Leo: You may find this helpful: http://indoos.wordpress.com/2010/06/24/hive-remote-debugging/
On Thu, Nov 18, 2010 at 2:57 PM, Leo Alekseyev <dnqu...@gmail.com> wrote: > Hi Ning, > For the dataset I'm experimenting with, the total size of the output > is 2mb, and the files are at most a few kb in size. My > hive.input.format was set to default HiveInputFormat; however, when I > set it to CombineHiveInputFormat, it only made the first stage of the > job use fewer mappers. The merge job was *still* filtered out at > runtime. I also tried set hive.mergejob.maponly=false; that didn't > have any effect. > > I am a bit at a loss what to do here. Is there a way to see what's > going on exactly using e.g. debug log levels?.. Btw, I'm also using > dynamic partitions; could that somehow be interfering with the merge > job?.. > > I'm running a relatively fresh Hive from trunk (built maybe a month ago). > > --Leo > > On Thu, Nov 18, 2010 at 1:12 PM, Ning Zhang <nzh...@fb.com> wrote: > > The settings looks good. The parameter hive.merge.size.smallfiles.avgsize > is used to determine at run time if a merge should be triggered: if the > average size of the files in the partition is SMALLER than the parameter and > there are more than 1 file, the merge should be scheduled. Can you try to > see if you have any big files as well in your resulting partition? If it is > because of a very large file, you can set the parameter large enough. > > > > Another possibility is that your Hadoop installation does not support > CombineHiveInputFormat, which is used for the new merge job. Someone > reported previously merge was not successful because of this. If that's the > case, you can turn off CombineHiveInputFormat and use the old > HiveInputFormat (though slower) by setting hive.mergejob.maponly=false. > > > > Ning > > On Nov 17, 2010, at 6:00 PM, Leo Alekseyev wrote: > > > >> I have jobs that sample (or generate) a small amount of data from a > >> large table. At the end, I get e.g. about 3000 or more files of 1kb > >> or so. This becomes a nuisance. How can I make Hive do another pass > >> to merge the output? I have the following settings: > >> > >> hive.merge.mapfiles=true > >> hive.merge.mapredfiles=true > >> hive.merge.size.per.task=256000000 > >> hive.merge.size.smallfiles.avgsize=16000000 > >> > >> After setting hive.merge* to true, Hive started indicating "Total > >> MapReduce jobs = 2". However, after generating the > >> lots-of-small-files table, Hive says: > >> Ended Job = job_201011021934_1344 > >> Ended Job = 781771542, job is filtered out (removed at runtime). > >> > >> Is there a way to force the merge, or am I missing something? > >> --Leo > > > > >
