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 >> > > >> > >>
