[Klone-users] threading

[Stefano Barbato]

Hi Robert,

On Nov 1, 2007, at 8:19 PM, Robert Finking wrote:

> Hi,
>
> Is it possible to configure the server to be single threaded? I wrote 
> a simple page with a static int in it and incremented it on each view. 
> In the browser the value displayed went 0, 1, 2, 3, 4, 0 ,5, 1, 6, 2, 
> 7 etc. which I guess means separate threads are running.
>
> My plan is to use the server as the front end to an event driven 
> application, so spawning separate threads each time will mean having 
> to have the entire app run in another separate thread and then 
> communicate with the webserver over sockets or something, which I'd 
> like to avoid if poss.
>
> So, is it possible to run the server single threaded? Alternatively do 
> you have other ways around this?
>
> Thanks again for your rapid response to my previous question.
>
> Regards
>
> Robert Finking

Yes, it's possible.

KLone supports three server models: prefork (default), fork and 
iterative.

In "prefork" mode a few processes (not threads, klone never use 
multi-threading) are spawn at startup to serve client requests; each 
process continuosly pops a request (if any) from the list of pending 
HTTP connections and fulfills it. If you care about performance prefork 
model is what you should choose.

When using "fork" model KLone spawns a new process for each new client 
request.  Choosing fork model makes sense just if you want to save 
resources for very low traffic web applications and when performance is 
not an issue.

There's a third model called "iterative" that uses a single process 
(single thread) to serve all connections. This is what you could use 
for your project.
Note that in iterative mode just one request at a time is served and 
multiple concurrent connections are not possible.

To switch to iterative model set the "model" key in the config file 
(webapp/etc/kloned.conf) and restart kloned:

-------------------------
server_list    app_http

   [...]

app_http
{
     type            http
     model           iterative   ##### <--- here

     addr.type       IPv4
     addr.port       8080
     dir_root        /www
}
--------------------------

A side note:

if you don't need the prefork server model MinGW is a better choice 
because it produces a smaller executable that doesn't depend on any 
external library while with Cygwin you must distribute the cygwin1 DLL 
or install the whole framework on any machine that runs the kloned.exe 
daemon.

bye,
stefano