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HBase, mail # user - split table data into two or more tables


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alxsss@... 2013-02-08, 18:36
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Kevin Odell 2013-02-08, 18:41
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Ted Yu 2013-02-08, 18:40
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Ted Yu 2013-02-08, 18:51
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alxsss@... 2013-02-08, 18:59
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Marcos Ortiz 2013-02-08, 14:52
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Re: split table data into two or more tables
alxsss@... 2013-02-08, 22:16

 Hi,

here is the hbase-site.xml file.

<property>
  <name>hbase.hregion.majorcompaction</name>
  <value>0</value>
</property>
     <property>
  <name>hbase.regionserver.codecs</name>
  <value>snappy,gz</value>
</property>
<property>
    <name>hbase.rootdir</name>
    <value>hdfs://master:9000/hbase</value>
  </property>
  <property>
    <name>hbase.zookeeper.quorum</name>
    <value>master,slave,serverslave</value>
  </property>
  <property>
    <name>hbase.cluster.distributed</name>
    <value>true</value>
  </property>
 <property>
    <name>dfs.support.append</name>
    <value>true</value>
  </property>
 <property>
    <name>hbase.hregion.memstore.mslab.enabled</name>
    <value>true</value>
  </property>
 <property>
    <name>hbase.regionserver.handler.count</name>
    <value>40</value>
  </property>
 <property>
    <name>hbase.regionserver.global.memstore.upperLimit</name>
    <value>0.45</value>
  </property>
 <property>
    <name>hbase.regionserver.global.memstore.lowerLimit</name>
    <value>0.4</value>
  </property>
 <property>
    <name>hfile.block.cache.size</name>
    <value>0.3</value>
  </property>

<property>
  <name>mapred.map.tasks.speculative.execution</name>
  <value>false</value>
</property>
<property>
  <name>mapred.reduce.tasks.speculative.execution</name>
  <value>false</value>
</property>

<!-- default is 256MB 268435456, this is 1.5GB -->
  <property>
    <name>hbase.hregion.max.filesize</name>
    <value>161061273600</value>
  </property>

  <!-- default is 2 -->
  <property>
    <name>hbase.hregion.memstore.block.multiplier</name>
    <value>4</value>
  </property>

  <!-- default is 64MB 67108864 -->
  <property>
    <name>hbase.hregion.memstore.flush.size</name>
    <value>134217728</value>
  </property>

  <!-- default is 7, should be at least 2x compactionThreshold -->
  <property>
    <name>hbase.hstore.blockingStoreFiles</name>
    <value>200</value>
  </property>
<property>
    <name>hbase.regionserver.lease.period</name>
    <value>1800000</value> <!-- 30 minutes -->
  </property>
  <property>
    <name>hbase.rpc.timeout</name>
    <value>1800000</value> <!-- 30 minutes -->
  </property>

 

 Thanks.
Alex.

 

 

-----Original Message-----
From: Marcos Ortiz <[EMAIL PROTECTED]>
To: alxsss <[EMAIL PROTECTED]>
Cc: user <[EMAIL PROTECTED]>
Sent: Fri, Feb 8, 2013 11:52 am
Subject: Re: split table data into two or more tables
              
    
On 02/08/2013 01:59 PM, [EMAIL PROTECTED]      wrote:
    
    
      
Hi,

The rationale is that I have a mapred job that adds new records to an hbase table, constantly.
The next mapred job selects these new records, but it must iterate over all records and check if it is a candidate for selection.
Since there are too many old records iterating though them in a cluster of 2 nodes +1 master takes about 2 days. So I thought, splitting them into two tables must reduce this time, and as soon as I figure out that there is no more new record left in one of the new tables I will not run mapred job on it.
    
    This use-case is very common and a good practice here is to    pre-split the regions to control exactly where to put your data and    the size of it, keeping
    always the numbers of regions more manageable.
    
      
Currently, we have 7 regions including ROOT and META.
    
    Can you share your conf/hbase-site.xml ?
    
    
      

Thanks.
Alex.
 

 

-----Original Message-----
From: Ted Yu <[EMAIL PROTECTED]>
To: user <[EMAIL PROTECTED]>
Sent: Fri, Feb 8, 2013 10:40 am
Subject: Re: split table data into two or more tables
May I ask the rationale behind this ?
Were you aiming for higher write throughput ?

Please also tell us how many regions you have in the current table.

Thanks

BTW please consider upgrading to 0.94.4

On Fri, Feb 8, 2013 at 10:36 AM, <[EMAIL PROTECTED]> wrote:
    
    
      
        
Hello,

I wondered if there is a way of splitting data from one table into two or
more tables in hbase with iidentical schemas, i.e. if table A has 100M
records put 50M into table B, 50M into table C and delete table A.
Currently, I use hbase-0.92.1 and hadoop-1.4.0

Thanks.
Alex.
      
      
 
    
    
    
      Marcos Ortiz Valmaseda,
      Product Manager && Data Scientist at UCI
      Blog: http://marcosluis2186.posterous.com
      Twitter: @marcosluis2186
  
 
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Ted Yu 2013-02-08, 19:04
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Ted Yu 2013-02-08, 19:22
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alxsss@... 2013-02-09, 01:47
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Ted Yu 2013-02-09, 02:22
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ramkrishna vasudevan 2013-02-09, 10:42
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alxsss@... 2013-02-21, 02:27
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ramkrishna vasudevan 2013-02-21, 04:29