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Guozhang Wang commented on KAFKA-6925: -------------------------------------- This seems to be a known issue that we have fixed in trunk. I'll let [~vvcephei] to double check if it is the case as he has recently worked on it. > Memory leak in > org.apache.kafka.streams.processor.internals.StreamThread$StreamsMetricsThreadImpl > ------------------------------------------------------------------------------------------------- > > Key: KAFKA-6925 > URL: https://issues.apache.org/jira/browse/KAFKA-6925 > Project: Kafka > Issue Type: Bug > Components: streams > Affects Versions: 1.0.1 > Reporter: Marcin Kuthan > Priority: Major > > The retained heap of > org.apache.kafka.streams.processor.internals.StreamThread$StreamsMetricsThreadImpl > is surprisingly high for long running job. Over 100MB of heap for every > stream after a week of uptime, when for the same application a few hours > after start heap takes 2MB. > For the problematic instance majority of memory StreamsMetricsThreadImpl is > occupied by hash map entries in parentSensors, over 8000 elements 100+kB > each. For fresh instance there are less than 200 elements. > Below you could find retained set report generated from Eclipse Mat but I'm > not fully sure about correctness due to complex object graph in the metrics > related code. Number of objects in single > StreamThread$StreamsMetricsThreadImpl instance. > > {code:java} > Class Name | Objects | Shallow Heap > ----------------------------------------------------------------------------------------------------------- > org.apache.kafka.common.metrics.KafkaMetric | 140,476 | 4,495,232 > org.apache.kafka.common.MetricName | 140,476 | 4,495,232 > org.apache.kafka.common.metrics.stats.SampledStat$Sample | 73,599 | 3,532,752 > org.apache.kafka.common.metrics.stats.Meter | 42,104 | 1,347,328 > org.apache.kafka.common.metrics.stats.Count | 42,104 | 1,347,328 > org.apache.kafka.common.metrics.stats.Rate | 42,104 | 1,010,496 > org.apache.kafka.common.metrics.stats.Total | 42,104 | 1,010,496 > org.apache.kafka.common.metrics.stats.Max | 28,134 | 900,288 > org.apache.kafka.common.metrics.stats.Avg | 28,134 | 900,288 > org.apache.kafka.common.metrics.Sensor | 3,164 | 202,496 > org.apache.kafka.common.metrics.Sensor[] | 3,164 | 71,088 > org.apache.kafka.streams.processor.internals.StreamThread$StreamsMetricsThreadImpl| > 1 | 56 > ----------------------------------------------------------------------------------------------------------- > {code} > -- This message was sent by Atlassian JIRA (v7.6.3#76005)