ar·chi·tec·ture ˈärkəˌtek(t)SHər/ noun noun: architecture 1.
the art or practice of designing and constructing buildings. synonyms:building design, building style, planning, building, construction; formalarchitectonics "modern architecture" the style in which a building is designed or constructed, especially with regard to a specific period, place, or culture. plural noun: architectures "Victorian architecture" 2. the complex or carefully designed structure of something. "the chemical architecture of the human brain" the conceptual structure and logical organization of a computer or computer-based system. "a client/server architecture" synonyms:structure, construction, organization, layout, design, build, anatomy, makeup; informalsetup "the architecture of a computer system" Introduction ========= OpenStack is a big system. We have debated what it actually is [1], and there are even t-shirts to poke fun at the fact that we don't have good answers. But this isn't what any of us wants. We'd like to be able to point at something and proudly tell people "This is what we designed and implemented." And for each individual project, that is a possibility. Neutron can tell you they designed how their agents and drivers work. Nova can tell you that they designed the way conductors handle communication with API nodes and compute nodes. But when we start talking about how they interact with each other, it's clearly just a coincidental mash of de-facto standards and specs that don't help anyone make decisions when refactoring or adding on to the system. Oslo and cross-project initiatives have brought some peace and order to the implementation and engineering processes, but not to the design process. New ideas still start largely in the project where they are needed most, and often conflict with similar decisions and ideas in other projects [dlm, taskflow, tooz, service discovery, state machines, glance tasks, messaging patterns, database patterns, etc. etc.]. Often times this creates a log jam where none of the projects adopt a solution that would align with others. Most of the time when things finally come to a head these things get done in a piecemeal fashion, where it's half done here, 1/3 over there, 1/4 there, and 3/4 over there..., which to the outside looks like <architecture> chaos, because that's precisely what it is. And this isn't always a technical design problem. OpenStack, for instance, isn't really a micro service architecture. Of course, it might look like that in diagrams [2], but we all know it really isn't. The compute node is home to agents for every single concern, and the API interactions between the services is too tightly woven to consider many of them functional without the same lockstep version of other services together. A game to play is ask yourself what would happen if a service was isolated on its own island, how functional would its API be, if at all. Is this something that we want? No. But there doesn't seem to be a place where we can go to actually design, discuss, debate, and ratify changes that would help us get to the point of gathering the necessary will and capability to enact these efforts. Maybe nova-compute should be isolated from nova, with an API that nova, cinder and neutron talk to. Maybe we should make the scheduler cross-project aware and capable of scheduling more than just nova instances. Maybe we should have experimental groups that can look at how some of this functionality could perhaps be delegated to non-openstack projects. We hear that Mesos, for example to help with the scheduling aspects, but how do we discuss these outside hijacking threads on the mailing list? These are things that we all discuss in the hallways and bars and parties at the summit, but because they cross projects at the design level, and are inherently a lot of social and technical and exploratory work, Many of us fear we never get to a place of turning our dreams into reality. So, with that, I'd like to propose the creation of an Architecture Working Group. This group's charge would not be design by committee, but a place for architects to share their designs and gain support across projects to move forward with and ratify architectural decisions. That includes coordinating exploratory work that may turn into being the base of further architectural decisions for OpenStack. I would expect that the people in this group would largely be senior at the companies involved and, if done correctly, they can help prioritize this work by advocating for people/fellow engineers to actually make it 'real'. This will give weight to specs and implementation changes to make these designs a reality, and thus I believe this group would do well to work closely with the Oslo Team, where many of the cross-cutting efforts will need to happen. How to get involved =================== If the idea is well received, I'd like to propose a bi-weekly IRC meeting at a time convenient for the most interested individuals. I'd also like to see a #openstack-architecture channel for gathering real time chatter about architecture, and an architecture tag. Finally, I'd like to see this group collaborate on direct work using the existing openstack-specs repository. In closing ========== First, thanks for reading this whole message and considering this evolution of our processes. I am excited to begin this discussion, and hope that we can arrive at a plan quickly that leads to us all being able to discuss the architecture of OpenStack productively. Also, thanks to those of you who helped me review and edit this document. [1] http://lists.openstack.org/pipermail/openstack-dev/2016-May/095452.html [2] http://docs.openstack.org/admin-guide/_images/openstack-arch-kilo-logical-v1.png __________________________________________________________________________ OpenStack Development Mailing List (not for usage questions) Unsubscribe: openstack-dev-requ...@lists.openstack.org?subject:unsubscribe http://lists.openstack.org/cgi-bin/mailman/listinfo/openstack-dev