Just a thought - we could hook an application level startup script (or controller function) into cron. As cron already takes care of cgi/ fastcgi/wsgi/cherrypy, timings and some threading peculiarities it shouldn't be too hard to integrate. How do you feel about that ?
-1 * * * * * web2py *applications/myapp/private/script.py billf 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. 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