool.java:99)
at org.apache.sqoop.Sqoop.run(Sqoop.java:147)
at org.apache.hadoop.util.ToolRunner.run(ToolRunner.java:70)
at org.apache.sqoop.Sqoop.runSqoop(Sqoop.java:183)
at org.apache.sqoop.Sqoop.runTool(Sqoop.java:234)
at org.apache.sqoop.Sqoop.runTool(Sqoop.java:243)
at org.apache.sqoop.Sqoop.main(Sqoop.java:252)

当指定map为1时：

sqoop export 
　　--connect jdbc:mysql://centos1:3306/test \\
　　--username root 　　--password root 　　--table order_uid 　　--export-dir /user/hive/warehouse/test.db/order_uid 　　--fields-terminated-by ‘,‘      --m 1

运行成功了！！！

sqoop默认情况下的map数量为4，也就是说这种情况下1个map能运行成功，而多个map会失败。于是将map改为2又试了一遍：

sqoop export 
　　--connect jdbc:mysql://centos1:3306/test \\
　　--username root 　　--password root 　　--table order_uid 　　--export-dir /user/hive/warehouse/test.db/order_uid 　　--fields-terminated-by ‘,‘      --m 2

执行结果为：

19/03/27 19:17:22 INFO mapreduce.Job: Counters: 32
        File System Counters
                FILE: Number of bytes read=0
                FILE: Number of bytes written=145181
                FILE: Number of read operations=0
                FILE: Number of large read operations=0
                FILE: Number of write operations=0
                HDFS: Number of bytes read=705
                HDFS: Number of bytes written=0
                HDFS: Number of read operations=4
                HDFS: Number of large read operations=0
                HDFS: Number of write operations=0
        Job Counters 
                Failed map tasks=1
                Launched map tasks=2
                Data-local map tasks=1
                Rack-local map tasks=1
                Total time spent by all maps in occupied slots (ms)=88960
                Total time spent by all reduces in occupied slots (ms)=0
                Total time spent by all map tasks (ms)=88960
                Total vcore-milliseconds taken by all map tasks=88960
                Total megabyte-milliseconds taken by all map tasks=91095040
        Map-Reduce Framework
                Map input records=5
                Map output records=5
                Input split bytes=141
                Spilled Records=0
                Failed Shuffles=0
                Merged Map outputs=0
                GC time elapsed (ms)=278
                CPU time spent (ms)=1200
                Physical memory (bytes) snapshot=159162368
                Virtual memory (bytes) snapshot=2087399424
                Total committed heap usage (bytes)=77070336
        File Input Format Counters 
                Bytes Read=0
        File Output Format Counters 
                Bytes Written=0
19/03/27 19:17:22 INFO mapreduce.ExportJobBase: Transferred 705 bytes in 99.4048 seconds (7.0922 bytes/sec)
19/03/27 19:17:22 INFO mapreduce.ExportJobBase: Exported 5 records.
19/03/27 19:17:22 ERROR mapreduce.ExportJobBase: Export job failed!
19/03/27 19:17:22 ERROR tool.ExportTool: Error during export: 
Export job failed!
        at org.apache.sqoop.mapreduce.ExportJobBase.runExport(ExportJobBase.java:445)
        at org.apache.sqoop.manager.SqlManager.exportTable(SqlManager.java:931)
        at org.apache.sqoop.tool.ExportTool.exportTable(ExportTool.java:80)
        at org.apache.sqoop.tool.ExportTool.run(ExportTool.java:99)
        at org.apache.sqoop.Sqoop.run(Sqoop.java:147)
        at org.apache.hadoop.util.ToolRunner.run(ToolRunner.java:70)
        at org.apache.sqoop.Sqoop.runSqoop(Sqoop.java:183)
        at org.apache.sqoop.Sqoop.runTool(Sqoop.java:234)
        at org.apache.sqoop.Sqoop.runTool(Sqoop.java:243)
        at org.apache.sqoop.Sqoop.main(Sqoop.java:252)

 可以看到它成功的导入了5条记录！！！

通过jobhistory窗口可以看到两个map一个成功，一个执行失败

 点击task的name：

成功的任务由centos4节点运行的，失败的task由centos1运行，又回到了问题1，就是centos1不能访问centos1的mysql数据！

最终一个朋友告诉我再centos1上单独添加对centos1的远程访问权限：

grant all privileges on *.* to ‘root‘@‘centos1‘ identified by ‘root‘ with grant option;     
flush privileges;

然后重新运行一下，问题1和问题2都被愉快的解决了！！！

当时在centos1上的mysql里执行了：

GRANT ALL PRIVILEGES ON *.* TO ‘root‘@‘%‘ IDENTIFIED BY ‘root‘ WITH GRANT OPTION; 

flush privileges;

对其他节点添加了远程访问，但没有对自己添加远程访问权限。