For some businesses, containers seem too new and thorny, while VMs seem too antiquated and slow. So now vendors are exploring a sweet spot between the two.
Joyent's Triton Elastic Container host uses SmartOS's (from Solaris) native containerization functions to run containers on bare metal instead of in VMs. It now allows Canonical Ubuntu Linux to run as a "container-native Linux image," says Joyent.
The big gain, according to Joyent, is that Ubuntu images can run inside Triton with the isolation normally associated with VMs, as well as a level of performance better associated with bare metal. (Canonical has also agreed to provide official Ubuntu images for Triton.)
Bare metal for everyone
Joyent is pitching this Triton-plus-Ubuntu mix at two primary sets of customers. First is people who run some variety of Linux (typically in a multitenant environment), but have held back on containerizing their workloads. The second: Existing Ubuntu users who run their workloads in VMs but are unenthused by the performance hit VMs typically impose.
The main customer, said Joyent CTO Bryan Cantrill in a phone call, is someone who is "partly Dockerized" -- that is, with some of their workloads already encapsulated in containers -- "and is interested in the benefits of containers, but doesn't want to go all the way with Docker for a variety of reasons." He cited databases like Postgres or MySQL as an example of applications that benefit from running as close to bare metal as possible.
In all cases, said Cantrill, the target customer is someone "who needs on-metal performance, but wants elasticity."
Making Ubuntu better
Cantrill also emphasized how Triton facilitates the use of the DTrace debugging tool in Ubuntu. DTrace, a powerful real-time debugging system, has thus far only shown up in Oracle's commercial Linux offering and has been difficult to fully integrate into Linux due to licensing issues.
Ubuntu has made a name for itself as a distribution commonly associated with cloud deployments by way of OpenStack. Its most recent edition added a hybrid container technology, LXD, intended to incorporate the most useful aspects of both containers and VMs -- a technology that provides some of the same benefits as Triton.
Triton doesn't (yet) leverage LXD directly, but Cantrill admitted that Joyent is "very interested in what Canonical has done with LXD." He saw "a lot of potential for LXD on the Triton stack," although he refrained from making a specific feature support announcement at this time.