Apache Karaf 4.2.9中TimeBasedRollingPolicy支持性及配置问询

需求说明 #

使用Apache Karaf内置的Pax Logging配置TimeBasedRollingPolicy实现日志按天滚动，由于核心代码不可见，只能通过覆写属性的方式启用该策略，且不需要使用SizeBasedTriggeringPolicy。

问题 #

1. Apache Karaf 4.2.9是否支持TimeBasedRollingPolicy？
2. 若支持，请提供包含TimeBasedRollingPolicy及相关属性的org.ops4j.pax.logging.cfg示例配置文件？

当前使用的org.ops4j.pax.logging.cfg配置 #

# 滚动文件追加器
log4j2.appender.rolling.type = RollingRandomAccessFile
log4j2.appender.rolling.name = RollingFile
log4j2.appender.rolling.fileName = [路径]/karaf.log
log4j2.appender.rolling.filePattern = [路径]/app-name-%d{yyyy-MM-dd-HH-mm}-%i.log
# 取消注释可关闭强制磁盘刷新
#log4j2.appender.rolling.immediateFlush = false
log4j2.appender.rolling.append = true
log4j2.appender.rolling.layout.type = PatternLayout
log4j2.appender.rolling.layout.pattern = %d %p %C{1.} [%t] %m%n
log4j2.appender.rolling.policies.type = Policies
log4j2.appender.rolling.policies.size.type = SizeBasedTriggeringPolicy
log4j2.appender.rolling.policies.size.size = 16MB

# 审计文件追加器
log4j2.appender.audit.type = RollingRandomAccessFile
log4j2.appender.audit.name = AuditRollingFile
log4j2.appender.audit.fileName = [路径]/security.log
log4j2.appender.audit.filePattern = [路径]/security.log.%i
log4j2.appender.audit.append = true
log4j2.appender.audit.layout.type = PatternLayout
log4j2.appender.audit.layout.pattern = %m%n
log4j2.appender.audit.policies.type = Policies
log4j2.appender.audit.policies.size.type = SizeBasedTriggeringPolicy
log4j2.appender.audit.policies.size.size = 8MB

# OSGi追加器
log4j2.appender.osgi.type = PaxOsgi
log4j2.appender.osgi.name = PaxOsgi
log4j2.appender.osgi.filter = *
log4j2.appender.rolling.policies.time.type = TimeBasedRollingPolicy
log4j2.appender.rolling.policies.time.interval = 1
log4j2.appender.rolling.policies.time.modulate = TRUE
log4j.appender.out.file = ${mkv.logsdir}/karaf.log

问题解答 #

问题1：Apache Karaf 4.2.9是否支持TimeBasedRollingPolicy？ #

Apache Karaf 4.2.9内置的Pax Logging基于Log4j 2.x，TimeBasedRollingPolicy对应Log4j 2.x中的TimeBasedTriggeringPolicy，是标准的时间滚动触发策略，因此Karaf 4.2.9完全支持该功能，只需通过配置属性覆写即可启用。

问题2：示例配置文件 #

以下是仅使用时间滚动策略实现按天滚动的org.ops4j.pax.logging.cfg配置示例，已移除SizeBasedTriggeringPolicy相关内容：

# 滚动文件追加器（按天滚动）
log4j2.appender.rolling.type = RollingRandomAccessFile
log4j2.appender.rolling.name = RollingFile
log4j2.appender.rolling.fileName = [路径]/karaf.log
# 按天命名归档日志，%d{yyyy-MM-dd}指定日期格式
log4j2.appender.rolling.filePattern = [路径]/app-name-%d{yyyy-MM-dd}.log
log4j2.appender.rolling.append = true
log4j2.appender.rolling.layout.type = PatternLayout
log4j2.appender.rolling.layout.pattern = %d %p %C{1.} [%t] %m%n
log4j2.appender.rolling.policies.type = Policies
# 配置按天滚动的时间触发策略
log4j2.appender.rolling.policies.time.type = TimeBasedTriggeringPolicy
# 滚动间隔为1天
log4j2.appender.rolling.policies.time.interval = 1
# 开启时间调制，确保滚动时间对齐到自然天（如凌晨0点）
log4j2.appender.rolling.policies.time.modulate = true

# 审计文件追加器（按天滚动）
log4j2.appender.audit.type = RollingRandomAccessFile
log4j2.appender.audit.name = AuditRollingFile
log4j2.appender.audit.fileName = [路径]/security.log
log4j2.appender.audit.filePattern = [路径]/security-%d{yyyy-MM-dd}.log
log4j2.appender.audit.append = true
log4j2.appender.audit.layout.type = PatternLayout
log4j2.appender.audit.layout.pattern = %m%n
log4j2.appender.audit.policies.type = Policies
log4j2.appender.audit.policies.time.type = TimeBasedTriggeringPolicy
log4j2.appender.audit.policies.time.interval = 1
log4j2.appender.audit.policies.time.modulate = true

# OSGi追加器
log4j2.appender.osgi.type = PaxOsgi
log4j2.appender.osgi.name = PaxOsgi
log4j2.appender.osgi.filter = *

注意事项：

• Log4j 2.x中时间滚动触发策略的正确类型是TimeBasedTriggeringPolicy，而非Log4j 1.x中的TimeBasedRollingPolicy
• filePattern中的%d{yyyy-MM-dd}确保每天生成一个独立的归档日志文件，无需%i分片标识
• modulate=true会让滚动时间对齐到自然天起始点，避免从服务启动时间开始计算24小时的偏移

内容的提问来源于stack exchange，提问作者Ashish