the process that checks for the crontab runs but it does not spawns additional processes if nothing to do.
On Apr 2, 4:14 pm, Jonathan Lundell <jlund...@pobox.com> wrote: > On Apr 2, 2010, at 12:25 PM, AchipA wrote: > > > There was talk about this a few months back, and I even have a dev > > branch that does exactly this. There *are* some concerns, that's why I > > have not yet submitted that to Massimo until I resolve GIL/locking/etc > > issues. > > It also occurs to me that I can accomplish the same thing (though not through > crontab) by expiring sessions through a model file. Touch an empty file in > sessions/ to use as a timestamp, and when its mtime is more than an hour old, > run the expiry logic. > > BTW, does cron run if there's no crontab? > > > > > On Apr 2, 12:07 am, Jonathan Lundell <jlund...@pobox.com> wrote: > >> On Apr 1, 2010, at 11:20 AM, AchipA wrote: > > >>> Exactly, hardcron checks once a minute, softcron checks on each page > >>> load. The 'check' is calling a function or two and comparing a file's > >>> timestamp, so not *that* much more expensive. > > >> Thanks. > > >> In that case, I have a suggestion, perhaps not entirely thought out. If > >> cron is being used only for something relatively simple, say > >> expire_sessions.py, how about a kind of 'cron lite' that runs its tasks in > >> the context of an application rather than spawning an entirely new > >> instance of python+web2py to do the work? > > >> At the point where softcron is invoked, at the end of a request, if we're > >> running in litecron mode, process only the crontab file for the current > >> app, and run the cron tasks more or less as if they were models (that is, > >> exec in environment). > > >>> On Apr 1, 7:51 pm, Jonathan Lundell <jlund...@pobox.com> wrote: > >>>> On Apr 1, 2010, at 10:37 AM, AchipA wrote: > > >>>>> There is some overhead, but efficiency is a disputable term - there is > >>>>> certainly more overhead than hardcron, but IMO not in a way that would > >>>>> affect overall performance unless you're running it on a site that has > >>>>> hundreds of thousands of hits per day... > > >>>> Perhaps we could change (or eliminate) the wording. How about simply > >>>> 'Using softcron'? > > >>>> I'm curious: what is the extra overhead of soft vs hard cron? Just that > >>>> it does a test on each page access? I'm guessing that's pretty cheap. > > >>>>> On Apr 1, 5:40 pm, Jonathan Lundell <jlund...@pobox.com> wrote: > >>>>>> Section 4.17 (cron) mentions hard vs soft cron defaults, but doesn't > >>>>>> say how to override them. > > >>>>>> Section 4.1 (cli) doesn't list --softcron > > >>>>>> The startup message for soft cron says: 'Using softcron (but this is > >>>>>> not very efficient)' > > >>>>>> In what sense "not efficient"? I understand that the timing is less > >>>>>> consistent, but is there really more overhead? softcron seems like a > >>>>>> pretty reasonable choice if all you're doing it deleting expired > >>>>>> sessions. > > > -- > > You received this message because you are subscribed to the Google Groups > > "web2py-users" group. > > To post to this group, send email to web...@googlegroups.com. > > To unsubscribe from this group, send email to > > web2py+unsubscr...@googlegroups.com. > > For more options, visit this group > > athttp://groups.google.com/group/web2py?hl=en. -- You received this message because you are subscribed to the Google Groups "web2py-users" group. To post to this group, send email to web...@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.
