Abstract
The X.500 directory can help resolve X.400 routing and name resolution problems. However, useful directory assistance for X.400 is dependent upon small response times from X.500 servers. One way to decrease these response times is to introduce caching. Caching has been found to dramatically increase performance in disks, processors or databases. Recently we provided evidence showing that caching also decreases response times in X.500. In this paper, we expand on this previous work. We discuss issues related to implementing caches in X.500, and we evaluate the impact of a standard LRU cache in X.500 on the name resolution time in X.400. We then introduce partitioning, in which the LRU cache is divided into smaller LRU caches, each one associated with a different class of X.400 request. We describe how to dimension the partitions to obtain optimal or near-optimal performance. Our overall conclusion is that partitioning the cache further decreases the average resolution time. However, we find two limitations with cache partitioning. Specifically, the performance of a partitioned cache is more sensitive to the amount of locality in the stream of names being resolved than that of a non-partitioned cache. Furthermore, the identification of the different classes of requests (corresponding to the different partitions) is not always easy in practice. We briefly discuss a scheme that overcomes these limitations.
| Original language | English |
|---|---|
| Pages (from-to) | 327-340 |
| Number of pages | 14 |
| Journal | IFIP Transactions C: Communication Systems |
| Issue number | C-25 |
| Publication status | Published - 1 Dec 1994 |
| Externally published | Yes |
| Event | Proceedings of the IFIP TC6/WG6.5 International Conference on Upper Layer Protocols, Architecture and Applications - Barcelona, Spain Duration: 1 Jun 1994 → 3 Jun 1994 |