We’re wondering if it is possible to configure the LOCKSS Plugin in a way that it can work with different, individual PLNs. As I’ve read PKP developed a toolkit for the servers harvesting the content of participating journals. Is it possible for other institutions or networks to establish a similar network? We have a client in Switzerland and LOCKSS is quite well established over there. Is it possible for them to establish a network similar to PKP’s PLN while using the LOCKSS PLN Plugin?
And in addition: which information are being archived and sent to the PLN? I’ve read that it uses SWORD but I’m not familiar enough with the data structure to actually deduce the answer from that information.
Yes, it is possible to create other PLNs that use the PKP PLN’s architecture and tools. Have you been talking to Vicky Reich at LOCKSS about doing this?
On the OJS side, all journals participating in the local PLN will need to have the URL of the PLN’s staging server set in their config.php files as described at the bottom of https://github.com/pkp/ojs/tree/ojs-stable-2_4_8/plugins/generic/pln; then, a copy of the staging server tools we have developed (GPL licensed) would need to be installed on that PLN’s staging server; and finally, you would have to run an instance of LOCKSS-O-Matic (also GPL) to sit between your staging server and your LOCKSS boxes.
We are just rolling out the PKP PLN, so it’s a bit early for us to assist with setting up alternate PLNs like the one you are describing, and we’d be more comfortable doing so after the PKP PLN has been running for a while, but what you are asking it completely possible.
To answer your question about what gets sent to the PLN, whenever a journal publishes an issue, the native OJS export XML version of the issue is put in a Bag along with some metadata about the journal (like its licensing policy). The journal then tells the staging server that the issue-level deposit is ready for harvesting. The staging server fetches the Bag and then applies a number of validation processes to it. When those processes are complete, the staging server repackages the issue XML and some additional metadata in a new Bag and informs LOCKSS-O-Matic that the Bag is ready for harvesting by the LOCKSS boxes. All of the communication between OJS and the staging server, and the staging server and LOCKSS-O-Matic, is done via simple SWORD requests.
Some journals don’t publish issues (these are known as “continuous publication” journals). Just replace “issue” with “article” in the above paragraph.
We intend to document publicly pretty much every aspect of the PKP PLN once we are in production. Until then, let us know if you have any additional questions.