Thanks, Ryan. Yes, It only count rows. :)
On Fri, Jul 30, 2010 at 11:13 AM, Ryan Rawson <[email protected]> wrote: > RowCounter job counts rows. Its answer will be how many distinct row keys > were in the table approximately at a given time range. > > Even if the implementation uses first kv filter nothing about what I just > said is false. > > A KeyValue counter would tell you how many cells and versions there were > total don't you think? > > On Jul 29, 2010 7:58 PM, "Angus He" <[email protected]> wrote: >> Column names are just optional for RowCounter job. >> >> To be more accurate, RowCounter is a KeyValueCounter. >> If no columns are specified, only the first KeyValues of each row are >> included, then get the RowCounter. >> >> >> On Fri, Jul 30, 2010 at 9:28 AM, Ted Yu <[email protected]> wrote: >>> If someone can share the commandline for running RowCounter, that would > be >>> great. >>> >>> Also, hbase shell count doesn't require column name. Why does RowCounter >>> require it ? >>> >>> Thanks >>> >>> On Thu, Jul 29, 2010 at 4:55 PM, Ryan Rawson <[email protected]> wrote: >>> >>>> Hi, >>>> >>>> That table appears to be empty. Eg: >>>> >>>> 10/07/29 22:38:43 INFO mapred.JobClient: Map input records=0 >>>> >>>> >>>> So back to the count issue... Counting in databases is a classic >>>> problem. Unless your DB system is keeping stats on how many >>>> inserts/deletes and thus how big it thinks the table is, you have to >>>> count all the rows by reading them. HBase is no different, and a >>>> little harder, because we have a variable length data format, so we >>>> can't just estimate row sizes from file sizes. Keeping distributed >>>> stats is not impossible, but certainly not on any priority list to be >>>> implemented - of course JIRAs/patches welcome etc. >>>> >>>> -ryan >>>> >>>> >>>> On Thu, Jul 29, 2010 at 3:48 PM, Ted Yu <[email protected]> wrote: >>>> > We use HBase 0.20.5 >>>> > >>>> > Here is the snippet from RowCounter output: >>>> > >>>> > 10/07/29 22:38:42 DEBUG client.HTable$ClientScanner: Finished with >>>> scanning >>>> > at REGION => {NAME => >>>> > >>>> > '2__HB_NOINC_ORCL_SQLLDR_0728-THREEGPPSPEECHCALLS-1280408509541-0,DFF46493EB352D0E31CBFA4652E6EC06,1280412540858', >>>> > STARTKEY => 'DFF46493EB352D0E31CBFA4652E6EC06', ENDKEY => '', ENCODED > => >>>> > 1375318608, TABLE => {{NAME => >>>> > '2__HB_NOINC_ORCL_SQLLDR_0728-THREEGPPSPEECHCALLS-1280408509541-0', >>>> FAMILIES >>>> > => [{NAME => 'd', COMPRESSION => 'GZ', VERSIONS => '2', TTL => >>>> '31536000', >>>> > BLOCKSIZE => '65536', IN_MEMORY => 'false', BLOCKCACHE => 'false'}, > {NAME >>>> => >>>> > 'i', COMPRESSION => 'GZ', VERSIONS => '2', TTL => '31536000', > BLOCKSIZE >>>> => >>>> > '65536', IN_MEMORY => 'false', BLOCKCACHE => 'false'}, {NAME => 'v', >>>> > COMPRESSION => 'GZ', VERSIONS => '2', TTL => '31536000', BLOCKSIZE => >>>> > '65536', IN_MEMORY => 'false', BLOCKCACHE => 'false'}]}} >>>> > 10/07/29 22:38:42 INFO mapred.TaskRunner: >>>> Task:attempt_local_0001_m_000000_0 >>>> > is done. And is in the process of commiting >>>> > 10/07/29 22:38:42 INFO mapred.LocalJobRunner: >>>> > 10/07/29 22:38:42 INFO mapred.TaskRunner: Task >>>> attempt_local_0001_m_000000_0 >>>> > is allowed to commit now >>>> > 10/07/29 22:38:42 INFO mapred.FileOutputCommitter: Saved output of > task >>>> > 'attempt_local_0001_m_000000_0' to >>>> > file:/usr/local/hadoop/trunk.80-275066/hbase-0.20.5/rc >>>> > 10/07/29 22:38:42 INFO mapred.LocalJobRunner: >>>> > 10/07/29 22:38:42 INFO mapred.TaskRunner: Task >>>> > 'attempt_local_0001_m_000000_0' done. >>>> > 10/07/29 22:38:43 INFO mapred.JobClient: map 100% reduce 0% >>>> > 10/07/29 22:38:43 INFO mapred.JobClient: Job complete: job_local_0001 >>>> > 10/07/29 22:38:43 INFO mapred.JobClient: Counters: 6 >>>> > 10/07/29 22:38:43 INFO mapred.JobClient: FileSystemCounters >>>> > 10/07/29 22:38:43 INFO mapred.JobClient: FILE_BYTES_READ=1592883 >>>> > 10/07/29 22:38:43 INFO mapred.JobClient: > FILE_BYTES_WRITTEN=1624956 >>>> > 10/07/29 22:38:43 INFO mapred.JobClient: Map-Reduce Framework >>>> > 10/07/29 22:38:43 INFO mapred.JobClient: Map input records=0 >>>> > 10/07/29 22:38:43 INFO mapred.JobClient: Spilled Records=0 >>>> > 10/07/29 22:38:43 INFO mapred.JobClient: Map input bytes=0 >>>> > 10/07/29 22:38:43 INFO mapred.JobClient: Map output records=0 >>>> > >>>> > [sjc1-hadoop8.sjc1:hadoop 3705]ls -l >>>> > /usr/local/hadoop/trunk.80-275066/hbase-0.20.5/rc/part-00000 >>>> > -rwxrwxrwx 1 hadoop users 0 Jul 29 22:38 >>>> > /usr/local/hadoop/trunk.80-275066/hbase-0.20.5/rc/part-00000 >>>> > >>>> > But there are many records in the table I was querying. >>>> > >>>> > Can someone comment ? >>>> > >>>> > On Thu, Jul 29, 2010 at 2:26 PM, Jean-Daniel Cryans < > [email protected] >>>> >wrote: >>>> > >>>> >> In 0.89 you can specify CACHE for the count command. Set it higher > (it >>>> >> defaults to 10 rows per call). >>>> >> >>>> >> Also you can use the RowCounter MR job. >>>> >> >>>> >> J-D >>>> >> >>>> >> On Thu, Jul 29, 2010 at 2:22 PM, Ted Yu <[email protected]> wrote: >>>> >> > Hi, >>>> >> > The count method in HBase shell is quite slow. >>>> >> > Is there a way to obtain count faster ? >>>> >> > >>>> >> > Thanks >>>> >> > >>>> >> >>>> > >>>> >>> >> >> >> >> -- >> Regards >> Angus > -- Regards Angus
