When using SiftingAppender and RollingFileAppender files do not get rolled on close.

logback.xml

<configuration>
  	
	<logger name="com.client.gcm" level="${log.level}" />
	<logger name="com.client.system" level="${log.level}" />
	<logger name="org.apache.commons.dbcp.DriverConnectionFactory" level="${log.level}" />
	<logger name="httpclient" level="WARN" />
	<logger name="org.apache" level="WARN" />
	<logger name="org.apache.commons.httpclient" level="WARN" />
	<logger name="org.apache.camel" level="${log.level}" />
	<logger name="org.apache.activemq.transport" level="WARN" />
	<logger name="org.hibernate" level="WARN" />
	<logger name="org.hibernate.cfg.AnnotationBinder" level="WARN" />
	<logger name="org.hibernate.cfg.annotations" level="WARN" />
	<logger name="org.quartz" level="WARN" />
	<logger name="org.springframework" level="WARN" />
	<logger name="org.springframework.jdbc.core.JdbcTemplate" level="${log.level}"/>
	<logger name="org.datasynapse" level="WARN" />
	
	<!-- if we are given a file name, then log to file, else log to stdout -->
	<if condition='!property("messagepricer.log.dir").isEmpty()'>
		<then>
			<appender name="WITHOUT_LOGFILKEY" class="ch.qos.logback.classic.sift.SiftingAppender">
				<filter class="ch.qos.logback.core.filter.EvaluatorFilter">
					<evaluator> <!-- defaults to type ch.qos.logback.classic.boolex.JaninoEventEvaluator -->
						<expression>return mdc.containsKey("logfileKey");</expression>
					</evaluator>
					<OnMismatch>NEUTRAL</OnMismatch>
					<OnMatch>DENY</OnMatch>
				</filter>
				
				<!-- in the absence of the class attribute, it is assumed that the desired 
					discriminator type is ch.qos.logback.classic.sift.MDCBasedDiscriminator -->
				<discriminator>
					<key>logfileType</key>
					<defaultValue>main</defaultValue>
				</discriminator>
				<sift>
					<appender name="ROLLING-${logfileType}" class="ch.qos.logback.core.rolling.RollingFileAppender">
						<file>${messagepricer.log.dir}/messagepricer.${logfileType}.${HOSTNAME}.log</file>
						<rollingPolicy class="ch.qos.logback.core.rolling.TimeBasedRollingPolicy">
							<fileNamePattern>${messagepricer.log.dir}/archive-main/messagepricer.${logfileType}.${HOSTNAME}.%d{yyyy-MM-dd}.log.gz</fileNamePattern>
							<maxHistory>${messagepricer.log.maxHistory}</maxHistory>
						</rollingPolicy>
						<encoder>
							<pattern>%d{yyyy-MM-dd HH:mm:ss.SSS} [%-16thread] %-5level %-35.35logger{30} - %msg%n</pattern>
						</encoder>
					</appender>
				</sift>
			</appender>
			
			<appender name="WITH_LOGFILKEY" class="ch.qos.logback.classic.sift.SiftingAppender">
				<filter class="ch.qos.logback.core.filter.EvaluatorFilter">
					<evaluator> <!-- defaults to type ch.qos.logback.classic.boolex.JaninoEventEvaluator -->
						<expression>return !mdc.containsKey("logfileKey");</expression>
					</evaluator>
					<OnMismatch>NEUTRAL</OnMismatch>
					<OnMatch>DENY</OnMatch>
				</filter>
				
				<!-- in the absence of the class attribute, it is assumed that the desired 
					discriminator type is ch.qos.logback.classic.sift.MDCBasedDiscriminator -->
				<discriminator>
					<key>logfileKey</key>
					<defaultValue>messagepricer.%d{yyyy-MM-dd-HH-mm}.${HOSTNAME}</defaultValue>
				</discriminator>
				<sift>
					<appender name="ROLLING-${logfileKey}" class="ch.qos.logback.core.rolling.RollingFileAppender">
						<file>${messagepricer.log.dir}/${logfileKey}.log</file>
						<rollingPolicy class="ch.qos.logback.core.rolling.TimeBasedRollingPolicy">
							<fileNamePattern>${messagepricer.log.dir}/archive-msg/messagepricer.${logfileKey}.${HOSTNAME}.%d{yyyy-MM-dd-HH-mm}.log.gz</fileNamePattern>
							<maxHistory>${messagepricer.log.maxHistory}</maxHistory>
						</rollingPolicy>
						<encoder>
							<pattern>%d{yyyy-MM-dd HH:mm:ss.SSS} [%-16thread] %-5level %-35.35logger{30} - %msg%n</pattern>
						</encoder>
					</appender>
				</sift>
			</appender>
		
			<appender name="ASYNC-ROLLING" class="ch.qos.logback.classic.AsyncAppender">
				<appender-ref ref="WITHOUT_LOGFILKEY" />
			</appender>
			<appender name="ASYNC-FILE" class="ch.qos.logback.classic.AsyncAppender">
				<appender-ref ref="WITH_LOGFILKEY" />
			</appender>
			<root level="${log.level}">
				<appender-ref ref="ASYNC-ROLLING" />
				<appender-ref ref="ASYNC-FILE" />
			</root>
		</then>
		<else>
			<appender name="STDOUT" class="ch.qos.logback.core.ConsoleAppender">
				<encoder>
					<pattern>%d{yyyy-MM-dd HH:mm:ss.SSS} [%-16thread] %-5level %-35.35logger{30} - %msg%n</pattern>
				</encoder>
			</appender>
			<root level="${log.level}">
				<appender-ref ref="STDOUT" />
			</root>
		</else>
	</if>

</configuration>

Were you able to find out why it wasn't working?