[HBASE-15377] Per-RS Get metric is time based, per-region metric is size-based

• Type: Sub-task
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Fix Version/s: 1.3.0, 2.0.0
• Hadoop Flags: Incompatible change, Reviewed

Release Note

Per-region metrics related to Get histograms are changed from being response size based into being latency based similar to the per-regionserver metrics of the same name.

Added GetSize histogram metrics at the per-regionserver and per-region level for the response sizes.

• Assignee: Heng Chen
• Reporter: Enis Soztutar
• Created: 02/Mar/16 02:43
• Updated: 01/Jul/22 20:30
• Resolved: 15/Mar/16 20:52

Description

We have metrics for Get operations at the region server level and region level.

   "Get_num_ops" : 4837505,
    "Get_min" : 0,
    "Get_max" : 296,
    "Get_mean" : 0.2934618155433431,
    "Get_median" : 0.0,
    "Get_75th_percentile" : 0.0,
    "Get_95th_percentile" : 1.0,
    "Get_99th_percentile" : 1.0,

and

   "Namespace_hbase_table_meta_region_1588230740_metric_get_num_ops" : 103,
    "Namespace_hbase_table_meta_region_1588230740_metric_get_min" : 450,
    "Namespace_hbase_table_meta_region_1588230740_metric_get_max" : 470,
    "Namespace_hbase_table_meta_region_1588230740_metric_get_mean" : 450.19417475728153,
    "Namespace_hbase_table_meta_region_1588230740_metric_get_median" : 460.0,
    "Namespace_hbase_table_meta_region_1588230740_metric_get_75th_percentile" : 470.0,
    "Namespace_hbase_table_meta_region_1588230740_metric_get_95th_percentile" : 470.0,
    "Namespace_hbase_table_meta_region_1588230740_metric_get_99th_percentile" : 470.0,

The problem is that the report values for the region server shows the latency, versus the reported values for the region shows the response sizes. There is no way of telling this without reading the source code.

I think we should deprecate response size histograms in favor of latency histograms.

See also HBASE-15376.