jython-users

[Jython-users] Multithreading in Jython

[R D. <rd...@cr...>]

Hi all,

I am working on a program to simulate stress testing (large number of 
users) on JDBC connections. I would like to multithread the JDBC operations.

I would appreciate some input (samples, tips etc) with anyone that has 
tried multithreading within jython scripts.

Thanks
Raj

Thanks
Raj Datta
Professional Services                           Direct   : 408-530-4932
CrossAccess Corp                                Cell       : 408-316-5473
2900 Gordon Ave #100                       Fax       : 408-735-0328
Santa Clara CA 95051                         Email   : rd...@cr...

Re: [Jython-users] Multithreading in Jython

[Kevin B. <kb...@ca...>]

Here's a little sample code.
---
from threading import Thread
from time import time

class Job( Thread ):
    def run( self ):
        v = 0L
        for i in xrange( 1, 200000 ):
            v = v + i
        self.value = v

def _test( n=1 ):
    jobs = []
    for i in range( n ):
        jobs.append( Job() )

    start = time()
    map( Job.start, jobs )
    map( Job.join, jobs )
    t = time() - start

    print "%d: %.3f/%.3f" % (n, t, n and t/n)
        
map( _test, range( 5 ))

---

Note that the example above doesn't get a speedup from multiple threads, even on a two CPU box. 
Of course, if your threads are blocking on a JDBC call, you'll see a speedup...  :-)

<ObDisc>
These are microbenchmarks are thus not worth the electrons it takes to view them.
</ObDisc>

Although Jython doesn't appear to have a "global interpreter lock" a la CPython, my 2-CPU NT box shows 1 CPU utilized for 1 thread, both CPUs fully utilized for two or more threads, but the times look like:

0: 0.000/0.000
1: 0.719/0.719
2: 1.656/0.828
3: 2.485/0.828
4: 3.329/0.832

So, more threads use more CPU, but are slightly slower, even on a two-CPU box.

If you just run the 'run' method of all the jobs, instead of starting a new thread for each of them, you get better times:

0: 0.000/0.000
1: 0.656/0.656
2: 1.297/0.648
3: 1.953/0.651
4: 2.594/0.648

FWIW, the numbers for CPython are much worse (thank that global interpreter lock):

0: 0.000/0.000
1: 0.703/0.703
2: 5.360/2.680
3: 10.969/3.656
4: 11.656/2.914

CPython only uses one CPU, but still incurs the overhead of thread switching - not a pretty picture.

These results were obtained on:

Jython 2.1a1 on java1.3.0 (JIT: null)
Sun JDK 1.3.0
WinNT 4.0 SP 6a
2x PIII 600

kb


R Datta wrote:
> 
> Hi all,
> 
> I am working on a program to simulate stress testing (large number of
> users) on JDBC connections. I would like to multithread the JDBC operations.
> 
> I would appreciate some input (samples, tips etc) with anyone that has
> tried multithreading within jython scripts.
> 
> Thanks
> Raj
> 
> Thanks
> Raj Datta
> Professional Services                           Direct   : 408-530-4932
> CrossAccess Corp                                Cell       : 408-316-5473
> 2900 Gordon Ave #100                       Fax       : 408-735-0328
> Santa Clara CA 95051                         Email   : rd...@cr...
> 
> _______________________________________________
> Jython-users mailing list
> Jyt...@li...
> https://lists.sourceforge.net/lists/listinfo/jython-users

Re: [Jython-users] Multithreading in Jython

[John M. <joh...@ya...>]

Attached is an pair of example programs that compare the single
threading in CPython with the true multi-threading by using the Java
threads.  


 utah: /home/mudd/misc[1]  ls ?ThreadTestSerialize.py
cThreadTestSerialize.py  jThreadTestSerialize.py
 utah: /home/mudd/misc[1]  cThreadTestSerialize.py
self.id=1
self.id=2
self.id=0
Elapsed: 0.1126 sec
 utah: /home/mudd/misc[1]  jThreadTestSerialize.py
self.id=2
self.id=0
self.id=1
Elapsed: 0.2870 sec
 utah: /home/mudd/misc[1]  


--- R Datta <rd...@cr...> wrote:
> Hi all,
> 
> I am working on a program to simulate stress testing (large number of
> 
> users) on JDBC connections. I would like to multithread the JDBC
> operations.
> 
> I would appreciate some input (samples, tips etc) with anyone that
> has 
> tried multithreading within jython scripts.
> 
> Thanks
> Raj
> 
> Thanks
> Raj Datta
> Professional Services                           Direct   :
> 408-530-4932
> CrossAccess Corp                                Cell       :
> 408-316-5473
> 2900 Gordon Ave #100                       Fax       : 408-735-0328
> Santa Clara CA 95051                         Email   :
> rd...@cr...
> 
> 
> _______________________________________________
> Jython-users mailing list
> Jyt...@li...
> https://lists.sourceforge.net/lists/listinfo/jython-users


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Re: [Jython-users] Multithreading in Jython

[Frank C. <fc...@pu...>]

Raj: From what I've seen and read about Jython's threading, I think Java
threads are the better way to go. In your architecture you would write Java
modules that implements Thread and handles all the get/set methods needed to
set-up and operate the JDBC connection. Jython would instantiate your JDBC
thread (or multiple threads to check scalability) and respond to result sets
returned.

I think you may find what you're wanting to build in Load, an open-source
project I maintain. I am in the process of moving Load to use Jython as a
script language. Details are at: http://www.pushtotest.com.

And, of course, PushToTest has consulting solutions to add functions needed
to test your application. Let me know if we can help.

-Frank

-- 
Frank Cohen, founder, PushToTest, www.pushtotest.com, phone: 408 374 7426
Come to PushToTest for Load, a free open-source tool for performance and
scalability testing and data migration.

> From: R Datta <rd...@cr...>
> Date: Thu, 20 Sep 2001 12:11:40 -0700
> To: jyt...@li...
> Subject: [Jython-users] Multithreading in Jython
> 
> Hi all,
> 
> I am working on a program to simulate stress testing (large number of
> users) on JDBC connections. I would like to multithread the JDBC operations.
> 
> I would appreciate some input (samples, tips etc) with anyone that has
> tried multithreading within jython scripts.
> 
> Thanks
> Raj
> 
> Thanks
> Raj Datta
> Professional Services                           Direct   : 408-530-4932
> CrossAccess Corp                                Cell       : 408-316-5473
> 2900 Gordon Ave #100                       Fax       : 408-735-0328
> Santa Clara CA 95051                         Email   : rd...@cr...
> 
> 
> _______________________________________________
> Jython-users mailing list
> Jyt...@li...
> https://lists.sourceforge.net/lists/listinfo/jython-users