Re: Multi-Threaded Dev Server
Hi, I'd like to point out that as you've stated, django is deployed in mulit-threaded environments successfully, employing an app that makes use of geodjango in a multi-threaded environment is not. Justin (Bronn) will testify to this I'm sure (as I and others have run into this issue whilst attempting to deploy mod_wsgi/mod_python/others in a mutli-threaded environment. (This is due to the underlying libgeos c library not being thread safe itself) I should (and will) create a ticket to make this clear in the django docs for the geodjango parts, so that others may avoid the pain we went throught a few months back. Cheers, Matt 2008/11/17 Jacob Kaplan-Moss <[EMAIL PROTECTED]> > > On Mon, Nov 17, 2008 at 10:54 AM, Ludvig Ericson > <[EMAIL PROTECTED]> wrote: > > There are bugs. Django isn't thread-safe, and we know that. > > Um... > > That's just not true. At one point (two years ago?) it wasn't, but > these days Django's deployed all over the place in mutli-threaded > situations. If it wasn't threadsafe we'd hear about it. > > Jacob > > > > -- Cheers, Matt --~--~-~--~~~---~--~~ You received this message because you are subscribed to the Google Groups "Django developers" group. To post to this group, send email to django-developers@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-developers?hl=en -~--~~~~--~~--~--~---
Re: Multi-Threaded Dev Server
On Nov 17, 7:25 pm, "Jacob Kaplan-Moss" <[EMAIL PROTECTED]> wrote: > > That's just not true. At one point (two years ago?) it wasn't, but > these days Django's deployed all over the place in mutli-threaded > situations. If it wasn't threadsafe we'd hear about it. > As I understand it, there are some areas where you have to be careful. For example, you can't be sure that caching templates won't lead to problems, because there are some template tags where rendering state is held in the nodes rather than the context. This post may give more information: http://lucumr.pocoo.org/cogitations/2008/09/16/why-jinja-is-not-django-and-why-django-should-have-a-look-at-it/#comment-12073 If you ensure that templates are always compiled from source for each request, then this shouldn't bite you. Best regards, Vinay Sajip --~--~-~--~~~---~--~~ You received this message because you are subscribed to the Google Groups "Django developers" group. To post to this group, send email to django-developers@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-developers?hl=en -~--~~~~--~~--~--~---
Re: Multi-Threaded Dev Server
On Nov 17, 6:54 pm, Ludvig Ericson <[EMAIL PROTECTED]> wrote: > On Nov 16, 2008, at 07:26, Chris wrote: > > > 3. Fear of multi-threading bugs shouldn't be a reason to avoid multi- > > threading, especially when it could be very useful. We don't even know > > if there are multi-threading bugs. And even if there are, they can be > > fixed. > > There are bugs. Django isn't thread-safe, and we know that. Which bugs in particular? By all means, if you find one, report it. I have run Django with mod_wsgi threaded daemon mode with no ill effects for a long time. See http://code.djangoproject.com/wiki/DjangoSpecifications/Core/Threading , all bugs found during the review were fixed a long time ago (and only one of them, #6950, was serious-ish). --~--~-~--~~~---~--~~ You received this message because you are subscribed to the Google Groups "Django developers" group. To post to this group, send email to django-developers@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-developers?hl=en -~--~~~~--~~--~--~---
Re: Multi-Threaded Dev Server
On Mon, Nov 17, 2008 at 4:14 PM, matt westerburg <[EMAIL PROTECTED]> wrote: > Is there any documentation as to why Django is not threadsafe? It just > seems to me that with the Global Interpreter Lock and all, it would be > threadsafe. That wouldn't as nice as "really-really thread safe". You know, there are GIL-less Python implementations out there ;-) -- Leo Soto M. http://blog.leosoto.com --~--~-~--~~~---~--~~ You received this message because you are subscribed to the Google Groups "Django developers" group. To post to this group, send email to django-developers@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-developers?hl=en -~--~~~~--~~--~--~---
Re: Multi-Threaded Dev Server
On Mon, Nov 17, 2008 at 10:54 AM, Ludvig Ericson <[EMAIL PROTECTED]> wrote: > There are bugs. Django isn't thread-safe, and we know that. Um... That's just not true. At one point (two years ago?) it wasn't, but these days Django's deployed all over the place in mutli-threaded situations. If it wasn't threadsafe we'd hear about it. Jacob --~--~-~--~~~---~--~~ You received this message because you are subscribed to the Google Groups "Django developers" group. To post to this group, send email to django-developers@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-developers?hl=en -~--~~~~--~~--~--~---
Re: Multi-Threaded Dev Server
Is there any documentation as to why Django is not threadsafe? It just seems to me that with the Global Interpreter Lock and all, it would be threadsafe. I don't intend to start a flame, I am just curious about learning why this might be. I am favor of the mutlitprocess approach layed out by Ludvig. --~--~-~--~~~---~--~~ You received this message because you are subscribed to the Google Groups "Django developers" group. To post to this group, send email to django-developers@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-developers?hl=en -~--~~~~--~~--~--~---
Re: Multi-Threaded Dev Server
On Nov 16, 2008, at 07:26, Chris wrote: > 3. Fear of multi-threading bugs shouldn't be a reason to avoid multi- > threading, especially when it could be very useful. We don't even know > if there are multi-threading bugs. And even if there are, they can be > fixed. There are bugs. Django isn't thread-safe, and we know that. The best solution I can come up with would be to use the type of multitasking given by the processing library in py2.6. http://pypi.python.org/pypi/processing Ludvig Ericson --~--~-~--~~~---~--~~ You received this message because you are subscribed to the Google Groups "Django developers" group. To post to this group, send email to django-developers@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-developers?hl=en -~--~~~~--~~--~--~---
Re: Multi-Threaded Dev Server
The last thing new people need when they come in and start playing around with the dev server is to worry about all the issues that can come up with threading. I would never recommend to anyone who doesn't really know what they're doing and anyone who does can easily use any one of the number of solutions other than the dev server to test those setups. Keep it simple. Keep everyone sane. Even if it was added as some optional flag, I can guarantee that a number of people without enough of an understanding of threads are just going to enable it when they read about it thinking "threads make it faster" and thinking no more about it. I strongly urge this to not be added to what should be a simple dev server. On Sun, Nov 16, 2008 at 8:44 PM, David Cramer <[EMAIL PROTECTED]> wrote: > > I think I may have to actually agree that multi-threading is somewhat > needed, since it does limit these kind of features from working. I, > however, would deem it less a priority than most thing. If you can > write a patch for it (or if one exists, I didn't look) though, I don't > see any reason to not extend runserver to use it. > > On Nov 16, 6:45 am, Steve Holden <[EMAIL PROTECTED]> wrote: >> Julian wrote: >> > [...] I think some people want to use snippets like that [...] >> >> Wouldn't you agree that's a pretty feeble use case for something as >> potentially disruptive as multi-threaded serving? Particularly when the >> CherryPy alternative is so readily available. >> >> regards >> Steve >> -- >> Steve Holden+1 571 484 6266 +1 800 494 3119 >> Holden Web LLC http://www.holdenweb.com/ > > > -- Read my blog! I depend on your acceptance of my opinion! I am interesting! http://techblog.ironfroggy.com/ Follow me if you're into that sort of thing: http://www.twitter.com/ironfroggy --~--~-~--~~~---~--~~ You received this message because you are subscribed to the Google Groups "Django developers" group. To post to this group, send email to django-developers@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-developers?hl=en -~--~~~~--~~--~--~---
Re: Multi-Threaded Dev Server
I think I may have to actually agree that multi-threading is somewhat needed, since it does limit these kind of features from working. I, however, would deem it less a priority than most thing. If you can write a patch for it (or if one exists, I didn't look) though, I don't see any reason to not extend runserver to use it. On Nov 16, 6:45 am, Steve Holden <[EMAIL PROTECTED]> wrote: > Julian wrote: > > [...] I think some people want to use snippets like that [...] > > Wouldn't you agree that's a pretty feeble use case for something as > potentially disruptive as multi-threaded serving? Particularly when the > CherryPy alternative is so readily available. > > regards > Steve > -- > Steve Holden +1 571 484 6266 +1 800 494 3119 > Holden Web LLC http://www.holdenweb.com/ --~--~-~--~~~---~--~~ You received this message because you are subscribed to the Google Groups "Django developers" group. To post to this group, send email to django-developers@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-developers?hl=en -~--~~~~--~~--~--~---
Re: Multi-Threaded Dev Server
On Nov 16, 5:21 pm, "Waylan Limberg" <[EMAIL PROTECTED]> wrote: > On Sun, Nov 16, 2008 at 1:26 AM, Chris <[EMAIL PROTECTED]> wrote: > Especially considering there are already working solutions out there. > I seem to recall at least one management command someone put together > that runs a multithreaded cherrypy server. Why reinvent the wheel? > Lets focus on real, useful features. > Especially since Alex Gaynor helpfully posted a link to that specific solution earlier in this thread. Here it is again: http://www.oebfare.com/blog/2008/nov/03/writing-custom-management-command/ Regards, Vinay Sajip --~--~-~--~~~---~--~~ You received this message because you are subscribed to the Google Groups "Django developers" group. To post to this group, send email to django-developers@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-developers?hl=en -~--~~~~--~~--~--~---
Re: Multi-Threaded Dev Server
On Sun, Nov 16, 2008 at 1:26 AM, Chris <[EMAIL PROTECTED]> wrote: > > I think http://code.djangoproject.com/ticket/3357 should be given > another look at enabling optional multi-threading on the dev server. > 3. Fear of multi-threading bugs shouldn't be a reason to avoid multi- > threading, especially when it could be very useful. We don't even know > if there are multi-threading bugs. And even if there are, they can be > fixed. > Yet, the time spent identifying and fixing those buds means less time developing real features that I need and can use on my production sites. I'd say the developers time is better spent elsewhere. Especially considering there are already working solutions out there. I seem to recall at least one management command someone put together that runs a multithreaded cherrypy server. Why reinvent the wheel? Lets focus on real, useful features. -- Waylan Limberg [EMAIL PROTECTED] --~--~-~--~~~---~--~~ You received this message because you are subscribed to the Google Groups "Django developers" group. To post to this group, send email to django-developers@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-developers?hl=en -~--~~~~--~~--~--~---
Re: Multi-Threaded Dev Server
Julian wrote: > [...] I think some people want to use snippets like that [...] Wouldn't you agree that's a pretty feeble use case for something as potentially disruptive as multi-threaded serving? Particularly when the CherryPy alternative is so readily available. regards Steve -- Steve Holden+1 571 484 6266 +1 800 494 3119 Holden Web LLC http://www.holdenweb.com/ --~--~-~--~~~---~--~~ You received this message because you are subscribed to the Google Groups "Django developers" group. To post to this group, send email to django-developers@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-developers?hl=en -~--~~~~--~~--~--~---
Re: Multi-Threaded Dev Server
Some months ago I tried a snippet from djangosnippets.org which shows a upload progress bar. I think some people want to use snippets like that and a multi-threaded server would help you developing such applications. 2008/11/16 Vinay Sajip <[EMAIL PROTECTED]> > > > > On Nov 16, 6:26 am, Chris <[EMAIL PROTECTED]> wrote: > > I thinkhttp://code.djangoproject.com/ticket/3357should be given > > another look at enabling optional multi-threading on the dev server. > > > > Jacob previously closed this ticket, noting the patch could introduce > > threading bugs, and would provide functionality too similar to that of > > a production environment. > > > > This is my rationale to accept this ticket: > > 1. Ajax is very common place, and often requires a multi-threaded > > server. The dev server is very convenient, but by not providing multi- > > threading support, we're preventing it from being even more useful. > > 2. Since multi-threading would be an optional setting, the default > > scenario would still be single-threaded and would not break anything. > > Only those specifically desiring multi-threading would subject > > themselves to any unforeseen bugs. > > 3. Fear of multi-threading bugs shouldn't be a reason to avoid multi- > > threading, especially when it could be very useful. We don't even know > > if there are multi-threading bugs. And even if there are, they can be > > fixed. > > > > Regards, > > Chris > > I would second what David Cramer said. You don't need, in the general > case, need multi-threading on the server side for Ajax - it's really > about browser-side multi-threading. I'm not sure where your point 1 > comes from: I use AJAX with the standard, single-threading development > server all the time, and I have not encountered any issues at all. I'd > say leave it as it is, unless of course you have encountered some > specific problem relating to the single-threaded nature of the server. > In that case, please post some details. > > It's theoretically possible that with the server tied up with some > long-running request, the browser might time out before the server got > around to servicing an AJAX request which was next in line. However, > you should be able to configure client-side time-outs appropriately to > mitigate this. > > Regards, > > Vinay Sajip > > > --~--~-~--~~~---~--~~ You received this message because you are subscribed to the Google Groups "Django developers" group. To post to this group, send email to django-developers@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-developers?hl=en -~--~~~~--~~--~--~---
Re: Multi-Threaded Dev Server
On Nov 16, 6:26 am, Chris <[EMAIL PROTECTED]> wrote: > I thinkhttp://code.djangoproject.com/ticket/3357should be given > another look at enabling optional multi-threading on the dev server. > > Jacob previously closed this ticket, noting the patch could introduce > threading bugs, and would provide functionality too similar to that of > a production environment. > > This is my rationale to accept this ticket: > 1. Ajax is very common place, and often requires a multi-threaded > server. The dev server is very convenient, but by not providing multi- > threading support, we're preventing it from being even more useful. > 2. Since multi-threading would be an optional setting, the default > scenario would still be single-threaded and would not break anything. > Only those specifically desiring multi-threading would subject > themselves to any unforeseen bugs. > 3. Fear of multi-threading bugs shouldn't be a reason to avoid multi- > threading, especially when it could be very useful. We don't even know > if there are multi-threading bugs. And even if there are, they can be > fixed. > > Regards, > Chris I would second what David Cramer said. You don't need, in the general case, need multi-threading on the server side for Ajax - it's really about browser-side multi-threading. I'm not sure where your point 1 comes from: I use AJAX with the standard, single-threading development server all the time, and I have not encountered any issues at all. I'd say leave it as it is, unless of course you have encountered some specific problem relating to the single-threaded nature of the server. In that case, please post some details. It's theoretically possible that with the server tied up with some long-running request, the browser might time out before the server got around to servicing an AJAX request which was next in line. However, you should be able to configure client-side time-outs appropriately to mitigate this. Regards, Vinay Sajip --~--~-~--~~~---~--~~ You received this message because you are subscribed to the Google Groups "Django developers" group. To post to this group, send email to django-developers@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-developers?hl=en -~--~~~~--~~--~--~---
Re: Multi-Threaded Dev Server
If the patch that's currently on there works with no changes at all, I'd be hesitantly in favor of it, however if there any bugs, or other complications associated with it, my answer is to use a real server, setting up something like CherryPy locally is almost no effort, as seen here: http://www.oebfare.com/blog/2008/nov/03/writing-custom-management-command/ On Nov 16, 1:39 am, "Calvin Spealman" <[EMAIL PROTECTED]> wrote: > Does it need to be multi-threaded? Can you get a multi-process dev > server instead/also? > > > > On Sun, Nov 16, 2008 at 1:26 AM, Chris <[EMAIL PROTECTED]> wrote: > > > I thinkhttp://code.djangoproject.com/ticket/3357should be given > > another look at enabling optional multi-threading on the dev server. > > > Jacob previously closed this ticket, noting the patch could introduce > > threading bugs, and would provide functionality too similar to that of > > a production environment. > > > This is my rationale to accept this ticket: > > 1. Ajax is very common place, and often requires a multi-threaded > > server. The dev server is very convenient, but by not providing multi- > > threading support, we're preventing it from being even more useful. > > 2. Since multi-threading would be an optional setting, the default > > scenario would still be single-threaded and would not break anything. > > Only those specifically desiring multi-threading would subject > > themselves to any unforeseen bugs. > > 3. Fear of multi-threading bugs shouldn't be a reason to avoid multi- > > threading, especially when it could be very useful. We don't even know > > if there are multi-threading bugs. And even if there are, they can be > > fixed. > > > Regards, > > Chris > > -- > Read my blog! I depend on your acceptance of my opinion! I am > interesting!http://techblog.ironfroggy.com/ > Follow me if you're into that sort of thing:http://www.twitter.com/ironfroggy --~--~-~--~~~---~--~~ You received this message because you are subscribed to the Google Groups "Django developers" group. To post to this group, send email to django-developers@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-developers?hl=en -~--~~~~--~~--~--~---
Re: Multi-Threaded Dev Server
Does it need to be multi-threaded? Can you get a multi-process dev server instead/also? On Sun, Nov 16, 2008 at 1:26 AM, Chris <[EMAIL PROTECTED]> wrote: > > I think http://code.djangoproject.com/ticket/3357 should be given > another look at enabling optional multi-threading on the dev server. > > Jacob previously closed this ticket, noting the patch could introduce > threading bugs, and would provide functionality too similar to that of > a production environment. > > This is my rationale to accept this ticket: > 1. Ajax is very common place, and often requires a multi-threaded > server. The dev server is very convenient, but by not providing multi- > threading support, we're preventing it from being even more useful. > 2. Since multi-threading would be an optional setting, the default > scenario would still be single-threaded and would not break anything. > Only those specifically desiring multi-threading would subject > themselves to any unforeseen bugs. > 3. Fear of multi-threading bugs shouldn't be a reason to avoid multi- > threading, especially when it could be very useful. We don't even know > if there are multi-threading bugs. And even if there are, they can be > fixed. > > Regards, > Chris > > > > -- Read my blog! I depend on your acceptance of my opinion! I am interesting! http://techblog.ironfroggy.com/ Follow me if you're into that sort of thing: http://www.twitter.com/ironfroggy --~--~-~--~~~---~--~~ You received this message because you are subscribed to the Google Groups "Django developers" group. To post to this group, send email to django-developers@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-developers?hl=en -~--~~~~--~~--~--~---
