KairosDB creates its log files in /opt/kairosdb/log/. Log rotation works on a daily basis, so every day a new log is created and named as kairosdb.log; when the next day comes kairosdb.log is compressed and renamed to kairosdb.<YYYY-MM-DD>.log, where <YYYY-MM-DD> is the date when this specific log file was created.

Starting from KairosDB 1.1.2, a more robust logging system will be used. From this version, KairosDB will compress logs everyday in order to minimize the space used for log files. Also, every time a log file reaches 100mb, it will be compressed and a new one will be generated for the same day (until the end of the day, when a new log file will be generated too).

Note: KairosDB uses the well-known Logback framework to manage its log files. If you have questions about Logback, please refer to their forums.

If you want to change these logging settings, please take a look at /opt/kairosdb/conf/logging/logback.xml and at Logback documentation.