Commodity distributed systems

分布式系统的创建是一项主要的工程，通常要花费数百万美元来设计，并且要花费几倍的时间来操作。事实上，在北美，光是维持现有计算系统运转的总成本每年就超过400亿美元。尽管如此，计算机系统通常是不安全和不可靠的。造成这个问题的唯一主要原因是，这些系统的复杂性超出了除了最优秀的人类专家之外的所有人的能力。即使是安装一台联网的家庭计算机也常常需要大量的系统知识。证据表明，这种复杂性是与生俱来的。随着时间的推移，这个问题会变得更糟，而不是更好，因为我们建立了更大的系统，并将这些系统相互连接起来。

The creation of a distributed system is a major engineering exercise, often costing many millions of dollars to design, and several times more to operate. Indeed, the total cost in North America just to keep existing computing systems functioning exceeds $40 billion annually. In spite of this expense, computer systems are typically insecure and unreliable. The single major cause of this problem is that the complexity of these systems exceeds the abilities of all but the very best of human experts. Even the installation of a networked home computer often requires significant systems knowledge. The evidence suggests that this complexity is inherent. Over time this problem will get worse not better, as we build larger systems and inter-connect those systems.