java Sqoop无法将MySQL导入Hadoop,引发ClassNotFoundException
我安装了Sqoop 1.4.6,并尝试使用以下命令将一些数据从MySQL 5.6.29导入Hadoop 2.7.2版:
sqoop import --connect jdbc:mysql://<server_name>:3306/<dbname> --username <user-name> --password <password> --m 1 --table <table-name> --target-dir <hadoop-target-folder>
然后,我得到以下错误:
java.lang.Exception: java.lang.RuntimeException:
java.lang.ClassNotFoundException: Class <ClassName> not found
at org.apache.hadoop.mapred.LocalJobRunner$Job.runTasks(LocalJobRunner.java:462)
at org.apache.hadoop.mapred.LocalJobRunner$Job.run(LocalJobRunner.java:522)
Caused by: java.lang.RuntimeException: java.lang.ClassNotFoundException: Class <ClassName> not found
at org.apache.hadoop.conf.Configuration.getClass(Configuration.java:2195)
at org.apache.sqoop.mapreduce.db.DBConfiguration.getInputClass(DBConfiguration.java:403)
at org.apache.sqoop.mapreduce.db.DataDrivenDBInputFormat.createDBRecordReader(DataDrivenDBInputFormat.java:237)
at org.apache.sqoop.mapreduce.db.DBInputFormat.createRecordReader(DBInputFormat.java:263)
at org.apache.hadoop.mapred.MapTask$NewTrackingRecordReader.<init>(MapTask.java:515)
at org.apache.hadoop.mapred.MapTask.runNewMapper(MapTask.java:758)
at org.apache.hadoop.mapred.MapTask.run(MapTask.java:341)
at org.apache.hadoop.mapred.LocalJobRunner$Job$MapTaskRunnable.run(LocalJobRunner.java:243)
at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511)
at java.util.concurrent.FutureTask.run(FutureTask.java:266)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
at java.lang.Thread.run(Thread.java:745)
Caused by: java.lang.ClassNotFoundException: Class <ClassName> not found
at org.apache.hadoop.conf.Configuration.getClassByName(Configuration.java:2101)
at org.apache.hadoop.conf.Configuration.getClass(Configuration.java:2193)
... 12 more
可能有一个类似的问题,但我没有找到答案
有什么想法吗? 谢谢
# 1 楼答案
生成jar:
scoop codegen connect "jdbc:mysql://example.com/sqoop" username sqoop password sqoop table tbl
在output:Writing jar文件中查找以下行:
在导入命令中使用上述jar:
# 2 楼答案
根本原因是,当使用LocalJobRunner执行导入作业时,它无法加载sqoop生成的jar
解决方案1。将hadoop更改为在单节点集群模式下运行http://hadoop.apache.org/docs/current/hadoop-project-dist/hadoop-common/SingleCluster.html
解决方案2。首先生成jar文件,然后使用-libjars参数