SonOfABatchScanner
uses a source and sink for the publishing of results, such that ordering is maintained across multiple scan tasks. 
this can be useful if using a tertiary store ( which is also a source/sink -- i.e. voldemort, mysql ). 

I'll create a voldemort example soon and upload the POM I'm using locally. 

Note that the locking capabilities are VERY immature. do not use this in production without improving them.