Update readme and changelog

CHANGELOG.md

@@ -22,6 +22,7 @@
 
 #### New Processors
 
+- [dedup](/plugins/processors/dedup/README.md) - Contributed by @igomura
 - [template](/plugins/processors/template/README.md) - Contributed by @RobMalvern
 - [s2_geo](/plugins/processors/s2_geo/README.md) - Contributed by @alespour
 

README.md

@@ -360,6 +360,7 @@ For documentation on the latest development code see the [documentation index][d
 * [clone](/plugins/processors/clone)
 * [converter](/plugins/processors/converter)
 * [date](/plugins/processors/date)
+* [dedup](/plugins/processors/dedup)
 * [enum](/plugins/processors/enum)
 * [override](/plugins/processors/override)
 * [parser](/plugins/processors/parser)

plugins/processors/dedup/README.md

@@ -1,11 +1,6 @@
 # Dedup Processor Plugin
 
-If a metric sends the same value over successive intervals, suppress sending
+Filter metrics whose field values are exact repetitions of the previous values.
-the same value to the TSD until this many seconds have elapsed.  This helps
-graphs over narrow time ranges still see timeseries with suppressed datapoints.
-
-This feature can be used to reduce traffic when metric's value does not change over
-time while maintain proper precision when value gets changed rapidly
 
 ### Configuration
 
@@ -15,3 +10,15 @@ time while maintain proper precision when value gets changed rapidly
   dedup_interval = "600s"
 ```
 
+### Example
+
+```diff
+- cpu,cpu=cpu0 time_idle=42i,time_guest=1i
+- cpu,cpu=cpu0 time_idle=42i,time_guest=2i
+- cpu,cpu=cpu0 time_idle=42i,time_guest=2i
+- cpu,cpu=cpu0 time_idle=44i,time_guest=2i
+- cpu,cpu=cpu0 time_idle=44i,time_guest=2i
++ cpu,cpu=cpu0 time_idle=42i,time_guest=1i
++ cpu,cpu=cpu0 time_idle=42i,time_guest=2i
++ cpu,cpu=cpu0 time_idle=44i,time_guest=2i
+```

plugins/processors/dedup/dedup.go

@@ -24,7 +24,7 @@ func (d *Dedup) SampleConfig() string {
 }
 
 func (d *Dedup) Description() string {
-	return "Deduplicate repetitive metrics"
+	return "Drop metrics with repeating field values"
 }
 
 // Remove single item from slice
@@ -73,7 +73,7 @@ func (d *Dedup) Apply(metrics ...telegraf.Metric) []telegraf.Metric {
 			continue
 		}
 
-		// For each filed compare value with the cached one
+		// For each field compare value with the cached one
 		changed := false
 		for _, f := range metric.FieldList() {
 			if value, ok := m.GetField(f.Key); ok && value != f.Value {