please send me an email so that it does not get lost. Massimo
On Jan 8, 10:49 am, achipa <[email protected]> wrote: > OK, I just realized I can't attach files to postings. So, until I > figure out what am I not seeing in the google groups interface, the > patch can be downloaded fromhttp://www.atombiztos.hu/cron-2009-01-08.patch > > On Jan 8, 5:40 pm, achipa <[email protected]> wrote: > > > The long discussed (and maybe) awaited cron patch is here. Here's a > > transcript which should make it more cloear how works ands what's it > > good for. If you have any questions, or if you notice something I > > messed up, please let me know. > > > ====== > > This does a couple of interesting things. It can dispatch things to be > > executed after the client is > > gone, and in a programmable way (it's in a not pretty yet, but in a > > works-as-intended phase). You can put this into a controller > > > class dummy(gluon.contrib.wsgihooks.PostConnectionTask): > > def run(self): > > logging.warning("hello") > > from time import sleep > > sleep(10) > > logging.warning(self.env) > > logging.warning("world") > > > def mycontrollerfunc(): > > gluon.contrib.wsgihooks.localposttasks.append(dummy(request)) > > > Localposttasks are those that get executed once and are then > > discarded, > > globalposttasks are those that should be executed after each > > connection. > > Maybe it would make sense to wrap this nicely into a T2 feature. > > Someone with more time and python skills could make this work as > > decorators, which should be a bit cleaner. > > > ======== > > > Cron patch. Simplified it a bit. The postconnection part works as did > > previously, the cron works more like a regular crontab. It looks for > > an > > applications/[application]/cron/crontab file which is in regular > > crontab > > format. Three modes of operation are available: > > > - softcron: cron routines are checked after page content has been > > served, does > > not guarantee execution precision. For unprivileged apache CGI/WSGI > > installs. > > > - hardcron: a cron thread gets started on web2py startup. For windows > > and > > cherrypy/standalone installs. > > > - extcron: cron functions get force-called from the command line, > > usually from > > the system crontab. For unix systems and places where the cron > > triggers need > > to be executed even if web2py is not running at the moment. Also good > > for > > CGI/WSGI installs if we have access to the system crontab. > > > ====== > > > > 1) you do you modify wsgihandler? Do I get the cron only if I use > > > this handler? > > > Yes (it is modified) and no (you get it also with cherrypy). > > wsgihandler gives > > you softcron by default. Either way (cherrypy or wsgi), can opt for > > extcron > > if you have system crontab access (nice, but not required). I might > > have > > forgotten to patch the fastcgi handler, will check that (I don't have > > a > > fastcgi setup at hand). > > > > 2) your cron jobs are executed in threads. Will the web server kill > > > them if they exceed max time? > > > Hardcron (cherrypy handler) and extcron no, WSGI/fastcgi softcron also > > no > > (with the exception of having the webserver or the wsgi/fastcgi task > > restarted itself). The only execution combination that is limited by > > webserver max time should be plain CGI. We *could* implement a > > maxtime > > checking of our own to avoid zombie threads accumulating for bad cron > > tasks > > (you don't have that with regular cron either, so not sure about > > that). > > > > 3) If we have multiple web2py installations, only one process should > > > run the hardcron. Am I wrong? How is this handled? > > > All types of cron check for admin/cron/cron.master dates. Only the > > instance > > that manages to modify cron.master will execute the cron check cycle. > > However, your question made made me wonder that you might want a > > 'disable > > cron' parameter in web2py to make sure all cron tasks are started by > > the same > > instance. > > > > 4) the soft crons, in which environment are they executed, do they > > > see request, response, session, etc? > > > No, they are executed completely outside web2py by the wsgi callback > > function > > (=they are executed in the wsgi/cgi environment, but without the > > ability to > > return a response to user as the connection has already been closed). > > > > 5) It is important that no reference to SQLDB objects is passed to > > > the cron threads or this may break web2py. It looks like you are fine > > > but can you confirm? > > > Confirmed. Cron threads by default do not use anything from gluon. For > > cases > > where you DO need the DAL or gluon functionality, the cron actually > > creates/invokes a new web2py environment and runs the controller/task > > there > > (so it gets it's own connection, objects, etc). --~--~---------~--~----~------------~-------~--~----~ You received this message because you are subscribed to the Google Groups "web2py Web Framework" group. To post to this group, send email to [email protected] To unsubscribe from this group, send email to [email protected] For more options, visit this group at http://groups.google.com/group/web2py?hl=en -~----------~----~----~----~------~----~------~--~---
