public static void main(String[] args) throws Exception {
    int ret = ToolRunner.run(HBaseConfiguration.create(), new ScanPerformanceEvaluation(), args);
    System.exit(ret);
  }
A simple performance evaluation tool for single client and MR scans and snapshot scans.
hbase-diagnostics/src/main/java/org/apache/hadoop/hbase/ScanPerformanceEvaluation.java