Ok, so this is and expected error in the logs, although not nice it can be ignored (IN A CLUSTER).
Taken from the oracle documentation: (http://docs.oracle.com/cd/E28271_01/webcenter.1111/e25595/jpsdg_deploy_portlets.htm)
This is expected behavior. When you deploy your application, the producer metadata exported into the EAR file (as a MAR file) needs to be imported into an MDS schema for use in the production environment. Importing the metadata occurs automatically during deployment. This import only needs to happen with one node in the cluster, so a lock is created to prevent other nodes in the cluster trying to perform the same operation.