[ https://issues.apache.org/jira/browse/KAFKA-13936?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=17558339#comment-17558339 ]
Prashanth Joseph Babu commented on KAFKA-13936: ----------------------------------------------- [~mjsax] I looked into the doc section and thought of adding a NOTE under `The maximum lag in terms of number of records for any partition in this window` . However if i look for this text in the repository , I see it in the file FetcherMetricsRegistry.java . Is this where the change is supposed to happen ( and it gets auto generated to html somewhere else ) ? . I don't see a html file or any markdown document which has this text. > Invalid consumer lag when monitoring from a kafka streams application > --------------------------------------------------------------------- > > Key: KAFKA-13936 > URL: https://issues.apache.org/jira/browse/KAFKA-13936 > Project: Kafka > Issue Type: Bug > Components: streams > Reporter: Prashanth Joseph Babu > Priority: Major > > I have a kafka streams application and I'm trying to monitor the consumer lag > via stream metrics. > Here's some code snippet > {code:java} > metrics = streams.metrics(); > lag = 0; > for (Metric m : metrics.values()) { > tags = m.metricName().tags(); > if ( m.metricName().name().equals(MONITOR_CONSUMER_LAG) && > tags.containsKey(MONTOR_TAG_TOPIC) && > tags.get(MONTOR_TAG_TOPIC).equals(inputTopic) ) { > partitionLag = > Float.valueOf(m.metricValue().toString()).floatValue(); > if ( !partitionLag.isNaN() ) { > lag += partitionLag; > } > } > } > {code} > Here MONITOR_CONSUMER_LAG is {{{}records-lag-max{}}}. > However these numbers dont match with the consumer lag we see in the kafka UI > . is records-lag-max the right metric to track for a kafka streams > application when the objective is to get consumer lag? -- This message was sent by Atlassian Jira (v8.20.7#820007)