Thanks Thomas for the guidance. i tried out Clustering of jackrabbit in repository.xml and it worked for me. Now I have two member Guvnors in a clustered environment. Both poiting to same DB for fileSystem, persistentManager and DataStore.
Now What I did for testing is brought one cluster node down and make some changes in the other one. Now brought the second node alive and running and could see my latest assets even the changes made by other node was also available.
So this resolves my issue of keeping assets in DB to avoid backingup repository directory. Now I can depend on Database.