One of the common questions I am asked is whether Momentum can be configured to rotate logs on an hourly basis instead of on a daily basis. The answer is yes. Log rotation is scheduled at /etc/cron.d/msys-ecelerity-core but keep in mind that ec_rotate is configured to retain only seven rotations. So if you switch to hourly rotations you will only retain seven hours of log data.

Retention is configured in /opt/msys/ecelerity/etc/ec_rotate.conf (if the file is not present you can copy it in from /opt/msys/ecelerity/etc/sample-configs/ec_rotate.conf) as “retention = 7”, if you want to rotate on an hourly basis and still maintain a week’s worth of logs you need to change this value to 168 (7 days * 24 rotations).

The most common reason for such regular log rotation is to decrease the lag between an event being logged and that event being updated in a backend database by a log processor. Momentum includes support for JLOG, an indexed log format that allows for near real time log processing, support check-pointing and automatic garbage collection. Watch this space for a future update on how you can take advantage of JLOG to simplify your log processing using JLOG.