changed the base value we use for the increments

README.md

@@ -137,7 +137,7 @@ the delay between every repetition.
 
 Default: `false`.
 
-When a group reaches its limit, metrics will be emitted for the logs being dropped if this value is true . This metrics can be scraped like any other metrics emitted in prometheus format. `podname` is a additional label available to identify the throttled groups. \\
+When a group reaches its limit, metrics will be emitted for the logs being dropped if this value is true . This metrics can be scraped like any other metrics emitted in prometheus format. Group keys are available to identify the throttled groups as additional labels. \\
 Metrics for the filter is
 - `fluentd_throttle_rate_limit_exceeded`
 

lib/fluent/plugin/filter_throttle.rb

@@ -117,15 +117,15 @@ def filter(tag, time, record)
 
       # Ruby hashes are ordered by insertion.
       # Deleting and inserting moves the item to the end of the hash (most recently used)
-      counter = @counters[group] = @counters.delete(group) || Group.new(0, now, 0, 0, now, nil, @group_bucket_limit)
+      counter = @counters[group] = @counters.delete(group) || Group.new(0, now, 0, 0, now, nil, 0)
 
       counter.rate_count += 1
       since_last_rate_reset = now - counter.rate_last_reset
       if since_last_rate_reset >= 1
         # compute and store rate/s at most every second
         counter.aprox_rate = (counter.rate_count / since_last_rate_reset).round()
         counter.rate_count = 0
-        counter.rate_count_last = @group_bucket_limit
+        counter.rate_count_last = 0
         counter.rate_last_reset = now
       end
 
@@ -186,8 +186,8 @@ def log_rate_limit_exceeded(now, group, counter)
         groupped_label = @group_key_symbols.zip(group).to_h
         metric = @metrics[:throttle_rate_limit_exceeded]
         log.debug("current rate",counter.rate_count,"current metric",metric.get(labels: @base_labels.merge(groupped_label)))
-        metric.increment(by: counter.rate_count - counter.rate_count_last, labels: @base_labels.merge(groupped_label))
-        counter.rate_count_last = counter.rate_count
+        metric.increment(by: counter.rate_count - counter.rate_count_last - @group_bucket_limit, labels: @base_labels.merge(groupped_label))
+        counter.rate_count_last = counter.rate_count - @group_bucket_limit
       end
 
       emit = counter.last_warning == nil ? true \