系统与数据库2017usenix.org
将退役移动设备用作廉价节能的计算节点
Decommissioned mobile devices as cheap energy-efficient compute nodes
入门 · 约 30 分钟读完前置知识：计算机体系结构基础、Linux 系统基础
导读
这篇 HotCloud'17 论文探讨了将退役手机作为廉价、低功耗的计算节点重新利用的可行性，例如搭建手机集群来承载云计算工作负载。作者认为旧手机算力不弱、能耗低且几乎零成本，是数据中心之外一种有潜力的低成本算力来源。
HN 关注点：如何用闲置硬件低成本搭建计算设施，讨论焦点集中在旧手机实际部署中的工程障碍：设备锁定、散热、ECC 内存缺失和硬件快速迭代带来的维护成本。
HN 评论精选
这几条评论里：质疑 2 补充 1 亲历 1
质疑实际满载运行会遇到散热、内核 bug、设备迭代和固件锁定等现实障碍
想法有意思，但实际做起来很快会遇到现实限制。我认识有人用开发板搭编译农场，发现 24x7 满载运行会触发正常使用中碰不到的内核 bug 或过热问题，手机估计也类似。手机迭代太快，要不断把新型号纳入集群（root、组网、定制机架等），而且淘汰更换的频率会比少量专为服务器设计的节点高得多。论文还建议在上面跑 hypervisor，但大多数手机的固件/启动 ROM 很可能会锁死 EL2（hypervisor 模式）。
pm215查看英文原文
Interesting idea, but I suspect if you tried it you'd quickly run into practical limitations. I know people who've tried running build farms with "development board" hardware have found that the stress of 24x7 100% compute hits kernel bugs or overheating issues that 'normal use' doesn't, and I suspect mobile phones would be similar. The pace of phone evolution means you'd have an ongoing effort to get new kinds of devices into your 'cluster' (figuring out how to root them, identifying how to network them, rigging up some kind of custom rack-mounting hardware, etc). And there'd be a bigger turnover of 'replace expired device' than with fewer newer designed-for-server nodes. The paper also suggests running a hypervisor on these, but I suspect you'd find that firmware/boot rom locks you out of EL2 (hypervisor mode) on most hardware.
亲历旧手机做用户控制的随身网关很有价值，自带电池供电是关键优势
我们公司正在做口袋大小的路由器/防火墙/DNS 服务器，放在手机和不可信的（如公共）WiFi 之间，充当用户控制的网关。用户只需在手机上改一次设置即可使用，可以在任何地方拦截广告和不需要的出站连接。设备运行用户自选的开源系统（从 Plan9 到 BSD 到 Linux），基带要么不存在要么被物理禁用。我认为利用旧手机的主要优势在于电源——市面上旅行路由器虽小，但一般不可充电。
feelin_googley查看英文原文
My company is working on pocket-sized routers/firewalls/DNS servers. These sit between the "smartphone" and the untrusted, e.g., public, wifi router, acting as a user-controlled gateway. The user makes a one-time change to the settings on their smartphone to use the user-controlled gateway. This enables blocking ads and other unwanted outgoing connections without having to be physically at home or work, i.e. in a location where the user can "trust" the network. The pocket-sized router runs open source software chosen and installed by the user. Users have a generous choice of operating systems, from Plan9 to BSD to Linux, as they do for the RPi. Baseband is either absent or physically disabled. The main advantage I see to leveraging old "phones" for this is the power supply. While I have seen small form factor routers made for travel, they are generally not rechargeable.
补充缺 ECC 内存是服务器场景的硬伤，但旧手机很适合家庭自托管服务
走这条路会碰到很多挑战，不过很高兴看到有人认真研究。文章没提的一点是移动设备没有 ECC 内存——做 IaaS 的话，Rowhammer 攻击的风险难道不是严重问题吗？我更希望看到面向家庭用户的类似方案：与其把一切推给第三方服务，不如在家用一堆设备跑自己的服务和应用，重拾分布式互联网的梦想。多数家庭服务不需要大功率或高可用性，最大的风险是数据备份，加密后推到云上即可解决。
TheAceOfHearts查看英文原文
It seems like you'd encounter so many challenges in taking this path, although I think it's awesome that people are seriously looking into this. One point that they article doesn't mention is that mobile devices don't have ECC RAM. I'm not very familiarized with the server space, but I thought that was pretty much a standard requirement? e.g. If you're providing IaaS, isn't the risk of falling prey to rowhammer attacks a serious concern? What I'd love to see is something similar but for home users. Instead of continuing to push stuff into third-party services, you can hook up a mix of devices to run services and applications from home. Bring back the distributed internet dream! Most home services don't need tons of power or high availability. The biggest risk is probably with handling data backups, which you can easily solve by encrypting assets and pushing em up to some cloud provider.
质疑设备锁定和驱动支持差，让旧手机难以运行标准 Linux
这类设备的问题在于通常被锁定，即使解锁或破解后，让它们跑接近主线版本的 Linux 也相当费劲。
josteink查看英文原文
The problem with these devices are that they are often locked down, and even unlocked/hacked open getting them to run anything like mainline Linux is hard-ish.
历次讨论
- 2017Hacker News 讨论帖160 分 · 72 评
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