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From Serega Sheypak <serega.shey...@gmail.com>
Subject Re: Splits are not preserved during table copy using getAdmin().createTable(tableDescriptor);
Date Fri, 03 Oct 2014 16:29:03 GMT
So easy, thanks :) I've missed that method.

2014-10-03 20:23 GMT+04:00 Ted Yu <yuzhihong@gmail.com>:

> You can simplify your code by utilizing the following from HTable:
>
>   public byte [][] getStartKeys() throws IOException {
>
> No need to sort the keys.
>
> Cheers
>
> On Fri, Oct 3, 2014 at 9:10 AM, Serega Sheypak <serega.sheypak@gmail.com>
> wrote:
>
> > Thanks, I'm already updated my end-to-end test, waiting for the result.
> >
> > Here is my code snippet, is it ok?
> >
> >  @SneakyThrows(IOException.class)
> >     private byte[][] collectSplits(String tableName){
> >         HTable table = new HTable(configuration, tableName);
> >         int splitSize =
> > table.getRegionLocations().descendingKeySet().size();
> >
> >         if(splitSize < 2){
> >             LOG.info(String.format("There is only one region for a
> > table[%s]. No splits to recreate", tableName));
> >             return new byte[][]{};
> >         }
> >         LOG.info(String.format("There are [%s] regions for a table[%s].
> > Skip pre-splitting", splitSize, tableName));
> >
> >         byte[][] splits = new byte[splitSize][];
> >       *  Iterator<HRegionInfo> itr =
> > table.getRegionLocations().descendingKeySet().iterator();*
> > *        int index = 0;*
> > *        while (itr.hasNext()){*
> > *            splits[index] = itr.next().getStartKey();*
> > *            index++;*
> > *        }*
> >
> >         table.close();
> >
> >         Arrays.sort(splits, Bytes.BYTES_COMPARATOR);
> >         return splits;
> >     }
> >
> >
> > 2014-10-03 20:02 GMT+04:00 Ted Yu <yuzhihong@gmail.com>:
> >
> > > Take a look at this method in HTable:
> > >
> > >   public Pair<byte[][],byte[][]> getStartEndKeys() throws IOException
{
> > >
> > > You would see that the first dimension corresponds to the number of
> > > regions.
> > >
> > >
> > > Cheers
> > >
> > > On Fri, Oct 3, 2014 at 8:33 AM, Serega Sheypak <
> serega.sheypak@gmail.com
> > >
> > > wrote:
> > >
> > > > Ok, I found them:
> > > > hTable.getRegionLocations().descendingKeySet()
> > > > and
> > > > HRegionInfo has startKey and endKey
> > > > I have to prepare splits[][].
> > > > I'm confused a little, how keys should be placed there? splits[][]
> > shoud
> > > by
> > > > and array with length=region count and width = 2?
> > > >
> > > >
> > > > 2014-10-03 17:57 GMT+04:00 Serega Sheypak <serega.sheypak@gmail.com
> >:
> > > >
> > > > > Hi, here is my code:
> > > > >
> > > > > public void dropIfExistsAndCreate(String sourceTableName, String
> > > > > newTableName) throws IOException {
> > > > >         LOG.info(String.format("Use [%s] to create [%s]",
> > > > sourceTableName,
> > > > > newTableName));
> > > > >         HTableDescriptor descriptor =
> getDescriptor(sourceTableName);
> > > > >         dropIfExists(newTableName); // doesn't matter
> > > > >         createTable(descriptor, newTableName);
> > > > >     }
> > > > >
> > > > >     private void createTable(HTableDescriptor descriptor, String
> > > > > newTableName) throws IOException {
> > > > >         descriptor.setName(Bytes.toBytes(newTableName));
> > > > >         getAdmin().createTable(descriptor);
> > > > >         LOG.info(String.format("Table created[%s]", newTableName));
> > > > >     }
> > > > >
> > > > > My source table has 256 regions, newly created table has no splits.
> > > > > Is there any possibility to copy splits from source table?
> > > > >
> > > > > I supposed, that HTableDescriptor encasulates splits, but it was
> bad
> > > > > assumption.
> > > > >
> > > >
> > >
> >
>

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