mirror of
https://github.com/LCTT/TranslateProject.git
synced 2025-03-21 02:10:11 +08:00
Merge remote-tracking branch 'LCTT/master'
This commit is contained in:
Xingyu Wang
commit
ff2fa5faad
@ -0,0 +1,155 @@
|
||||
[#]: collector: (lujun9972)
|
||||
[#]: translator: (Yufei-Yan)
|
||||
[#]: reviewer: (wxy)
|
||||
[#]: publisher: (wxy)
|
||||
[#]: url: (https://linux.cn/article-12411-1.html)
|
||||
[#]: subject: (What is IoT? The internet of things explained)
|
||||
[#]: via: (https://www.networkworld.com/article/3207535/what-is-iot-the-internet-of-things-explained.html)
|
||||
[#]: author: (Josh Fruhlinger https://www.networkworld.com/author/Josh-Fruhlinger/)
|
||||
|
||||
物联网（IoT）简介
|
||||
======
|
||||
|
||||
> 物联网（IoT）是一个由智能设备连接起来的网络，并提供了丰富的数据，但是它也有可能是一场安全领域的噩梦。
|
||||
|
||||
|
||||
|
||||
<ruby>物联网<rt>Internet of Things</rt></ruby>（IoT）是一个统称，指的是越来越多不属于传统计算设备，但却连接到互联网接收或发送数据，或既接收也发送的电子设备组成的网络。
|
||||
|
||||
现在有数不胜数的东西可以归为这一类：可以联网的“智能”版传统设备，比如说电冰箱和灯泡；那些只能运行于有互联网环境的小设备，比如像 Alexa 之类的电子助手；与互联网连接的传感器，它们正在改变着工厂、医疗、运输、物流中心和农场。
|
||||
|
||||
### 什么是物联网？
|
||||
|
||||
物联网将互联网、数据处理和分析的能力带给了现实的实物世界。对于消费者来说，这就意味着不需要键盘和显示器这些东西，就能和这个全球信息网络进行互动；他们的日常用品当中，很多都可以通过该网络接受操作指令，而只需很少的人工干预。
|
||||
|
||||
互联网长期以来为知识工作提供了便利，在企业环境当中，物联网也能为制造和分销带来同样的效率。全球数以百万计甚至数十亿计的嵌入式具有互联网功能的传感器正在提供令人难以置信丰富的数据集，企业可以利用这些数据来保证他们运营的安全、跟踪资产和减少人工流程。研究人员也可以使用物联网来获取人们的喜好和行为数据，尽管这些行为可能会严重影响隐私和安全。
|
||||
|
||||
### 它有多大？
|
||||
|
||||
一句话：非常庞大。[Priceonomics 对此进行了分析][2]：在 2020 年的时候，有超过 50 亿的物联网设备，这些设备可以生成 4.4 <ruby>泽字节<rt>zettabyte</rt></ruby>（LCTT 译注：1 zettabyte = 10<sup>9</sup> terabyte = 10<sup>12</sup> gigabyte）的数据。相比较，物联网设备在 2013 年仅仅产生了 1000 亿<ruby>千兆字节<rt>gigabyte</rt></ruby>的数据。在物联网市场上可能挣到的钱也同样让人瞠目；到 2025 年，这块市场的价值可以达到 1.6 万亿美元到 14.4 万亿美元不等。
|
||||
|
||||
### 物联网的历史
|
||||
|
||||
一个联网设备和传感器无处不在的世界，是科幻小说中最经典的景象之一。物联网传说中将 1970 年 [卡耐基•梅隆大学的一台连接到 APRANET 的自动贩卖机][3] 称之为世界上第一个物联网设备，而且许多技术都被吹捧为可以实现 “智能” 的物联网式特征，使其颇具有未来主义的光彩。但是“物联网”这个词是由英国的技术专家 [Kevin Ashton][4] 于 1999 年提出来的。
|
||||
|
||||
一开始，技术是滞后于当时对未来的憧憬的。每个与互联网相连的设备都需要一个处理器和一种能和其他东西通信的方式，无线的最好，这些因素都增加了物联网大规模实际应用的成本和性能要求，这种情况至少一直持续到 21 世纪头十年中期，直到摩尔定律赶上来。
|
||||
|
||||
一个重要的里程碑是 [RFID 标签的大规模使用][5]，这种价格低廉的极简转发器可以被贴在任何物品上，然后这些物品就可以连接到更大的互联网上了。对于设计者来说，无处不在的 Wi-Fi 和 4G 让任何地方的无线连接都变得非常简单。而且，IPv6 的出现再也不用让人们担心把数十亿小设备连接到互联网上会将 IP 地址耗尽。（相关报道：[物联网网络可以促进 IPv6 的使用吗？][6]）
|
||||
|
||||
### 物联网是如何工作的？
|
||||
|
||||
物联网的基本元素是收集数据的设备。广义地说，它们是和互联网相连的设备，所以每一个设备都有 IP 地址。它们的复杂程度不一，这些设备涵盖了从工厂运输货物的自动驾驶车辆到监控建筑温度的简单传感器。这其中也包括每天统计步数的个人手环。为了让这些数据变得有意义，就需要对其收集、处理、过滤和分析，每一种数据都可以通过多种方式进行处理。
|
||||
|
||||
采集数据的方式是将数据从设备上传输到采集点。可以通过各种无线或者有线网络进行数据的转移。数据可以通过互联网发送到具有存储空间或者计算能力的数据中心或者云端，或者这些数据也可以分段进行传输，由中间设备汇总数据后再沿路径发送。
|
||||
|
||||
处理数据可以在数据中心或者云端进行，但是有时候这不太可行。对于一些非常重要的设备，比如说工业领域的关停设备，从设备上将数据发送到远程数据中心的延迟太大了。发送、处理、分析数据和返回指令（在管道爆炸之前关闭阀门）这些操作，来回一趟的时间可能要花费非常多的时间。在这种情况下，<ruby>边缘计算<rt>edge-computing</rt></ruby>就可以大显身手了，智能边缘设备可以汇总数据、分析数据，在需要的时候进行回应，所有这些都在相对较近的物理距离内进行，从而减少延迟。边缘设备可以有上游连接，这样数据就可以进一步被处理和储存。
|
||||
|
||||
![][7]
|
||||
|
||||
*物联网是如何工作的。*
|
||||
|
||||
### 物联网设备的一些例子
|
||||
|
||||
本质上，任何可以搜集来自于真实世界数据，并且可以发送回去的设备都可以参与到物联网生态系统中。典型的例子包括智能家居设备、射频识别标签（RFID）和工业传感器。这些传感器可以监控一系列的因素，包括工业系统中的温度和压力、机器中关键设备的状态、患者身上与生命体征相关的信号、水电的使用情况，以及其它许许多多可能的东西。
|
||||
|
||||
整个工厂的机器人可以被认为是物联网设备，在工业环境和仓库中移动产品的自主车辆也是如此。
|
||||
|
||||
其他的例子包括可穿戴设备和家庭安防系统。还有一些其它更基础的设备，比如说[树莓派][8]和[Arduino][9]，这些设备可以让你构建你自己的物联网终端节点。尽管你可能会认为你的智能手机是一台袖珍电脑，但它很可能也会以非常类似物联网的方式将你的位置和行为数据传送到后端服务。
|
||||
|
||||
#### 设备管理
|
||||
|
||||
为了能让这些设备一起工作，所有这些设备都需要进行验证、分配、配置和监控，并且在必要时进行修复和更新。很多时候，这些操作都会在一个单一的设备供应商的专有系统中进行；要么就完全不会进行这些操作，而这样也是最有风险的。但是整个业界正在向[标准化的设备管理模式][10]过渡，这使得物联网设备之间可以相互操作，并保证设备不会被孤立。
|
||||
|
||||
#### 物联网通信标准和协议
|
||||
|
||||
当物联网上的小设备和其他设备通信的时候，它们可以使用各种通信标准和协议，这其中许多都是为这些处理能力有限和电源功率不大的设备专门定制的。你一定听说过其中的一些，尽管有一些设备使用的是 Wi-Fi 或者蓝牙，但是更多的设备是使用了专门为物联网世界定制的标准。比如，ZigBee 就是一个低功耗、远距离传输的无线通信协议，而 MQTT（<ruby>消息队列遥测传输<rt>Message Queuing Telemetry Transport</rt></ruby>）是为连接在不可靠或者易发生延迟的网络上的设备定制的一个发布/订阅信息协议。（参考 Network World 的词汇表：[物联网标准和协议](11)。）
|
||||
|
||||
物联网也会受益于 5G 为蜂窝网络带来的高速度和高带宽，尽管这种使用场景会[滞后于普通的手机][12]。
|
||||
|
||||
### 物联网、边缘计算和云
|
||||
|
||||
![][13]
|
||||
|
||||
*边缘计算如何使物联网成为可能。*
|
||||
|
||||
对于许多物联网系统来说，大量的数据会以极快的速度涌来，这种情况催生了一个新的科技领域，<ruby>[边缘计算][14]<rt>edge computing</rt></ruby>，它由放置在物联网设备附近的设备组成，处理来自那些设备的数据。这些机器对这些数据进行处理，只将相关的素材数据发送到一个更集中的系统系统进行分析。比如，想象一个由几十个物联网安防摄像头组成的网络，边缘计算会直接分析传入的视频，而且只有当其中一个摄像头检测到有物体移动的时候才向安全操作中心（SoC）发出警报，而不会是一下子将所有的在线数据流全部发送到建筑物的 SoC。
|
||||
|
||||
一旦这些数据已经被处理过了，它们又去哪里了呢？好吧，它也许会被送到你的数据中心，但是更多情况下，它最终会进入云。
|
||||
|
||||
对于物联网这种间歇或者不同步的数据来往场景来说，具有弹性的云计算是再适合不过的了。许多云计算巨头，包括[谷歌][15]、[微软][16]和[亚马逊][17]，都有物联网产品。
|
||||
|
||||
### 物联网平台
|
||||
|
||||
云计算巨头们正在尝试出售的，不仅仅是存放传感器搜集的数据的地方。他们正在提供一个可以协调物联网系统中各种元素的完整平台，平台会将很多功能捆绑在一起。本质上，物联网平台作为中间件，将物联网设备和边缘网关与你用来处理物联网数据的应用程序连接起来。也就是说，每一个平台的厂商看上去都会对物联网平台应该是什么这个问题有一些稍微不同的解释，以更好地[与其他竞争者拉开差距][18]。
|
||||
|
||||
### 物联网和数据
|
||||
|
||||
正如前面所提到的，所有这些物联网设备收集了 ZB 级的数据，这些数据通过边缘网关被发送到平台上进行处理。在很多情况下，这些数据就是要部署物联网的首要原因。通过从现实世界中的传感器搜集来的数据，企业就可以实时的作出灵活的决定。
|
||||
|
||||
例如，Oracle 公司[假想了一个这样的场景][19]，当人们在主题公园的时候，会被鼓励下载一个可以提供公园信息的应用。同时，这个程序会将 GPS 信号发回到公园的管理部门来帮助他们预测排队时间。有了这些信息，公园就可以在短期内（比如通过增加员工数量来提升景点的一些容量）和长期内（通过了解哪些设施最受欢迎，那些最不受欢迎）采取行动。
|
||||
|
||||
这些决定可以在没有人工干预的情况作出。比如，从化工厂管道中的压力传感器收集的数据可以通过边缘设备的软件进行分析，从而发现管道破裂的威胁，这样的信息可以触发关闭阀门的信号，从而避免泄漏。
|
||||
|
||||
### 物联网和大数据分析
|
||||
|
||||
主题公园的例子可以让你很容易理解，但是和许多现实世界中物联网收集数据的操作相比，就显得小菜一碟了。许多大数据业务都会使用到来自物联网设备收集的信息，然后与其他数据关联，这样就可以分析预测到人类的行为。Software Advice 给出了[一些例子][20]，其中包括由 Birst 提供的一项服务，该服务将从联网的咖啡机中收集的咖啡冲泡的信息与社交媒体上发布的帖子进行匹配，看看顾客是否在网上谈论咖啡品牌。
|
||||
|
||||
另一个最近才发生的戏剧性的例子，X-Mode 发布了一张基于位置追踪数据的地图，地图上显示了在 2020 年 3 月春假的时候，正当新冠病毒在美国加速传播的时候，人们在<ruby>劳德代尔堡<rt>Ft. Lauderdale</rt></ruby>聚会完[最终都去了哪里][21]。这张地图令人震撼，不仅仅是因为它显示出病毒可能的扩散方向，更是因为它说明了物联网设备是可以多么密切地追踪我们。（更多关于物联网和分析的信息，请点击[此处][22]。）
|
||||
|
||||
### 物联网数据和 AI
|
||||
|
||||
物联网设备能够收集的数据量远远大于任何人类能够以有效的方式处理的数据量，而且这肯定也不是能实时处理的。我们已经看到，仅仅为了理解从物联网终端传来的原始数据，就需要边缘计算设备。此外，还需要检测和处理可能就是[完全错误的数据][23]。
|
||||
|
||||
许多物联网供应商也同时提供机器学习和人工智能的功能，可以用来理解收集来的数据。比如，IBM 的 Jeopardy!-winning Watson 平台就可以在[物联网数据集上进行训练][24]，这样就可以在预测性维护领域产生有用的结果 —— 比如说，分析来自无人机的数据，可以区分桥梁上轻微的损坏和需要重视的裂缝。同时，ARM 也在研发[低功耗芯片][25]，它可以在物联网终端上提供 AI 的能力。
|
||||
|
||||
### 物联网和商业
|
||||
|
||||
物联网的商业用途包括跟踪客户、库存和重要部件的状态。[IoT for All][26] 列举了四个已经被物联网改变的行业：
|
||||
|
||||
* **石油和天然气**：与人工干预相比，物联网传感器可以更好的检测孤立的钻井现场。
|
||||
* **农业**：通过物联网传感器获得的田间作物的数据，可以用来提高产量。
|
||||
* **采暖通风**：制造商可以监控全国各地的气候控制系统。
|
||||
* **实体零售**：当顾客在商店的某些地方停留的时候，可以通过手机进行微目标定位，提供优惠信息。
|
||||
|
||||
更普遍的情况是，企业正在寻找能够在[四个领域][27]上获得帮助的物联网解决方案：能源使用、资产跟踪、安全领域和客户体验。
|
||||
|
||||
--------------------------------------------------------------------------------
|
||||
|
||||
via: https://www.networkworld.com/article/3207535/what-is-iot-the-internet-of-things-explained.html
|
||||
|
||||
作者：[Josh Fruhlinger][a]
|
||||
选题：[lujun9972][b]
|
||||
译者：[Yufei-Yan](https://github.com/Yufei-Yan)
|
||||
校对：[wxy](https://github.com/wxy)
|
||||
|
||||
本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出
|
||||
|
||||
[a]: https://www.networkworld.com/author/Josh-Fruhlinger/
|
||||
[b]: https://github.com/lujun9972
|
||||
[1]: https://www.networkworld.com/category/internet-of-things/
|
||||
[2]: https://priceonomics.com/the-iot-data-explosion-how-big-is-the-iot-data/
|
||||
[3]: https://www.machinedesign.com/automation-iiot/article/21836968/iot-started-with-a-vending-machine
|
||||
[4]: https://www.visioncritical.com/blog/kevin-ashton-internet-of-things
|
||||
[5]: https://www.networkworld.com/article/2319384/rfid-readers-route-tag-traffic.html
|
||||
[6]: https://www.networkworld.com/article/3338106/can-iot-networking-drive-adoption-of-ipv6.html
|
||||
[7]: https://images.idgesg.net/images/article/2020/05/nw_how_iot_works_diagram-100840757-orig.jpg
|
||||
[8]: https://www.networkworld.com/article/3176091/10-killer-raspberry-pi-projects-collection-1.html
|
||||
[9]: https://www.networkworld.com/article/3075360/arduino-targets-the-internet-of-things-with-primo-board.html
|
||||
[10]: https://www.networkworld.com/article/3258812/the-future-of-iot-device-management.html
|
||||
[11]: https://www.networkworld.com/article/3235124/internet-of-things-definitions-a-handy-guide-to-essential-iot-terms.html
|
||||
[12]: https://www.networkworld.com/article/3291778/what-s-so-special-about-5g-and-iot.html
|
||||
[13]: https://images.idgesg.net/images/article/2017/09/nw_how_edge_computing_works_diagram_1400x1717-100736111-orig.jpg
|
||||
[14]: https://www.networkworld.com/article/3224893/what-is-edge-computing-and-how-it-s-changing-the-network.html
|
||||
[15]: https://cloud.google.com/solutions/iot
|
||||
[16]: https://azure.microsoft.com/en-us/overview/iot/
|
||||
[17]: https://aws.amazon.com/iot/
|
||||
[18]: https://www.networkworld.com/article/3336166/why-are-iot-platforms-so-darn-confusing.html
|
||||
[19]: https://blogs.oracle.com/bigdata/how-big-data-powers-the-internet-of-things
|
||||
[20]: https://www.softwareadvice.com/resources/iot-data-analytics-use-cases/
|
||||
[21]: https://www.cnn.com/2020/04/04/tech/location-tracking-florida-coronavirus/index.html
|
||||
[22]: https://www.networkworld.com/article/3311919/iot-analytics-guide-what-to-expect-from-internet-of-things-data.html
|
||||
[23]: https://www.networkworld.com/article/3396230/when-iot-systems-fail-the-risk-of-having-bad-iot-data.html
|
||||
[24]: https://www.networkworld.com/article/3449243/watson-iot-chief-ai-can-broaden-iot-services.html
|
||||
[25]: https://www.networkworld.com/article/3532094/ai-everywhere-iot-chips-coming-from-arm.html
|
||||
[26]: https://www.iotforall.com/4-unlikely-industries-iot-changing/
|
||||
[27]: https://www.networkworld.com/article/3396128/the-state-of-enterprise-iot-companies-want-solutions-for-these-4-areas.html
|
||||
@ -1,120 +0,0 @@
|
||||
[#]: collector: (lujun9972)
|
||||
[#]: translator: (geekpi)
|
||||
[#]: reviewer: ( )
|
||||
[#]: publisher: ( )
|
||||
[#]: url: ( )
|
||||
[#]: subject: (Docker and Fedora 32)
|
||||
[#]: via: (https://fedoramagazine.org/docker-and-fedora-32/)
|
||||
[#]: author: (Kevin "Eonfge" Degeling https://fedoramagazine.org/author/eonfge/)
|
||||
|
||||
Docker and Fedora 32
|
||||
======
|
||||
|
||||
![][1]
|
||||
|
||||
With the release of Fedora 32, regular users of [Docker][2] have been confronted by a small challenge. At the time of writing, Docker is not supported on Fedora 32. There are alternatives, like [Podman][3] and [Buildah][4], but for many existing users, switching now might not be the best time. As such, this article can help you set up your Docker environment on Fedora 32.
|
||||
|
||||
### Step 0: Removing conflicts
|
||||
|
||||
This step is for any user upgrading from Fedora 30 or 31. If this is a fresh installation of Fedora 32, you can move on to step 1.
|
||||
|
||||
To remove docker and all its related components:
|
||||
|
||||
```
|
||||
sudo dnf remove docker-*
|
||||
sudo dnf config-manager --disable docker-*
|
||||
```
|
||||
|
||||
### Step 1: System preparation
|
||||
|
||||
With the last two versions of Fedora, the operating system has moved to two new technologies: CGroups and NFTables for the Firewall. While the details of these new technologies is behind the scope of this tutorial, it’s a sad fact that docker doesn’t support them yet. As such, you’ll have to make some changes to facilitate Docker on Fedora.
|
||||
|
||||
#### Enable old CGroups
|
||||
|
||||
The previous implementation of CGroups is still supported and it can be enabled using the following command.
|
||||
|
||||
```
|
||||
sudo grubby --update-kernel=ALL --args="systemd.unified_cgroup_hierarchy=0"
|
||||
```
|
||||
|
||||
#### Whitelist docker in firewall
|
||||
|
||||
To allow Docker to have network access, two commands are needed.
|
||||
|
||||
```
|
||||
sudo firewall-cmd --permanent --zone=trusted --add-interface=docker0
|
||||
sudo firewall-cmd --permanent --zone=FedoraWorkstation --add-masquerade
|
||||
```
|
||||
|
||||
The first command will add the Docker-interface to the trusted environment which allows Docker to make remote connections. The second command will allow docker to make local connections. This is particularly useful when multiple Docker containers are in as a development environment.
|
||||
|
||||
### Step 2: installing Moby
|
||||
|
||||
[Moby][5] is the open-source, white label version of Docker. It’s based on the same code but it does not carry the trademark. It’s included in the main Fedora repository, which makes it easy to install.
|
||||
|
||||
```
|
||||
sudo dnf install moby-engine docker-compose
|
||||
```
|
||||
|
||||
This installs _moby-engine_, _docker-compose_, _containerd_ and some other related libraries. Once installed, you’ll have to enable the system-wide daemon to run docker.
|
||||
|
||||
```
|
||||
sudo systemctl enable docker
|
||||
```
|
||||
|
||||
### Step 3: Restart and test
|
||||
|
||||
To ensure that all systems and settings are properly processed, you’ll now have to reboot your machine.
|
||||
|
||||
```
|
||||
sudo systemctl reboot
|
||||
```
|
||||
|
||||
After that, you can validate your installation using the Docker hello-world package.
|
||||
|
||||
```
|
||||
sudo docker run hello-world
|
||||
```
|
||||
|
||||
You are then greeted by the Hello from Docker! unless something went wrong.
|
||||
|
||||
#### Running as admin
|
||||
|
||||
Optionally, you can now also add your user to the group account of Docker, so that you can start docker images without typing _sudo_.
|
||||
|
||||
```
|
||||
sudo groupadd docker
|
||||
sudo usermod -aG docker $USER
|
||||
```
|
||||
|
||||
Logout and login for the change to take effect. If the thought of running containers with administrator privileges concerns you, then you should look into Podman.
|
||||
|
||||
### In summary
|
||||
|
||||
From this point on, Docker will work how you’re used to, including docker-compose and all docker-related tools. Don’t forget to check out the official documentation which can help you in many cases where something isn’t quite right.
|
||||
|
||||
The current state of Docker on Fedora 32 is not ideal. The lack of an official package might bother some, and there is an [issue upstream][6] where this is discussed. The missing support for both [CGroups][7] and [NFTables][8] is more technical, but you can check their progress in their public issues.
|
||||
|
||||
These instruction should allow you to continue working like nothing has happened. If this has not satisfied your needs, don’t forget to address your technical issues at the Moby or Docker Github pages, or take a look at Podman which might prove more robust in the long-term future.
|
||||
|
||||
--------------------------------------------------------------------------------
|
||||
|
||||
via: https://fedoramagazine.org/docker-and-fedora-32/
|
||||
|
||||
作者：[Kevin "Eonfge" Degeling][a]
|
||||
选题：[lujun9972][b]
|
||||
译者：[译者ID](https://github.com/译者ID)
|
||||
校对：[校对者ID](https://github.com/校对者ID)
|
||||
|
||||
本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出
|
||||
|
||||
[a]: https://fedoramagazine.org/author/eonfge/
|
||||
[b]: https://github.com/lujun9972
|
||||
[1]: https://fedoramagazine.org/wp-content/uploads/2020/06/f32-04-twilight-816x459.png
|
||||
[2]: https://docs.docker.com/
|
||||
[3]: https://podman.io/getting-started/
|
||||
[4]: https://buildah.io/
|
||||
[5]: https://mobyproject.org/
|
||||
[6]: https://github.com/docker/for-linux/issues/955
|
||||
[7]: https://github.com/moby/moby/issues/40360
|
||||
[8]: https://github.com/moby/moby/issues/26824
|
||||
@ -1,5 +1,5 @@
|
||||
[#]: collector: (lujun9972)
|
||||
[#]: translator: ( )
|
||||
[#]: translator: (nophDog)
|
||||
[#]: reviewer: ( )
|
||||
[#]: publisher: ( )
|
||||
[#]: url: ( )
|
||||
|
||||
@ -1,5 +1,5 @@
|
||||
[#]: collector: (lujun9972)
|
||||
[#]: translator: ( )
|
||||
[#]: translator: (geekpi)
|
||||
[#]: reviewer: ( )
|
||||
[#]: publisher: ( )
|
||||
[#]: url: ( )
|
||||
|
||||
@ -0,0 +1,133 @@
|
||||
[#]: collector: (lujun9972)
|
||||
[#]: translator: ( )
|
||||
[#]: reviewer: ( )
|
||||
[#]: publisher: ( )
|
||||
[#]: url: ( )
|
||||
[#]: subject: (Recovering audio from a lost format with open source)
|
||||
[#]: via: (https://opensource.com/article/20/7/hdcd)
|
||||
[#]: author: (Chris Hermansen https://opensource.com/users/clhermansen)
|
||||
|
||||
Recovering audio from a lost format with open source
|
||||
======
|
||||
The history of HDCD format and how I recovered lost audio on Linux.
|
||||
![11 CDs in a U shape][1]
|
||||
|
||||
Back in the early 2000s, we made a family decision to upgrade the living room stereo. The equipment in place at the time was based on a collection of gear that I had purchased some 20 years earlier when I first had a steady post-university income. That early collection could best be described as "industrial chic," most notably the [Hafler amplifiers][2] I had built from kits and the [Polk speakers][3] made from some kind of composite wood product and finished with an ugly faux-rosewood vinyl wrap. They produced decent sound, but the dorm-room-style decor just wasn't working out in the living room.
|
||||
|
||||
Those of you who remember the early 2000s will recall that most of the world was still consuming music on CD. Our family was no exception, and we ended up with a fine CD player that had an interesting feature—it was able to decode regular CDs as well as high-definition-compatible digital (HDCD) discs.
|
||||
|
||||
According to [Wikipedia][4], HDCD is a proprietary audio encode-decode process that claims to provide increased dynamic range over that of standard Red Book audio CDs, while retaining backward compatibility with existing compact disc players.
|
||||
|
||||
The [manual for our CD player][5] states: "HDCD system is manufactured under license from Pacific Microsonics, Inc." and "HDCD is a digital signal processing system developed by Pacific Microsonics of California which conceals control codes into a very small fraction of the recorded CD digital audio stream. An HDCD decoder recognizes these control codes and uses them to process the digital audio to increase its dynamic range and resolution, while leaving the original digital stream compatible with conventional CD players."
|
||||
|
||||
How does HDCD work this magic, you may ask? The same Wikipedia entry states, "HDCD encodes the equivalent of 20 bits worth of data in a 16-bit digital audio signal by using custom dithering, audio filters, and some reversible amplitude and gain encoding; Peak Extend, which is a reversible soft limiter; and Low-Level Range Extend, which is a reversible gain on low-level signals."
|
||||
|
||||
Whatever the merits of this technology, its parent company was unable to continue business and ceased operations sometime in 2000. The Wikipedia article indicates that Microsoft acquired the company and incorporated code in Windows Media Player to allow the decoding of HDCD, but seemingly lost interest in its promotion. Perhaps this was due to the emergence of other proprietary high-resolution audio formats such as SACD and DVD-A, which were able to encode a full 24 bits of signal on a similar-looking but incompatible media. Neither of these latter formats was especially successful, at least not in commercial terms, though studios continue to release music on SACD. As it happens, SACD included a "hybrid" standard that provided both SACD and backward-compatible CD layers on the same disc, allowing the playback of those albums on regular CD players at standard CD resolution.
|
||||
|
||||
How many artists and studios actually made use of HDCD? Well, Discogs offers [a list of 11,284 HDCD recordings][6] (as of this writing). [This web site][7] offers an interesting analysis of some of the facilities HDCD provided, using actual HDCD encoded music. And for those interested in the original patent, which Google Patents claims has expired, [it can be found here][8].
|
||||
|
||||
### My HDCD story
|
||||
|
||||
Anyone who is interested enough in audio equipment to read promotional brochures or audiophile magazines will recognize the fascination many audiophiles have with proprietary designs—they seem to view a patent as validation of the equipment that uses that technology.
|
||||
|
||||
Though now I do what I can to avoid being swayed by "proprietary technology fascination," I admit I was not such a staunch proponent of all things open back in the early 2000s. Not only did I buy the aforementioned fine CD player with its proprietary innards, but I also bought—the horror!—a few actual HDCD-encoded titles.
|
||||
|
||||
This past weekend, I managed to find three of them in our collection, but I am certain there are more. The three I managed to find include Ensemble Dumont's [La Messe du Roi][9], Musica Secreta's [Dangerous Graces][10], and the Orchestra of the Age of Enlightenment's [Vivaldi Concerti][11], all from the Linn Records Linux-friendly [music store][12]. While making sure these titles were still available, I noticed that they are no longer offered in HDCD.
|
||||
|
||||
Given that I have these albums on hand and that the patent seems to have expired, I decided to find out whether I could convert these discs in their full intended resolution to an open music format, and moreover, whether I could do so without using proprietary software.
|
||||
|
||||
The first software I stumbled upon for decoding HDCD format was hdcd.exe., [described and offered here][13]. Since the source code for this software was not offered, and since it required Windows, or at least Wine, to run, my initial interest mostly evaporated.
|
||||
|
||||
The Wikipedia article noted above mentioned that some other Windows-based music players offered HDCD decoding. Hmm. But then I spotted:
|
||||
|
||||
"FFmpeg's libavfilter includes an HDCD filter as of FFmpeg 3.1 (June 2016) that will convert 16-bit PCM with HDCD data to 20-bit PCM."
|
||||
|
||||
This seemed like a promising starting point, so I installed `ffmpeg` from my distro's repositories, and then went looking for some more hints, at which point I stumbled on [the very concise description on hydrogenaudio][14], which even supplies a script for finding HDCD-encoded files in one's music directory. I used the line that runs `ffmpeg` against one of the files ripped from the Musica Secreta CD mentioned previously, as follows:
|
||||
|
||||
|
||||
```
|
||||
ffmpeg -hide_banner -nostats -y -v verbose -i \
|
||||
'01 - Musica Secreta - Questi odorati fiori.flac'
|
||||
-vn -af hdcd -f s24le /dev/null 2>&1 | grep "_hdcd_"
|
||||
```
|
||||
|
||||
and received the following output:
|
||||
|
||||
|
||||
```
|
||||
[Parsed_hdcd_0 @ 0x55b2137e2c80] Disabling automatic format conversion.
|
||||
[Parsed_hdcd_0 @ 0x55b2137e2c80] Auto-convert: disabled
|
||||
[Parsed_hdcd_0 @ 0x55b2137e2c80] Looking for 16-bit HDCD in sample format s16
|
||||
[Parsed_hdcd_0 @ 0x55b2137e2c80] CDT period: 2000ms (88200 samples @44100Hz)
|
||||
[Parsed_hdcd_0 @ 0x55b2137e2c80] Process mode: process stereo channels together
|
||||
[Parsed_hdcd_0 @ 0x55b2137e2c80] Force PE: off
|
||||
[Parsed_hdcd_0 @ 0x55b2137e2c80] Analyze mode: [0] disabled
|
||||
[Parsed_hdcd_0 @ 0x55b2137e2c80] Channel 0: counter A: 0, B: 1657, C: 1657
|
||||
[Parsed_hdcd_0 @ 0x55b2137e2c80] Channel 0: pe: 1657, tf: 0, almost_A: 0, checkfail_B: 0, unmatched_C: 0, cdt_expired: 0
|
||||
[Parsed_hdcd_0 @ 0x55b2137e2c80] Channel 0: tg 0.0: 1657
|
||||
[Parsed_hdcd_0 @ 0x55b2137e2c80] Channel 1: counter A: 0, B: 1657, C: 1657
|
||||
[Parsed_hdcd_0 @ 0x55b2137e2c80] Channel 1: pe: 1657, tf: 0, almost_A: 0, checkfail_B: 0, unmatched_C: 0, cdt_expired: 0
|
||||
[Parsed_hdcd_0 @ 0x55b2137e2c80] Channel 1: tg 0.0: 1657
|
||||
[Parsed_hdcd_0 @ 0x55b2137e2c80] Packets: type: B, total: 3314
|
||||
[Parsed_hdcd_0 @ 0x55b2137e2c80] HDCD detected: yes, peak_extend: enabled permanently, max_gain_adj: 0.0 dB, transient_filter: not detected, detectable errors: 0
|
||||
```
|
||||
|
||||
Note the last line above mentioning that HDCD was, in fact, detected. Also, it seems that the "peak extend" capability is enabled. As I understand this capability, it reverses the compression/limiting applied to the loudest parts of the music after dropping the overall signal level by a factor of two, thus restoring some of the original recording's extra dynamic range. Goodwin's High End's web site has a detailed description of this topic [here][15].
|
||||
|
||||
At this point, it was time to try this whole thing out. For some reason, I did not feel confident doing a one-step conversion from 16-bit undecoded FLAC to 24-bit decoded FLAC, so I ran the conversion in two steps, as follows:
|
||||
|
||||
|
||||
```
|
||||
for f16 in *.flac; do
|
||||
trk=`basename "$f16" .flac`
|
||||
w24="$trk"_24.wav
|
||||
ffmpeg -i "$f16" -af hdcd -acodec pcm_s24le "$w24"
|
||||
flac "$w24"
|
||||
done
|
||||
```
|
||||
|
||||
This gave me a set of 24-bit 44.1kHz FLAC files, which I verified with the **file** command. At that point, all I needed to do was make sure all the tags looked good, and that was that.
|
||||
|
||||
### And speaking of music…
|
||||
|
||||
I've been taking a break from this music column this year, as I haven't done much except listen to things I already have on hand. But a few new items have crept into my collection.
|
||||
|
||||
Emancipator's latest, [Mountain of Memory][16], is available from that great Linux-friendly and artist-friendly online store, [Bandcamp][17]. If you like Emancipator's earlier stuff, you won't be disappointed with this.
|
||||
|
||||
The Choir of Clare College at Cambridge and the Dmitri Ensemble have released [a fine collection of music by Arvo Pärt, Peteris Vasks, and James MacMillan][18], entitled "Arvo Pärt Stabat." I haven't listened to this album carefully, but even so, I am struck by the similarity between the three composers' work presented here. Maybe something about the shared influence of a northern European landscape and weather? I bought this beautiful choral music as a 96/24 FLAC download from [Presto Classical][19], another fine Linux-friendly online store. For those interested in more information on this music, there is an interview on that site with Graham Ross, the conductor of the Choir of Clare College.
|
||||
|
||||
Finally, some other interesting news—an online store with lots of great high-resolution downloads that has frustrated me for many years (to the point of sending them numerous whiny emails), [HDtracks][20], has finally made it possible to purchase music from them without using their download manager! I haven't actually bought anything there yet, but I will soon give it a whirl and report back.
|
||||
|
||||
--------------------------------------------------------------------------------
|
||||
|
||||
via: https://opensource.com/article/20/7/hdcd
|
||||
|
||||
作者：[Chris Hermansen][a]
|
||||
选题：[lujun9972][b]
|
||||
译者：[译者ID](https://github.com/译者ID)
|
||||
校对：[校对者ID](https://github.com/校对者ID)
|
||||
|
||||
本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出
|
||||
|
||||
[a]: https://opensource.com/users/clhermansen
|
||||
[b]: https://github.com/lujun9972
|
||||
[1]: https://opensource.com/sites/default/files/styles/image-full-size/public/lead-images/life_cd_dvd.png?itok=RBwVIzmi (11 CDs in a U shape)
|
||||
[2]: https://audiokarma.org/forums/index.php?threads/questions-about-hafler-dh-110-connections.790899/
|
||||
[3]: https://forum.polkaudio.com/discussion/166859/monitor-7b-question
|
||||
[4]: https://en.wikipedia.org/wiki/High_Definition_Compatible_Digital
|
||||
[5]: https://docs.linn.co.uk/wiki/images/0/08/Ikemi_genki_user_manual.pdf
|
||||
[6]: https://www.discogs.com/search/?format_exact=HDCD
|
||||
[7]: http://www.audiomisc.co.uk/HFN/HDCD/Examined.html
|
||||
[8]: https://patents.google.com/patent/US5479168?oq=US5479168
|
||||
[9]: https://www.linnrecords.com/recording-la-messe-du-roi
|
||||
[10]: https://www.linnrecords.com/recording-dangerous-graces-music-cipriano-de-rore-and-pupils
|
||||
[11]: https://www.linnrecords.com/recording-vivaldi-concerti
|
||||
[12]: https://www.linnrecords.com/
|
||||
[13]: http://forum.doom9.org/showthread.php?t=129136
|
||||
[14]: https://wiki.hydrogenaud.io/index.php?title=High_Definition_Compatible_Digital#FFmpeg
|
||||
[15]: http://www.goodwinshighend.com/music/hdcd/gain_scaling.htm
|
||||
[16]: https://emancipator.bandcamp.com/album/mountain-of-memory
|
||||
[17]: https://bandcamp.com/
|
||||
[18]: https://www.clarecollegechoir.com/product/arvo-p%C3%A4rt-stabat
|
||||
[19]: https://www.prestomusic.com/classical/products/8766094--arvo-part-stabat-mater
|
||||
[20]: https://www.hdtracks.com/
|
||||
@ -0,0 +1,143 @@
|
||||
[#]: collector: (lujun9972)
|
||||
[#]: translator: ( )
|
||||
[#]: reviewer: ( )
|
||||
[#]: publisher: ( )
|
||||
[#]: url: ( )
|
||||
[#]: subject: (Top 5 Open Source Video Conferencing Tools for Remote Working and Online Meetings)
|
||||
[#]: via: (https://itsfoss.com/open-source-video-conferencing-tools/)
|
||||
[#]: author: (Ankush Das https://itsfoss.com/author/ankush/)
|
||||
|
||||
Top 5 Open Source Video Conferencing Tools for Remote Working and Online Meetings
|
||||
======
|
||||
|
||||
You will find several video conferencing tools available online. Some are tailored for professional use and some for daily casual conversations.
|
||||
|
||||
However, with hundreds of options to choose from, security and privacy is often a concern when picking a video conferencing app or service. Among the list of options, what’s usually the best and the most secure service?
|
||||
|
||||
Well, all (or most of them) claim to provide the best possible security and privacy. But you know that this cannot be taken at face value.
|
||||
|
||||
Fortunately, at It’s FOSS, we focus on open-source solutions and privacy-friendly options. So, let’s take a look at a list of open-source video conferencing tools that you can utilize.
|
||||
|
||||
### Top Open Source Video Conferencing Solutions
|
||||
|
||||
![][1]
|
||||
|
||||
Most of the video conferencing solutions can be installed on your own servers if you are a small business or enterprise.
|
||||
|
||||
For normal, non-sysadmins, some of these solutions also provide ready-to-use, free, web-based video conferencing service. I’ll mention this information in the description of each item on the list.
|
||||
|
||||
**Note:** The list is in no particular order of ranking.
|
||||
|
||||
#### 1\. Jitsi Meet
|
||||
|
||||
![][2]
|
||||
|
||||
Jitsi Meet is an impressive open-source video conferencing service. You can easily find out more about it on our separate coverage on [Jitsi Meet][3].
|
||||
|
||||
To give you a head start, it offers you free [official public instance][4] to test it and use it for free as long as you need it.
|
||||
|
||||
If you need to host it on your server while customizing some options for your requirements, you can download it from its [official website][5] for your server.
|
||||
|
||||
Even though they offer an electron-based app on Linux, you don’t need to download an app on your desktop to set it up. All you need is a browser and you’re good to go. For mobile, you will find apps for both Android and iOS.
|
||||
|
||||
[Jitsi Meet][5]
|
||||
|
||||
#### 2\. Jami
|
||||
|
||||
![][6]
|
||||
|
||||
Jami is a peer-to-peer based open-source video conferencing solution. It’s good to see a distributed service that does not rely on servers but peer-to-peer connections.
|
||||
|
||||
Of course, a distributed service has its pros and cons. But, it’s free and open-source, that’s what matters.
|
||||
|
||||
Jami is available for Linux, Windows, macOS, Android, and iOS, So, it’s a pure cross-platform solution for secure messaging and video conferencing. You can take a look at their [GitLab page][7] to explore more about it.
|
||||
|
||||
[Jami][8]
|
||||
|
||||
#### 3\. Nextcloud Talk
|
||||
|
||||
![][9]
|
||||
|
||||
[Nextcloud][10] is undoubtedly the open-source Swiss army of remote working tools. We at It’s FOSS utilize Nextcloud. So, if you already have your server set up, [Nextcloud Talk][11] can prove to be an excellent video conferencing and communication tool.
|
||||
|
||||
Of course, if you don’t have your own Nextcloud instance, you will require some technical expertise to set it up and start using Nextcloud Talk.
|
||||
|
||||
[Nextcloud Talk][11]
|
||||
|
||||
#### 4\. Riot.im
|
||||
|
||||
![][12]
|
||||
|
||||
Riot.im (soon going to be rebranded) is already one of the [best open source alternatives to slack][13].
|
||||
|
||||
It gives you the ability to create communities, send text messages, and start video conferences in a group/community. You can use it for free by using any of the public [Matrix servers][14] available.
|
||||
|
||||
If you want your own dedicated decentralized Matrix network, you can also opt for paid hosting plans on [Modular.im][15].
|
||||
|
||||
[Riot.im][16]
|
||||
|
||||
#### 5\. BigBlueButton
|
||||
|
||||
![][17]
|
||||
|
||||
BigBlueButton is an interesting open-source video conferencing option tailored for online learning.
|
||||
|
||||
If you are a teacher or running a school, you might want to try this out. Even though you can try it for free, there will be limitations for the free demo usage. So, it’s best to host it on your own server and you can also integrate it with your other products/services, if any.
|
||||
|
||||
It offers a good set of features that let you easily teach the students. You can explore its [GitHub page][18] to know more about it.
|
||||
|
||||
[BigBlueButton][19]
|
||||
|
||||
#### Additional mention: Wire
|
||||
|
||||
![][20]
|
||||
|
||||
Wire is a quite popular open-source secure messaging platform tailored for business and enterprise users. It also offers video calls or web conferencing options.
|
||||
|
||||
If you wanted a premium open-source option dedicated for your business or your team, you can try Wire and decide to upgrade it after the 30-day trial expires.
|
||||
|
||||
Personally, I love the user experience, but it comes at a cost. So, I’d recommend you to give it a try and explore its [GitHub page][21] before you decide
|
||||
|
||||
[Wire][22]
|
||||
|
||||
### Wrapping Up
|
||||
|
||||
Now that you know some popular open-source web conferencing options, which one do you prefer to use?
|
||||
|
||||
Did I miss any of your favorites? Let me know your thoughts in the comments below!
|
||||
|
||||
--------------------------------------------------------------------------------
|
||||
|
||||
via: https://itsfoss.com/open-source-video-conferencing-tools/
|
||||
|
||||
作者：[Ankush Das][a]
|
||||
选题：[lujun9972][b]
|
||||
译者：[译者ID](https://github.com/译者ID)
|
||||
校对：[校对者ID](https://github.com/校对者ID)
|
||||
|
||||
本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出
|
||||
|
||||
[a]: https://itsfoss.com/author/ankush/
|
||||
[b]: https://github.com/lujun9972
|
||||
[1]: https://i1.wp.com/itsfoss.com/wp-content/uploads/2020/07/open-source-video-conferencing-tools.jpg?ssl=1
|
||||
[2]: https://i2.wp.com/itsfoss.com/wp-content/uploads/2020/06/jitsi-meet-browser-screenshot.png?ssl=1
|
||||
[3]: https://itsfoss.com/jitsi-meet/
|
||||
[4]: https://meet.jit.si/
|
||||
[5]: https://jitsi.org/jitsi-meet/
|
||||
[6]: https://i0.wp.com/itsfoss.com/wp-content/uploads/2020/07/jami-screenshot.png?ssl=1
|
||||
[7]: https://git.jami.net/savoirfairelinux/ring-project
|
||||
[8]: https://jami.net/
|
||||
[9]: https://i0.wp.com/itsfoss.com/wp-content/uploads/2020/07/nextcloud-talk.png?ssl=1
|
||||
[10]: https://itsfoss.com/nextcloud/
|
||||
[11]: https://nextcloud.com/talk/
|
||||
[12]: https://i2.wp.com/itsfoss.com/wp-content/uploads/2020/07/riot-communication-video.png?ssl=1
|
||||
[13]: https://itsfoss.com/open-source-slack-alternative/
|
||||
[14]: https://matrix.org/
|
||||
[15]: https://modular.im/
|
||||
[16]: https://about.riot.im/
|
||||
[17]: https://i0.wp.com/itsfoss.com/wp-content/uploads/2020/07/big-blue-button.png?ssl=1
|
||||
[18]: https://github.com/bigbluebutton/bigbluebutton
|
||||
[19]: https://itsfoss.com/open-source-video-conferencing-tools/bigbluebutton.org/
|
||||
[20]: https://i1.wp.com/itsfoss.com/wp-content/uploads/2020/07/wire-video-conferencing.png?ssl=1
|
||||
[21]: https://github.com/wireapp
|
||||
[22]: https://wire.com/en/
|
||||
@ -1,155 +0,0 @@
|
||||
[#]: collector: (lujun9972)
|
||||
[#]: translator: (Yufei-Yan)
|
||||
[#]: reviewer: ( )
|
||||
[#]: publisher: ( )
|
||||
[#]: url: ( )
|
||||
[#]: subject: (What is IoT? The internet of things explained)
|
||||
[#]: via: (https://www.networkworld.com/article/3207535/what-is-iot-the-internet-of-things-explained.html)
|
||||
[#]: author: (Josh Fruhlinger https://www.networkworld.com/author/Josh-Fruhlinger/)
|
||||
|
||||
什么是 IoT？物联网简介
|
||||
======
|
||||
|
||||
物联网（IoT）是一个将智能设备连接起来的网络，并提供了丰富的数据，但是它也有可能是一场安全领域的噩梦。
|
||||
|
||||
对于越来越多不用于传统计算，但却相互连接用来收发数据的电子设备来说，物联网（IoT）这个词可以说是最夺人眼球的。
|
||||
|
||||
现在有数不胜数的东西可以归为这一类：传统家用电器里面，可以联网的那一部分＂智能设备＂，比如说电冰箱和灯泡；那些只能运行于有互联网环境的小设备，比如像 Alexa 之类的电子助手；与互联网连接的传感器，他们正在改变着工厂、医疗、运输、物流中心和农场。
|
||||
|
||||
### 什么是物联网？
|
||||
|
||||
物联网（IoT）将互联网、数据处理和分析的能力带给了现实世界中的各种物品。对于消费者来说，这就意味着不需要键盘和显示器这些东西，就能和全世界的信息进行互动；日常用品当中，很多都可以通过网络得到操作指令，从而最大程度的减少了人工的操作。
|
||||
|
||||
**[更多关于物联网（IoT）在网络世界中的内容][1]**
|
||||
|
||||
在企业环境当中，互联网（Internet）长期以来为制造和分销提供了便利，物联网（IoT）也能带来同样的效率。互联网嵌入式传感器，即使没有几十亿，全世界数百万的此类传感器正在提供着丰富的数据，企业可以利用这些数据来保证他们运营的安全，跟踪资产和减少人工处理的次数。研究人员也可以使用物联网（IoT）来获取人们的喜好和行为数据，尽管这些行为可能会严重的涉及隐私和安全问题。
|
||||
|
||||
### 它有多大？
|
||||
|
||||
一句话：非常庞大。[Priceonomics 把它分开来看][2]：在2020年的时候，有超过50亿的物联网（IoT）设备，这些设备可以生成 4.4 泽字节（zettabyte，译者注：1 zettabyte = 10<sup>9</sup> terabyte = 10<sup>12</sup> gigabyte）的数据。相比较，物联网（IoT）设备在 2013 仅仅产生了 1000 亿千兆字节（gigabyte）的数据。在物联网（IoT）市场上可能挣到的钱也同样让人瞠目；到 2025 年，这块市场的价值可以达到 1.6 万亿美元到 14.4 万亿美元。
|
||||
|
||||
### 物联网（IoT）的历史
|
||||
|
||||
一个所有设备和传感器无处不链接的世界，是科幻小说中最经典的景象之一。物联网（IoT）的知识早在 1970 的时候就已经实现了，世界上第一个物联网设备，[卡耐基•梅隆大学的自动贩卖机][3]，它还用来和 APRANET 相连，而且很多其他的技术也已经被发明出来并给大家展示了一个充满未来感和智慧的物联网。但是直到 1999 年，物联网这个词才由英国的技术人员，[Kevin Ashton][4] 提出来。
|
||||
|
||||
一开始，技术是滞后于当时对未来的憧憬的。每个与互联网相连的设备都需要一个处理器和一种能和其他东西通信的方式，无线的最好，这些因素都增加了物联网（IoT）大规模实际应用的成本和性能要求，这种情况至少一直持续到 21 世纪头十年中期，直到摩尔定律赶上来。
|
||||
|
||||
一个重要的里程碑是当 [RFID 的大规模使用][5]，这种价格低廉的转发器可以被贴在任何物品上，然后这些物品就可以连接到更大的互联网上了。对于设计者来说，无处不在的 Wi-Fi 和 4G 让任何地方的无线连接都变得非常简单。而且，IPv6 的出现在也不用让人们担心把数十亿小设备连接到互联网上会将 IP 地址耗尽。（相关故事：[物联网（IoT）网络可以促进IPv6的使用吗？][6]）
|
||||
|
||||
### 物联网（IoT）是如何工作的？
|
||||
|
||||
物联网（IoT）的基本元素是收集的数据的设备。广义地说，他们是和互联网相连的设备，所以每一个设备都有 IP 地址。这些设备涵盖了从从工厂运输货物的自动驾驶车辆到简单的温度监控的传感器。这其中也包括每天统计步数的个人手环。为了让这些数据变得有意义，就需要收集、处理、过滤和分析这些数据，又会有很多种办法来实现这些过程。
|
||||
|
||||
搜集数据是通过把数据从设备上发送到搜集端。可以通过各种无线或者有线网络进行数据的转移。数据可以通过无联网发送到有存储空间或者计算能力的数据中心或者云端，或者这些数据可以分段的进行传输，中间设备在发送之前会将这些数据聚集在一起。
|
||||
|
||||
处理数据可以在数据中心或者云端进行，但是有时候这不太可行。对于一些非常重要的设备，比如说工业领域的关停设备，从设备上将数据发送到远程数据中心的延迟，代价实在是太高了。发送、处理、分析数据和返回指令（在管道爆炸之前关闭阀门）这些操作，来回一趟的时间可能要花费非常多的时间。在这种情况下，边缘计算（edge-computing）就可以大显身手了。边缘计算是一个智能的边缘设备可以聚集数据并且进行分析，在需要的时候进行回应，所有的这一系列操作都是距离所需要控制的设备很近的，所以也就降低了延迟。边缘设备可以有上游连接，这样数据就可以进一步被处理和储存。
|
||||
|
||||
[][7] 网络世界 / IDG
|
||||
|
||||
物联网（IoT）是如何工作的。
|
||||
|
||||
### **物联网（IoT）设备的一些例子**
|
||||
|
||||
本质上，任何可以搜集来自于真实世界数据，并且可以发送回去的设备都可以参与到物联网（IoT）生态系统中。典型的例子包括智能家居设备，射频识别标签（RFID）和工业传感器。这些传感器可以监控一系列的要素，包括工业系统中的温度和压力，机器中关键设备的状态，患者身上与生命体征相关的信号，也可以利用水和电已经其他许多可能的东西。
|
||||
|
||||
一台工厂的机器人可以被认为是物联网（IoT）设备，因为他们可以看作是自动化的载具将货物在仓库之间转移
|
||||
|
||||
其他的例子包括可穿戴设备和家庭安防系统。还有一些其他更基础的设备，比如说[树莓派（Raspberry Pi）][8]和[Arduino][9]，这些设备可以让你构建你自己的物联网（IoT）终端节点。
|
||||
|
||||
#### **设备管理**
|
||||
|
||||
为了能让这些设备一起工作，所有这些设备都需要进行验证、合理分配、调试和监控，并且在需要的时候进行更新。要么这些操作会经常的出现在由一个设备供应商制造的系统中；要么这些操作根本就不会发生，这样也是最有风险的。但是整个工业界正在向[标准化的设备管理模型][10]过渡，这样也就允许物联网（IoT）设备之间进行互相操作，也可以保证设备不会被孤立。
|
||||
|
||||
#### **物联网（IoT）通信标准和协议**
|
||||
|
||||
当物联网（IoT）小设备和其他设备通信的时候，他们可以使用各种通信标准和协议，这其中许多都是为这些处理能力有限和缺少电源供应的设备专门定制的。你一定听说过其中的一些，尽管说有一些设备使用的是Wi-Fi或者蓝牙，但是更多的设备是使用了专门为物联网（IoT）世界定制的标准。比如，ZigBee，就是一个低功耗、远距离传输的无线通信协议，而 MQTT（Message Queuing Telemetry Transport）是为链接在不可靠或者有延迟网络上的设备定制的一个发布/订阅（publish/subscribe）模式的信息传递协议。（参考网络世界的词汇表：[物联网（IoT）标准和协议](11)。）
|
||||
|
||||
物联网（IoT）也会受益于5G为蜂窝网络带来的高速度和高带宽，尽管这种使用场景会[滞后于普通的手机][12]。
|
||||
|
||||
### 物联网（IoT）, 边缘计算（edge computing）和云（cloud）
|
||||
|
||||
[][23] 网络世界 / IDG
|
||||
|
||||
边缘计算如何使物联网（IoT）成为可能。
|
||||
|
||||
对于许多物联网（IoT）系统来说，大量的数据会以极快的速度涌来，这种情况催生了一个新的科技领域，[边缘计算（edge computing）][14]，它由放置在物联网（IoT）设备附近的设备组成，处理来自那些设备的数据。这些机器会处理这些数据，并且只将相关的材料发送到一个更集中的系统系统进行分析。比如，假设在一个有几十个物联网（IoT）安防摄像头的网络中，边缘计算会直接分析传入的视频，而且只有当其中一个摄像头检测到有物体移动的时候才向SoC发出警报，而不会是一下子将所有的在线数据流全部发送到大楼的安全操作中心（SoC）。
|
||||
|
||||
一旦这些数据已经被处理过了，他们有去哪里了呢？好吧，它也许会被送到你的数据中心，但是更多情况下，它最终会进入云。
|
||||
|
||||
对于物联网（IoT）这种间歇或者不同步的数据来往场景来说，具有弹性的云计算是再适合不过的了。许多云计算巨头，包括[谷歌][15]，[微软][16]，和[亚马逊][17]，都会提供物联网（IoT）产品。
|
||||
|
||||
### 物联网（IoT）平台
|
||||
|
||||
云计算巨头们正在尝试出售的，不仅仅是存放传感器搜集的数据。他们要提供一个可以协调物联网（IoT）系统中各种元素的网正完整平提案，平台会将很多功能捆绑在一起。本质上，物联网（IoT）平台作为中间件，将物联网（IoT）设备和边缘网关用处理物联网（IoT）数据的应用程序连接起来。也就是说，每一个平台的厂商看上去都会对物联网（IoT）平台应该是什么这个问题有一些稍微不同的解释，这样就能更好的[与其他竞争者拉开差距][18]。
|
||||
|
||||
### 物联网（IoT）和数据
|
||||
|
||||
正如前面所提到的，所有那些物联网（IoT）设备收集了有泽字节（zettabytes）这个数量级的数据，这些数据通过边缘网关被发送到平台上进行处理。在很多情况下，这些数据就是首先要部署物联网（IoT）的原因。通过从现实世界中的传感器搜集来的数据，各种组织就可以实时的作出灵活的决定。
|
||||
|
||||
例如，Oracle 公司[假设了一个场景][19]，当人们在主题公园的时候，会被鼓励下载一个可以提供公园信息的应用。同时，这个程序会将 GPS 信号发回到公园的管理部门来帮助他们预测排队时间。有了这些信息，公园就可以在短期内（比如通过增加员工数量来提高一些景点的容量）和长期内（通过了解哪些设施最受欢迎，那些最不受欢迎）采取行动。
|
||||
|
||||
这些决定完全可以在没有人工干预的情况作出。比如，从化工厂管道中的压力传感器收集的数据可以通过边缘设备的软件进行分析，从而发现管道破裂的威胁，这样的信息可以触发关闭阀门从而避免泄漏的信号。
|
||||
|
||||
### 物联网（IoT）和大数据分析
|
||||
|
||||
主题公园的例子可以让你很容易理解，但是和许多现实世界中物联网（IoT）收集数据的操作相比，就显得小菜一碟了。许多打数据操作都会使用到来自物联网（IoT）设备收集的信息，然后与其他数据关联，这样就可以分析预测到人类的行为。_Software Advice_ 给出了[一些例子][20]，其中包括由Birst提供的一项服务，该服务将从联网的咖啡机中收集的咖啡冲泡的信息与社交媒体上发布的帖子进行匹配，看看顾客是否在网上谈论咖啡品牌。
|
||||
|
||||
另一个最近才发生的戏剧性的例子，X-Mode 发布了一张基于位置追踪数据的地图，地图上显示了在 2020 年 3 月春假的时候，正当新冠病毒在美国加速传播的时候，人们在劳德代尔堡（Ft. Lauderdale）聚会完[最终都去了哪里][21]。这张地图令人震撼，不仅仅是因为它显示出病毒可能的扩散方向，更是因为它说明了物联网（IoT）设备是可以多么密切地追踪我们。（更多关于物联网（IoT）和分析的信息，请点击[此处][22]）
|
||||
|
||||
### 物联网（IoT）数据和AI
|
||||
|
||||
物联网（IoT）设备能够收集的数据量远远大于任何人类能够以有效的方式处理的数据量，而且这肯定不是实时的。我们已经看到，来自于物联网（IoT）终端的原始数据需要边缘计算设备去进行解释。还需要检测和处理可能[完全错误的数据][23]。
|
||||
|
||||
许多物联网（IoT）供应商也同时提供机器学习和人工只能的功能，可以用来理解收集来的数据。比如，在 Watson 平台上获胜的 IBM Jeopard! ，就可以在[物联网（IoT）数据集进行训练][24]，这样就可以在预测行维护领域产生有用的结果 - 比如说，分析来自无人机的数据，可以区分桥梁上轻微的损坏和需要重视的裂缝。同时，ARM 也在研发[低功耗芯片][25]，它可以在物联网（IoT）终端上提供AI的能力。
|
||||
|
||||
### 物联网（IoT）和贸易
|
||||
|
||||
贸易领域， 物联网（IoT）可以用于包括跟踪客户，库存和重要部件的状态。[IoT for All][26] 列举了四个已经被物联网（IoT）改变的行业：
|
||||
|
||||
* **石油和天然气**：与人工干预相比，无联网传感器可以更好的检测孤立的钻井场地。
|
||||
* **农业**：通过物联网（IoT）传感器获得的田间作物的数据，可以用来提高产量。
|
||||
* **采暖通风**：制造商可以监控全国各地的气候控制系统。
|
||||
* **实体零售**：当顾客在商店的某一部分停留的时候，可以给他们的手机上发送优惠信息从而进行精准定位。
|
||||
|
||||
更普遍的情况是，企业正在寻找能够在[四个领域][27]上获得帮助的物联网（IoT）解决方案：能源使用，资产跟踪，安全领域和客户体验。
|
||||
|
||||
--------------------------------------------------------------------------------
|
||||
|
||||
via: https://www.networkworld.com/article/3207535/what-is-iot-the-internet-of-things-explained.html
|
||||
|
||||
作者：[Josh Fruhlinger][a]
|
||||
选题：[lujun9972][b]
|
||||
译者：[Yufei-Yan](https://github.com/Yufei-Yan)
|
||||
校对：[校对者ID](https://github.com/校对者ID)
|
||||
|
||||
本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出
|
||||
|
||||
[a]: https://www.networkworld.com/author/Josh-Fruhlinger/
|
||||
[b]: https://github.com/lujun9972
|
||||
[1]: https://www.networkworld.com/category/internet-of-things/
|
||||
[2]: https://priceonomics.com/the-iot-data-explosion-how-big-is-the-iot-data/
|
||||
[3]: https://www.machinedesign.com/automation-iiot/article/21836968/iot-started-with-a-vending-machine
|
||||
[4]: https://www.visioncritical.com/blog/kevin-ashton-internet-of-things
|
||||
[5]: https://www.networkworld.com/article/2319384/rfid-readers-route-tag-traffic.html
|
||||
[6]: https://www.networkworld.com/article/3338106/can-iot-networking-drive-adoption-of-ipv6.html
|
||||
[7]: https://images.idgesg.net/images/article/2020/05/nw_how_iot_works_diagram-100840757-orig.jpg
|
||||
[8]: https://www.networkworld.com/article/3176091/10-killer-raspberry-pi-projects-collection-1.html
|
||||
[9]: https://www.networkworld.com/article/3075360/arduino-targets-the-internet-of-things-with-primo-board.html
|
||||
[10]: https://www.networkworld.com/article/3258812/the-future-of-iot-device-management.html
|
||||
[11]: https://www.networkworld.com/article/3235124/internet-of-things-definitions-a-handy-guide-to-essential-iot-terms.html
|
||||
[12]: https://www.networkworld.com/article/3291778/what-s-so-special-about-5g-and-iot.html
|
||||
[13]: https://images.idgesg.net/images/article/2017/09/nw_how_edge_computing_works_diagram_1400x1717-100736111-orig.jpg
|
||||
[14]: https://www.networkworld.com/article/3224893/what-is-edge-computing-and-how-it-s-changing-the-network.html
|
||||
[15]: https://cloud.google.com/solutions/iot
|
||||
[16]: https://azure.microsoft.com/en-us/overview/iot/
|
||||
[17]: https://aws.amazon.com/iot/
|
||||
[18]: https://www.networkworld.com/article/3336166/why-are-iot-platforms-so-darn-confusing.html
|
||||
[19]: https://blogs.oracle.com/bigdata/how-big-data-powers-the-internet-of-things
|
||||
[20]: https://www.softwareadvice.com/resources/iot-data-analytics-use-cases/
|
||||
[21]: https://www.cnn.com/2020/04/04/tech/location-tracking-florida-coronavirus/index.html
|
||||
[22]: https://www.networkworld.com/article/3311919/iot-analytics-guide-what-to-expect-from-internet-of-things-data.html
|
||||
[23]: https://www.networkworld.com/article/3396230/when-iot-systems-fail-the-risk-of-having-bad-iot-data.html
|
||||
[24]: https://www.networkworld.com/article/3449243/watson-iot-chief-ai-can-broaden-iot-services.html
|
||||
[25]: https://www.networkworld.com/article/3532094/ai-everywhere-iot-chips-coming-from-arm.html
|
||||
[26]: https://www.iotforall.com/4-unlikely-industries-iot-changing/
|
||||
[27]: https://www.networkworld.com/article/3396128/the-state-of-enterprise-iot-companies-want-solutions-for-these-4-areas.html
|
||||
120
translated/tech/20200626 Docker and Fedora 32.md
Normal file
120
translated/tech/20200626 Docker and Fedora 32.md
Normal file
@ -0,0 +1,120 @@
|
||||
[#]: collector: (lujun9972)
|
||||
[#]: translator: (geekpi)
|
||||
[#]: reviewer: ( )
|
||||
[#]: publisher: ( )
|
||||
[#]: url: ( )
|
||||
[#]: subject: (Docker and Fedora 32)
|
||||
[#]: via: (https://fedoramagazine.org/docker-and-fedora-32/)
|
||||
[#]: author: (Kevin "Eonfge" Degeling https://fedoramagazine.org/author/eonfge/)
|
||||
|
||||
Docker 和 Fedora 32
|
||||
======
|
||||
|
||||
![][1]
|
||||
|
||||
随着 Fedora 32 的发布，[Docker][2] 的普通用户面临着一个小挑战。在编写本文时，Fedora 32 不支持 Docker。还有其他选择，例如 [Podman][3] 和 [Buildah][4]，但是对于许多现有用户而言，现在切换可能不是最佳时机。因此，本文可以帮助你在 Fedora 32 上设置 Docker 环境。
|
||||
|
||||
### 步骤 0：消除冲突
|
||||
|
||||
此步骤适用于从 Fedora 30 或 31 升级的任何用户。如果全新安装的 Fedora 32，那么可以跳到步骤 1。
|
||||
|
||||
删除 docker 及其所有相关组件：
|
||||
|
||||
```
|
||||
sudo dnf remove docker-*
|
||||
sudo dnf config-manager --disable docker-*
|
||||
```
|
||||
|
||||
### 步骤 1：系统准备
|
||||
|
||||
在 Fedora 的最后两个版本中，操作系统已迁移到两项新技术：用于防火墙的 CGroups 和 NFTables。尽管这些新技术的详细信息不在本教程的讨论范围之内，但是令人遗憾的是，Docker 还不支持这些新技术。因此，你必须进行一些更改才能在 Fedora 上使用 Docker。
|
||||
|
||||
#### 启用旧的 CGroups
|
||||
|
||||
Fedora 仍然支持 CGroups 的先前实现，可以使用以下命令启用它。
|
||||
|
||||
```
|
||||
sudo grubby --update-kernel=ALL --args="systemd.unified_cgroup_hierarchy=0"
|
||||
```
|
||||
|
||||
#### 将防火墙中的 Docker 列入白名单
|
||||
|
||||
为了让 Docker 具有网络访问权限，需要两个命令。
|
||||
|
||||
```
|
||||
sudo firewall-cmd --permanent --zone=trusted --add-interface=docker0
|
||||
sudo firewall-cmd --permanent --zone=FedoraWorkstation --add-masquerade
|
||||
```
|
||||
|
||||
第一个命令将 Docker 接口添加到受信任的环境，它允许 Docker 建立远程连接。第二个命令将允许 docker 建立本地连接。当有多个 Docker 容器作为开发环境时，这特别有用。
|
||||
|
||||
### 步骤 2：安装 Moby
|
||||
|
||||
[Moby][5] 是 Docker 的开源白标版本。它基于相同的代码，但没有商标。它包含在 Fedora 的主仓库中，因此很容易安装。
|
||||
|
||||
```
|
||||
sudo dnf install moby-engine docker-compose
|
||||
```
|
||||
|
||||
这将安装 _moby-engine _、_ docker-compose _、_ containerd_ 和其他一些相关的库。安装完成后，你必须启用系统级守护程序才能运行 docker。
|
||||
|
||||
```
|
||||
sudo systemctl enable docker
|
||||
```
|
||||
|
||||
### 步骤 3：重新启动并测试
|
||||
|
||||
为了确保正确处理所有系统和设置，你现在必须重启计算机。
|
||||
|
||||
```
|
||||
sudo systemctl reboot
|
||||
```
|
||||
|
||||
之后，你可以使用 Docker hello-world 包来验证安装。
|
||||
|
||||
```
|
||||
sudo docker run hello-world
|
||||
```
|
||||
|
||||
除非遇到问题，不然你就会看到来自 Docker 的 Hello 问候！
|
||||
|
||||
#### 以管理员身份运行
|
||||
|
||||
可选地，你现在还可以将用户添加到 Docker 的组帐户中，以便无需输入 _sudo_ 即可启动 Docker 镜像。
|
||||
|
||||
```
|
||||
sudo groupadd docker
|
||||
sudo usermod -aG docker $USER
|
||||
```
|
||||
|
||||
注销并登录以使更改生效。如果以管理员权限运行容器的想法让你顾虑，那么你应该研究 Podman。
|
||||
|
||||
### 总结
|
||||
|
||||
从现在起，Docker 将按照你的习惯工作，包括 docker-compose 和所有与 docker 相关的工具。不要忘记查看官方文档，这在很多情况下可以为你提供帮助。
|
||||
|
||||
Fedora 32 上 Docker 的当前状态并不理想。缺少官方软件包可能会困扰一些人，并且有一个[上游问题][6]对此进行了讨论。对 [CGroups][7] 和 [NFTables][8] 都缺少支持更多是技术问题，但是你可以查看它们在其公共问题上的进展。
|
||||
|
||||
这些指导应可以让你就像什么都没有发生一样继续工作。如果这不能满足你的需求，请不要忘记到 Moby 或 Docker Github 页面去解决你的技术问题，或者看看 Podman，长期它可能会更加强大。
|
||||
|
||||
--------------------------------------------------------------------------------
|
||||
|
||||
via: https://fedoramagazine.org/docker-and-fedora-32/
|
||||
|
||||
作者：[Kevin "Eonfge" Degeling][a]
|
||||
选题：[lujun9972][b]
|
||||
译者：[geekpi](https://github.com/geekpi)
|
||||
校对：[校对者ID](https://github.com/校对者ID)
|
||||
|
||||
本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出
|
||||
|
||||
[a]: https://fedoramagazine.org/author/eonfge/
|
||||
[b]: https://github.com/lujun9972
|
||||
[1]: https://fedoramagazine.org/wp-content/uploads/2020/06/f32-04-twilight-816x459.png
|
||||
[2]: https://docs.docker.com/
|
||||
[3]: https://podman.io/getting-started/
|
||||
[4]: https://buildah.io/
|
||||
[5]: https://mobyproject.org/
|
||||
[6]: https://github.com/docker/for-linux/issues/955
|
||||
[7]: https://github.com/moby/moby/issues/40360
|
||||
[8]: https://github.com/moby/moby/issues/26824
|
||||
Loading…
Reference in New Issue
Block a user