On Sun, 2002-06-23 at 20:58, Brian Pane wrote: > For what it's worth, I just tried the test case that you posted. On my > test system, 2.0 is faster when I run ab without -k, and 1.3 is faster > when I run with -k.
I studied this test case and found out why 2.0 runs faster in the non-keepalive case and slower in the non-keepalive case. It's because of the logic in core_output_filter() that tries to avoid small writes when c->keepalive is set. In Rasmus's test, the file size is only 1KB, so core_output_filter reads in and buffers the contents of 8 requests before it finally reaches the 8KB threshold and starts calling writev. 1.3, in contrast, writes out each request's response immediately, with no buffering. I'm somewhat inclined to remove the buffering in this case, and let core_output_filter send the response as soon as it sees EOS for each request, even if that means sending a small packet. I just tried this in my working tree, and it does speed up 2.0 for this particular test case. On the other hand, I'm not a fan of small write calls in general. Anyone else care to offer an opinion on whether we should remove the buffering in this situation? --Brian
