[hunchentoot-devel] hunchentoot file upload performance

[Mac Chan]

Hi all,

I've been using tbnl behind mod_lisp2 for quite a while.

After Edi merged tbnl with hunchentoot I wanted to get rid of apache
and run hunchentoot in standalone mode for easier deployment (not to
mention the coolness factor of running everything in lisp).

However, I've found that the file upload performance of hunchentoot is
4-10 times slower than tbnl (standalone or behind mod_lisp). I tested
this by uploading a 30mb file in the test upload page.

I'm guessing that Chunga might be the reason, since this is the only
new component introduced.

[ Chunga is currently not optimized towards performance - it is rather
intended to be easy to use and (if possible) to behave correctly.]

On a side note, while the file is being uploaded the cpu will go up to
90-100% (This happens to both tbnl and hunchentoot).

This is not the case when I upload the same file to a php script w/
apache.

Again, my guess is that rfc2388 repeatedly call read-char instead of
grabbing a buffer with read-sequence and decode it as a chunk.

These two issues make migrating to hunchentoot particular painful
because if one of the users uploads a huge file the whole site will
become very unresponsive (in tbnl the cpu spike goes away a lot
faster, but improving the i/o routine is still a big win).


I don't want to blindly guess, but I don't know how to use lispworks'
profiler to profile a multi-threaded server app.

The lispworks profiler requires you to run (profile <forms>) and it
will return the profiling data after running the <form>.

Is there a way to profile hunchentoot without writing individual test
case that simulates uploading a 30 mb file?

What about people using sbcl? How do you go about profiling apps like
hunchentoot?

Thanks.