• Hbase预分区种子生成


    提前生成Hbase预分区种子,在创建Hbase表时也进行相应的预分区,同时设置预分区的个数,预分区的范围对应Hbase监控页面的Region Server的start key与End key,从而使数据能够均匀的分布于各个Region中。

    private static final String[] PARTITIONS = generatPartitionSeed();
    
    
    //生成3844个分区种子
    public static String[] generatPartitionSeed(){
        List<Character>seeds = List.newArrayList();
        for(int i='0';i<='9';i++){
            seeds.add((char) i);
        }
        for(int i = 'A';i<='Z';i++){
            seeds.add((char) i);
        }
        for(int i = 'a';i<='z';i++){
            seeds.add((char) i);
        }
        int k = 0;
       //获得总共的分区个数
        String[] partions = new String[seeds.size()*seeds.get(j));
        for(int i =0;i<seeds.size();i++){
            for(int j=0;j<seeds.size();j++){
               //两两组合成为分区start key
                partions[k] = StringUtil.join(seeds.get(i),seeds.get(j));
                k++;
            }
        }
        return partions;
    }    
    
    //按指定数量生成分区种子
    public static String[] generatPartitionSeed(int limit){
        int size = PARTITIONS.length;
        int[] space = new int[limit];
        for(int pt = 0;pt<size;){
            for(int j=0;j<space.length;j++){
                ++space[j];
                pt++;
                if(pt == size){
                    break;
                }
            }
        }
    String[] seed = new String[limit+1];
    int position = 0;
    for(int i =0;i<space.length;i++){
          seed[i] = PARTITIONS[position];
          position += space[i];
    }
    seed[seed.length -1] = PARTITIONS[PARTITIONS.length -1];
    return seed;
    }
    
    //生成后的rowkey
    public static String generatRow(String str){
        int i = Math.abs(str.hashCode() % PARTITION.length);
        return StringUtils.join(PARTITIONS[i],"-",str);
    }
    
    public static void main(String[] args){
        String[] arr = generatPartitionSeed(100);
        for(int i = 0;i<arr.length;i++){
            System.out.println(arr[i]);
        }
    }
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  • 原文地址:https://www.cnblogs.com/itboys/p/9977366.html
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