Hbase 快速统计行数 [英] Hbase quickly count number of rows

问题描述

现在我像这样在 ResultScanner 上实现行计数

Right now I implement row count over ResultScanner like this

for (Result rs = scanner.next(); rs != null; rs = scanner.next()) {
    number++;
}

如果数据达到百万次计算量很大，我想实时计算不想用Mapreduce

If data reaching millions time computing is large.I want to compute in real time that i don't want to use Mapreduce

如何快速计算行数.

推荐答案

在 HBase 中使用 RowCounterRowCounter 是一个 mapreduce 作业，用于计算表的所有行.这是一个很好的实用程序，可用作健全性检查，以确保在存在元数据不一致问题时 HBase 可以读取表的所有块.它会在一个进程中运行所有的 mapreduce，但如果你有一个 MapReduce 集群来利用它，它会运行得更快.

Use RowCounter in HBase RowCounter is a mapreduce job to count all the rows of a table. This is a good utility to use as a sanity check to ensure that HBase can read all the blocks of a table if there are any concerns of metadata inconsistency. It will run the mapreduce all in a single process but it will run faster if you have a MapReduce cluster in place for it to exploit.

$ hbase org.apache.hadoop.hbase.mapreduce.RowCounter <tablename>

Usage: RowCounter [options] 
    <tablename> [          
        --starttime=[start] 
        --endtime=[end] 
        [--range=[startKey],[endKey]] 
        [<column1> <column2>...]
    ]

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