# Volunteer Down: How COVID-19 Created the Largest Idling Supercomputer on Earth
## 1 Introduction  
On 28 April 2020, [PERSON]--director of the volunteer computing (VC) project Folding@home--posted this on Twitter [[https://twitter.com/drGregBowman/status/1255142727760543744](https://twitter.com/drGregBowman/status/1255142727760543744)]([https://twitter.com/drGregBowman/status/1255142727760543744](https://twitter.com/drGregBowman/status/1255142727760543744)):  
_@Folding@home is continuing its growth spurt! There are now 3.5 M devices participating, including 2.8 M CPUs (19 M cores!) and 700 K GPUs._  
According to Figure 1, the volunteer computing project Folding@home had even access to more computing power than all TOP-500 supercomputers together could provide! Just two months earlier, only 30,000 devices contributed to this project. Thus, what caused this tremendous increase in processing power? It was COVID-19 and the willingness of hundreds of thousands of \"nerds\" to fight COVID-19 by supporting Sars-CoV-2 computational bioscience research that was processed by the Folding@home project. Our research is mainly dealing with cloud computing and corresponding software engineering and architecture questions. However, like many others, we surprisingly faced the COVID-19 shutdown impacts and decided on 23 March 2020 spontaneously to support Sars-CoV-2 computational bioscience-related research. Our lab set up two 32 CPU virtual machines from our virtualization cluster that is usually used for our cloud computing research and student projects. Moreover, we called our students for support, and our students boarded almost immediately providing their most valuable assets: Gaming graphic cards. On 1 May 2020, we ranked on place 2145 of 252,771 teams worldwide ([[https://stats.foldingathome.org/team/245623](https://stats.foldingathome.org/team/245623)]([https://stats.foldingathome.org/team/245623](https://stats.foldingathome.org/team/245623))). Thus, we weresuddenly among the top 1% of contributors as a very modest-sized University of Applied Sciences! Even the local newspaper reported about this. Furthermore, it is essential to mention that such kind of teams not only grew up in Lubeck, but this also happened all over the world. In total, the biggest supercomputer on earth emerged somehow by accident. We were impressed by our students and by these numbers. Nevertheless, we also looked at the usage statistics of our provided machines gathered by our virtualization cluster. However, these data were so-so (see Figure 2). Our machines, although being configured to run at full power, had only usage rates between 40% or 50%. In other words, we had assigned two machines, but, on average, only one was used. At the end of March, this was even more severe. In that phase, many teams and individual contributors boarded and the Folding@home network grew massively. However, the effect was that our machines ran at ridiculous low usage rates. We first checked whether we had misconfigured the machines, but our machines were operating correctly. The processing pipelines were empty, and the master nodes needed hardware upgrades to handle all these new processing nodes. The control plane of the Folding@home project could not scale-out fast enough. In cloud computing, we would say that Folding@home was not elastic enough. It took all of April to make full use of the provided volunteer resources (see Figure 2). Figure 1: Processing speed posted by Folding@home project, 13 April 2020, [[https://twitter.com/foldingathome/status/1249778379634675712](https://twitter.com/foldingathome/status/1249778379634675712)]([https://twitter.com/foldingathome/status/1249778379634675712](https://twitter.com/foldingathome/status/1249778379634675712)). Figure 2: Example usage data of two virtual machines provided to the Folding@home project (compiled from our own data); red area: overload of master nodes, white area: recovering phase, green area: normal operation. One obvious question arises here. Would it not be better in such a situation to use the amount of contributed nodes for other VC projects?