[HBASE-11767] [0.94] Unnecessary garbage produced by schema metrics during scanning

• Type: Bug
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Fix Version/s: 0.94.23
• Hadoop Flags: Reviewed
• Assignee: Lars Hofhansl
• Reporter: Lars Hofhansl
• Created: 16/Aug/14 07:23
• Updated: 09/Sep/14 04:19
• Resolved: 17/Aug/14 04:52

Description

Near the end of StoreScanner.next(...) we find this gem:

    } finally {
      if (cumulativeMetric > 0 && metric != null) {
        RegionMetricsStorage.incrNumericMetric(this.metricNamePrefix + metric,
            cumulativeMetric);
      }
    }

So, for each row generated we build up a new metric string, that will be identical for each invocation of the StoreScanner anyway (a store scanner is valid for at most one region and one operation).