If there is an adage that is particularly true in the technology business, it is that you can either creatively destroy your own products in the markets you come to dominate or someone else will. Those companies who manage such transitions last for decades, a few so far for a century or more. And those that don’t, we don’t even bother to remember them much.
VMware, which is one of the dominant platform companies of the modern age of commercial computing, wants to continue to rake in money from its ESXi and vSphere server virtualization platform, but it also knows that companies grouse about the high prices of this software and they are looking for a lighter weight, less expensive way to isolate application and systems software. (Even VMware has basically called peak server virtualization recently.)
The Photon Platform takes the knowledge and some of the assets that VMware developed in its ESXi hypervisor and strips them down to be a better fit for software container environments where heavy virtualization – meaning the need to emulate a full-on X86 system in the software like ESXi does – is absolutely overkill. The platform has three key elements – Photon OS, Photon Machine, and Photon Controller. These are moving closer and closer to production status, specifically this week Photon Controller, which orchestrates various frameworks atop Photon Machine runtimes that employ Photon OS, is advancing one more notch.
Photon OS, which we detailed extensively when it debuted last April, is a minimalist variant of Linux that has just enough components to run containers and is intended to be more secure, less costly, and lighter than a standard Linux environment. Photon OS is distributed under a GPL v2 license and it has been optimized for container formats such as Docker, rkt, and Garden and is distributed with the ESXi hypervisor for the moment so companies can play with it. The minimalist Linux created by VMware is in technology preview at the moment, and there are images to run locally on vSphere stacks as well as on virtualized compute instances on Amazon Web Services, Google Compute Engine, Microsoft Azure, and VMware vCloud Air. Photon OS is not intended to run on bare metal and assumes some virtualization layer, no matter how skinny.
Photon Machine is a stripped down ESXi hypervisor, which VMware is calling a microvisor and which has Photon OS built in. This is distinct from the “Project Bonneville” virtual machine (really a Docker daemon that allows an ESXi VM to be treated exactly like a Docker container) that is being added to ESXi , which we told you about last June, to create something that is not quite as light as a Docker contrainer but pretty close – at least compared to a full-on VM running atop a real ESXi hypervisor. The Bonneville VMs are part of vSphere Integrated Containers, a variant of Docker embedded with ESXi that is heavier than the Photon Platform will be.
Photon Controller is, as the name suggests, a piece of management software that links the Photon Machines and their Photon OS Linuxes to various container orchestration frameworks – it can be Mesos, Kubernetes, Docker Swarm, or Cloud Foundry mixed with Lattice from VMware sister company Pivotal. Like the container controllers long since implemented at the hyperscalers, Photon Controller is also open sourced on GitHub and is intended to be controlled through APIs and REST interfaces to automagically configure up light VMs and Linuxes as container workloads are deployed. (It is reasonable to ask how many layers of control are needed in this system, and the answer appears to be, several, even in the homegrown hyperscaler stacks.) Photon Controller is distributed and multi-tenant from the start, which means it can be used as a consolidation platform for those building private or public container clouds.
There are a number of components in the Photon Controller, as you can see in the block diagram above. VMware announced Lightwave along with the Photon OS a year ago, and this is an identity and access management layer for containers that hooks either the open source Open Virtual Network or full-on NSX virtual networking software from VMware. (You can see our take on Lightwave here.) Photon Controller also includes the Zookeeper configuration manager from the Hadoop stack, a replicated document store built from Lucene called Project Xenon that underpins the CloudStore service shown at the heart of the controller.
None of this software is quite ready for primetime, but it is getting closer, James Zabala, senior product manager for cloud-native apps at VMware, tells The Next Platform, particularly with the Photon Controller 0.8 release that comes out today. There were 36 developers working on the 0.8 release and committing over 750 patches to the code, and with this release the effort was focused on setting up real-world container stacks and scaling them out.
With the past iterations of Photon Controller that came out in November, it was a bare bones system that could be run on a sandbox on a laptop and little more than that. Now, Photon Controller can be used to manage the deployment and scheduling of workloads on the real ESXi hypervisor. To be precise, a chunk of ESXi instances on a cluster can be used to run containers under the watchful eye of Photon Controller and the rest can be left alone to run plain vanilla server virtualization.
The controller has also been tweaked so it scales further, and Zabala says that the controller was designed to scale to thousands of hosts and hundreds of thousands of objects in its current incarnation. Theoretical limits are one thing, but tested ones are what matter, and Zabala says that VMware’s engineers have been able to push a container stack using Kubernetes to around 200 nodes and has been able to push Mesos to around 700 nodes. This is perhaps not the kind of scale that enterprises will ultimately need, but as Kubernetes and Mesos scale, VMware will have to keep pace. “Most of the scalability testing that we can do is limited not by the software, but by the hardware that we have to run the tests,” says Zabala. (This is a common problem with open source projects.)
VMware has also automated the upgrade process for Photon Controller. With other types of management layers, such as the OpenStack cloud controller, upgrading is not a single affair and it can result in a lot of downtime. But Zabala says that a small Photon Controller setup can do a rolling upgrade across its control plane nodes in 30 seconds and a large one in a few minutes, which is not a lot of downtime. (It would be best to have no downtime at all, of course.)
In other tweaks, Photon Controller no longer requires a shared storage infrastructure (such as a SAN or NAS array) for replicating container images; you can point it at a more generic datastore and it will do replication. The management console now has integrated statistics charting using Graphite to help admins make sense of the telemetry culled from their container environments.
As the release number suggests, Photon Controller is getting closer to production, but is not quite there yet. But considering that work on Photon Platform did not start until early 2015, and VMware has not done open source development in the public view before, this is a pretty fast ramp.
“It is not prime time, and we do not feel comfortable telling people they can run production workloads on this until it is at a 1.0 release, which is the way with any open source project,” says Zabala. As for commercialization of the Photon Platform, VMware is waiting for the 1.0 release of the controller to be ready and then it is working on the strategy that will determine how it comes to market, what kind of support is going to be available, and what it will cost. Photon Machine has to be ready as well, since this is the virtualization layer that most companies will want to use rather than the full-on ESXi hypervisor that Photon Controller supports today.
VMware is working with beta customers to see what support they will require and what additional features need to be added before this can happen, but Zabala tells us that it is reasonable to expect for a commercial variant of Photon Controller to appear late in 2016. We would guess it would be rolled out at the VMworld extravaganza in late August and be available by October or November, and we would also guess that the Photon Platform stack will be considerably less expensive than an ESXi plus vSphere stack.
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