Hummm... I am hoping that there is a bug in the Apache code cause the alternatives are
not
pretty...
For now, I would suggest completely avoid using CacheFile/sendfile and focus
exclusively
on why MMapFile is not working. We know this can be made to work in a
process-per-request
MPM from our experience with mod_mmap_static in Apache 1.3. We don't know the same
about
sendfile or MMapFile in a Linux threaded MPM. There may be OS problems with sharing
an fd
(or mmap segment) across multiple threads. If I get some time, I'll do some tests on
my
AIX box.
Bill
>
> Hey...
>
> I've been doing some benchmarks on mod_file_cache, and I'm getting
> numbers that confuse the hell out of me. Here's what I've seen (this is
> on a RHL 7.1 box with kernel 2.4.3 running on an AMD Athlon 1.2GHz with
> 1GB RAM, using /manual/index.html.en as the test file):
>
>
> Request for static file:
>
> No keepalives Keepalives
> -------------------------- ----------------------------
> no cache 118.98 req/s 676.92 KB/s 2280.06 req/s 13053.79 KB/s
> CacheFile 90.19 req/s 511.21 KB/s 2181.21 req/s 12440.95 KB/s (WTF?!)
> MMapFile 80.90 req/s 458.54 KB/s 1978.32 req/s 11283.72 KB/s (WTF?!)
>
>
> Request for server-parsed file:
>
> No keepalives Keepalives
> -------------------------- ----------------------------
> no cache 31.81 req/s 183.68 KB/s 453.38 req/s 2647.38 KB/s
> CacheFile 87.20 req/s 501.66 KB/s 682.49 req/s 3965.77 KB/s
> MMapFile 104.17 req/s 599.30 KB/s 674.94 req/s 3925.77 KB/s
>
>
>
> Clearly there's something screwy going on (as seen in the static file
> case). I verified with gdb that sendfile IS being used in the static
> tests with both the cached and non-cached file handles (I also examined
> those apr_file_t's and they looked right). Maybe a 5KB file should be
> below the sendfile() threshold on Linux? That doesn't explain why it goes
> SLOWER using sendfile on a cached file handle than it does using sendfile
> on a file handle it has to open up on every request. Maybe it's
> something with the apr_sendfile() implementation on Linux? I've looked
> at it and no problems jump right out at me, though. I'm stumped.
>
> Anyway, I don't consider this a showstopper for the T&R, because it serves
> the requests correctly (one way or another) without segfaulting... but
> clearly I need to figure out what's going on at some point soon.
>
> (On the other hand, these results tell me that you get a nifty keen
> speedup by using mod_file_cache to accelerate server-parsed requests under
> 2.0 (as I'd hoped), which is something you couldn't really do in 1.3. :-)
>
>
> --Cliff
>
>
> --------------------------------------------------------------
> Cliff Woolley
> [EMAIL PROTECTED]
> Charlottesville, VA
>
