Re: mod_python, multiple django-sites, memory usage
If you are considering running mod_fcgi systems, take a loot at mod_wsgi first. It's quite stable already, the setup is not any more difficult than mod_fcgi and it's a lot more easy to configure the finer details. Additionally, some simplistic tests show quite good performance, although that's yet to be targeted with a more suitable benchmark. --~--~-~--~~~---~--~~ You received this message because you are subscribed to the Google Groups "Django users" group. To post to this group, send email to django-users@googlegroups.com To unsubscribe from this group, send email to [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/django-users?hl=en -~--~~~~--~~--~--~---
Re: mod_python, multiple django-sites, memory usage
hi I,am new one to django, I am very intrst to learn Django, so i install python latest verson, and try to install daango latest verson but it want;s's to configure .. mod_python module , can u help me am using WINDOWS XP SYSTEM now am working in PHP MYSQL USING XAMPLITE (APACHE +PHP + MYSQL Package) i read the documentation for mod_python intallation but i cant able to get ckear idea wher do iwant to configure path apache\bin i found APXS file ...I wwant to configure(write inside the apxs file ) or apache\conf\ httpd.config file... where do i want to write a configuration code , can u pls give me the details and code and were exactly write it please give me the step by step.. to run django . thanks what On Jul 24, 1:28 pm, Gábor Farkas <[EMAIL PROTECTED]> wrote: > hi, > > how does it work exactly, when i have multiple django sites running in > one apache server usingmod_python? > > for example, imagine that i have 10 django sites running in one apache > server. > > does that mean, that in every apache process, i have 10 python > interpreters loaded? > > or in other words, if i have 10 django sites in one apache, does it use > 10times more memory than when running only one django site? > > thanks, > gabor --~--~-~--~~~---~--~~ You received this message because you are subscribed to the Google Groups "Django users" group. To post to this group, send email to django-users@googlegroups.com To unsubscribe from this group, send email to [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/django-users?hl=en -~--~~~~--~~--~--~---
Re: mod_python, multiple django-sites, memory usage
On Jul 24, 8:30 pm, Gábor Farkas <[EMAIL PROTECTED]> wrote: > Graham Dumpleton wrote: > > So, the question is, what are you trying to achieve or want? Was there > > a specific reason for the question? Knowing what you are really trying > > to do, might be able to suggest others things you can read to learn > > how Apache manages processes and how Python sub interpreters are used > > in this scenario. > > thanks for the information. > > for various reasons, some of our django applications are running using > apache+fastcgi, and some using apache+mod_python. we were preferring > mod_python (because it's the "recommended" setup for django), > and only used the fastcgi-solution where we could not use mod_python > (again, various stupid reasons :) > > but now we will probably have to add more django applications to the > system, so i was thinking if it should be done using mod_python or > fastcgi (i am sorry but i did not consider mod_wsgi, because i had the > feeling that it's still "too new". btw. would you consider it > production-ready? (i understand that it's a stupid question :)) There will hopefully be a 1.0 release candidate for mod_wsgi made available in the next few days. Only reason it will not be a 1.0 release is that there is still a bit of extra documentation that I want to finish up first, especially in the area of how web hosting companies may make best use of it so we might finally get some good cheap Python hosting available. So, releasing it as 1.0c1 rather than 1.0 is partly to try and defer large scale adoption a bit longer so I can still find time to write the documentation instead of perhaps answering questions from a lot of new users. :-) > so from what i've read here, it seems fastcgi/mod_wsgi-daemon-mode would > be the safest route (i've read the discussion about psycopg2+decimal on > django-devel). > > btw. what do you think about having multiple apache-servers with > mod_python, each hosting only one django-application. > > would that be an overkill? > > p.s: the django-applications i am talking about are intranet-apps, so we > do not think there will be much load on them... Nothing wrong with using multiple Apache instances. When one goes that track the issue is more along the lines of the extra effort involved in setting them up and maintaining them and any proxy in front. If the load is indeed light and you can validate your applications are multithread safe, then running each server with 'worker' MPM and 2 child processes would probably be a reasonable solution which still keeps memory usage down thus allowing you to still run many servers on the one box. Graham --~--~-~--~~~---~--~~ You received this message because you are subscribed to the Google Groups "Django users" group. To post to this group, send email to django-users@googlegroups.com To unsubscribe from this group, send email to [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/django-users?hl=en -~--~~~~--~~--~--~---
Re: mod_python, multiple django-sites, memory usage
Graham Dumpleton wrote: > On Jul 24, 6:28 pm, Gábor Farkas <[EMAIL PROTECTED]> wrote: >> hi, >> >> how does it work exactly, when i have multiple django sites running in >> one apache server using mod_python? >> >> for example, imagine that i have 10 django sites running in one apache >> server. >> >> does that mean, that in every apache process, i have 10 python >> interpreters loaded? > > Yes. > >> or in other words, if i have 10 django sites in one apache, does it use >> 10times more memory than when running only one django site? > > More or less, yes. > > If you tested that your code on top of Django and any third party > modules you use is multithread safe then you can limit the overal > memory used across all processes by using the 'worker' MPM for Apache > rather than the 'prefork' MPM. This helps because with 'worker' you > run with a lot less Apache child processes than with 'prefork'. The > number of Apache child processes can still spike up with 'worker' MPM > when there is the demand, but as demand drops off, Apache will kill > off excess processes. Even so, that each instance occupies memory in > each process still means a lot of memory overall. > > If you need more control than that then you would need to explore > other options such as daemon mode of mod_wsgi or mod_fastcgi, which > both provide the ability to run each Django instance in a defined > number of distinct daemon processes. In the extreme case, you could > run Django on top of a Python WSGI server and run it in just a single > process behind Apache by proxying requests to it. > > Memory use of running multiple Django instances under Apache using > mod_python is only one of the problems that can arise in this > instance. Other problems are the ability for the Django instances to > interfere with each other due to C extension modules which haven't > been written properly to be used from multiple sub interpreters at the > same time, or even attempts to use different versions of a C extension > module from the different Django instances. Using mod_wsgi or > mod_fastcgi may therefore be a better solution given they allow > separation of the Django instances. > > So, the question is, what are you trying to achieve or want? Was there > a specific reason for the question? Knowing what you are really trying > to do, might be able to suggest others things you can read to learn > how Apache manages processes and how Python sub interpreters are used > in this scenario. thanks for the information. for various reasons, some of our django applications are running using apache+fastcgi, and some using apache+mod_python. we were preferring mod_python (because it's the "recommended" setup for django), and only used the fastcgi-solution where we could not use mod_python (again, various stupid reasons :) but now we will probably have to add more django applications to the system, so i was thinking if it should be done using mod_python or fastcgi (i am sorry but i did not consider mod_wsgi, because i had the feeling that it's still "too new". btw. would you consider it production-ready? (i understand that it's a stupid question :)) so from what i've read here, it seems fastcgi/mod_wsgi-daemon-mode would be the safest route (i've read the discussion about psycopg2+decimal on django-devel). btw. what do you think about having multiple apache-servers with mod_python, each hosting only one django-application. would that be an overkill? p.s: the django-applications i am talking about are intranet-apps, so we do not think there will be much load on them... thanks, gabor --~--~-~--~~~---~--~~ You received this message because you are subscribed to the Google Groups "Django users" group. To post to this group, send email to django-users@googlegroups.com To unsubscribe from this group, send email to [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/django-users?hl=en -~--~~~~--~~--~--~---
Re: mod_python, multiple django-sites, memory usage
On Jul 24, 7:53 pm, David Reynolds <[EMAIL PROTECTED]> wrote: > On 24 Jul 2007, at 10:35 am, Graham Dumpleton wrote: > > > Memory use of running multiple Django instances under Apache using > > mod_python is only one of the problems that can arise in this > > instance. Other problems are the ability for the Django instances to > > interfere with each other due to C extension modules which haven't > > been written properly to be used from multiple sub interpreters at the > > same time, or even attempts to use different versions of a C extension > > module from the different Django instances. Using mod_wsgi or > > mod_fastcgi may therefore be a better solution given they allow > > separation of the Django instances. > > I'm glad you say this, as this has been happening to me and I wasn't > sure what was going on. We have about 38 sites running on mod_python/ > apache and on odd occasions we get the wrong site appearing, although > a swift restart of apache seems to cure it. Seeing the completely wrong site is not something I would expect based on the problems I have seen so far. Generally it is much more subtle things causing strange Python exceptions. This doesn't mean it can't happen, as have seen one instance of the wrong site appearing before. All I could put it down to at the time was Apache not always selecting virtual host definitions correctly because of a ServerAlias in one VirtualHost overlapping with actual ServerName of another VirtualHost. > Presumably the more > sites we get, the worse this problem will get and it may be wise for > us to look into using mod_fastcgi in future. > > Does anyone have any experience of using fastcgi with 30 odd sites? Care to give mod_wsgi a go instead? :-) Grahamd --~--~-~--~~~---~--~~ You received this message because you are subscribed to the Google Groups "Django users" group. To post to this group, send email to django-users@googlegroups.com To unsubscribe from this group, send email to [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/django-users?hl=en -~--~~~~--~~--~--~---
Re: mod_python, multiple django-sites, memory usage
On 24 Jul 2007, at 10:35 am, Graham Dumpleton wrote: Memory use of running multiple Django instances under Apache using mod_python is only one of the problems that can arise in this instance. Other problems are the ability for the Django instances to interfere with each other due to C extension modules which haven't been written properly to be used from multiple sub interpreters at the same time, or even attempts to use different versions of a C extension module from the different Django instances. Using mod_wsgi or mod_fastcgi may therefore be a better solution given they allow separation of the Django instances. I'm glad you say this, as this has been happening to me and I wasn't sure what was going on. We have about 38 sites running on mod_python/ apache and on odd occasions we get the wrong site appearing, although a swift restart of apache seems to cure it. Presumably the more sites we get, the worse this problem will get and it may be wise for us to look into using mod_fastcgi in future. Does anyone have any experience of using fastcgi with 30 odd sites? Thanks, David -- David Reynolds [EMAIL PROTECTED] smime.p7s Description: S/MIME cryptographic signature
Re: mod_python, multiple django-sites, memory usage
On Jul 24, 6:28 pm, Gábor Farkas <[EMAIL PROTECTED]> wrote: > hi, > > how does it work exactly, when i have multiple django sites running in > one apache server using mod_python? > > for example, imagine that i have 10 django sites running in one apache > server. > > does that mean, that in every apache process, i have 10 python > interpreters loaded? Yes. > or in other words, if i have 10 django sites in one apache, does it use > 10times more memory than when running only one django site? More or less, yes. If you tested that your code on top of Django and any third party modules you use is multithread safe then you can limit the overal memory used across all processes by using the 'worker' MPM for Apache rather than the 'prefork' MPM. This helps because with 'worker' you run with a lot less Apache child processes than with 'prefork'. The number of Apache child processes can still spike up with 'worker' MPM when there is the demand, but as demand drops off, Apache will kill off excess processes. Even so, that each instance occupies memory in each process still means a lot of memory overall. If you need more control than that then you would need to explore other options such as daemon mode of mod_wsgi or mod_fastcgi, which both provide the ability to run each Django instance in a defined number of distinct daemon processes. In the extreme case, you could run Django on top of a Python WSGI server and run it in just a single process behind Apache by proxying requests to it. Memory use of running multiple Django instances under Apache using mod_python is only one of the problems that can arise in this instance. Other problems are the ability for the Django instances to interfere with each other due to C extension modules which haven't been written properly to be used from multiple sub interpreters at the same time, or even attempts to use different versions of a C extension module from the different Django instances. Using mod_wsgi or mod_fastcgi may therefore be a better solution given they allow separation of the Django instances. So, the question is, what are you trying to achieve or want? Was there a specific reason for the question? Knowing what you are really trying to do, might be able to suggest others things you can read to learn how Apache manages processes and how Python sub interpreters are used in this scenario. Graham --~--~-~--~~~---~--~~ You received this message because you are subscribed to the Google Groups "Django users" group. To post to this group, send email to django-users@googlegroups.com To unsubscribe from this group, send email to [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/django-users?hl=en -~--~~~~--~~--~--~---
