[HBASE-25148] Scan metrics are not reported to Hadoop MapReduce counters

• Type: Bug
• Status: Open
• Priority: Major
• Resolution: Unresolved
• Affects Version/s: 1.2.0
• Component/s: Client, mapreduce, scan
• Assignee: Unassigned
• Reporter: Leonid Vasilev
• Created: 02/Oct/20 13:23
• Updated: 02/Oct/20 14:09

Description

I setup a MapReduce job that scans HBase table with scan metrics enabled via Java API:

Scan scan = ...;
scan.setScanMetricsEnabled(true);
// Or via attribute
scan.setAttribute(                                               
        Scan.SCAN_ATTRIBUTES_METRICS_ENABLE,                             
        Bytes.toBytes(true));
TableMapReduceUtil.initTableMapperJob(...);                                                                 
job.waitForCompletion(true)

I expect HBase scan related counters to appear with current values in Hadoop web UI after job starts or in CLI after job ends alongside other counters such as CPU_MILLISECONDS. But no metrics were displayed. I can clearly see that scan is performed and mappers got non-zero inputs.

The JAR version is  1.2.0-cdh5.16.1.