ePIC provides many highly reliable, redundant and performant services to the scientific research community. While some of the services and activities are completely hidden from the users, other services, such as the one responsible for PID registration, is publicly visible.
Here is an overview of the most important services offered by ePIC for its users.
Among PID user communities, there is a debate about sensible policies for PID management. For example, some of our users regularly delete PIDs when the referred digital object no longer exists. Others feel that PIDs must never be deleted, even if the underlying data object does not exist anymore, because the PIDs still may contain some valuable data about the deleted object, at least some hint of its existence in the past. Similar debates exist about requiring copyright information, or digital fingerprints.
ePIC itself feels that these debates are beyond the scope of its primary goal. But we do provide the tools to enforce every thinkable policy. For example, if you feel that PIDs should never be deleted, always contain a digital signature, or follow a certain syntax, we can easily configure our service to follow precisely these policies inside your PID namespace.
However we recommend to take the persistency promise of PIDs seriously. Furthermore we will provide services, that make the reliability of the PIDs of a namespace publicly transparent.
The PID service is the main interface to register and manage persistent identifiers in ePIC. To help the users, the ePIC service providers share the same interfaces. The PID service is implemented as a RESTful web service and it is continously being developed by ePIC. If new features are required, ePIC registeres these as change requests and a common decision about the implementation is made by the ePIC partners.
PID Prefix and Server Hosting
A PID service consists of a prefix, an API and the servers running the service. ePIC provides new prefixes in the namespace “21.” allotted to GWDG through the membership in DONA. ePIC members will issue a new prefix and provide the hosting service on behalf of a scientific institution or community. Other authorities that can issue new prefixes are e.g. CNRI or IDF, each responsible for a different prefix namespace.
The PID Resolution system of ePIC is responsible for forwarding the users to the current location of an identified object. Among the current location, other information about the object (such as author or expiration date) can also be provided. ePIC utilizes the Handle System to achieve a redundant and load-balanced setup between the data centers. ePIC replicates the PID databases to guarantee an all time availibilty of the PID resolution. The resolution services of ePIC are also included into the worldwide Handle infrastructure to guarantee a highly reliable and performant resolution of PIDs issued by ePIC.
ePIC provides highly reliable, performant and redundant services. Currently, five european data centers work together to replicate each other’s persitent identifiers. When a data center is temporarily not available, the other ePIC centers still resolve the PIDs.
Global Handle Mirror Server
The PID infrastructure used by ePIC is based on a worldwide hierarchy. The Global Handle Systems are on the highest level of the hiearachy. These systems are registries where the most important information of the prefixes is stored. Global Handle System Mirrors are therefore deployed on every continents. The GWDG, one of the ePIC founders, hosts a Global Handle System Mirror in Europe to ensure the resolution of the prefixes even if other parts of the global network are temporarily not available.