Preventing Schema Locks in ArcSDE from ArcGIS Server 10.1.

By default, ArcGIS Server creates a schema lock on all layers and tables in a Map Service while the service is running.  This will prevent adding or deleting fields or records. 

At 10.1 this and a lot of other admin tasks can be done directly on the rest endpoint as described below.

By default, ArcGIS Server map services use schema locking to prevent other users from altering the geodatabase schema while the service is running. If the schema locks are impeding your workflow, you can disable them by using the ArcGIS Server Administrator Directory.

To disable schema locking for a service, perform the following steps:

1. Navigate to http://:6080/arcgis/admin.
2. Click services.
3. Click the service for which you want to disable schema locking.
4. Click edit.
5. Add the "schemaLockingEnabled" = "false" property within the service JSON, as in the following example:

   …………………………………………………..

   "maxImageHeight": "2048",

   "schemaLockingEnabled": "false",

   "maxRecordCount": “1000",

   …………………………………………………..

6. Click Save Edits.

This has been reblogged from

http://djmapper.tumblr.com/post/25068172061/prevent-arcgis-server-10-1-s...