Just to add the name is depreciated in new Hadoop Try to find mapreduce.job.reduces
On Tue, Sep 11, 2012 at 9:43 PM, Bejoy Ks <[email protected]> wrote: > Hi Lin > > The default values for all the properties are in > core-default.xml > hdfs-default.xml and > mapred-default.xml > > > Regards > Bejoy KS > > > On Tue, Sep 11, 2012 at 5:06 PM, Jason Yang <[email protected]>wrote: > >> Hi, Bejoy >> >> Thanks for you reply. >> >> where could I find the default value of mapred.reduce.tasks ? I have >> checked the core-site.xml, hdfs-site.xml and mapred-site.xml, but I haven't >> found it. >> >> >> 2012/9/11 Bejoy Ks <[email protected]> >> >>> Hi Lin >>> >>> The default value for number of reducers is 1 >>> >>> <name>mapred.reduce.tasks</name> >>> <value>1</value> >>> >>> It is not determined by data volume. You need to specify the number of >>> reducers for your mapreduce jobs as per your data volume. >>> >>> Regards >>> Bejoy KS >>> >>> On Tue, Sep 11, 2012 at 4:53 PM, Jason Yang <[email protected]>wrote: >>> >>>> Hi, all >>>> >>>> I was wondering what's the default number of reducer if I don't set it >>>> in configuration? >>>> >>>> Will it change dynamically according to the output volume of Mapper? >>>> >>>> -- >>>> YANG, Lin >>>> >>>> >>> >> >> >> -- >> YANG, Lin >> >> >
