Thank you for your help. On Tuesday, August 11, 2020 at 8:30:27 AM UTC+3, Graham Dumpleton wrote: > > If it is a minor quick running script that does something simple it should > be okay. It is just having long running processes would be more concerned > about. > > On 11 Aug 2020, at 3:18 pm, Paul Royik <[email protected] <javascript:>> > wrote: > > You are absolutely correct. Need to change the architecture. > One more question. I also use subprocess.check_output from django. Is it > also bad idea? I'm trying to run a script (non-python) and get it output. > > On Tuesday, August 11, 2020 at 1:55:51 AM UTC+3, Graham Dumpleton wrote: >> >> Personally I would be concerned about the architecture you are using if >> you have long running tasks like you describe. It is not usually a good >> idea to use 'multiprocessing.Process' to create sub processes directly from >> a web server process to perform work. A better architecture would be to off >> load the work into a queue using something like Celery and have the >> separate job processing system pull the jobs from the queue and process >> them. You would also be better off to model the interaction from the front >> end as queueing the job and immediately responding with an acknowledgement >> to say is queued. The front end can then start polling periodically to see >> if the job has finished, and when it has it would get the response back. >> The front end can then display the data or save it locally as needed. >> >> This model avoids the problem of requests being parked doing nothing for >> a long time, which with your server configuration is going to be hugely >> expensive on memory and not scale very well because of limitations of using >> WSGI process/threading model. You might even consider not using a WSGI >> application at all. Instead, use an async web application paired with >> Celery for execution of the jobs. Using an async web application means you >> can handle as many parked requests as you want and they can quite happily >> sit there waiting for Celery to finish the job and don't need to use >> polling. Only thing am not sure about in that is what async clients there >> are for Celery. >> >> Graham >> >> On 10 Aug 2020, at 9:09 pm, Paul Royik <[email protected]> wrote: >> >> My django app makes heavy calculations which can be infinite. >> That's why, when user enters the site, i.e. makes a request, heavy >> calculations are wrapped into multiprocessing.Process which runs at most 7 >> seconds. >> I can't use threads, because third-party packages are not thread-safe. >> >> So, I have around 30 concurrent requests per second. If each request can >> take up to 7 seconds, then it is 30*7=210 concurrent requests in the worst >> case. >> Each of these concurrent requests opens multiprocessing.Process, which >> gives (I guess) 210*2=420 (close to 500) concurrent requests in the worst >> case. >> That' how I got 500 requests. Possibly, my calculations are incorrect. >> >> Average page load time (average response times) is 10 seconds. >> >> I use MPM worker. >> >> I set WSGIProcessGroup >> >> StartServers 100 >> ServerLimit 500 >> >> ThreadsPerChild 1 >> ThreadLimit 1 >> >> MaxRequestWorkers 500 >> MaxConnectionsPerChild 10000 >> >> WSGIApplicationGroup %{GLOBAL} >> WSGIDaemonProcess django_app processes=75 threads=1 python-path='...' >> maximum-requests=10000 request-timeout=20 >> WSGIProcessGroup django_app >> >> WSGIRestrictEmbedded On >> WSGILazyInitialization On >> >> >> >> On Monday, August 10, 2020 at 1:12:30 PM UTC+3, Graham Dumpleton wrote: >>> >>> What sort of application are you running? >>> >>> What is your average response times? >>> >>> Do you have long running requests, if yes, how long? >>> >>> What Apache MPM are you actually using? >>> >>> My initial impression is that is a quite poor configuration which is >>> only going to chew up huge amounts of memory for no good reason, but I >>> don't know your application requirements. >>> >>> Also, are you even setting WSGIProcessGroup? If it isn't set it makes >>> the whole daemon process configuration moot as it isn't even being used. >>> >>> On 10 Aug 2020, at 7:24 pm, Paul Royik <[email protected]> wrote: >>> >>> StartServers 50 >>> ServerLimit 200 >>> >>> ThreadsPerChild 1 >>> ThreadLimit 1 >>> >>> MaxRequestWorkers 200 >>> MaxConnectionsPerChild 10000 >>> >>> WSGIApplicationGroup %{GLOBAL} >>> WSGIDaemonProcess process processes=75 threads=1 >>> >>> >>> >>> Is it enough? Or can it handle only 75 concurrent requests? I don't know >>> how to synchronize apache and mod_wsgi settings. >>> >>> >>> -- >>> You received this message because you are subscribed to the Google >>> Groups "modwsgi" group. >>> To unsubscribe from this group and stop receiving emails from it, send >>> an email to [email protected]. >>> To view this discussion on the web visit >>> https://groups.google.com/d/msgid/modwsgi/bce72a22-5047-4d4d-a7cb-1657672b4d3ao%40googlegroups.com >>> >>> <https://groups.google.com/d/msgid/modwsgi/bce72a22-5047-4d4d-a7cb-1657672b4d3ao%40googlegroups.com?utm_medium=email&utm_source=footer> >>> . >>> >>> >>> >> -- >> You received this message because you are subscribed to the Google Groups >> "modwsgi" group. >> To unsubscribe from this group and stop receiving emails from it, send an >> email to [email protected]. >> To view this discussion on the web visit >> https://groups.google.com/d/msgid/modwsgi/df05d905-b28c-42ce-bc46-5b754e2ddcbeo%40googlegroups.com >> >> <https://groups.google.com/d/msgid/modwsgi/df05d905-b28c-42ce-bc46-5b754e2ddcbeo%40googlegroups.com?utm_medium=email&utm_source=footer> >> . >> >> >> > -- > You received this message because you are subscribed to the Google Groups > "modwsgi" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to [email protected] <javascript:>. > To view this discussion on the web visit > https://groups.google.com/d/msgid/modwsgi/ce91f94b-9c57-464a-9dd2-79d7ad3184c6o%40googlegroups.com > > <https://groups.google.com/d/msgid/modwsgi/ce91f94b-9c57-464a-9dd2-79d7ad3184c6o%40googlegroups.com?utm_medium=email&utm_source=footer> > . > > >
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