HBASE count方法总结

一. 用hbase自带的mapreduce程序来计算如下，

/usr/hdp/2.3.0.0-2557/hbase/bin
[root@node1 bin]# ./hbase org.apache.hadoop.hbase.mapreduce.RowCounter 'testtable0728'

计算结果如下：

2016-07-28 16:52:31,924 INFO  [main] mapreduce.Job:  map 0% reduce 0%
2016-07-28 16:53:41,616 INFO  [main] mapreduce.Job:  map 25% reduce 0%
2016-07-28 16:54:21,630 INFO  [main] mapreduce.Job:  map 50% reduce 0%
2016-07-28 16:55:11,663 INFO  [main] mapreduce.Job:  map 75% reduce 0%
2016-07-28 16:55:15,750 INFO  [main] mapreduce.Job:  map 100% reduce 0%
2016-07-28 16:55:16,798 INFO  [main] mapreduce.Job: Job job_1469584130491_0002 completed successfully
2016-07-28 16:55:17,263 INFO  [main] mapreduce.Job: Counters: 31
    File System Counters
        FILE: Number of bytes read=0
        FILE: Number of bytes written=620452
        FILE: Number of read operations=0
        FILE: Number of large read operations=0
        FILE: Number of write operations=0
        HDFS: Number of bytes read=816
        HDFS: Number of bytes written=0
        HDFS: Number of read operations=4
        HDFS: Number of large read operations=0
        HDFS: Number of write operations=0
    Job Counters 
        Launched map tasks=4
        Data-local map tasks=4
        Total time spent by all maps in occupied slots (ms)=987150
        Total time spent by all reduces in occupied slots (ms)=0
        Total time spent by all map tasks (ms)=493575
        Total vcore-seconds taken by all map tasks=493575
        Total megabyte-seconds taken by all map tasks=758131200
    Map-Reduce Framework
        Map input records=10103174
        Map output records=0
        Input split bytes=816
        Spilled Records=0
        Failed Shuffles=0
        Merged Map outputs=0
        GC time elapsed (ms)=1687
        CPU time spent (ms)=153920
        Physical memory (bytes) snapshot=775319552
        Virtual memory (bytes) snapshot=8299081728
        Total committed heap usage (bytes)=1178075136
    org.apache.hadoop.hbase.mapreduce.RowCounter$RowCounterMapper$Counters
        ROWS=10103174
    File Input Format Counters 
        Bytes Read=0
    File Output Format Counters 
        Bytes Written=0

二、加大count命令的CACHE

如下：

hbase(main):001:0> count 'testtable0728', INTERVAL => 100000,CACHE => 100000

结果，数据量大时依然较慢，不及RowCounter一半，RowCounter数一千万条数据三分钟