介质故障后即时恢复
Instant restore after a media failure
摘要：
介质故障通常会使数据库系统在几个小时内不可用，直到恢复完成，特别是在具有大型设备和高事务量的应用程序中。以前的工作引入了一种称为单通道恢复的技术，该技术增加了恢复带宽，从而大大减少了修复时间。即时恢复更进一步，因为它允许对正在进行恢复的设备上的任何数据进行读/写访问-即使是尚未恢复的数据-通过按需恢复单个数据段。因此，恢复过程主要由应用程序的需求指导，并且观察到的平均修复时间从几个小时有效地减少到几秒钟。本文介绍了即时恢复的实现和评估。该技术是增量实现的系统从传统的ARIES设计日志和恢复。实验表明，在媒体故障后感知的事务延迟可以减少到小于一秒，并且该技术对正常处理的开销是最小的。净效果是使用简单和低开销的软件技术向系统添加了几个“9”的可用性。
英文摘要：
Media failures usually leave database systems unavailable for several hours until recovery is complete, especially in applications with large devices and high transaction volume. Previous work introduced a technique called single-pass restore, which increases restore bandwidth and thus substantially decreases time to repair. Instant restore goes further as it permits read/write access to any data on a device undergoing restore--even data not yet restored--by restoring individual data segments on demand. Thus, the restore process is guided primarily by the needs of applications, and the observed mean time to repair is effectively reduced from several hours to a few seconds. This paper presents an implementation and evaluation of instant restore. The technique is incrementally implemented on a system starting with the traditional ARIES design for logging and recovery. Experiments show that the transaction latency perceived after a media failure can be cut down to less than a second and that the overhead imposed by the technique on normal processing is minimal. The net effect is that a few "nines" of availability are added to the system using simple and low-overhead software techniques.
机构、总结、中文摘要均由AI分析而来，可能存在错误，请以论文正文为准。
