Identity Connectors16 Aug 2010
Only a small pieces remainded from the Sun Identity Manager (IDM) after Oracle swallowed Sun. One of the biggest pieces is Identity Connectors Framework. I guess it was an attempt to replace Sun IDM adapters - a part of the system that was asking for re-engineering since the times of Waveset back in 2003. Yet, Identity Connectors are not really an ideal replacement.
The goal of Identity Connector is to connect to a remote system. It should provide list of accounts, groups, roles or any other objects that are interesting from identity management point of view. It should be also able to manage such objects - to create, modify and delete them. Identity Connector Framework provides typical API/SPI abstraction to plug in connectors for various systems. It even seems to isolate the individual connectors to a separate classloaders. It allows to run connector on a remote host. So far everything is pretty much OK.
It is naïve to expect that all target system will use the same structure for accounts and groups and other objects. Therefore the connector provides a schema that describes how such objects are structured by the resource. That is major improvement over Sun adapters and it also should be a major competitive advantage of Identity Connectors. Only if it was designed a bit more carefully. First of all, it looks like the intent was for the schema to use native naming of object classes and attributes from the target system. E.g. complete LDAP schema with native object class names and attributes is visible using the connector. On the other hand, the framework provides pre-defined and fixed object class names __ACCOUNT__ and __GROUP__ and even predefined attribute names for __NAME__ and few others. I cannot understand this dichotomy: on one hand exposing the full native schema, on the other to hide it behind a cumbersome abstraction. This duality complicates the design of any system that is trying to use the connectors correctly. E.g. both __ACCOUNT__ and inetOrgPerson object classes are exposed by the LDAP identity connector and they are the same. Which one should be used? The root cause of this problem seems to go a bit deeper: the connector does not have clearly defined responsibilities. Should the connector only provide access to the object on target resource (i.e. be a simple protocol adapter)? If yes then there is no need for special __ACCOUNT__ and __GROUP__ object classes. Or should the connector also map the target system schema and provisioning system schema? For that it does not have sufficient features (see below). It looks like the connector goes somewhere in between, trying - and failing - to address both problems.
Yet another feature that I would expect from a "next generation" identity connector is to handle object references or membership. It means that provisioning system should be able to discover that there are two grouping mechanisms for LDAP and one (proprietary) mechanism for roles. That will allow provisioning system to provide much better GUI and business logic support out of the box. Yet, identity connectors do not provide such feature. The unix group attributes are of type string. There is no information in the schema that would suggest that a __NAME__ (or Uid?) of an object from the __GROUP__ object class belongs there. There is even no way how to know that there is more than one grouping mechanism (that is pretty common in LDAP and in many custom systems). How can provisioning system handle that? Either it cannot and leave that to business logic (which make deployment hard) or it can build an adaptation layer on top of connector. Abstraction on top of abstraction. Insane.
Overall it looks like the folks at Sun have chosen the wrong way. Identity Connectors are not that much of an improvement over older adapters that I would expect. It looks like the responsibilities should have been defined much better. And I would suggest that schema annotation is much preferable over schema transformation in this case. The Identity Connectors Framework needs a radical improvement even before they have gained any serious acceptance.
The punch line is that Oracle is planning to use this very mis-designed framework to improve their Oracle Identity Manager.