HPC in the Cloud?
Back in 2015, my long-time friend and scientific collaborator James (Jim) Freemantle suggested I give a talk to his local association of remote-sensing professionals. In hindsight, and much more importantly it would turn out for me, was his suggestion to juxtapose Cloud computing and High Performance Computing (HPC) in this talk. Although it’s still available via the Ontario Association of Remote Sensing (OARS) website here, the abstract for my talk High Performance Computing in the Cloud? read:
High Performance Computing (HPC) in the Cloud is viable in numerous applications. Common to all successful applications for cloud-based HPC is the ability to embrace latency. Early successes were achieved with embarrassingly parallel HPC applications involving minimal amounts of data – in other words, there was little or no latency to be hidden. More recently the HPC-cloud community has become increasingly adept in its ability to ‘hide’ latency and, in the process, support increasingly more sophisticated HPC applications in public and private clouds. In this presentation, real-world applications, deemed relevant to remote sensing, will illustrate aspects of these sophistications for hiding latency in accounting for large volumes of data, the need to pass messages between simultaneously executing components of distributed-memory parallel applications, as well as (processing) workflows/pipelines. Finally, the impact of containerizing HPC for the cloud will be considered through the relatively recent creation of the Cloud Native Computing Foundation.
As you can read for yourself from the abstract and slides, or hear in the Univa webinar that followed in February 2016, I placed a lot of emphasis on latency in juxtaposing the cloud and HPC; from the perspective of HPC workloads, an emphasis that remains justifiable today. Much later however, in working hands-on on various cloud projects for Univa, I’d appreciate the challenges and opportunities that data introduces; but more on that (data) another time …
Also in hindsight, I am pleased to see that I made this relatively early connection (for me, anyway) with the ‘modern’ notion of what it means to be cloud native. Unfortunately, this is a phrase bandied about with reckless abandon at times – usage that causes the phrase to become devoid of meaning. So, in part, in my OARS talk and the Univa webinar, I related cloud native as understood by the Cloud Native Computing Foundation:
Cloud native computing uses an open source software stack to deploy applications as microservices, packaging each part into its own container, and dynamically orchestrating those containers to optimize resource utilization.
If you even possess just a working knowledge of HPC at a high level, you’ll immediately appreciate that there’s the possibility for more than a little tension that’s likely to surface in realizing any vision of ‘cloud-native HPC’. Why? HPC applications have not traditionally been architected with microservices in mind; in fact, they employ the polar opposite of microservices in implementation. Therefore, the notion of taking existing HPC applications and simply executing them within a Docker container can present some challenges and opportunities – even though numerous examples of successfully containerized HPC applications do exist (see, for example, the impressive array of case studies over at UberCloud).
In some respects, when it comes to containerizing HPC applications, this is just the tip of the iceberg. In following up on the Univa webinar with a Q&A blog on HPC in the Cloud in February 2016, I quoted Univa CTO Fritz Ferstl in regard to a question on checkpointing Docker containers:
The mainstream of the container ecosystem views them as ephemeral – i.e., you can just kill them, restart them (whether on the same node or elsewhere), and then they somehow re-establish ‘service’ (i.e., what they are supposed to do … even though this isn’t an intrinsic capability of a Docker container).
Whereas ephemeral resonates soundly with microservices-based applications, this is hardly a ‘good fit’ for HPC applications. And because they share numerous characteristics with traditional HPC applications, emerging applications and workloads in AI, Deep Learning and Machine Learning suffer a similar fate: They aren’t always a good fit for traditional containers along the implementation lines of Docker. From nvidia-docker to the relatively recent and impressive integration between Univa Grid Engine and Docker, it’s blatantly evident that there are significant technical gymnastics required to leverage GPUs for applications that one seeks to execute within a Docker container. For years now for traditional HPC applications and workflows, and more recently for Deep Learning use cases, there is an implied requirement to tap into GPUs as computational resources.
A Singular Fit
For these and other reasons, Singularity has been developed, as a ‘vehicle’ for containerization that is simply a better fit for HPC and Deep Learning applications and their corresponding workflows. Because I have very recently joined the team at Sylabs, Inc. as a technical writer, you can expect to hear a whole lot more from me on containerization via Singularity – here, or even more frequently, over at the Sylabs blog and in Lab Notes.
Given that my acknowledged bias towards Distributed computing includes a significant dose of Cloud computing, I’m sure you can appreciate that it’s with so much more than a casual degree of enthusiasm that I regard my new opportunity with Sylabs – a startup that is literally defining how GOV/EDU as well as enterprise customers can sensibly and easily acquire the benefits of containerizing their applications and workflows on everything from isolated PCs (laptops and desktops) to servers, VMs and/or instances that exist in their datacenters and/or clouds.
From my ‘old’ friend/collaborator Jim to the team at Sylabs that I’ve just joined, and to everyone in between, it’s hard not to feel a sense of gratitude at this juncture. With HPC’s premiere event less than a month away in Dallas, I look forward to reconnecting with ‘my peeps’ at SC18, and ensuring they are aware of the exciting prospects Singularity brings to their organizations.