a supervsior may decide to kill a task started by one of his team members. On Mon, Mar 11, 2013 at 4:50 PM, Niphlod <[email protected]> wrote:
> "business condition" like ???? > it seems a poor design to have a task, than watch it and if it "hangs for > some reason" kill it abruptly not based on "task started a while ago" > > PS: are you on windows ? signal management on win poses a lot of > limitations. > > > On Monday, March 11, 2013 10:27:17 PM UTC+1, dlypka wrote: >> >> timeout does not handle the case where it is discovered that the task >> needs to be stopped ASAP due to a business condition. >> For example the remote server may have limited connections available so >> if a task runs into trouble, the process needs >> to be killed ASAP to release the precious remote connection. That is the >> case in my application. >> >> Even with a while loop, there will have to be a way get the win32 process >> id of the python task for a given worker so the right one >> can be killed. >> >> Looks like a better solution is for the task to have its own manager >> thread that can listen for kill requests. >> i.e. the scheduler tasks need to be written using a standard piece of >> scaffolding code to provide fine-grained task management. >> >> On Monday, March 11, 2013 3:27:35 PM UTC-5, Niphlod wrote: >>> >>> having a single worker for each task can be daunting (well, you could >>> wrap web2py.py -K appname in a never-ending loop so it's restarted as soon >>> as it gets killed).... >>> #!/bin/sh >>> while true >>> do web2py/web2py.py -K yourapp >>> echo 'killed, restarting in a bit' >>> sleep 2 >>> done >>> >>> but I'm curious about your use-case. Why do you need to terminate a >>> RUNNING task (that can't be accomplished using the timeout parameter)? >>> >>> >>> On Monday, March 11, 2013 9:18:48 PM UTC+1, dlypka wrote: >>>> >>>> Thanks for the quick reply. >>>> I suppose a workaround is to have a separate worker for each task. >>>> The I can TERMINATE the worker. >>>> >>>> A suggestion: can you suggest some standard python scaffolding to >>>> include in each >>>> task function to make it listen for a kill signal / message? >>>> >>>> On Monday, March 11, 2013 3:05:21 PM UTC-5, Niphlod wrote: >>>>> >>>>> once the task is inserted you should not change it's values unless its >>>>> in the QUEUED status (technically the ASSIGNED works too, but it's NOT >>>>> recommended). >>>>> there's no way for the scheduler to terminate a specific task once the >>>>> task is started, unless you KILL the worker (setting the worker to >>>>> TERMINATE will kill the worker as soon as the RUNNING task is finished). >>>>> PS: if you need to execute a task n times, use the repeat argument. >>>>> using time.sleep(something) in a task has the side-effect of NOT returning >>>>> to the main loop to execute potentially new QUEUED tasks (every scheduler >>>>> process is allowed to process a single task at a time). >>>>> if you need to limit the time the task runs, use the timeout parameter. >>>>> >>>>> If something is not clear please ask. >>>>> >>>>> On Monday, March 11, 2013 8:04:52 PM UTC+1, dlypka wrote: >>>>>> >>>>>> >>>>>> I need a way to terminate a specific Scheduled Task while it is >>>>>> RUNNING. >>>>>> I tried using Admin Database Admin to update the >>>>>> scheduler_task.stop_time to a time close to now while it was running. >>>>>> But the task continued for several more minutes and COMPLETED its >>>>>> normal 5 minute run. >>>>>> The task calls time.sleep(300) to make it run for 5 minutes. >>>>>> >>>>>> I guess the Scheduler is not looking at the db values every 3 seconds. >>>>>> Is it just checking the in memory task object properties? >>>>>> >>>>>> Is there a way to update the in memory object properties of a task >>>>>> while it is running? >>>>>> >>>>>> Thanks. >>>>>> >>>>> -- > > --- > You received this message because you are subscribed to a topic in the > Google Groups "web2py-users" group. > To unsubscribe from this topic, visit > https://groups.google.com/d/topic/web2py/7-ZOS_In8IU/unsubscribe?hl=en. > To unsubscribe from this group and all its topics, send an email to > [email protected]. > For more options, visit https://groups.google.com/groups/opt_out. > > > -- --- You received this message because you are subscribed to the Google Groups "web2py-users" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. For more options, visit https://groups.google.com/groups/opt_out.
