Log file rollover is not working in BW6.5.0. Log file size goes beyond the 10 MB (default) size and consecutive rollover log files such as "bwappnode1.log",bwappnode2.log" are not created.
In some cases, these files are created randomly without adhering to the logback appender rules(size, numbers of files, etc)

This change needs to be done in logback.xml at the following locations.

Location 1: <Tibco_install>bw\6.x\config 

Location 2 : <Tibco_install>bw\6.x\domains\<doman>\appnodes\<appspace>\<appnode>

Location 1 change will fix the issue for future nodes.
Location 2 change will fix the issue for the existing nodes.

After this change, please restart nodes.

Change the appender-ref in logback.xml for the below logger : 

<!-- Default Log activity logger -->

  <logger name="com.tibco.bw.palette.generalactivities.Log" additivity="false">

    <level value="DEBUG"/>

    <appender-ref ref="APPLICATION-FILE"/>

  </logger>

to

<!-- Default Log activity logger -->

  <logger name="com.tibco.bw.palette.generalactivities.Log" additivity="false">

    <level value="DEBUG"/>

    <appender-ref ref="FILE"/>

  </logger>