[receiver/kafkametrics] Fix issue with incorrect consumer offset (#33336

)

Fix issue when consumer offset store random value

Fixes: #33309

.chloggen/patch-1.yaml

@@ -0,0 +1,27 @@
+# Use this changelog template to create an entry for release notes.
+
+# One of 'breaking', 'deprecation', 'new_component', 'enhancement', 'bug_fix'
+change_type: bug_fix
+
+# The name of the component, or a single word describing the area of concern, (e.g. filelogreceiver)
+component: kafkametricsreceiver
+
+# A brief description of the change.  Surround your text with quotes ("") if it needs to start with a backtick (`).
+note: Fix issue with incorrect consumer offset
+
+# Mandatory: One or more tracking issues related to the change. You can use the PR number here if no issue exists.
+issues: [33309]
+
+# (Optional) One or more lines of additional information to render under the primary note.
+# These lines will be padded with 2 spaces and then inserted directly into the document.
+# Use pipe (|) for multiline entries.
+subtext: 
+
+# If your change doesn't affect end users or the exported elements of any package,
+# you should instead start your pull request title with [chore] or use the "Skip Changelog" label.
+# Optional: The change log or logs in which this entry should be included.
+# e.g. '[user]' or '[user, api]'
+# Include 'user' if the change is relevant to end users.
+# Include 'api' if there is a change to a library API.
+# Default: '[user]'
+change_logs: []

receiver/kafkametricsreceiver/consumer_scraper.go

@@ -142,7 +142,7 @@ func (s *consumerScraper) scrape(context.Context) (pmetric.Metrics, error) {
 				for partition, block := range partitions {
 					consumerOffset := block.Offset
 					offsetSum += consumerOffset
-					s.mb.RecordKafkaConsumerGroupOffsetDataPoint(now, offsetSum, group.GroupId, topic, int64(partition))
+					s.mb.RecordKafkaConsumerGroupOffsetDataPoint(now, consumerOffset, group.GroupId, topic, int64(partition))
 
 					// default -1 to indicate no lag measured.
 					var consumerLag int64 = -1