News Archive

OpenStack Icehouse Incubation Roundup

The OpenStack Technical Committee met last night to consider the status of incubated projects for the upcoming Icehouse cycle. As a result, database provisioning will be an official part of the Icehouse (2014.1) release, while message queues and bare-metal server provisioning will be in incubation with a view to becoming official in the as-yet-unnamed J (2014.2) release. (Update 2013-09-25: MapReduce as a service will also be incubated.)

First up was the Marconi project, which was applying for incubation. Marconi is a message queue service that is comparable in scope to Amazon’s SQS. This application was discussed in detail at the meeting last week ahead of the final discussion and vote yesterday. Interestingly, the need for a queue service was readily accepted even by some folks who are on-record as favouring a very limited scope for OpenStack. We certainly have use cases waiting for something like this in Heat already.

Nevertheless, Marconi is in some ways breaking new ground for OpenStack because it is a complete implementation of a message queue in Python with plug-in backends for storage and transport. (In contrast, a project like Nova is effectively just an API to an underlying hypervisor that does the heavy lifting.) Message queues in general are difficult, complex and performance-sensitive pieces of software, so it’s not obvious that we want to commit the OpenStack project to maintaining one. To mitigate this the API has been designed to be flexible enough to allow a different implementation based on AMQP, and plugins using RabbitMQ and Proton are planned for the future. Of course, the success of the API design in this respect remains unproven for now.

Another topic of discussion was that the only production-capable storage plugin currently available is for MongoDB, which is licensed under the AGPL. (An SQLite plugin is used for testing.) Although the Python client library is permissively licensed—meaning the OpenStack Foundation’s obligation to distribute code only under the Apache License 2.0 is not even in question—this does not solve the problem of MongoDB itself being a required component in the system. The biggest drawback I see with the AGPL is that it effectively expands the group of stakeholders who need to understand and be comfortable with the implications of the license from all distributors of the code (hard) to all users of the code (intractable). The committee resolved this issue by indicating that a second storage plugin option would likely be considered a condition of graduation from incubation.

In the final vote, Marconi was accepted into incubation by a comfortable margin (11 in favour, 4 abstentions). I cannot speak for the committee members, but for me the project benefits from the presumption of competence that comes from being developed entirely in the open from the very beginning without anybody in the community coming forward to say that it’s a terrible idea. Anyone else looking to get a project accepted into incubation should take note.

The next thing on the agenda was a review of the Trove project (formerly known as RedDwarf), which was incubated in the Havana cycle, for graduation. Trove is a database provisioning service for both relational and non-relational databases.

One requirement imposed by the committee was that Trove provide an option to use Heat for orchestration instead of direct calls to Nova and Cinder. Progress on this has been good (a working patch is up for review), and Trove appears well-placed to take advantage of this feature in the future.

In future, projects will also be required to provide integration tests for the Tempest suite before graduation. This is a new requirement, though, and is not being strictly enforced retroactively. So while Trove is not yet integrated with Tempest, the existence of continuous integration tests that can be integrated with Tempest during the Icehouse development was considered sufficient.

The committee voted in favour of graduation, and Trove will be an official part of the OpenStack Icehouse release.

The final project to be reviewed was Ironic, the bare-metal provisioning service that was split out of Nova into incubation at the beginning of the Havana cycle. No vote was held, because the development team indicated that the project is not ready to graduate. However, it is still progressing and neither was there any interest in curtailing it. Therefore, Ironic will remain in incubation for the Icehouse cycle.