
Since ECMS 2.1.6/PLF 3.0.6, the _ClearOrphanSymlinksJob_ service is used as a CRON job to periodically clear WCM orphan symlinks that do not point to any target nodes at a specific time or date.

By defaut, the value of the _ClearOrphanSymlinksCronJob_ parameter is "{noformat}0 0/20 * * * ?{noformat}". It means that orphan symlinks are cleared every 20 minutes.

In which:

* *Asterisk* {noformat}(*){noformat}: indicates that the CRON expression will match for all values of the field.  
* *Slash* {noformat}(/){noformat}: is used to describe increments of ranges (e.g. 0/20 means that every 20 minutes).
* *Question mark* (?): is used to omit the specification of a value for the day-of-month and day-of-week fields (e.g. every day in a week).

You can schedule the job by adding _wcm.linkjob.cron.expression_ in the _configuration.properties_ file. 

Example:

{code}
# Clear WCM orphan symlinks every 25 minutes
wcm.linkjob.cron.expression=0 0/25 * * * ?
{code}

Or

{code}
# Clear WCM orphan symlinks at 1.30 a.m every day
wcm.linkjob.cron.expression=0 30 1 * * ? 
{code}

{note}
To understand more about CRON expression, refer to [http://en.wikipedia.org/wiki/CRON_expression#CRON_expression].
{note}
