sqoopexport导出map100%reduce0%卡住的多种原因及解决

[root@host25 ~]# 
sqoop export --connect "jdbc:mysql://172.16.xxx.xxx:3306/dbname&＃63;useUnicode=true&characterEncoding=utf-8" 
--username=root --password=xxxxx --table rule_tag --update-key rule_code 
--update-mode allowinsert 
--export-dir /user/hive/warehouse/lmj_test.db/rule_tag --input-fields-terminated-by '\t' 
--input-null-string '\\N' --input-null-non-string '\\N' -m1

#截取部分
19/06/11 09:39:57 INFO mapreduce.Job: The url to track the job: http://dthost25:8088/proxy/application_1554176896418_0537/
19/06/11 09:39:57 INFO mapreduce.Job: Running job: job_1554176896418_0537
19/06/11 09:40:05 INFO mapreduce.Job: Job job_1554176896418_0537 running in uber mode : false
19/06/11 09:40:05 INFO mapreduce.Job: map 0% reduce 0%
19/06/11 09:40:19 INFO mapreduce.Job: map 100% reduce 0%
19/06/11 09:45:34 INFO mapreduce.Job: Task Id : attempt_1554176896418_0537_m_000000_0, Status : FAILED
AttemptID:attempt_1554176896418_0537_m_000000_0 Timed out after 300 secs
19/06/11 09:45:36 INFO mapreduce.Job: map 0% reduce 0%
19/06/11 09:45:48 INFO mapreduce.Job: map 100% reduce 0%
19/06/11 09:51:04 INFO mapreduce.Job: Task Id : attempt_1554176896418_0537_m_000000_1, Status : FAILED
AttemptID:attempt_1554176896418_0537_m_000000_1 Timed out after 300 secs
19/06/11 09:51:05 INFO mapreduce.Job: map 0% reduce 0%
19/06/11 09:51:17 INFO mapreduce.Job: map 100% reduce 0%
19/06/11 09:56:34 INFO mapreduce.Job: Task Id : attempt_1554176896418_0537_m_000000_2, Status : FAILED
AttemptID:attempt_1554176896418_0537_m_000000_2 Timed out after 300 secs
19/06/11 09:56:35 INFO mapreduce.Job: map 0% reduce 0%
19/06/11 09:56:48 INFO mapreduce.Job: map 100% reduce 0%
19/06/11 10:02:05 INFO mapreduce.Job: Job job_1554176896418_0537 failed with state FAILED due to: Task failed task_1554176896418_0537_m_000000
Job failed as tasks failed. failedMaps:1 failedReduces:0
19/06/11 10:02:05 INFO mapreduce.Job: Counters: 9
 Job Counters 
 Failed map tasks=4
 Launched map tasks=4
 Other local map tasks=3
 Data-local map tasks=1
 Total time spent by all maps in occupied slots (ms)=2624852
 Total time spent by all reduces in occupied slots (ms)=0
 Total time spent by all map tasks (ms)=1312426
 Total vcore-seconds taken by all map tasks=1312426
 Total megabyte-seconds taken by all map tasks=2687848448
19/06/11 10:02:05 WARN mapreduce.Counters: Group FileSystemCounters is deprecated. Use org.apache.hadoop.mapreduce.FileSystemCounter instead
19/06/11 10:02:05 INFO mapreduce.ExportJobBase: Transferred 0 bytes in 1,333.3153 seconds (0 bytes/sec)
19/06/11 10:02:05 WARN mapreduce.Counters: Group org.apache.hadoop.mapred.Task$Counter is deprecated. Use org.apache.hadoop.mapreduce.TaskCounter instead
19/06/11 10:02:05 INFO mapreduce.ExportJobBase: Exported 0 records.
19/06/11 10:02:05 ERROR tool.ExportTool: Error during export: Export job failed!
Time taken: 1340 s 
task IDE_TASK_ADE56470-B5A3-4303-EA75-44312FF8AA0C_20190611093945147 is complete.

 
 yarn.nodemanager.resource.memory-mb 
 20480 
 
 
 yarn.scheduler.minimum-allocation-mb 
 2048 
 
 
 yarn.nodemanager.vmem-pmem-ratio 
 2.1