Research of Zhang and Advisee Gains Real-World Prominence

The research of Song Jiang and Xiaodong Zhang has been adopted by MySQL, one of the foremost database systems, supporting numerous applications all over the world. The LIRS (Low Inter-Reference Recency Set) caching algorithm, originally published in the ACM Conference of SIGMETRICS in 2002, entitled "LIRS: an Efficient Low Inter-Reference Recency Set Replacement to Improve Buffer Cache Performance," is such an integral part MySQL's most recent version 5.1(released in November 2008), it is called "Jiang-Zhang LIRS Caching Algorithm" in the MySQL documentation.

MySQL is the world's most widely used open source database software, with over 100 million copies of its software downloaded or distributed throughout its history. This relational database management system has more than 11 million installations. The LIRS caching algorithm serves as a critical component in the buffer pool management in MySQL, which can maximize the hit ratio of data accesses in the DRAM memory to significantly improve the database performance.

Many of the world's largest and fastest-growing organizations use MySQL to save time and money powering their high-volume Web sites, critical business systems, and packaged software including industry leaders such as Yahoo!, Alcatel-Lucent, Google, Nokia, YouTube, Wikipedia, and Booking.com. Several high-traffic web sites (including Flickr, Facebook, Wikipedia, Google, Nokia and YouTube) use MySQL for its data storage and logging of user data.

"When our paper was published 7 years ago, we were very confident that the LIRS caching algorithm had fundamentally addressed the limits of the commonly used LRU caching algorithm. Since then, this work has continuously shown its transformational impact on memory management in major software systems on different types of computing platforms, first in operating systems, and then in database systems. For example, a system implementation based LIRS called Clock-Pro was first reported in a USENIX'05 paper, then was quickly adopted in the NetBSD operating system and patched in Linux kernels, and in other data-processing servers." said Professor Xiaodong Zhang who joined Ohio State in 2006 as the Robert M. Critchfield Professor in Engineering and Department Chair of Computer Science and Engineering. "We feel very happy and rewarding to see the influential contributions of our research work to MySQL that provides indispensible services to millions of important data transactions in the human society."

The original research and article were done while Song Jiang was Professor Zhang's Ph.D. student at the College of William and Mary. Dr. Jiang is now an Assistant Professor in the Department of Electrical and Computer Engineering at Wayne State University in Detroit, Michigan. He received a National Science Foundation CAREER Award this year.