ERROR tool.ExportTool: Error during export:  because

Export job failed!
    at org.apache.sqoop.mapreduce.ExportJobBase.runExport(ExportJobBase.java:439)
    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)
Warning: /usr/lib/sqoop/../accumulo does not exist! Accumulo imports will fail.

sqoop import export其實也是mapreduce ，然後問題出現在map階段執行完，export 到mysql中

大概原因是：hive表結構和mysql表結構不一致，主要表現在

欄位數量，欄位型別，非空約束等比如說hive表結構中有null，而mysql卻有非空約束，顯然會錯，

還有sqoop匯出到mysql需要指定export -dir 為hdfs上的路徑，確定hdfs路徑是否有問題，hdfs路徑下是否有多個檔案，

如果sqoop被azkaban執行的話，還需要在sqoop任務中新增jdk路徑，jdk路徑是否正確

export JAVA_HOME=/usr/local/jdk1.8
export CLASSPATH=.:$JAVA_HOME/lib/dt.jar:$JAVA_HOME/lib/tools.jar
export PATH=$JAVA_HOME/bin:$PATH