[ https://issues.apache.org/jira/browse/KAFKA-7660?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16704399#comment-16704399 ]
Patrik Kleindl commented on KAFKA-7660: --------------------------------------- Last question, who should "resolve" the Jira issue? I guess that is done by the person who fixed it to supply fixVersion etc? > Stream Metrics - Memory Analysis > -------------------------------- > > Key: KAFKA-7660 > URL: https://issues.apache.org/jira/browse/KAFKA-7660 > Project: Kafka > Issue Type: Bug > Components: metrics, streams > Affects Versions: 2.0.0 > Reporter: Patrik Kleindl > Priority: Minor > Attachments: Mem_Collections.jpeg, Mem_DuplicateStrings.jpeg, > Mem_DuplicateStrings2.jpeg, Mem_Hotspots.jpeg, Mem_KeepAliveSet.jpeg, > Mem_References.jpeg, heapdump-1543441898901.hprof > > > During the analysis of JVM memory two possible issues were shown which I > would like to bring to your attention: > 1) Duplicate strings > Top findings: > string_content="stream-processor-node-metrics" count="534,277" > string_content="processor-node-id" count="148,437" > string_content="stream-rocksdb-state-metrics" count="41,832" > string_content="punctuate-latency-avg" count="29,681" > > "stream-processor-node-metrics" seems to be used in Sensors.java as a > literal and not interned. > > 2) The HashMap parentSensors from > org.apache.kafka.streams.processor.internals.StreamThread$StreamsMetricsThreadImpl > was reported multiple times as suspicious for potentially keeping alive a > lot of objects. In our case the reported size was 40-50MB each. > I haven't looked too deep in the code but noticed that the class Sensor.java > which is used as a key in the HashMap does not implement equals or hashCode > method. Not sure this is a problem though. > > The analysis was done with Dynatrace 7.0 > We are running Confluent 5.0/Kafka2.0-cp1 (Brokers as well as Clients) > > Screenshots are attached. -- This message was sent by Atlassian JIRA (v7.6.3#76005)