Infrastructure

Hardware

Greenhost fully owns and controls its hardware. This ensures independence from third parties and proper access control.

We buy High Performance Computing (HPC) hardware, meaning that our hardware has relatively high resources for the physical space it uses. Although this hardware has high energy usage in absolute terms, it has a low energy usage when compared to the performance. The small form factor also makes that less materials and minerals are required to build this hardware.

Most of our storage is built around SSD. SSD has higher access speeds and is more durable and more reliable than HDD. It is also far more energy efficient and therefore the more environmentally friendly option.

We have selected HP as preferred supplier for our hardware for the majority of our network. HP is well known to provide stable and fast products, and scores well with regards to a number of environmental aspects.

As for switching and routing we use Arista. The choices in this respect are limited, as there are only a few companies active in this market (Juniper, Cisco, Arista). Arista comes out as the preferred choice as it is relatively open with respect to the required software and has a low energy usage when compared to these other suppliers. At the end their lifespan as routers, we can reuse this hardware in other parts of our network.

We are critical towards all our suppliers, with regard to performance, stability and environmental impact, both in use and in production. We keep a close look on Greenpeace's "Guide to Greener Electronics" which reports on environmental impact of consumer hardware. We also ask our suppliers for information on their supply chain(s), although this information is not always disclosed by the suppliers. However, we believe that if we keep asking critical question, they will improve transparency, resulting in more sustainable hardware.

Software

In our software selection, open source stands out as the first choice. Proprietary software comes into view only if no open source alternative is available. The list of applications in use is long, but some of our favourites are Ceph, Xen, HAProxy and GitLab.

Greenhost also actively contributes in software developing. The Service Centre where customers can control and manage their Greenhost Services is developed in-house. This enables us to include technologies like Let’s Encrypt and offer these seamlessly in our hosting environment. Our open source projects are available on our GitLab. Our contributions to other open source projects can be found on GitHub.

Storage: Ceph

Our storage is centred around Ceph. Ceph is a unified, distributed storage system with good performance, reliability and scalability. Most alternatives still have controllers, indexes or monitors leading to weaknesses or single points of failure. As this is not the case with Ceph, this open source technology enables us to run a fully redundant storage platform. Our primary storage platform uses only SSDs, with a factor three redundancy.

Virtualisation: Xen

Greenhost started with virtualisation back in 2005 when the majority of other hosts was still running on bare-metal. Our virtualisation is built around Xen, which has enabled us to create a flexible and scalable platform. Xen is a well known, open and mature software product, providing paravirtualisation (PV) and hardware virtualisation (HVM) modes. However, we have decided to configure Xen using the relatively new paravirtualisation with assisted hardware virtualisation (PVH) mode. This mode has best of both worlds in terms of performance and security. All nodes are using (modern) Xeon CPUs to provide great CPU performance.

As we are using Xen in combination with Ceph, we do not rely on local storage. This way, we can provide a flexible and scalable platform while limiting points of failure.

Connectivity

Greenhost is RIPE and APNIC member. We own our IPv4 and IPv6 spaces and have full control over the use and routing of those address spaces. For connectivity we use multiple transit and peering providers, making our network so called 'multi homed'. This way no single third party can be a limiting factor. Our primary transit providers are FiberRing and IX-reach. The selection of those providers is based on their infrastructure and routes. In addition we are member of AMS-IX, one of the most important Internet Exchanges in the world. Here we are peering with a large set of peering partners to optimise routes and connectivity.

Transparency

We like to share our knowledge, and are eager to learn more. If you have any questions with regards to the setup of our platform, please feel free to ask them.. In order to protect our platform and its users we will not be able to disclose all details, but in general, our engineers are happy to answer your questions.