Introduction and definitions

OpenIO heavily relies on the Service Directory, its main function is locating a specific Service for a given Reference.


References are named groups of service links. Internally, their name is hashed to a 64 bytes hexadecimal string. References are managed by the second level of the service directory (Meta1).


Prefixes are the first bytes of hashed reference names. They are used to shard the references on the first level of the service directory (Meta0). In the current implementation, prefixes are 16 bits long, so there is exactly 65536 of them.


Once a reference is created, you can link a set of Services to it. This used for example for Object Storage Container Services.