BIND 10 #2179: Update Stats to support differential statistics updates

[BIND 10 Development]

#2179: Update Stats to support differential statistics updates
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                   Reporter:         |                 Owner:  UnAssigned
  naokikambe                         |                Status:  reviewing
                       Type:         |             Milestone:
  enhancement                        |  Sprint-20120904
                   Priority:         |            Resolution:
  medium                             |             Sensitive:  0
                  Component:         |           Sub-Project:  DNS
  statistics                         |  Estimated Difficulty:  8
                   Keywords:         |           Total Hours:  0
            Defect Severity:  N/A    |
Feature Depending on Ticket:         |
        Add Hours to Ticket:  0      |
                  Internal?:  0      |
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Comment (by naokikambe):

 Replying to [comment:7 naokikambe]:
 > Implementing the stats module for supporting  a real "differential"
 update would be done after the end of Sept. because of the complexity.

 This is not directly related to this ticket. For supporting a real
 "differential" update, I think we should introduce a new attribute into
 the statistics spec. For example, this case is that a "item_aggregation"
 attribute is introduced (Everyone has likes or dislikes about that
 naming:):
 {{{#!js
 { "item_name": "name",
   "item_type": "type",
   "item_optional": True | False,
   "item_default": "something",
   "item_aggregation": "cumulative" | "earliest" | "latest"
 }
 }}}
 The value of "item_aggregation" can be "cumulative" or "earliest" or
 "latest". "cumulative" means that multiple values are summable. This case
 matches with a value returned from the ''getstats_delta'' command of
 #2196. "earliest" means that once the value is set then the value is never
 replaced with other. "latest" means that the value is always replaced with
 the newest one. If this attribute is omitted, the default behavior should
 be "cumulative". Because most of statistics items in BIND 10 are counters,
 and such counter values should be summed.

-- 
Ticket URL: <https://bind10.isc.org/ticket/2179#comment:8>
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