[jira] [Commented] (KAFKA-15133) RequestMetrics MessageConversionsTimeMs count is ticked even when no conversion occurs

["Edoardo Comar (Jira)" <ji...@apache.org>]

    [ https://issues.apache.org/jira/browse/KAFKA-15133?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=17738205#comment-17738205 ] 

Edoardo Comar commented on KAFKA-15133:
---------------------------------------

[~rsivaram] - reading KIP 188

I am not sure if the intent of the MessageConversionsTimeMs Histogram was also to record the number of time there was no conversion, so that if only say 1% of messages required conversions, we'd see that in the percentile distribution

I found that I was comparing the count with the one in BrokerTopicMetrics and the mismatch was obvious

> RequestMetrics MessageConversionsTimeMs count is ticked even when no conversion occurs
> --------------------------------------------------------------------------------------
>
>                 Key: KAFKA-15133
>                 URL: https://issues.apache.org/jira/browse/KAFKA-15133
>             Project: Kafka
>          Issue Type: Bug
>          Components: core
>    Affects Versions: 3.5.0, 3.4.1
>            Reporter: Edoardo Comar
>            Assignee: Edoardo Comar
>            Priority: Minor
>
> The Histogram 
> {{{{{}{color:#000000}RequestChannel{color}.{}}}messageConversionsTimeHist}}
> is ticked even when a Produce/Fetch request incurred no conversion,
> because a new entry is added to the historgram distribution, with a 0ms value.
>  
> It's confusing comparing the Histogram
> kafka.network RequestMetrics MessageConversionsTimeMs
> with the Meter
> kafka.server BrokerTopicMetrics ProduceMessageConversionsPerSec
> because for the latter, the metric is ticked only if a conversion actually occurred



--
This message was sent by Atlassian Jira
(v8.20.10#820010)