Select the DataONE Tier

DataONE has defined several tiers, each of which designates a certain level of functionality exposed by the Member Node. The tiers enable Member Nodes to implement only the functionality for the level at which they wish to participate in the DataONE infrastructure.

The tiers are as follows:

Tier 1	Read, public objects Tier 2 Access controlled objects (authentication and authorization)
Tier 3	Write (create, update and delete objects)
Tier 4	Replication target

Each tier implicitly includes all lower numbered tiers. For instance, a Tier 3 Node must implement tiers 1, 2 and 3.

GMN supports all tiers. To select the tier for your Member Node, take the following into account:

• A Tier 1 Node is typically used for exposing existing data to DataONE. As there is no support for manipulating the data through DataONE interfaces in this tier, GMN cannot be populated with objects while in this tier. Therefore, GMN should not initially be set to this tier. Instead, set GMN to Tier 3, populate the Node with objects, and then set the Tier to 1.

• A Tier 2 Node allows the access to objects to be controlled via access control lists (ACLs). Using this Tier implies the same strategy as for Tier 1.

• A Tier 3 Node allows using DataONE interfaces to set up the objects on the Member Node, for instance by using the DataONE Command Line Interface or by creating Python scripts or Java programs that are based on the libraries provided by DataONE. The objects can be set up with storage managed either by GMN itself or by another, independent server that makes the object data available on the web. Access to the write functions is restricted by a whitelist.

• A Tier 4 member Node can act as a replication target, which allows the Member Node operator to provide storage space to DataONE (for storing object replicas).

When you have determined which tier to use, edit settings.py:

$ sudo nano /var/local/dataone/gmn_venv_py3/lib/python3.6/site-packages/d1_gmn/settings.py

• Set TIER to 1, 2, 3 or 4.