[web2py] Re: Threads in app
It is because pydal-db-connection is thread safe and as you switch to another thread there is no initialized pydal-db-connection in that thread so you can try *db._adapter.reconnect() i*n your target function (this is that py4web does on every request) And (as far as I understand) you cannot share uncommitted db-changes between threads as they each have their own db connection суббота, 30 января 2021 г. в 08:58:50 UTC+3, snide...@gmail.com: > On Saturday, December 12, 2020 at 3:20:46 AM UTC-8 ermolaev...@gmail.com > wrote: > >> code: >> threadGetRate = Thread(target=get_from_exch, args=(db, exchg)) >> threadGetRate.start() >> >> I start app by: >> >> > web2py.py -S 7pay_in -M -R applications/7pay_in/modules/serv_rates.py >> -A True 60 >> >> rise error - for connection to DB >> > > > I'm not sure what you are trying to do here, and I don't what error you > are saying is happening. > > Can you provide more information? > > (typically, each request runs in its own thread, and how many threads > there are may depend on the front end (Rocket, NginX, Apache, unicorn, > etc); The scheduler also managers a pool of threads).) > > /dps > > > > -- Resources: - http://web2py.com - http://web2py.com/book (Documentation) - http://github.com/web2py/web2py (Source code) - https://code.google.com/p/web2py/issues/list (Report Issues) --- 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 web2py+unsubscr...@googlegroups.com. To view this discussion on the web visit https://groups.google.com/d/msgid/web2py/1d631b25-85ff-4c3f-961c-e41566431d4cn%40googlegroups.com.
[web2py] Re: Threads in app
On Saturday, December 12, 2020 at 3:20:46 AM UTC-8 ermolaev...@gmail.com wrote: > code: > threadGetRate = Thread(target=get_from_exch, args=(db, exchg)) > threadGetRate.start() > > I start app by: > > > web2py.py -S 7pay_in -M -R applications/7pay_in/modules/serv_rates.py -A > True 60 > > rise error - for connection to DB > I'm not sure what you are trying to do here, and I don't what error you are saying is happening. Can you provide more information? (typically, each request runs in its own thread, and how many threads there are may depend on the front end (Rocket, NginX, Apache, unicorn, etc); The scheduler also managers a pool of threads).) /dps -- Resources: - http://web2py.com - http://web2py.com/book (Documentation) - http://github.com/web2py/web2py (Source code) - https://code.google.com/p/web2py/issues/list (Report Issues) --- 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 web2py+unsubscr...@googlegroups.com. To view this discussion on the web visit https://groups.google.com/d/msgid/web2py/17446d3a-c6df-4cc7-844e-458c179271aen%40googlegroups.com.
[web2py] Re: Threads with homemade task queues
Not all all. A backgrund process can create processes and thread and spawn processes as needed. (with the limitations summarized here and discussion below: http://www.reddit.com/r/Python/comments/tpixc/ive_spent_the_past_week_tracking_down_a_bug_in/) The restriction I taked about applies only to models, controllers and views and this is not a web2py specific restriction. Massimo On Friday, 18 May 2012 15:02:17 UTC-5, David Phillips wrote: I've read hearty admonishments on this forum against creating threads in controller and model files, but what about the case of a background job launched as a separate process – like what chapter four of the book calls homemade task queues and chapter eight calls a background task? My application has a long-running job that make frequent, periodic http requests. After struggling with various approaches, I've finally got a prototype algorithm working efficiently and correctly that makes synchronous, parallel http request in a number of worker threads. I could probably run my code as a separate, non-web2py python script, but it would be convenient to be able to access the model. Do the reasons for not running creating threads inside controllers still apply in the case of a separate background process? Thanks. David
[web2py] Re: Threads operating on database causing a crash
Seriously, no one?
[web2py] Re: Threads operating on database causing a crash
*Update:* Issue has been addressed in the following thread https://groups.google.com/forum/#!topic/web2py/R8N2CRP-ifYhttps://groups.google.com/forum/#!topic/web2py/R8N2CRP-ifY
[web2py] Re: Threads operating on database causing a crash
P.S. What are you trying to accomplish? Web2py has a scheduler which takes care of running background tasks in parallel. Massimo On Oct 16, 3:38 pm, Massimo Di Pierro massimo.dipie...@gmail.com wrote: You should not start threads within actions because they are already running into threads created by the web sever. The web server monitors the threads and kills them on timeout. Moreover you are used the db object in the thread. That is not thread safe. Every thread should have its own db connection. Web2py handles this for you (every action runs in its own thread and has its own db) but you break it if you make your own threads. On Oct 16, 3:22 pm, Harshad hash0...@gmail.com wrote: class Worker(threading.Thread): def run(self): print self.name, running... while True: if db(db.temperature).isempty(): print empty else: print not empty time.sleep(1) Running the above code causes the application to seg fault. Any ideas?
[web2py] Re: Threads operating on database causing a crash
The design is discussed here: https://groups.google.com/forum/#!topic/web2py/R8N2CRP-ifY I was hoping to get some feedback on that but never got any :(
Re: [web2py] Re: Threads :-)
I found the solution, I was making it too complicated. Thank you for indirectly solving my problem. I moved the whol stuff to the cron job and make the frontend lean and mean. So no need anymore for threads the frontend. One question. when I run web2py in a cronjob can I use thread there ? Or is it also connected to the webserver ? Thanks for the response, There are two problems: - do not do print, breaks mod_wsgi - do not start threads from an action because the threads are controller by the web server and it may kill it. Good warnings. you should queue the task in database or cache and then run a background task Well actually its function is to queue tasks in redis so a cronjob can excute it. Well it seems I get errors while accessing the database File gluon/contrib/pymysql/connections.py, line 184, in defaulterrorhandler raise errorclass, errorvalue gluon.contrib.pymysql.err.InterfaceError: (0, '') . If pushing data to redis takes too long it defies the purpose of using redis. Well its collecting the data and combining it in redis that takes time. On Oct 9, 11:22 pm, Mike Veltman mike.velt...@gmail.com wrote: Ok, I need to push data in a redis database. And my problem is that it takes a while while the data is pushed in. So the screen would be waiting and a user would be irritated. My solution would be something like this. if framequeue.check_frame_lock() == False: if session.deployment == True: pass else: import thread print session.deployment print Running deployment thread.start_new_thread(default_frame_deployment,()) So the thread is running in the background and the page displays the log. But then I get gluon (database) errors in the functions. Any idea's or is there a better/ more elegant solution to this problem ? With regards, Mike Veltman With regards, Mike Veltman With regards, Mike Veltman
[web2py] Re: Threads :-)
On Oct 10, 2:54 am, Mike Veltman mike.velt...@gmail.com wrote: I found the solution, I was making it too complicated. Thank you for indirectly solving my problem. I moved the whol stuff to the cron job and make the frontend lean and mean. So no need anymore for threads the frontend. One question. when I run web2py in a cronjob can I use thread there ? Or is it also connected to the webserver ? yes you can. Thanks for the response, There are two problems: - do not do print, breaks mod_wsgi - do not start threads from an action because the threads are controller by the web server and it may kill it. Good warnings. you should queue the task in database or cache and then run a background task Well actually its function is to queue tasks in redis so a cronjob can excute it. Well it seems I get errors while accessing the database File gluon/contrib/pymysql/connections.py, line 184, in defaulterrorhandler raise errorclass, errorvalue gluon.contrib.pymysql.err.InterfaceError: (0, '') . If pushing data to redis takes too long it defies the purpose of using redis. Well its collecting the data and combining it in redis that takes time. On Oct 9, 11:22 pm, Mike Veltman mike.velt...@gmail.com wrote: Ok, I need to push data in a redis database. And my problem is that it takes a while while the data is pushed in. So the screen would be waiting and a user would be irritated. My solution would be something like this. if framequeue.check_frame_lock() == False: if session.deployment == True: pass else: import thread print session.deployment print Running deployment thread.start_new_thread(default_frame_deployment,()) So the thread is running in the background and the page displays the log. But then I get gluon (database) errors in the functions. Any idea's or is there a better/ more elegant solution to this problem ? With regards, Mike Veltman With regards, Mike Veltman With regards, Mike Veltman
Re: [web2py] Re: Threads :-)
On Oct 10, 2011, at 6:51 AM, Massimo Di Pierro wrote: On Oct 10, 2:54 am, Mike Veltman mike.velt...@gmail.com wrote: I found the solution, I was making it too complicated. Thank you for indirectly solving my problem. I moved the whol stuff to the cron job and make the frontend lean and mean. So no need anymore for threads the frontend. One question. when I run web2py in a cronjob can I use thread there ? Or is it also connected to the webserver ? yes you can. Except for softcron, presumably?
[web2py] Re: Threads :-)
oops. true. On Oct 10, 9:30 am, Jonathan Lundell jlund...@pobox.com wrote: On Oct 10, 2011, at 6:51 AM, Massimo Di Pierro wrote: On Oct 10, 2:54 am, Mike Veltman mike.velt...@gmail.com wrote: I found the solution, I was making it too complicated. Thank you for indirectly solving my problem. I moved the whol stuff to the cron job and make the frontend lean and mean. So no need anymore for threads the frontend. One question. when I run web2py in a cronjob can I use thread there ? Or is it also connected to the webserver ? yes you can. Except for softcron, presumably?
[web2py] Re: Threads :-)
There are two problems: - do not do print, breaks mod_wsgi - do not start threads from an action because the threads are controller by the web server and it may kill it. you should queue the task in database or cache and then run a background task. If pushing data to redis takes too long it defies the purpose of using redis. On Oct 9, 11:22 pm, Mike Veltman mike.velt...@gmail.com wrote: Ok, I need to push data in a redis database. And my problem is that it takes a while while the data is pushed in. So the screen would be waiting and a user would be irritated. My solution would be something like this. if framequeue.check_frame_lock() == False: if session.deployment == True: pass else: import thread print session.deployment print Running deployment thread.start_new_thread(default_frame_deployment,()) So the thread is running in the background and the page displays the log. But then I get gluon (database) errors in the functions. Any idea's or is there a better/ more elegant solution to this problem ? With regards, Mike Veltman
Re: [web2py] Re: Threads :-)
Thanks for the response, There are two problems: - do not do print, breaks mod_wsgi - do not start threads from an action because the threads are controller by the web server and it may kill it. Good warnings. you should queue the task in database or cache and then run a background task Well actually its function is to queue tasks in redis so a cronjob can excute it. Well it seems I get errors while accessing the database File gluon/contrib/pymysql/connections.py, line 184, in defaulterrorhandler raise errorclass, errorvalue gluon.contrib.pymysql.err.InterfaceError: (0, '') . If pushing data to redis takes too long it defies the purpose of using redis. Well its collecting the data and combining it in redis that takes time. On Oct 9, 11:22 pm, Mike Veltman mike.velt...@gmail.com wrote: Ok, I need to push data in a redis database. And my problem is that it takes a while while the data is pushed in. So the screen would be waiting and a user would be irritated. My solution would be something like this. if framequeue.check_frame_lock() == False: if session.deployment == True: pass else: import thread print session.deployment print Running deployment thread.start_new_thread(default_frame_deployment,()) So the thread is running in the background and the page displays the log. But then I get gluon (database) errors in the functions. Any idea's or is there a better/ more elegant solution to this problem ? With regards, Mike Veltman With regards, Mike Veltman
