Safe and automatic live update

Tanenbaum, A.S. [Promotor

Understanding and Validating Database System Administration

1 Introduction Most enterprises rely on at least one database manage-ment system (DBMS) running on commodity computers to maintain their data. A large fraction of these enter-prises, such as Internet services and world-wide corporations, need to keep their databases operational at alltimes. Unfortunately, doing so has been a difficult task. A key source of unavailability in these systems isdatabase administrator (DBA) mistakes [10, 15, 20]. Database administration is mistake-prone as it involvesmany complex tasks, such as storage space management, database structure management, and performance tun-ing. Even worse, as shall be seen, DBA mistakes ar

Abstract Understanding and Validating Database System Administration

A large number of enterprises need their commodity database systems to remain available at all times. Although administrator mistakes are a significant source of unavailability and cost in these systems, no study to date has sought to quantify the frequency of mistakes in the field, understand the context in which they occur, or develop system support to deal with them explicitly. In this paper, we first characterize the typical administrator tasks, testing environments, and mistakes using results from an extensive survey we have conducted of 51 experienced administrators. Given the results of this survey, we next propose system support to validate administrator actions before they are made visible to users. Our prototype implementation creates a validation environment that is an extension of a replicated database system, where administrator actions can be validated using real workloads. The prototype implements three forms of validation, including a novel form in which the behavior of a database replica can be validated even without an example of correct behavior for comparison. Our results show that the prototype can detect the major classes of administrator mistakes.