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  • HBase change split policy on an existing table

    hbase(main):006:0> create 'test_table_region', 'username'
    0 row(s) in 1.2150 seconds
    
    hbase(main):009:0> put 'test_table_region', '1', 'username:nick' ,'3'
    0 row(s) in 0.0050 seconds
    
    hbase(main):010:0> scan 'test_table_region'
    ROW                                COLUMN+CELL                                                                                      
     1                                 column=username:nick, timestamp=1436859225880, value=3                                           
    1 row(s) in 0.1370 seconds
    
    hbase(main):011:0> describe 'test_table_region'
    DESCRIPTION                                                                           ENABLED                                       
     {NAME => 'test_table_region', FAMILIES => [{NAME => 'username', DATA_BLOCK_ENCODING  true                                          
     => 'NONE', BLOOMFILTER => 'NONE', REPLICATION_SCOPE => '0', VERSIONS => '3', COMPRES                                               
     SION => 'NONE', MIN_VERSIONS => '0', TTL => '2147483647', KEEP_DELETED_CELLS => 'fal                                               
     se', BLOCKSIZE => '65536', IN_MEMORY => 'false', ENCODE_ON_DISK => 'true', BLOCKCACH                                               
     E => 'true'}]}                                                                                                                     
    1 row(s) in 0.4040 seconds
    
    
    hbase(main):013:0> disable 'test_table_region'
    0 row(s) in 3.1710 seconds
    
    hbase(main):001:0> alter 'test_table_region', {METHOD => 'table_att', SPLIT_POLICY => 'org.apache.hadoop.hbase.regionserver.ConstantSizeRegionSplitPolicy', MAX_FILESIZE => '5000000000'}
    Updating all regions with the new schema...
    1/1 regions updated.
    Done.
    0 row(s) in 4.5130 seconds
    
    hbase(main):003:0> enable 'test_table_region'
    0 row(s) in 6.0330 seconds
    
    hbase(main):046:0> describe 'test_table_region'
    DESCRIPTION                                                                           ENABLED                                       
     {NAME => 'test_table_region', SPLIT_POLICY => 'org.apache.hadoop.hbase.regionserver. true                                          
     ConstantSizeRegionSplitPolicy', MAX_FILESIZE => '5000000000', FAMILIES => [{NAME =>                                                
     'username', DATA_BLOCK_ENCODING => 'NONE', BLOOMFILTER => 'NONE', REPLICATION_SCOPE                                                
     => '0', COMPRESSION => 'NONE', VERSIONS => '3', TTL => '2147483647', MIN_VERSIONS =>                                               
      '0', KEEP_DELETED_CELLS => 'false', BLOCKSIZE => '65536', ENCODE_ON_DISK => 'true',                                               
      IN_MEMORY => 'false', BLOCKCACHE => 'true'}]}                                                                                     
    1 row(s) in 0.4610 seconds

    the alter split_policy does not work for hbase before version 0.94

    we need to use java code to change the split policy of an existing table

     protected void changeSplitPolicy(String tableName, Configuration conf) throws IOException, IllegalAccessException, InstantiationException {
        HBaseAdmin admin = new HBaseAdmin(conf);
        HTable hTable = new HTable(conf, tableName);
        HTableDescriptor htd = hTable.getTableDescriptor();
        HTableDescriptor tableDesc = new HTableDescriptor(htd);
    
        tableDesc.setValue(HTableDescriptor.SPLIT_POLICY, ConstantSizeRegionSplitPolicy.class.getName());
        tableDesc.setValue(HTableDescriptor.MAX_FILESIZE, "5000000000");
    
        if(admin.isTableEnabled(tableName)) {
          admin.disableTable(tableName);
        }
        admin.modifyTable(Bytes.toBytes(tableName), tableDesc);
        hTable.close();
        admin.close();
        System.out.println("change split policy over");
      }
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  • 原文地址:https://www.cnblogs.com/yanghuahui/p/4645878.html
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