Disruptor + many logger.error("aa", new Exception("aaa"))，stuck on Th…

[hailshao]

…rowableProxyHelperbak#loadClass

1、log4j2.component.properties
Log4jContextSelector=org.apache.logging.log4j.core.async.AsyncLoggerContextSelector
2、for (int i = 0; i < 600000; i++) {
logger.error("aa", aa);
}
3、iotop（linux）only 13M/s
stuck on ThrowableProxyHelper#loadClass
4、 iotop（linux）new way:140M/s

[github-actions]

Job	Requested goals	Build Tool Version	Build Outcome	Build Scan®
build-macos-latest	clean install	3.9.8	❌
build-ubuntu-latest	clean install	3.9.8	❌
build-windows-latest	clean install	3.9.8	❌

Generated by gradle/develocity-actions

[vy]

@hailshao, thanks for your contribution. Would you mind helping with the following questions, please?

1. Which version of Log4j Core are you using?
2. Could you share your log4j2.xml, please?
3. Exception rendering has been rewritten since the last release. Could you see if the most recent 2.25.0-SNAPSHOT is also problematic, please? (Or just build locally from the 2.x tip.)
4. Is it possible for you to switch from %xEx to %ex? (Collecting extended stack trace information is slow, has always been problematic, in particular, while in an async. context, and %ex is just fine in almost all use cases.)

[hailshao]

1、Which version of Log4j Core are you using?
answer：
force 'org.apache.logging.log4j:log4j-slf4j-impl:2.24.1'
force 'org.apache.logging.log4j:log4j-core:2.24.1'
force 'org.apache.logging.log4j:log4j-api:2.24.1'
force 'org.apache.logging.log4j:log4j-jul:2.24.1'

2、Could you share your log4j2.xml, please?
answer：The file has been uploaded

3、Exception rendering has been rewritten since the last release. Could you see if the most recent 2.25.0-SNAPSHOT is also problematic, please? (Or just build locally from the 2.x tip.)
answer：I will try later

4、Is it possible for you to switch from %xEx to %ex? (Collecting extended stack trace information is slow, has always been problematic, in particular, while in an async. context, and %ex is just fine in almost all use cases.)
answer：I will try later

log4j.zip

[ppkarwasz]

#队列满时放弃日志操作
log4j2.AsyncQueueFullPolicy=Discard
#队列满时放弃级别小于等于指定级别的日志，默认值INFO
log4j2.DiscardThreshold=INFO
#开启日志全异步。System.setProperty或者启动参数方式生效场景有：开发环境和jar包方式启动，而tomcat环境却不生效
Log4jContextSelector=org.apache.logging.log4j.core.async.AsyncLoggerContextSelector
#当队列满时同步入列，这是默认值，实际还是走AsyncQueueFullPolicy策略
#AsyncLoggerConfig.SynchronizeEnqueueWhenQueueFull=true
#队列长度，Disruptor使用的不是真正意义上的队列，而是类似于计数器+事件的方式。
#AsyncLoggerConfig.RingBufferSize=131072

This is unrelated to your problem, but I wanted to give you the heads up that we changed the official names of the properties you are using in version 2.10 to log4j2.asyncQueueFullPolicy, log4j2.discardThreshold, log4j2.contextSelector, log4j2.asyncLoggerSynchronizeEnqueueWhenQueueFull and log4j2.asyncLoggerRingBufferSize. The old property names are supported for backward compatibility, but support for them will be dropped in 3.0.0.

[hailshao]

1、jar
a) 2.24.1 (gradle download)
force 'org.apache.logging.log4j:log4j-slf4j-impl:2.24.1'
force 'org.apache.logging.log4j:log4j-core:2.24.1'
force 'org.apache.logging.log4j:log4j-api:2.24.1'
force 'org.apache.logging.log4j:log4j-jul:2.24.1'

b) 2.25.0-SNAPSHOT（manual download）:
https://repository.apache.org/content/groups/snapshots/org/apache/logging/log4j/log4j-core/2.25.0-SNAPSHOT/log4j-core-2.25.0-20241016.104251-51.jar
https://repository.apache.org/content/groups/snapshots/org/apache/logging/log4j/log4j-api/2.25.0-SNAPSHOT/log4j-api-2.25.0-20241016.104251-51.jar
https://repository.apache.org/content/groups/snapshots/org/apache/logging/log4j/log4j-jul/2.25.0-SNAPSHOT/log4j-jul-2.25.0-20241016.104251-51.jar
https://repository.apache.org/content/groups/snapshots/org/apache/logging/log4j/log4j-slf4j-impl/2.25.0-SNAPSHOT/log4j-slf4j-impl-2.25.0-20241016.104251-51.jar

2、DISK WRITE
a) speed1（slow）
Log4jContextSelector=org.apache.logging.log4j.core.async.AsyncLoggerContextSelector + 2.24.1
iotop: 13M/s

b) speed2（slower）
Log4jContextSelector=org.apache.logging.log4j.core.async.AsyncLoggerContextSelector + 2.25.0-SNAPSHOT
or
log4j2.contextSelector=org.apache.logging.log4j.core.async.AsyncLoggerContextSelector + 2.25.0-SNAPSHOT
iotop: 4.5M/s

c) speed3(fast)
Log4jContextSelector=org.apache.logging.log4j.core.async.AsyncLoggerContextSelector + 2.24.1 + %ex
iotop: 110M/s

3、result
Thank you very much, we have accepted your proposal: switch %xEx to% ex.

Please refer to the attachment for details
speed.zip

[ppkarwasz]

2、DISK WRITE a) speed1（slow） Log4jContextSelector=org.apache.logging.log4j.core.async.AsyncLoggerContextSelector + 2.24.1 iotop: 13M/s

b) speed2（slower） Log4jContextSelector=org.apache.logging.log4j.core.async.AsyncLoggerContextSelector + 2.25.0-SNAPSHOT or log4j2.contextSelector=org.apache.logging.log4j.core.async.AsyncLoggerContextSelector + 2.25.0-SNAPSHOT iotop: 4.5M/s

Thanks for the heads up. I have opened #3106 to check the cause of the performance loss you have reported and I am closing this PR, since I suppose it is no longer relevant.