Sector stores files on the native/local file system of each slave node.
Sector does not split files into blocks
Pro: simple/robust, suitable for wide area
Con: file size limit
Sector uses replications for better reliability and availability
The master node maintains the file system metadata. No permanent metadata is needed.
Topology aware
Read/Write
Write is exclusive
Replicas are updated in a chained manner: the client updates one replica, and then this replica updates another, and so on. All replicas are updated upon the completion of a Write operation.
Read: different replicas can serve different clients at the same time. Nearest replica to the client is chosen whenever possible.