ERROR:Hive桶表加载数据的时候报错Cannot run job locally: Number of reducers (= 4) is more than 1

本文主要是介绍ERROR:Hive桶表加载数据的时候报错Cannot run job locally: Number of reducers (= 4) is more than 1，希望对大家解决编程问题提供一定的参考价值，需要的开发者们随着小编来一起学习吧！

1.问题描述

桶表加载数据的时候报错Cannot run job locally: Number of reducers (= 4) is more than 1。首先创建桶表

create table emp_bu_2(  
empno int,  
ename string,
job string,  
mgr int,
hiredate string,  
sal double,  
comm double,  
deptno int
)CLUSTERED BY(deptno) INTO 4 BUCKETS
row format delimited  fields terminated by '\t';

然后加载数据

insert overwrite table emp_bu_2 select * from emp;

报错

hive (hadoop)> insert overwrite table emp_bu_2 select * from emp;
Query ID = hadoop_20181106211010_c7fc887a-874c-42ca-943b-a922afc96c90
Total jobs = 1
Launching Job 1 out of 1
Number of reduce tasks determined at compile time: 4
In order to change the average load for a reducer (in bytes):set hive.exec.reducers.bytes.per.reducer=<number>
In order to limit the maximum number of reducers:set hive.exec.reducers.max=<number>
In order to set a constant number of reducers:set mapreduce.job.reduces=<number>
Cannot run job locally: Number of reducers (= 4) is more than 1
Starting Job = job_1541343004110_0528, Tracking URL = http://hadoop:8088/proxy/application_1541343004110_0528/
Kill Command = /opt/modules/hadoop-2.6.0-cdh5.15.0/bin/hadoop job  -kill job_1541343004110_0528

2.原因

reducer数量默认1，不足。

3.解决

增加reducer数量

set mapred.reduce.tasks = 4; 

 

这篇关于ERROR:Hive桶表加载数据的时候报错Cannot run job locally: Number of reducers (= 4) is more than 1的文章就介绍到这儿，希望我们推荐的文章对编程师们有所帮助！

---