John Heidemann / Software / LSAM Apache Patches

As part of my work with ISI’s LSAM project we have found some optimizations in http-server performance. We describe these problems in a web page which has been published in ACM Computer Communications Review.

We have made patches to Apache, a popular HTTP server to resolve these problems. Regrettably, they are made relative to several different versions of Apache. They should apply to the current version fairly easily.

• The ISI_MMAP patch. Use memory mapping for IO of large files. Note: a bug in the old version of this patch was found by Klaus Weide. Get the updated patch against Apache-1.0.5. A version of this patch appears in Apache-1.3b1.
• A patch for the Short-Initial-Segment Problem. Patch against Apache-1.1b4. This problem has been independently fixed by Apache-1.2b7 according to Dean Gaudet.
• A patch for the Odd/Short-Final-Segments Problem. Patch against Apache-1.1b4. A version of this patch appears in Apache-1.2.
• A patch for the Small Send Buffer Problem. Patch against Apache-1.1.1 with the above patches already applied (should apply to vanilla Apache-1.1.1 with line number differences). A version of this patch appears in Apache-1.2.

We welcome comments about this work and these patches.