Thanks Rita for logging the JIRA. Do you want to provide a patch ?
On Sat, Oct 29, 2011 at 7:29 AM, Rita <[email protected]> wrote: > Opened, https://issues.apache.org/jira/browse/HBASE-4702 > > > Please edit to your liking. > > > On Sun, Oct 9, 2011 at 9:05 PM, Himanshu Vashishtha < > [email protected] > > wrote: > > > MapReduce support in HBase inherently provides parallelism such that > > each Region is given to one mapper. > > > > Himanshu > > > > On Sun, Oct 9, 2011 at 6:44 PM, lars hofhansl <[email protected]> > wrote: > > > Be aware that the contract for a scan is to return all rows sorted by > > rowkey, hence it cannot scan regions in parallel by default.I have not > > played much HBase with MapReduce, but if order is not important you can > to > > split the scan into multiple scans. > > > > > > > > > ----- Original Message ----- > > > From: Tom Goren <[email protected]> > > > To: [email protected] > > > Cc: > > > Sent: Sunday, October 9, 2011 8:07 AM > > > Subject: Re: speeding up rowcount > > > > > > lol - i just ran a rowcount via mapreduce, and it took 6 hours for 7.5 > > > million rows... > > > > > > On Sun, Oct 9, 2011 at 7:50 AM, Rita <[email protected]> wrote: > > > > > >> Hi, > > >> > > >> I have been doing a rowcount via mapreduce and its taking about 4-5 > > hours > > >> to > > >> count a 500million rows in a table. I was wondering if there are any > map > > >> reduce tunings I can do so it will go much faster. > > >> > > >> I have 10 node cluster, each node with 8CPUs with 64GB of memory. Any > > >> tuning > > >> advice would be much appreciated. > > >> > > >> > > >> -- > > >> --- Get your facts first, then you can distort them as you please.-- > > >> > > > > > > > > > > > > -- > --- Get your facts first, then you can distort them as you please.-- >
