[
https://issues.apache.org/jira/browse/KAFKA-15141?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
]
Satish Duggana updated KAFKA-15141:
-----------------------------------
Fix Version/s: 3.7.0
> High CPU usage with log4j2
> --------------------------
>
> Key: KAFKA-15141
> URL: https://issues.apache.org/jira/browse/KAFKA-15141
> Project: Kafka
> Issue Type: Improvement
> Components: core
> Affects Versions: 3.3.2, 3.5.0, 3.4.1
> Reporter: Gaurav Narula
> Assignee: Gaurav Narula
> Priority: Major
> Fix For: 3.6.0, 3.7.0
>
>
> Kafka brokers make use of the [Logging
> trait|https://github.com/apache/kafka/blob/1f4cbc5d53259031123b6e9e6bb9a5bbe1e084e8/core/src/main/scala/kafka/utils/Logging.scala#L41]
> which instantiates a Logger object for every instantiation of the class
> using the trait by default.
> When using log4j2 as the logging implementation, the instantiation of a
> Logger object requires a stack traversal
> [[1]|https://github.com/apache/logging-log4j2/blob/2.x/log4j-api/src/main/java/org/apache/logging/log4j/spi/AbstractLoggerAdapter.java#L121]
> and
> [[2]|https://github.com/apache/logging-log4j2/blob/83bba1bc322e80e7e95edbebc2383f2724dbe0de/log4j-slf4j-impl/src/main/java/org/apache/logging/slf4j/Log4jLoggerFactory.java#L54].
> While LOG4J2-2940 ensures stack is not traversed unless required, the default
> {{{}ContextSelector{}}},
> [ClassLoaderContextSelector|https://logging.apache.org/log4j/2.x/log4j-core/apidocs/org/apache/logging/log4j/core/selector/ClassLoaderContextSelector.html]
> causes a stack traversal.
> These stack traversals are frequent and quite CPU intensive and profiling
> suggests they consume ~5% CPU time (of the CPU stacks we have profiled on a
> sample of clusters). While log4j2 users can potentially avoid this by
> changing the context selector in their configuration, it is easy to overlook
> and the default configurations results in high CPU usage inadvertently.
> An easy fix would be to instantiate the loggers statically for some commonly
> instantiated classes in Kafka which make use of the Logging trait.
--
This message was sent by Atlassian Jira
(v8.20.10#820010)
