From: Zev Blut <rubyzbibd@...>
Date: 2004-05-12T16:39:32+09:00
Subject: Pure Ruby FastCGI performance bug?

Hello,

I have noticed that, when using the pure Ruby implementation of
FastCGI, sending a response over 8K causes long delays before the
last chunk of data is sent.  The C version does not cause any
delay.

At the end of this message is a sample program to show the issue.

If you run the program a few times, usually after the second time, you
may see that around the last 8K of data takes a long time to be sent.
For example, a response of 100K takes about 30 seconds on my machine
when call the fcgi via localhost.

I am able to reproduce this with various RedHat Linux versions using
mod_fastcgi, Apache 1.3 or 2.0, and Ruby 1.8.1 or 1.6.8.

I thought some of you might want to know about this and if it is
reproducible elsewhere.

Best,
Zev Blut
----
#!/usr/local/bin/ruby1.8
FCGI_PURE_RUBY = true # Comment out if you want to test with c version

require 'fcgi'

RANDOM_CHAR = (("A".."Z").to_a + ("a".."z").to_a + ("0".."9").to_a).to_s

SIZE = 1024 * 100

def random_char()
   rnd = rand(RANDOM_CHAR.size)
   RANDOM_CHAR[rnd..rnd]
end


# Generate the data string once, to avoid computation during request.
data = ""
SIZE.times do |i|
   data<< random_char
end

FCGI.each do |request|
   request.out.print "Content-Type: text/plain\r\n"
   request.out.print "Content-Length: #{data.size}\r\n"
   request.out.print "\r\n"
   request.out.print data
   request.finish
end