Boosting End-to-End Database Isolation Checking via Mini-Transactions (Extended Version)

2025-04-03

AI Summary

Verifying strong isolation levels (e.g., strict serializability, snapshot isolation) in production databases via black-box testing incurs high overhead and low efficiency due to costly history generation and validation. Method: This paper introduces Mini-Transactions (MTs)—semantically rich, concise read-modify-write workloads that replace conventional long, random transactions. MTs reduce blocking and retry probabilities and enable efficient isolation verification with linear or quadratic time complexity. We design an MT modeling methodology, MT-based verification algorithms, an automated MT generation framework, and black-box techniques for history collection and isolation violation detection. Contribution/Results: Our implementation, MTC, outperforms state-of-the-art tools in both history generation and verification speed. It successfully uncovers real-world isolation bugs across multiple mainstream databases under diverse isolation levels, achieving high coverage while substantially reducing detection cost.

Technology Category

• Constraint Satisfaction and Optimization: Satisfiability Modulo Theories
• Data Mining & Knowledge Management: Representing, Reasoning, and Using Provenance, Trust
• Multiagent Systems: Mechanism Design

Application Category

• Security and Privacy: Large-scale security measurements
• Web Mining and Content Analysis: Web data provenance, reliability, and authenticity
• Systems and Infrastructure for Web, Mobile and WoT: Web performance, measurement, and characterization

Abstract

Transactional isolation guarantees are crucial for database correctness. However, recent studies have uncovered numerous isolation bugs in production databases. The common black-box approach to isolation checking stresses databases with large, concurrent, randomized transaction workloads and verifies whether the resulting execution histories satisfy specified isolation levels. For strong isolation levels such as strict serializability, serializability, and snapshot isolation, this approach often incurs significant end-to-end checking overhead during both history generation and verification. We address these inefficiencies through the novel design of Mini-Transactions (MTs). MTs are compact, short transactions that execute much faster than general workloads, reducing overhead during history generation by minimizing database blocking and transaction retries. By leveraging MTs' read-modify-write pattern, we develop highly efficient algorithms to verify strong isolation levels in linear or quadratic time. Despite their simplicity, MTs are semantically rich and effectively capture common isolation anomalies described in the literature. We implement our verification algorithms and an MT workload generator in a tool called MTC. Experimental results show that MTC outperforms state-of-the-art tools in both history generation and verification. Moreover, MTC can detect bugs across various isolation levels in production databases while maintaining the effectiveness of randomized testing with general workloads, making it a cost-effective solution for black-box isolation checking.

Problem

• Efficiently verifying database isolation levels
• Reducing overhead in isolation checking processes
• Detecting isolation bugs in production databases

Innovation

• Mini-Transactions reduce history generation overhead
• Efficient algorithms verify strong isolation levels
• MTC tool outperforms state-of-the-art solutions