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HBase >> mail # dev >> Re: Rebuild HBASE Table to reduce Regions per RS


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Re: Rebuild HBASE Table to reduce Regions per RS

Normally when people are doing merges they are scripting it (I.E., not
typing out or copying/pasting each region name), but if a table is that
far gone the least problematic way is to re-create assuming you have the
capacity (i.e., not just storage, but nodes to support all the extra hbase
regions before dropping the old table).

On 1/14/14 3:38 PM, "Upender Nimbekar" <[EMAIL PROTECTED]> wrote:

>Is there a way I can Merge w/o explicitly mentioning the region names. I
>have got a total of 50000 regions. There's no way I am going to name each
>and every region. Otherway is to MIRROR a new table. Use Map Reduce job to
>copy data from old table. Delete Old Table. And Rename new table. What do
>you think. I was almost inclined to used MERGE but looks like that's not
>the way.
>
>Thanks
>Upender
>
>
>On Tue, Jan 14, 2014 at 1:47 PM, Ted Yu <[EMAIL PROTECTED]> wrote:
>
>> Upender:
>> For 15.2.2 Merge, please note the following condition:
>>
>>     LOG.info("Verifying that HBase is not running...");
>>     try {
>>       HBaseAdmin.checkHBaseAvailable(getConf());
>>       LOG.fatal("HBase cluster must be off-line.");
>>
>> Cheers
>>
>>
>> On Tue, Jan 14, 2014 at 10:40 AM, Vladimir Rodionov
>> <[EMAIL PROTECTED]>wrote:
>>
>> > I have never tried this before but I think the following should work:
>> >
>> > 1. Alter your table:
>> >
>> > habse> alter 't1', METHOD => 'table_att', MAX_FILESIZE => '5000000000'
>> > (place your own number here)
>> >
>> > 2. Merge regions:
>> >
>> > http://hbase.apache.org/book/ops.regionmgt.html
>> >
>> >
>> >
>> >
>> > On Tue, Jan 14, 2014 at 7:21 AM, Upender Nimbekar <
>> > [EMAIL PROTECTED]> wrote:
>> >
>> > > Hi,
>> > > Does anyone have any experience rebuidling the HBASE table to reduce
>> the
>> > > number of regions. I am currently dealing with a situation where the
>> no.
>> > of
>> > > regions per RS have gone up quite significantly (500 per RS) and
>> thereby
>> > > causing some performance issues. This is how I am thinking of
>>bringing
>> it
>> > > down:
>> > >
>> > > increase the hbase.hregion.max.filesize from 500 MB to 2 GB
>> > >
>> > > And the rebuild the HBASE table. I am assuming if after table
>>rebuild,
>> I
>> > > should see the no. of regions come down to more than half. I would
>> > > basically like to stay within HBASE suggested no. of regions per RS
>> which
>> > > is about 50-200.
>> > >
>> > > Please suggest if someone has any experience doing it.
>> > >
>> > > Thanks
>> > > Upen
>> > >
>> >
>>