MySQL | EPFL Graph Search

MySQL (ˌmaɪˌɛsˌkjuːˈɛl) is an open-source relational database management system (RDBMS). Its name is a combination of "My", the name of co-founder Michael Widenius's daughter My, and "SQL", the acronym for Structured Query Language. A relational database organizes data into one or more data tables in which data may be related to each other; these relations help structure the data. SQL is a language that programmers use to create, modify and extract data from the relational database, as well as control user access to the database. In addition to relational databases and SQL, an RDBMS like MySQL works with an operating system to implement a relational database in a computer's storage system, manages users, allows for network access and facilitates testing database integrity and creation of backups. MySQL is free and open-source software under the terms of the GNU General Public License, and is also available under a variety of proprietary licenses. MySQL was ow

Techniques for Identifying Elusive Corner-Case Bugs in Systems Software

Radu Banabic

Modern software is plagued by elusive corner-case bugs (e.g., security bugs). Because there are no scalable, automated ways of finding them, such bugs can remain hidden until software is deployed in production. This thesis proposes approaches to solve this problem. First, we present black-box and white-box fault injection mechanisms, which allow developers to test the behavior of their own code in the presence of failures in external components, e.g., in libraries, in the kernel, or in remote nodes of a distributed system. We describe how to make black-box fault injection more efficient, by prioritizing tests based on their estimated impact. For white-box testing, we proposed and implemented a technique to find Trojan messages in distributed systems, i.e., messages that are accepted as valid by receiver nodes, yet cannot be sent by any correct sender node. We show that Trojan messages can lead to subtle semantic bugs. We used fault injection techniques to find new bugs in systems such as the MySQL database, the Apache HTTP server, the FSP file service protocol suite, and the PBFT Byzantine-fault-tolerant replication library. Testing can find bugs and build confidence in the correctness of a system. However, exhaustive testing is often unfeasible, and therefore testing may not discover all bugs before a system is deployed. In the second part of this thesis, we describe how to automatically harden production systems, reducing the impact of any corner-case bugs missed by testing. We present a framework that reduces the overhead cost of instrumentation tools such as memory error detectors. Lowering the cost enables system developers to use such tools in production to harden their systems, reducing the impact of any remaining corner-case bugs. We used our framework to generate a version of the Linux kernel hardened with Address Sanitizer. Our hardened kernel has most of the benefit of full instrumentation: it detects the same vulnerabilities as full instrumentation (7 out of 11 privilege escalation exploits from 2013-2014 can be detected using instrumentation tools). Yet, it obtains these benefits at only a quarter of the overhead.

EPFL2015

Fast black-box testing of system recovery code

Radu Banabic, George Candea

Fault injection-a key technique for testing the robustness of software systems-ends up rarely being used in practice, because it is labor-intensive and one needs to choose between performing random injections (which leads to poor coverage and low representativeness) or systematic testing (which takes a long time to wade through large fault spaces). As a result, testers of systems with high reliability requirements, such as MySQL, perform fault injection in an ad-hoc manner, using explicitly-coded injection statements in the base source code and manual triggering of failures. This paper introduces AFEX, a technique and tool for automating the entire fault injection process, from choosing the faults to inject, to setting up the environment, performing the injections, and finally characterizing the results of the tests (e.g., in terms of impact, coverage, and redundancy). The AFEX approach uses a metric-driven search algorithm that aims to maximize the number of bugs discovered in a fixed amount of time. We applied AFEX to real-world systems-MySQL, Apache httpd, UNIX utilities, and MongoDB-and it uncovered new bugs automatically in considerably less time than other black-box approaches. © 2012 ACM.

2012

A hybrid framework for industrial data storage and exploitation

Ioannis Tourkogiorgis

In this paper a hybrid framework is illustrated, with a software and hardware integration strategy, for an industrial platform that exploits features from a Relational Database (RDB) and Triplestore using the blackboard architectural pattern, ensuring efficient and accurate communication concerning data transfer among software applications and devices. Specifically, "Raw Data Handler", manages unstructured data from IoT devices that are kept in an Apache Cassandra instance, while "Production Data Handler" acts on structured data, persisted in a MySQL database. Filtered data is transformed into knowledge and persisted into the Triplestore database (DB) and can be retrieved by expert systems at any time. The proposed framework will be tested and validated within Z-FactOr project. (C) 2019 The Authors. Published by Elsevier Ltd.

Elsevier2019

Techniques for Identifying Elusive Corner-Case Bugs in Systems Software

Radu Banabic

EPFL2015