Publication and Distribution

Figure 1 illustrates how files are published in RCDS.

  
Figure 1: Publication of files in RCDS.

1. An author submits a file to RCDS using a publication tool. If this is a new file, a new description (containing catalog information) of that file is created and a new URN is assigned; otherwise, the description of the old URN is updated to reflect the new version of the file. A LIFN is assigned to the new file, and this LIFN is included in the description of that file. The part of the description containing the LIFN and file fingerprint (and perhaps other parts of it) is cryptographically signed by the author using the publication tool.
2. The publication tool deposits a copy of the file on a file server, and a copy of the description on any resource catalog server associated with the URN's domain. The publication tool also sends a copy of the description of the new file to interested parties, which might include file servers and search services.
3. The resource catalog server updates its peers with the new description.
4. The file server informs any location server associated with the LIFN's domain, that it has a copy of the file with that particular LIFN.
5. As other file servers find out about the existence of the new file, their collections managers decide whether to acquire it. When a file server acquires the new file and makes it accessible, it informs a location server about it.
6. The location servers propagate new file location information to one another.