For #2, see TableInputFormatBase.getSplits(): * Calculates the splits that will serve as input for the map tasks. The * number of splits matches the number of regions in a table.
On Mon, Jul 4, 2011 at 7:37 AM, Lior Schachter <[email protected]> wrote: > 1. yes - I configure my job using this line: > TableMapReduceUtil.initTableMapperJob(HBaseConsts.URLS_TABLE_NAME, scan, > ScanMapper.class, Text.class, MapWritable.class, job) > > which internally uses TableInputFormat.class > > 2. One split per region ? What do you mean ? How do I do that ? > > 3. hbase version 0.90.2 > > 4. no exceptions. the logs are very clean. > > > > On Mon, Jul 4, 2011 at 5:22 PM, Ted Yu <[email protected]> wrote: > > > Do you use TableInputFormat ? > > To scan large number of rows, it would be better to produce one Split per > > region. > > > > What HBase version do you use ? > > Do you find any exception in master / region server logs around the > moment > > of timeout ? > > > > Cheers > > > > On Mon, Jul 4, 2011 at 4:48 AM, Lior Schachter <[email protected]> > > wrote: > > > > > Hi all, > > > I'm running a scan using the M/R framework. > > > My table contains hundreds of millions of rows and I'm scanning using > > > start/stop key about 50 million rows. > > > > > > The problem is that some map tasks get stuck and the task manager kills > > > these maps after 600 seconds. When retrying the task everything works > > fine > > > (sometimes). > > > > > > To verify that the problem is in hbase (and not in the map code) I > > removed > > > all the code from my map function, so it looks like this: > > > public void map(ImmutableBytesWritable key, Result value, Context > > context) > > > throws IOException, InterruptedException { > > > } > > > > > > Also, when the map got stuck on a region, I tried to scan this region > > > (using > > > simple scan from a Java main) and it worked fine. > > > > > > Any ideas ? > > > > > > Thanks, > > > Lior > > > > > >
