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Wei-Chiu Chuang commented on HDFS-15924: ---------------------------------------- Reviewed the code in reload4j. This looks like still unresolved in the latest reload4j. The only solution is probably log4j2. > Log4j will cause Server handler blocked when audit log boom. > ------------------------------------------------------------ > > Key: HDFS-15924 > URL: https://issues.apache.org/jira/browse/HDFS-15924 > Project: Hadoop HDFS > Issue Type: Bug > Reporter: Qi Zhu > Priority: Major > Attachments: image-2021-03-26-16-18-03-341.png, > image-2021-03-26-16-19-42-165.png > > > !image-2021-03-26-16-18-03-341.png|width=707,height=234! > !image-2021-03-26-16-19-42-165.png|width=824,height=198! > The thread blocked when audit log boom show in above. > Such as [https://dzone.com/articles/log4j-thread-deadlock-case] , it seems > the same case when heavy load, should we update to Log4j2 or other things we > can do to improve it in heavy audit log. > > {code:java} > /** > Call the appenders in the hierrachy starting at > <code>this</code>. If no appenders could be found, emit a > warning. > <p>This method calls all the appenders inherited from the > hierarchy circumventing any evaluation of whether to log or not > to log the particular log request. > @param event the event to log. */ > public void callAppenders(LoggingEvent event) { > int writes = 0; > for(Category c = this; c != null; c=c.parent) { > // Protected against simultaneous call to addAppender, > removeAppender,... > synchronized(c) { > if(c.aai != null) { > writes += c.aai.appendLoopOnAppenders(event); > } > if(!c.additive) { > break; > } > } > } > if(writes == 0) { > repository.emitNoAppenderWarning(this); > } > }{code} > The log4j code, use the global synchronized, it will cause this happened. > cc [~weichiu] [~hexiaoqiao] [~ayushtkn] [~shv] [~ferhui] -- This message was sent by Atlassian Jira (v8.20.1#820001) --------------------------------------------------------------------- To unsubscribe, e-mail: hdfs-issues-unsubscr...@hadoop.apache.org For additional commands, e-mail: hdfs-issues-h...@hadoop.apache.org