四大因素威胁云计算未来

    上周早些时候，亚马逊（Amazon）部分云计算服务陷入瘫痪，影响到地理定位社交网站Foursquare、在线视频网站Netflix、图片共享网站Instagram以及数百万用户。虽然服务很快得以恢复，但这是亚马逊半年以来第二次发生如此严重事故，不禁令人对云计算产生了诸多疑虑。

    将公司部分或全部业务迁移至云端——用行话来说，就是将数据和应用程序存放在大型远程主机上。这种做法与依靠传统服务器和内部IT部门相比，通常可以大幅节约成本。不过倘若云计算平台出现上文那样的故障，这些公司恐怕会惨遭打击。

    云计算显然是未来的发展趋势。不过，云计算目前仍然需要警惕四大威胁：

稳定性

虽然亚马逊的这次事故表明云计算也会宕机。但其发生频率并不像你想的那样高。Box.net是一家位于加州帕洛阿尔托市的云计算服务公司。其首席执行官阿隆•列维表示：“云计算（的稳定性）取决于用户选择的供应商。从许多方面来看，无论是管理内容数据还是处理电子邮件，云计算实际要比绝大部分内部平台更为可靠和强健。”

    列维认为，云计算出现宕机通常非常少见，但更容易被外界察觉。“假如我们自己内部的IT服务突然宕机六个小时，对公司外的人而言，他们根本不会有所觉察。但由于类似这样的宕机影响了云计算平台服务商Heroku和视频网站Netflix，所以一旦出事，大家很容易发觉。”

安全性

    将越来越多的数据纳入云端，公司和个人是否将更容易遭遇黑客入侵和数据丢失的威胁？现在许多人仍会提出这个问题。事实是是，答案视情况而定。

    云计算安全问题伴随Dropbox事件浮出水面。今年六月，这家位于旧金山的热门文件同步新创企业承认，一处程序错误导致用户在四个小时里可以使用错误密码登陆账号。Dropbox修复了错误并在博客中承认了该问题，不过Dropbox是在有用户发现问题并表达忧虑后才采取的行动。

    其它安全问题则与代码错误毫无干系。一些公司利用磁带或磁盘备份客户数据，在一段时间之后才会将其销毁。弗雷斯特公司（Forrester）研究员王晨曦（音译——译注）最近对《财富》杂志（Fortune）透露，有家云计算供应商定期将备份的磁带送往一家数据销毁公司。结果有一次，数据销毁公司遗失了所有磁带，包括这家云计算公司的客户保存在磁带上的所有数据。（王并未透露公司的具体名称）

服务器

    一些云计算供应商在同一实体服务器上存储不同客户的数据。所以，客户A可能运行在一个“虚拟机”上，客户B则运行在另一个，但所有客户实际都运行在同一实体服务器上。经验丰富的黑客如果获取了客户A的访问权，那么他也有可能获取客户B的数据。王说：“这种风险可能很小，但也有可能非常致命，得取决于云计算供应商存储数据的方式。

不知所云

    虽然云计算在科技界炙手可热，但许多美国人仍不清楚云计算的确切含义，要么弄不清自己在那些方面使用了云计算。市场研究公司NPD Group最近的调查显示，虽然高达76%的美国消费者在使用谷歌（Goole）Gmail和在线视频网站Hulu等基于云计算的互联网服务，但仅有22%的美国消费者真正明白云计算的含义。

    从发送简单信息到观看电影，云计算随处可见，它已深深融入到最普遍的技术之中。随着云计算越来越普及，很多公司可能将致力于尽可能减小上述四大威胁带来的困扰。

    译者：项航

    Earlier this week, portions of Amazon's cloud computing service crashed, impairing Foursquare, Netflix and Instagram as well as millions of users. While service was quickly restored, it marked the second major incident of its kind in the last six months -- and that is raising concerns with some.

    Putting parts or all of your company in the cloud -- the oft-used term to describe large, remotely hosted data sets and applications -- is typically far more cost-effective than relying on traditional servers and internal IT departments. But, incidents like these can also bring a cloud-hosted company to its knees.

    Cloud computing is obviously here to stay. But, here are four ongoing issues to watch out for as adoption rises:

Outages

    As Amazon's (AMZN) latest incident proves, outages happen. But they may not happen as frequently as you might think. "In many ways the cloud, depending on what vendor you choose, is actually more reliable and often more robust than most internal environments, whether that's for managing content or managing email," says Aaron Levie, CEO of Box.net a Palo Alto, California-based cloud services firm.

    Levie argues that cloud outages are generally rare but much more visible to the outside world. "If my own internal IT service goes down for six hours, that's not really evident to anyone outside my organization, but because something like this also took down Heroku and Netflix (NFLX), it's more apparent that something happened."

Security

    By off-loading more data to the cloud, are companies and individuals opening themselves up to hacking and data loss? That's a question many still ask. The answer, it turns out, is it depends.

    Security became an issue with popular file-syncing startup Dropbox last June when the San Francisco-based company admitted that a programming glitch allowed users to log into accounts with the wrong password over a period of four hours. The company fixed the problem and admitted the flaw in a blog post, but not before some users caught on, expressing concern.

    Other security lapses have nothing to do with coding errors. Some firms backup clients' data on tapes or disk drives, destroying them after a period of time. Forrester researcher Chenxi Wang recently told Fortune about a cloud provider which routinely sent their back-up tapes to a data disposal company. In one case, the data disposal company lost all the tapes, along with all the cloud clients' data on them. (Wang would not reveal which firm it was specifically.)

Servers

    Some cloud providers store data from several clients on the same physical server. So, Client A might be running on one "virtual machine" and Client B could be running on another, but both may actually be on the same physical server. An experienced hacker gaining access to Client A could also potentially find their way into Client B's data too. "The risk of that, depending on how the cloud provider, may be minimal, or it may be quite substantial," Wang says.

Confusion

    Though the term has gotten buzzy in the tech world, many Americans still don't quite understand the term or its implications for the way they use technology. According to a recent study from the NPD Group, just 22% of American consumers understand the concept, even though 76% of the U.S. population uses Internet including cloud-based services like Google's (GOOG) Gmail or Hulu.

    Cloud services have already worked their way into the fabric of the most common technologies, from sending simple messages to watching movies. As the services grow more and more popular, companies will likely be focusing on minimizing these four threats as much as possible.