Synchronization is always showing Delta and never goes to Sleep (4253638)

Synchronization is stuck in "Delta Synchronization"

There are multiple possible reasons synchronization is stuck in Delta Synchronization. 

Occasionally, the Migration Manager console status may not reflect the actual DSA state.  There can be delays updating the UI status. 
To confirm the Synchronization Agent is busy processing updates, monitor the dsa.log on the agent host (Located here by default %\program files(x86)\Quest Software\Migration Manager\DSA\Configs\)

Possible reasons for such behavior:

-The DSA sleep period was changed to the very short value, such as 1 min. This can be modified in the console, Agent Manager, properties of DSA machine, Scheduling tab.  Default 15 minutes is to allow for AD replication in the forests. 
  -When the sleep is set to 1 minute, it is possible to visually miss the UI showing that the agent has gone to sleep for such a short period.

-There are a lot of groups with many members in the environment. Directory synchronization status will stay in Delta, while LinkResolver is working on AD objects' links, like managers and groups' memberships, updates and deletes

- DSA cache has become corrupt, causing it to perform resync on all objects in scope over and over, regardless if they were synchronized previously.  Please note, removal of DSA cache will require a full resynchronization to be performed to rebuild the cache.

- There are 3rd party tools or scripts in the source domain (or target domain in a 2 way synchronization), which are frequently modifying AD objects.  DSA depends on the AD objects modification timestamp. Once the attribute differs from the cached value, the object is synchronized again.  One such example is, where some HR applications purge group memberships, then repopulate them to ensure membership is accurate.  

- DSA preferred DC/GC is set to a remote or slow DC, which causes delays.  DSA issues a lot of LDAP queries and delay like this can contribute to overall slowness.