[jira] [Commented] (KAFKA-14597) [Streams] record-e2e-latency-max is not reporting correct metrics

["Bruno Cadonna (Jira)" <ji...@apache.org>]

    [ https://issues.apache.org/jira/browse/KAFKA-14597?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=17688362#comment-17688362 ] 

Bruno Cadonna commented on KAFKA-14597:
---------------------------------------

[~talestonini] Thank you for the ticket!

I noticed that in your screenshot record {{record-e2e-latency-max.jpg}} the metric {{process-total}} is 0 which means that no records were processed when the metric {{record-e2e-latency-max}} got recorded. That would explain why {{record-e2e-latency-max}} is too low. In the screenshot {{process-latency-max.jpg}} metric {{process-total}} is 1. Look at the very last line in the screenshot. The one that is only shown half. 

Could you run your Streams application and ensure that {{process-total}} is 1 or greater when you look at {{record-e2e-latency-max}}?

Please, let us know whether the value of the metric makes more sense then.  

> [Streams] record-e2e-latency-max is not reporting correct metrics 
> ------------------------------------------------------------------
>
>                 Key: KAFKA-14597
>                 URL: https://issues.apache.org/jira/browse/KAFKA-14597
>             Project: Kafka
>          Issue Type: Bug
>          Components: metrics, streams
>            Reporter: Atul Jain
>            Assignee: Tales Tonini
>            Priority: Major
>         Attachments: process-latency-max.jpg, record-e2e-latency-max.jpg
>
>
> I was following this KIP documentation ([https://cwiki.apache.org/confluence/display/KAFKA/KIP-613%3A+Add+end-to-end+latency+metrics+to+Streams]) and kafka streams documentation ([https://kafka.apache.org/documentation/#kafka_streams_monitoring:~:text=node%2Did%3D(%5B%2D.%5Cw%5D%2B)-,record%2De2e%2Dlatency%2Dmax,-The%20maximum%20end]) . Based on these documentations , the *record-e2e-latency-max* should monitor the full end to end latencies, which includes both *consumption latencies* and  {*}processing delays{*}.
> However, based on my observations , record-e2e-latency-max seems to be only measuring the consumption latencies. processing delays can be measured using *process-latency-max* .I am checking all this using a simple topology consisting of source, processors and sink (code added). I have added some sleep time (of 3 seconds) in one of the processors to ensure some delays in the processing logic. These delays are not getting accounted in the record-e2e-latency-max but are accounted in process-latency-max. process-latency-max was observed to be 3002 ms which accounts for sleep time of 3 seconds. However, record-e2e-latency-max observed in jconsole is 422ms, which does not account for 3 seconds of sleep time.
>  
> Code describing my topology:
> {code:java}
>    static Topology buildTopology(String inputTopic, String outputTopic) {
>         log.info("Input topic: " + inputTopic + " and output topic: " + outputTopic);
>         Serde<String> stringSerde = Serdes.String();
>         StreamsBuilder builder = new StreamsBuilder();
>         builder.stream(inputTopic, Consumed.with(stringSerde, stringSerde))
>                 .peek((k,v) -> log.info("Observed event: key" + k + " value: " + v))
>                 .mapValues(s -> {
>                     try {
>                         System.out.println("sleeping for 3 seconds");
>                         Thread.sleep(3000);
>                     }
>                     catch (InterruptedException e) {
>                         e.printStackTrace();
>                     }
>                     return  s.toUpperCase();
>                 })
>                 .peek((k,v) -> log.info("Transformed event: key" + k + " value: " + v))
>                 .to(outputTopic, Produced.with(stringSerde, stringSerde));
>         return builder.build();
>     } {code}
>  



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