Cloud provider ElasticHosts is utilising Linux containers for ‘true’ auto-scaling and consumption-based billing, claiming a 50 percent cost reduction over Amazon Web Services.
The ElasticContainer cloud service aims to increase billing accuracy for customers, offering per-MB CPU metering that can adjust quicker than the GB-size increments typically offered by cloud providers.
UK infrastructure as a service (Iaas) provider ElasticHosts says the improvements are down to building its new cloud service on container technology made available in the 3.8 update to the Linux, rather than relying on traditional hypervisor virtualisation.
“Containerisation technologies are inherently more flexible because you are allocating a partition that can shrink or grow depending on the size of the system. That means we can do usage-based billing to say how big the container is at a single point of time,” ElasticHosts CEO Richard Davies told ComputerworldUK.
Containerisation is an alternative virtualisation method that allows a user to partition off a portion of an underlying OS – in this case Linux – to assign to a workload, and can be expanded relatively easily to meet changes in demand. It differs from the creation of virtual machines using the traditional hypervisor-led approach, which creates a fix-sized ‘box’ of emulated hardware on which VMs can run.
According to Davies, the ‘block’-based hypervisor virtualisation which underpins major public deployments clouds is “crude and lacks precision” for metering.
For example, AWS might allow a customer to provision an 8GB server, and charge the user accordingly unless changed, even if the utilisation across the space of a week averages at around 4GB.
“In the traditional world of cloud you are using virtualisation, and the only thing that can be seen is that a fixed size block has been allocated, and therefore the only thing [suppliers such as AWS] can bill for is the whole of that block.”
Cloud pricing ‘lacks accuracy’
To address this, many large Iaas providers already offer the option of auto-scaling to meet changes in CPU demand, allowing customers to create ‘rules’ that adjust the size of virtual server without manual intervention.
However, even with current auto-scaling technologies, the method lacks the level of granularity afforded by Linux containers. This means additional capacity kicks in comparatively slowly, resulting in one of two scenarios: either with a cloud-hosted application slows down when CPU demand suddenly ramps up, or a customer pays over the odds as utilisation lags real-time demand.
Furthermore, while enterprises with large IT teams have the necessary staff and expertise to set up rules to govern scaling, smaller firms are less likely to have the resources to adopt this approach. This means that actual utilisation can be even lower for SMBs, with customers manually adjusting capacity on only a weekly or monthly basis.
ElasticHosts claims that the launch of its technology allows customers to access true usage-based billing, and can automatically scale so customers don’t need to spend time or resources on developing server provisioning ‘rules’.
The firm claims that, in a recent beta trial with 20 of its partners, its technology enabled customers to achieve up to 50 percent cost savings when compared to Amazon’s most recent compute prices, through improved accuracy.
ElasticHosts now plans to offer the service alongside its traditional hypervisor-based service, which remains vital for customers running Windows workloads.
According to Davies, whose company claims to have been the first Iaas provider to adopt the Linux KVM in 2008, the containerisation approach is likely to be used by other cloud providers in future in order to achieve better billing accuracy, and enable further price drops.
"We believe that this is an important development in the future of infrastructure clouds. We are going to continue selling both, and they will exist side by side,” he said.
“I imagine many of the other providers doing the same over time: selling both VMs and containers to customers who want either one."
Hypervisor and container public clouds
According to 451 Research senior analyst Owen Rogers, the ElasticContainers service allows ElasticHosts to differentiate from the large players in the increasingly crowded infrastructure cloud market.
"ElasticHosts’ model is interesting and it is quite unique,” he told ComputerworldUK. “Although cloud service are described as pay as you go, the reality is they are very much pay as you provision."
However, he questions the likelihood that other cloud providers will begin to reengineer their sizeable infrastructure in order to enable the usage-based billing afforded by Linux containers.
“The market is very much built on virtual machines, and I don’t think that ElasticHosts announcement will be a big enough catalyst to make all of the major cloud providers change their whole business model," he said.
“They won't feel they need to change unless they see a massive opportunity to differentiate, or if they see a significant threat to their business.”
He added that customers may become less focussed on gains made through detailed metering as the price drops and commoditisation of the cloud market continue.
"As the bigger cloud providers further cut prices, I wonder whether consumers are going to be as concerned with the getting super-accurate metering," he said.
“The cloud market still has a long way to go in terms of price cutting, and this is only really the tip of the iceberg.”