Infrastructure

the insert and read methods look like:

public String insert(String pid, InputStream object, String systemMetadata);
public InputStream read(String pid);

Since there is no different for creating a metadata and a data object, insert method will handle both. So upload method will be removed.

The insert and read methods will interact with the active MN nodes (selected by user). For insert, the new created object will set the authoritative member node to the active node id.

The attached file is the sequence diagram of the inserting.