DataONE Member Node Support
===========================

DataONE_ is a federation of data repositories that aims to improve 
interoperability among data repository software systems and advance the
preservation of scientific data for future use.
Metacat deployments can be configured to participate in DataONE_. This 
chapter describes the DataONE_ data federation,  its architecture, and the 
way in which Metacat can be used to participate as a node in the DataONE system.

.. _DataONE: http://dataone.org/

What is DataONE?
----------------
The DataONE_ project is a collaboration among scientists, technologists, librarians,
and social scientists to build a robust, interoperable, and sustainable system for
preserving and accessing Earth observational data at national and global scales.  
Supported by the U.S. National Science Foundation, DataONE partners focus on
technological, finalncial, and organizational sustainability approaches to 
building a distributed network of data repositories that are fully interoperable,
even when those repositories use divergent underlying software and support different
data and metadata content standards. DataONE defines a common web-service service 
programming interface that allows the main software components of the DataONE system
to seamlessly communicate. The components of the DataONE system include:

* DataONE Service Interface
* Member Nodes
* Coordinating Nodes
* Investigator Toolkit

Metacat implements the services needed to operate as a DataONE Member Node, 
as described below.  The service interface then allows many different scientific 
software tools for data management, analysis, visualization and other parts of 
the scientific lifecycle to directly communicate with Metacat without being
further specialized beyond the support needed for DataONE.  This streamlines the
process of writing scientific software on both for servers and client tools.

The DataONE Service Interface
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
DataONE acheives interoperability
by defining a lightweight but powerful set of web services that can be
implemented by various data management software systems to allow those systems
to effectively communicate with one another, exchange data, metadata, and other
scientific objects.  This `DataONE Service Interface`_
is an open standard that defines the communication protocols and technical 
expectations for software components that wish to participate in the DataONE
federation. This service interface is divided into `four distinct tiers`_, with the 
intention that any given software system may implement only those tiers that are 
relevant to their repository; for example, a data aggregator might only implement
the Tier 1 interfaces that provide anonymous access to public data sets, while
a complete data management system like Metacat can implement all four tiers:

1. **Tier 1:** Read-only, anonymous data access
2. **Tier 2:** Read-only, with authentication and access control
3. **Tier 3:** Full Write access
4. **Tier 4:** Replication target services

.. _DataONE Service Interface: http://releases.dataone.org/online/d1-architecture-1.0.0

.. _four distinct tiers: http://releases.dataone.org/online/d1-architecture-1.0.0/apis/index.html

Member Nodes
~~~~~~~~~~~~

Coordinating Nodes
~~~~~~~~~~~~~~~~~~

Investigator Toolkit
~~~~~~~~~~~~~~~~~~~~

Metacat as a Member Node
------------------------