I haven't tested against HEAD yet. But I was tweaking with <maxHistory>, and it doesn't appear to obey when the filename pattern changes on the folder. This might be an unsupported configuration, but thought it might work since I saw it as an example on the website. "/wombat/%d{yyyy/MM}/foo.txt" [1]
This is the config I'm testing with.
<appender name="FILE-${KEY}" class="ch.qos.logback.core.rolling.RollingFileAppender">
<encoder class="ch.qos.logback.classic.encoder.PatternLayoutEncoder">
<pattern>%d{HH:mm:ss.SSS zz} %-5level [%thread] %logger{35} [%-3X{KEY}] %msg%n</pattern>
</encoder>
<rollingPolicy class="com.touchnet.twp.contextconfig.lbclassic.CloseTBRP">
<fileNamePattern>${TEMP_FOLDER}/%d{HHmmss'/maxhist-key/key.'HHmmss}.${KEY}.%i.txt.zip</fileNamePattern>
<maxHistory>1</maxHistory> <!-- date periods to keep in addition to current -->
<timeBasedFileNamingAndTriggeringPolicy class="ch.qos.logback.core.rolling.CloseSTBFNATP">
<maxFileSize>1</maxFileSize> <!-- testing if index values were counted in history -->
</timeBasedFileNamingAndTriggeringPolicy>
</rollingPolicy>
</appender>
[1]
http://logback.qos.ch/manual/appenders.html