Pitching the Tent

Felling Trees in Neutron

Some cloud admins still freeze when they hear the word Neutron. Little wonder, given that this OpenStack SDN component has a reputation of being very complex and hard to manage. As if the developers had heard this criticism, they reacted in Kilo and cleaned up the giant Neutron project to a great extent. This does not mean that any functionality has been dropped, but that, in the future, the single, large Neutron project will be replaced by multiple small projects with specific functions (e.g., L2 or L3 network connectivity).

The parts that were outsourced, such as the LBaaS or VPNaaS plugins, will also benefit from this step: In the future, they will use defined APIs to talk to Neutron instead of directly accessing Neutron code. A separate Neutron library with separate code elements also helps. Kilo is only the first phase of the paradigm shift: By the time the M version is released, the other changes should be in place; each Neutron add-on component will then have its own API.

Perestroika has been dropped for the time being, it seems. This was the code name for a new plugin interface planned for Kilo and intended to offer more functionality for SDN plugins like Open vSwitch or OpenContrail. At the end of February, the developers had to ditch the plan; however, because much work has been completed, you can expect Perestroika to reappear in the OpenStack Liberty version.

If you use OpenStack with Windows, you will be happy to hear about the Neutron OVS agent for Windows, which also comes with Kilo. Cloudbase has again put in some excellent work, successfully managing the Open vSwitch port to Windows and delivering OpenStack integration.

Glance: Minor Changes, Major Effect

For the Glance image service, the Kilo developers only had 21 features on their to-do list – compared with twice this amount for Neutron or Nova. Compared directly with the other components, life in the world of the OpenStack image service seems uneventful. This situation was to be expected: Glance supports practically all the features that are relevant in a cloud.

To tackle the most urgent problem for Kilo, the developers have implemented an improved sorting order, including user specifications for outputting all images in Glance and support for version numbers in line with the Semantic Versioning (SemVer) standard [3]. Performance improvements, such as storing images in the OpenStack Swift object store and new performance tweaks, round off the changes to Glance.

More Drivers for Cinder

The service for persistent volumes, Cinder, is following Nova's lead and also moving towards an object-oriented setup. Based on this, it will be possible in the future to address each Cinder in the way that is already possible for Nova instances.

The reasons are identical and, in part, the Cinder developers are also copying Nova details. What administrators are likely to find far more interesting, however, is the fact that there will be new drivers for Cinder and a new driver interface. The ABC Python library provides the basis for this development. Initial drivers have already been ported to the new ABC interface, such as the rbd driver for Ceph, and others are likely to follow in the course of the Liberty release.

New drivers and driver extensions are available for HP 3PAR, StorPool, or Open vStorage. The Cinder developers have massively extended their iSCSI implementation. The NetApp driver in Kilo now also officially offers Fibre Channel support.