On Tuesday 27 July 2004 19:15, Neal D. Becker wrote: > Yes, here's the linux registry topic again. This project looks > interesting. Any comments? Yes, many comments! I think that almost everybody will agree that Linux needs a different approach to store configuration information for the system, applications and users, other than the traditional configuration files under /etc. The problem is that we do not agree how this new approach should look like. Perhaps, everybody agrees that it must be a kind of local centralized system with a common framework for accessing configuration information. Regarding to this new "Linux Registry" proposal, I see many problems: * It provides a system namespace but, how the information is organized? Does every application have its own registry subset? What if two or more applications share configuration values? Shall they duplicate configuration information? * "It is not an alternative to network information systems": fine, but it should take into account that most of the Linux boxes are networked machines, and presumably, centrally managed. So it should provide a (optional) mechanism for the synchronization with a central networked configuration database. * "It doesn't know a thing about the semantics of each data it stores": this is a bad thing because we cannot validate configuration information. It assumes that the registry administrator knows what he is doing, and people does not makes mistakes when typing. * It expects to rewrite all the applications to use the new framework. This is not realistic. I think that "Linux registry" is a nice step in the right direction, but if we have to change /etc, and change a lot of the already existing code, we should try to do it in the right way, and provide a much more powerful solution. I your are interested, you can take a look to the solution that the quattor project (see http://www.quattor.org) proposes. Quattor has not been designed as a replacement of the /etc directory, but it can be in the future. Among the advantages the quattor's local Configuration Cache Manager (http://hep-proj-grid-fabric-config.web.cern.ch/hep-proj-grid-fabric-config/documents/cache-spec.pdf) has with respect of the Linux Registry I can mention: * It provides a "User Conventions" (http://quattor.web.cern.ch/quattor/documentation/docs/PanUserConventions.pdf) document as a proposal for a standard to how to organize configuration information. * It provides the NVA-API library (http://hep-proj-grid-fabric-config.web.cern.ch/hep-proj-grid-fabric-config/documents/nva.pdf), to read configuration information (current implementation is in Perl) * It provides a set of wrapper "configuration components" that reads the cached configuration information and create traditional configuration files. This eases the adoption of the new technology. * It has a high level configuration language (called pan), that uses a much powerful syntax than these key-value pairs to describe configuration information, and it lets the system manager to perform validations (and then, it is compiled into an internal key-value pairs format) * It can be used in a networked environment to keep the configuration information centralized. I do not pretend to convice everybody to move to quattor, what I want to say is that we need a much powerful approach that this simple Linux Registry. Cheers -- Rafael Angel Garcia Leiva Universidad Autonoma Madrid http://www.uam.es/angel.leiva
