Right now you can run the script manually once for each app.

Massimo

On Jan 27, 12:52 pm, billf <billferr...@blueyonder.co.uk> wrote:
> My original question was about app-level configuration - I maybe
> confused things by my post #3.  The plugin stuff is really a separate
> tho' related thread.
>
> Re Massimo's post re  "web2py -S app -M -R private/script.py"
>
> How does this work if you have an instance of web2py with several
> active applications?  I suppose it wouldn't be bad to just include a
> line (in private/script.py) for each application, e.g. for app "bill"
> run script X, for app "Tim" run script Y.
>
> If you used this approach and wanted to change the config for app
> "bill" (script X) would you have to restart web2py or could you just
> run script X?
>
> On Jan 27, 6:09 pm, Timothy Farrell <tfarr...@swgen.com> wrote:
>
> > I think you're misunderstanding.  We're talking about the database
> > driver code that Bill coded together.  This has nothing to do with any
> > particular app.  Rather how and when sql.py starts up.
>
> > mdipierro wrote:
> > > I oppose any initialization that is not at the app level. It would
> > > introduces hidden dependencies in the apps.
>
> > > Massimo
>
> > > On Jan 27, 12:01 pm, Timothy Farrell <tfarr...@swgen.com> wrote:
>
> > >> I didn't think we were talking on the app level.
>
> > >> mdipierro wrote:
>
> > >>> I am skeptical about initialization code being initialized by the app
> > >>> because it may take time and web server may kill it.
>
> > >>> My approach is to create an initialization script in private and run
> > >>> it with
>
> > >>> web2py -S app -M -R private/script.py
>
> > >>> On Jan 27, 10:24 am, Timothy Farrell <tfarr...@swgen.com> wrote:
>
> > >>>> Yes, but WSGI/FCGI web-servers always have several new processes ready
> > >>>> for requests rather than having to wait for a process to start as soon
> > >>>> as a request is received.
>
> > >>>> Be careful about the multiple processes thing.  Separate processes can
> > >>>> import the same module and not be sharing data or code because they are
> > >>>> run under two separate interpreters in two separate processes.  You 
> > >>>> only
> > >>>> have to worry about this type of sharing with shared resources like 
> > >>>> files.
>
> > >>>> It seems that you're suggesting one interpreter process should parse 
> > >>>> the
> > >>>> available plugins and provide that data to other interpreter process.  
> > >>>> Now this could work with threads, but inter-process communication is
> > >>>> much more complicated and may take longer than it would for each 
> > >>>> process
> > >>>> to just parse it's own set of plugins.
>
> > >>>> -tim
>
> > >>>> achipa wrote:
>
> > >>>>> One itsy-bitsy note about the persistence of WSGI/FCGI/standalone -
> > >>>>> out of these, only the standalone has serious persistence. WSGI and
> > >>>>> FCGI can (and will) get restarted on the web server's whim (some
> > >>>>> webservers come with a predefined number of requests after which they
> > >>>>> restart the process, just in case). Also, with WSGI and FCGI you can
> > >>>>> have several parallel processes, which again complicates things (do
> > >>>>> you consider a second process starting a first load or can it re-use
> > >>>>> the results of the first one's startup ? It really depends on the
> > >>>>> usage scenario).
>
> > >>>>> As for main.wsgibase(), my bad, I wanted to say 'when' not 'where'.
>
> > >>>>> On Jan 27, 4:35 pm, Timothy Farrell <tfarr...@swgen.com> wrote:
>
> > >>>>>> I think you're confusing things.... see below
>
> > >>>>>> achipa wrote:
>
> > >>>>>>> The problem is that first start is a very relative term depending on
> > >>>>>>> how you run web2py, it's not the same for standalone/cherrypy, CGI,
> > >>>>>>> MOD_WSGI, parallel versions of these, etc.
>
> > >>>>>> Correct...sorta. We really have three categories here, threaded
> > >>>>>> persistent python interpreter, persistent distinct processes and
> > >>>>>> (non-persistent) distinct processes.  The third scenario is vanilla
> > >>>>>> CGI.  The core of web2py is started for every request with plain 
> > >>>>>> CGI.  
> > >>>>>> However WSGI, FCGI and the standalone setups use some variation of 
> > >>>>>> the
> > >>>>>> other two setups in which case imported modules are not rerun.  
> > >>>>>> (Google
> > >>>>>> agrees...http://code.google.com/appengine/docs/python/runtime.html#App_Caching)>
> > >>>>>>  This means that your
>
> > >>>>>>> startup code could be executed in a whole lot of places, not always
> > >>>>>>> where you want it. You also have to make arrangements for race
> > >>>>>>> conditions (what if a web request comes in while you are executing
> > >>>>>>> your startup function?)
>
> > >>>>>> This part is only true if your code is in the page processing path 
> > >>>>>> (i.e.
> > >>>>>> main.wsgibase() ).  If your code is in an imported module it will 
> > >>>>>> only
> > >>>>>> be run once per executed process.> As an idea, you might want to 
> > >>>>>> check/set a flag variable in cache.ram.
>
> > >>>>>>> If you don't see that flag, presume it's a first start, if it is
> > >>>>>>> there, consider yourself loaded. This also can lead to a few 
> > >>>>>>> gotcha's
> > >>>>>>> (use mutexes to prevent race conditions) and doesn't work with CGI,
> > >>>>>>> but until somebody suggests something better, it might be worth a 
> > >>>>>>> try.
>
> > >>>>>> This is a good point.  If you're module has module static variables 
> > >>>>>> then
> > >>>>>> those variables could be accessed from multiple threads and hence 
> > >>>>>> would
> > >>>>>> need to be protected with a lock-type.  To see an example of this, 
> > >>>>>> the
> > >>>>>> cache module has "meta_storage" that holds cached information and is
> > >>>>>> thread-safe.
>
> > >>>>>> -tim
>
> > >>>>>>> On Jan 27, 5:44 am, billf <billferr...@blueyonder.co.uk> wrote:
>
> > >>>>>>>> Basically, is there any code that receives control when an 
> > >>>>>>>> application
> > >>>>>>>> first starts that allows some initialisation/configuration that
> > >>>>>>>> doesn't have to run after every request?
>
> > >>>>>>>> I believe code could be put in db.py but that is not ideal
> > >>>>>>>> conceptually - and would run on every request?
>
> > >>>>>>>> I can see that there are pros and cons to the idea of "on start" 
> > >>>>>>>> code
> > >>>>>>>> and would be interested in peoples' views.
>
> > >>>>>> --
> > >>>>>> Timothy Farrell <tfarr...@swgen.com>
> > >>>>>> Computer Guy
> > >>>>>> Statewide General Insurance Agency (www.swgen.com)
>
> > >>>> --
> > >>>> Timothy Farrell <tfarr...@swgen.com>
> > >>>> Computer Guy
> > >>>> Statewide General Insurance Agency (www.swgen.com)
>
> > >> --
> > >> Timothy Farrell <tfarr...@swgen.com>
> > >> Computer Guy
> > >> Statewide General Insurance Agency (www.swgen.com)
>
> > --
> > Timothy Farrell <tfarr...@swgen.com>
> > Computer Guy
> > Statewide General Insurance Agency (www.swgen.com)
--~--~---------~--~----~------------~-------~--~----~
You received this message because you are subscribed to the Google Groups 
"web2py Web Framework" group.
To post to this group, send email to web2py@googlegroups.com
To unsubscribe from this group, send email to 
web2py+unsubscr...@googlegroups.com
For more options, visit this group at 
http://groups.google.com/group/web2py?hl=en
-~----------~----~----~----~------~----~------~--~---

Reply via email to