I have a question about running hadoop mapreduce job. I have a table staff, partitioned by join date. Create statement like that:
create table staff (id int, age int) partitioned by (join_date string) row format delimited fields terminated by '\;';
I put some data to parition '20130921' then when i execute statement bellow, the result is ok:
select count(*) from staff where join_date='20130921';**
But when i execute on partition '20130922' (partition without data), the map reduce job is pending too long, seem like is run forever:
hive> select count(*) from staff where join_date='20130922';**
Total MapReduce jobs = 1**
Launching Job 1 out of 1**
**Number of reduce tasks determined at compile time: 1**
**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 mapred.reduce.tasks=<number>**
**Starting Job** = `job_201309231116_0131, Tracking URL = ....jobid=job_201309231116_0131`
**Kill Command** = `/u01/hadoop-0.20.203.0/bin/../bin/hadoop job -kill job_201309231116_0131`
Hadoop job information for Stage-1: number of mappers: 0; number of reducers: 1
2013-09-23 17:19:07,182 Stage-1 map = 0%, reduce = 0%
2013-09-23 17:19:07,182 Stage-1 map = 0%, reduce = 0%
2013-09-23 17:19:07,182 Stage-1 map = 0%, reduce = 0%
The jobtracker show reduce task pending and this job dont seem like can finished.
Im using hadoop-0.20.203.0 and hive-0.10.0. I googled all day but didnt find any topic have same problem, please help me.
Best regards.
