如何找出是什么阻止了 FileAppender 正确滚动

Question

更新：有趣的是，我只看到以下问题发生在 Windows 环境中，但在每个部署的 Linux 环境中都可以正常工作。

我有一个带有 FileAppender 的 Log4j 1.2.17 的 Spring 应用程序 (3.2)，这是配置

log4j.rootCategory=TRACE, ROL

log4j.appender.ROL=org.apache.log4j.RollingFileAppender
log4j.appender.ROL.Encoding=UTF-8
log4j.appender.ROL.File=C:/logs/spring-app/application-log4j.log
log4j.appender.ROL.MaxFileSize=10000KB
log4j.appender.ROL.MaxBackupIndex=10
log4j.appender.ROL.layout=org.apache.log4j.PatternLayout
log4j.appender.ROL.layout.ConversionPattern=%d -- %p -- %c -- %m%n

由于某种原因，我发现日志文件有时会停止滚动并且变得非常大，因此我添加了 log4j 调试模式

-Dlog4j.debug

我发现以下问题是症状

这是记录过程正常工作的时候

log4j: rolling over count=10332832
log4j: maxBackupIndex=10
log4j: Renaming file C:\logs\spring-app\application-log4j.log.9 to C:\logs\spring-app\application-log4j.log.10
log4j: Renaming file C:\logs\spring-app\application-log4j.log.8 to C:\logs\spring-app\application-log4j.log.9
log4j: Renaming file C:\logs\spring-app\application-log4j.log.7 to C:\logs\spring-app\application-log4j.log.8
log4j: Renaming file C:\logs\spring-app\application-log4j.log.6 to C:\logs\spring-app\application-log4j.log.7
log4j: Renaming file C:\logs\spring-app\application-log4j.log.5 to C:\logs\spring-app\application-log4j.log.6
log4j: Renaming file C:\logs\spring-app\application-log4j.log.4 to C:\logs\spring-app\application-log4j.log.5
log4j: Renaming file C:\logs\spring-app\application-log4j.log.3 to C:\logs\spring-app\application-log4j.log.4
log4j: Renaming file C:\logs\spring-app\application-log4j.log.2 to C:\logs\spring-app\application-log4j.log.3
log4j: Renaming file C:\logs\spring-app\application-log4j.log.1 to C:\logs\spring-app\application-log4j.log.2
log4j: Renaming file C:\logs\spring-app\application-log4j.log to C:\logs\spring-app\application-log4j.log.1
log4j: setFile called: C:/STS/STS.3.2.0/logs/spring-app/application-log4j.log, true
log4j: setFile ended

这是 appender 失败的开始

log4j: rolling over count=10332832
log4j: maxBackupIndex=10
log4j: Renaming file C:\logs\spring-app\application-log4j.log.9 to C:\logs\spring-app\application-log4j.log.10
log4j: Renaming file C:\logs\spring-app\application-log4j.log.8 to C:\logs\spring-app\application-log4j.log.9
log4j: Renaming file C:\logs\spring-app\application-log4j.log.7 to C:\logs\spring-app\application-log4j.log.8
log4j: Renaming file C:\logs\spring-app\application-log4j.log.6 to C:\logs\spring-app\application-log4j.log.7
log4j: Renaming file C:\logs\spring-app\application-log4j.log.5 to C:\logs\spring-app\application-log4j.log.6
log4j: Renaming file C:\logs\spring-app\application-log4j.log.4 to C:\logs\spring-app\application-log4j.log.5
log4j: Renaming file C:\logs\spring-app\application-log4j.log.3 to C:\logs\spring-app\application-log4j.log.4
log4j: Renaming file C:\logs\spring-app\application-log4j.log.2 to C:\logs\spring-app\application-log4j.log.3
#Apparently fail the rename log.1 -> log.2
log4j: Renaming file C:\logs\spring-app\application-log4j.log to C:\logs\spring-app\application-log4j.log.1
log4j: setFile called: C:/STS/STS.3.2.0/logs/spring-app/application-log4j.log, true
log4j: setFile ended

这个问题使得旧的日志（log.3 ~ log.9）逐渐被重命名而全部消失，只留下第一个——application-log4j.log。所以这个文件可以疯狂地增长到 1 GB+，并且不会生成其他日志。

但现在我真的没有太多方法可以深入了解导致此问题的确切原因（第二个日志文件未能重命名，似乎是放在文件上的日志）

Answer 1

在 log4j 1.2.17 中存在与 org.apache.log4j.RollingFileAppender 相关的已知问题。例如，this bug in log4j 的描述与您的问题相似。

您应该在Apache Extras™ for Apache log4j™ 中使用rolling file appender，因为它是recommended in the Javadoc to do so。这是link on Maven Central to the library。

您是否尝试过以下配置以查看它是否解决了您的问题？

log4j.appender.ROL=org.apache.log4j.rolling.RollingFileAppender
log4j.appender.ROL.Encoding=UTF-8
log4j.appender.ROL.File=C:/logs/spring-app/application-log4j.log
log4j.appender.ROL.layout = org.apache.log4j.PatternLayout
log4j.appender.ROL.layout.ConversionPattern=%d -- %p -- %c -- %m%n
log4j.appender.ROL.TriggeringPolicy=org.apache.log4j.rolling.SizeBasedTriggeringPolicy
log4j.appender.ROL.TriggeringPolicy.MaxFileSize=10000KB 
log4j.appender.ROL.RollingPolicy=org.apache.log4j.rolling.FixedWindowRollingPolicy
log4j.appender.ROL.RollingPolicy.ActiveFileName=C:/logs/spring-app/application-log4j.log
log4j.appender.ROL.RollingPolicy.FileNamePattern=C:/logs/spring-app/application-log4j.log.%i
log4j.appender.ROL.RollingPolicy.MaxIndex=10

最后，log4j 是一个老库，没有积极开发。如果可行，您应该强烈考虑升级到 log4j 2.0。