[kafkareceiver] commit unprocessed messages

[arnitolog]

Describe the bug
it looks like Kafkareceiver commits even un-processed (or processed with error) messages.

Steps to reproduce
configure kafkareciver with the below config:

  receivers:
    kafka:
      protocol_version: 2.8.0
      brokers: kafka-cluster-kafka-bootstrap.kafka.svc.cluster.local:9093
      topic: jaeger-spans
      encoding: jaeger_proto
      group_id: otel-collector
      client_id: otel-collector
      auth:
        tls:
          ca_file: /tmp/certificates/ca.crt
          insecure: true
      autocommit:
        enable: false
      message_marking: 
        after: true
        on_error: false
  exporters:
    otlp:
      endpoint: some-fake-endpoint.svc.cluster.local:9999
      tls:
        insecure: true
  service:
    extensions:
      - health_check
    pipelines:
      traces:
        receivers: [kafka]
        exporters: [otlp]

Push traces into jaeger-spans topic and check LAG for otel-collector consumer group.

What did you expect to see?
LAG should constantly grow as we can't complete the pipeline due to the exporters endpoint is unavailable/not reachable

What did you see instead?
LAG is going up and down, which means that offsets are committed back

What version did you use?
Version:
opentelemetry collector 0.38.0

Additional context
queue and LAG:

spans accepted rate:

exporter sent rate:

[github-actions]

This issue has been inactive for 60 days. It will be closed in 60 days if there is no activity. To ping code owners by adding a component label, see Adding Labels via Comments, or if you are unsure of which component this issue relates to, please ping @open-telemetry/collector-contrib-triagers. If this issue is still relevant, please ping the code owners or leave a comment explaining why it is still relevant. Otherwise, please close it.

[atoulme]

Closing as completed.

[github-actions]

Pinging code owners for receiver/kafka: @pavolloffay @MovieStoreGuy. See Adding Labels via Comments if you do not have permissions to add labels yourself.