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Matt Sicker commented on LOG4J2-1892: ------------------------------------- https://github.com/conversant/disruptor/blob/master/src/main/java/com/conversantmedia/util/concurrent/SpinPolicy.java It looks like that may be expected as it's a policy that doesn't use normal blocking and is handy for a small number of threads. In general, low latency spin policies tend to use lots of CPU as they loop, waiting for input as soon as it's available. > High constant CPU usage with Async appender DisruptorBlockingQueue spinPolicy > 'WAITING' > --------------------------------------------------------------------------------------- > > Key: LOG4J2-1892 > URL: https://issues.apache.org/jira/browse/LOG4J2-1892 > Project: Log4j 2 > Issue Type: Bug > Components: Appenders > Affects Versions: 2.8.2 > Environment: OSX 10.11 JDK 7 Jetty 9.2 > but also observed in Docker container JDK 8/Tomcat 8 > Reporter: Daniel R > Labels: performance > Attachments: with spinPolicy BLOCKING.png, with spinPolicy WAITING.png > > > With {{spinPolicy="WAITING"}} CPU usage shoots up to 11% and stays right > there with no app activity. > With {{spinPolicy="BLOCKING"}} CPU usage goes down to near 0% with no app > usage. > See screenshots attached. > In my local dev environment the Async appender is configured but not used > (commented out in the <Root> section. > {{log4j2.xml}} config excerpt: > {code:xml} > <Appenders> > ... > <!-- Wrap the email error appender into an asynchronous appender --> > <Async name="ASYNC_EMAIL_ERROR" bufferSize="128" > > <DisruptorBlockingQueue spinPolicy="WAITING"/> > <AppenderRef ref="EMAIL_ERROR" /> > </Async> > </Appenders> > <Root level="INFO"> > <AppenderRef ref="CONSOLE"/> > <!--AppenderRef ref="FILE"/--> > <!--AppenderRef ref="FILE_ERROR"/--> > <!--AppenderRef ref="ASYNC_EMAIL_ERROR"/--> > </Root> > {code} -- This message was sent by Atlassian JIRA (v6.3.15#6346)