One can optimise embedded mode for better performance, but I would put a big caveat on that and say is only probably a good idea to tackle if you have the one web service.
Running 260 micro services in one Apache httpd instance with mod_wsgi sounds rather scary either way. If you use mod_wsgi daemon mode where each micro service is in its own daemon process group (with a single process and small number of threads), then you might get away with it if these aren't high volume sites. That said, it is still a lot of managed daemon mode processes and not sure how well Apache will handle that, especially on restarts. Running them all in embedded mode would be a bad idea if each needs a separate Python interpreter context because the Apache worker process would be huge in size. If Apache httpd was configured for prefork MPM it would be even worse because you would have a potentially large number of worker processes since all are single thread. You also run a big risk with micro services interfering with each other in strange ways if running in different sub interpreter contexts of the one process due to how Python imports C extensions, and process wide environment variables work. Various third party Python packages with C extensions will not even work in Python sub interpreters (eg., anything related to numpy). You definitely want event or worker MPM, but even then, for 260 micro services, if they need separate Python interpreter context I can't really recommend it still because of size concerns for processes and potential cross sub interpreter interference. So the question is whether when you said 260 micro services you really mean independent web applications, or whether you just mean you have 260 different unique HTTP handlers as part of the one application, and thus in the same Python interpreter context. When people talk about such large number of micro services, usually you would not be aiming to host them in a single Apache instance but would instead be looking at running something which can handle things at scale like Kubernetes and creating separate deployments for them in that, relying on the ingress routing Kubernetes provides to get traffic to the appropriate micro service. Graham > On 23 Jul 2024, at 7:13 PM, RajKumar Ambadipelli <arkkidd...@gmail.com> wrote: > > mod_wsgi in embeded mode allows graceful restart, > What are the potential issues that I will face if I use mod_wsgi in embedded > mode instead of daemon mode, > I have to host around 260 python micro services. > > I have saw your blog on 'why are you using mod_wsgi in embedded mode?' But, I > unable to understand it very well in that you mentioned if we configure mpm > settings correctly then mod_wsgi in embedded mode is better than daemon mode > but not mentioned any configurations. > > Thanking you, > RajKumar > > On Tuesday 23 July 2024 at 13:04:50 UTC+5:30 Graham Dumpleton wrote: >>> On 23 Jul 2024, at 4:09 PM, RajKumar Ambadipelli <arkki...@gmail.com <>> >>> wrote: >>> >> >>> I am using Apache Server with mod_wsgi for hosting my python django >>> applications. Versions: Python 3.9.18 Server version: Apache/2.4.57 >>> mod-wsgi==4.7.1 >>> >>> One of my application virtual host configuration with two different >>> versions: >>> >> >>> ... >>> >> >>> So, When the source code is modified I can referesh the wsgi daemon using >>> touch /home/uoadmin/releases/1.1.0/students/conf/wsgi.py touch >>> /home/uoadmin/releases/1.0.0/students/conf/wsgi.py But when I added new >>> virtualhost to the above configuration file or else when I modify above >>> file the apache server unable to recognize modifications made the existing >>> virtualhost or newly added virtualhost until doing apachectl graceful (or) >>> apachectl restart (or) systemctl reload httpd but all the commands above >>> killing the ongoing requests forcefully directly terminating them. >>> >>> How to handle above situation. >>> >>> I want to know how will apache server recognize modifications to >>> virtualhost or newly added virtual host without reloading or restarting. >>> >> >> It can't, Apache httpd requires you to perform a restart (reload) in order >> to read changes to the Apache configuration files. That is how it works. >> >>> If above is not possible then is there anyway for restarting or reloading >>> apache server gracefully that is without terminating or killing other >>> ongoing requests or daemons while using apache server + mod_wsgi for >>> serving python with django? >>> >> >> Unfortunately not. The way Apache httpd manages the mod_wsgi daemon >> processes it will force a restart of those as well and even though Apache >> has a concept of graceful restart for it's own worker child processes, it >> doesn't extend that to managed process like the mod_wsgi daemon process and >> always restarts them immediately even when it is a graceful restart. There >> is nothing that can be done about this. >> >> The only way you could handle it if you need to be able to freely restart >> the main Apache server and have it not affect your Python web applications, >> is to run the Python web applications in distinct secondary web server >> processes and use the main Apache server to only proxy requests through to >> the secondary web servers. >> >> For the second web servers you could use mod_wsgi-express to make things >> easier, but you could also just not use mod_wsgi for the secondary web >> servers and use gunicorn or some other standalone Python WSGI/asyncio web >> server. >> >> Graham >> >> > > > -- > 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 modwsgi+unsubscr...@googlegroups.com > <mailto:modwsgi+unsubscr...@googlegroups.com>. > To view this discussion on the web visit > https://groups.google.com/d/msgid/modwsgi/d28663bc-a143-4e4f-949d-38e065c5ac9fn%40googlegroups.com > > <https://groups.google.com/d/msgid/modwsgi/d28663bc-a143-4e4f-949d-38e065c5ac9fn%40googlegroups.com?utm_medium=email&utm_source=footer>. -- You received this message because you are subscribed to the Google Groups "modwsgi" group. 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