Output to system.log stops at 12:00 a.m. each day - cassandra

Question

Running: Cassandra 2.1.8.689 | DSE 4.7.3 on Linux 2.6
Configured logback.xml. Cassandra stops writing to log file at midnight each day. Last entry in log file:
INFO [CompactionExecutor:6550] 2017-01-05 23:59:58,928INFO ...
After changing filename in logback.xml (ie. system1.log to system2.log), writing resumes. The same behavior is consistent across 6 nodes.
Thank you Aaron. Logback details below.
<configuration scan="true">
<appender name="FIX_WINDOW_BASED_FILE"
class="ch.qos.logback.core.rolling.RollingFileAppender">
<file>${cassandra.logdir}/system.log</file>
<rollingPolicy class="ch.qos.logback.core.rolling.FixedWindowRollingPolicy">
<fileNamePattern>${cassandra.logdir}/system%i.log</fileNamePattern>
<minIndex>1</minIndex>
<maxIndex>31</maxIndex>
</rollingPolicy>
<triggeringPolicy class="ch.qos.logback.core.rolling.SizeBasedTriggeringPolicy">
<maxFileSize>200MB</maxFileSize>
</triggeringPolicy>
<encoder>
<pattern>%-5level [%thread] %date{ISO8601} %marker %F:%L - %msg%n</pattern>
<!-- old-style log format
<pattern>%5level [%thread] %date{ISO8601} %F (line %L) %msg%n</pattern>
-->
</encoder>
Problem resolved. After upgrading DSE from 4.7.3 to 4.8.11, output to the system.log is working fine.

Answer 1

You should be able to control this behavior in your logback.xml file. In that file should be an <appender> section, which should look something like this:
<appender name="stash" class="ch.qos.logback.core.rolling.RollingFileAppender">
<filter class="ch.qos.logback.classic.filter.ThresholdFilter">
<level>INFO</level>
</filter>
<file>/var/log/cassandra/system.log</file>
<rollingPolicy class="ch.qos.logback.core.rolling.TimeBasedRollingPolicy">
<!-- daily rollover -->
<fileNamePattern>/var/log/cassandra/system.log.%d{yyyy-MM-dd}-%i</fileNamePattern>
<timeBasedFileNamingAndTriggeringPolicy class="ch.qos.logback.core.rolling.SizeAndTimeBasedFNATP">
<!-- or whenever the file size reaches 50MB -->
<maxFileSize>50MB</maxFileSize>
</timeBasedFileNamingAndTriggeringPolicy>
<!-- keep 5 days' worth of history -->
<maxHistory>5</maxHistory>
</rollingPolicy>
<encoder class="net.logstash.logback.encoder.LogstashEncoder" />
</appender>
My guess is that the file rollover is triggered at midnight, but there must be something in your <fileNamePattern> preventing it from creating a new file.