In this paper, we proposed a new buffer management scheme called DEAR (DEtection based Adaptive Replacement) that automatically detects the block reference pattern of applications as sequential, looping, temporally-clustered, or probabilistic without any user intervention. Based on the detected reference pattern, the proposed DEAR scheme applies an appropriate replacement policy to each application.
We implemented the DEAR scheme in FreeBSD 2.2.5 and measured its performance using several real applications. The results showed that compared with the buffer management scheme in FreeBSD the proposed scheme reduces the number of disk I/Os by up to 51% (with an average of 23%) and the response time by up to 35% (with an average of 12%) in the case of single application executions. For multiple applications, the reduction in the number of disk I/Os is by up to 20% (with an average of 12%) while the reduction in the overall response time is by up to 18% (with an average of 8%).
We also compared the performance of the DEAR scheme with that of application-controlled file caching  through trace-driven simulations with the same set of application traces used in . The results showed that the DEAR scheme performs comparably to application-controlled file caching for the traces considered.
As we noted in Section 4.2, some applications have block reference behavior that cannot be characterized by a single reference pattern. One direction for future research is to extend the current DEAR scheme so that it can detect more complex reference patterns with parallel, sequence, and nested structures as well as to develop appropriate replacement policies for them. Another direction for future research is to study more advanced buffer allocation strategies for the DEAR scheme than the simple strategy explained in Section 3. A good buffer allocation strategy for the DEAR scheme should reward more to applications with larger reductions in the number of disk I/Os while preventing any one application from monopolizing the buffer space. Other directions for future research include applying the detection capability of the DEAR scheme to prefetching and considering block attribute types other than backward distance and frequency.
All the source code for the DEAR scheme and the applications run for the experiments can be found at http://ssrnet.snu.ac.kr/~choijm/cache.html.