A Study of Browser Caching Via Tracing

Yong Lu, Bo Zhan


World wide web has been more and more connected to people's daily life. Internet explorer and Netscape are two main commercial web browsers. In both cases, browser cache is used to accelerate the browsing process. But how does browser cache work? Does it help the user browsing experience? In our project, we did a study on web browser cache and related user browsing behavior. All the study is on IE v5.0. Finally, we implemented a cache monitor tool to help user make more intelligient usage for cache. We found that the cache replacement policy is based on LRU with the minimum cache stay of 10 minutes. In addition, file visiting frequency and embedded graphic file is taken into consideration. When cache is full, old files are flushed out until the cache size reduced to ~85% full. In evaluating the efficiency of the cache, cache hit rate and byte hit rate are used. Cache hit rate is more biased to small files while byte hit rate represent more accurate cache usage information. The trace file shows that most accessed files are small. The LRU policy will be more favor to small file since file size isn't taken into consideration. However, large file miss hurt the performance more than small file, we think it is a good idea  for cache management policy indcluding the file size information. Finally,  the survey shows that users are relied more on the system intelligence rather than themselves. The cache function in IE is usually not fully utilized by users.
 
 

Microsoft Powerpoint version
Postscript
Source Code

Contact information:
Yong Lu: lu@cs.wisc.edu
Bo Zhan bo@cs.wisc.edu