Merge lp:~mleinartas/graphite/aggregation_overwrite into lp:~graphite-dev/graphite/main

[Michael Leinartas]

keep aggregator from clobbering aggregated values with original ones

This is a small patch to address the issue here: https://answers.launchpad.net/graphite/+question/179788 which is something I also run into and have had to work around.

There is a use case for using carbon-aggregator to aggregate incoming metrics and have the original values discarded and replaced with the new, aggregated ones. This could, for instance, replace the role of statsd and its clones for some users. The existing behavior is also surprising and I cannot imagine a case where it would be a desired behavior.

[Michael Leinartas (mleinartas)]

Oops, the issue I meant to link was this one: https://answers.launchpad.net/graphite/+question/180328

[Michael Leinartas (mleinartas)]

Pushing this forward as it doesn't break any existing behavior and fixes a violation of "principal of least surprise"

review: Approve

=== modified file 'carbon/lib/carbon/aggregator/receiver.py'
--- carbon/lib/carbon/aggregator/receiver.py	2011-08-19 07:19:16 +0000
+++ carbon/lib/carbon/aggregator/receiver.py	2011-12-14 05:30:41 +0000
@@ -11,11 +11,15 @@
   for rule in RewriteRuleManager.preRules:
     metric = rule.apply(metric)
 
+  aggregate_metrics = []
+
   for rule in RuleManager.rules:
     aggregate_metric = rule.get_aggregate_metric(metric)
 
     if aggregate_metric is None:
       continue
+    else
+      aggregate_metrics.append(aggregate_metric)
 
     buffer = BufferManager.get_buffer(aggregate_metric)
 
@@ -27,4 +31,5 @@
   for rule in RewriteRuleManager.postRules:
     metric = rule.apply(metric)
 
-  events.metricGenerated(metric, datapoint)
+  if metric not in aggregate_metrics:
+    events.metricGenerated(metric, datapoint)