You can change either the retention time or the retained number of entries to enable automatic purging. By default, both are set to an indefinite retention time and number of entries. The time unit of milliseconds (ms), seconds (s), minutes (m), hours (h), days (d), or weeks (w), may be preceded by an integer to specify a quantity for that unit, such as "1 d", "52 w", etc. Once you configure the properties, the changes take effect immediately without the need for a server restart.
Note that the server will delete all of the soft-deleted entries according to the policy in effect. If the policy is changed while entries are in the process of being deleted, the new policy takes effect after the in-process batch of entries is deleted and applies to any remaining soft-deleted entries going forward according to the new policy.