[Zope] threading, dtml and performance

[Oliver Bleutgen]

Tony McDonald wrote:
> A lurker surfaces....
> [big snip]
> But now things get interesting. If you use 'ab' on the following External
> Method
> 
> import time
> 
> def sleep(self):
>     time.sleep(5)
> 
> You find this as you increase the concurrency (this is on a server with 4
> threads running)
> 
> % ab -c1 http://host/sleep
> Time taken for tests:   5.030 seconds
> % ab -c2 http://host/sleep
> Time taken for tests:   5.034 seconds
> % ab -c3 http://host/sleep
> Time taken for tests:   5.034 seconds
> % ab -c4 http://host/sleep
> Time taken for tests:   5.040 seconds
> % ab -c5 http://host/sleep
> Time taken for tests:   5.050 seconds
> % ab -c6 http://host/sleep
> Time taken for tests:   5.038 seconds
> 
> ?? The last two tests imply that there's more than one thread running, but
> wait - look at the access_log from the server
> 
> host - - [25/Feb/2002:13:53:13 +0000] "GET /sleep HTTP/1.0" 200 45
> host - - [25/Feb/2002:13:53:13 +0000] "GET /sleep HTTP/1.0" 200 45
> host - - [25/Feb/2002:13:53:13 +0000] "GET /sleep HTTP/1.0" 200 44
> host - - [25/Feb/2002:13:53:13 +0000] "GET /sleep HTTP/1.0" 200 45
> host - - [25/Feb/2002:13:53:18 +0000] "GET /sleep HTTP/1.0" 200 45
> host - - [25/Feb/2002:13:53:18 +0000] "GET /sleep HTTP/1.0" 200 45
> 
> The first four threads are kicked off, then two more (after 5 seconds).
> Apache bench returns after the first four threads have run - I have no idea
> why this is.

try ab -c 7 -n 7 URI
ab will return after it has recieved the number of requests specified 
with -n, default is 1. It will also only do the statistics about the 
number of requests you configured, i.e. one in your case. You should 
redo the tests.
FWIW, I did this test on a linux box, here's the result (with zope's 
standart 4 threads)

 > ab -c 20 -n 20 http://localhost:30080/sleep

This is ApacheBench, Version 1.3c <$Revision: 1.38 $> apache-1.3
Copyright (c) 1996 Adam Twiss, Zeus Technology Ltd, http://www.zeustech.net/
Copyright (c) 1998-1999 The Apache Group, http://www.apache.org/

Server Software:        Zope/Zope
Server Hostname:        localhost
Server Port:            30080

Document Path:          /sleep
Document Length:        0 bytes

Concurrency Level:      20
Time taken for tests:   25.085 seconds
Complete requests:      20
Failed requests:        0
Total transferred:      3600 bytes
HTML transferred:       0 bytes
Requests per second:    0.80
Transfer rate:          0.14 kb/s received

Connnection Times (ms)
               min   avg   max
Connect:       31    64    78
Processing:  5023 14997 24997
Total:       5054 15061 25075

I get what one would expect.


Btw. zope logs at the end of the transaction (more or less),
at least not at the beginning.

cheers,
oliver