Hi Graham, Thanks for your time.
We resolved the issue by adding the parameter connect-timeout to the deamon-process configuration as below WSGIDaemonProcess pe-ta-dev.knowdl.com python-path=/opt/data/knauthor/knauthor:/usr/lib64/python3.4/site-packages connect-timeout=300 Since our application need to support 5000 concurrent users we kept the time as 300 secs. Regards Mahesh On Fri, Jan 4, 2019 at 11:58 AM Graham Dumpleton <[email protected]> wrote: > I have been busy today so far so haven't had time to reply. > > Did you watch the video and read the blog post I linked? > > A couple of other videos worth watching to give you better background on > issues and how Apache/mod_wsgi works are: > > * https://www.youtube.com/watch?v=SGleKfigMsk&t=593s > > * https://www.youtube.com/watch?v=k6Erh7oHvns > > Watch the first of those especially and some of the problems with your > configuration should become more obvious. > > Graham > > On 4 Jan 2019, at 5:24 pm, Mahesh Vernekar <[email protected]> > wrote: > > Hi Graham, > > Did you get a chance to go through the apache configuration file ? > > Do you need more details ? > > > > Regards > > Mahesh Vernekar > > On Thu, Jan 3, 2019 at 3:56 PM Mahesh Vernekar <[email protected]> > wrote: > >> Hi Graham, >> >> I have attached the httpd.conf file contents. Will that help ? >> >> >> Regards >> >> Mahesh >> >> On Thu, Jan 3, 2019 at 12:04 PM Graham Dumpleton < >> [email protected]> wrote: >> >>> >>> >>> On 3 Jan 2019, at 5:26 pm, Mahesh Vernekar <[email protected]> >>> wrote: >>> >>> Hi Graham, >>> >>> Thanks for your response. Find my answers as below: >>> >>> What is your current mod_wsgi configuration? We are using deamon process >>> >>> >>> I need to see the actual configuration, just saying you are using daemon >>> mode is not enough as means I have to guess everything, which makes it >>> impossible to recommend anything. >>> >>> That is, I need to see the directives you put in the Apache >>> configuration file related to mod_wsgi. This is so I can see if embedded >>> mode is disabled, that daemon mode is configured appropriate for >>> processes/threads. Whether you set all the recommended timeouts etc etc. >>> >>> For a bit of background also suggest you watch: >>> >>> https://www.youtube.com/watch?v=CPz0s1CQsTE >>> >>> This blog post may also be relevant in upcoming discussion: >>> >>> http://blog.dscpl.com.au/2014/02/vertically-partitioning-python-web.html >>> >>> How long is typical request response time? Min : 2 secs / Max : 15 secs >>> >>> >>> That is a very large value for a web server that is dependent on >>> processes/threads and not async. >>> >>> Are the requests high CPU activities, or I/O bound waiting on a backend >>> service like a database? Though the application is connected to a backend >>> mariadb database there are no high cpu activities. The CPU does reaches 50% >>> during the tests. >>> >>> >>> Also, have you added any instrumentation your web application to >>> monitoring response times and/or mod_wsgi performance? >>> >>> >>> >>> Regards >>> >>> Mahesh >>> >>> >>> On Thu, Jan 3, 2019 at 3:06 AM Graham Dumpleton < >>> [email protected]> wrote: >>> >>>> What is your current mod_wsgi configuration? >>>> >>>> How long is typical request response time? >>>> >>>> Are the requests high CPU activities, or I/O bound waiting on a backend >>>> service like a database? >>>> >>>> On 3 Jan 2019, at 2:12 am, Mahesh Vernekar <[email protected]> >>>> wrote: >>>> >>>> We are hosting a web application with configuration as below: >>>> Application: Apache 2.4 / Python 3.4 / Django 2.0 >>>> >>>> Database servers x 6 : 32 GB / 8 cores behind load balancer >>>> Web servers x 6 : 4 GB / 2 cores behind load balancer >>>> >>>> Setup is in AWS so we are using AWS-Elastic load balancer. >>>> >>>> The application supports 2000 concurrent connections but failing for >>>> 2500 and beyond. >>>> In load testing around 1800 requests are failing out of 3.5 lakh total >>>> requests. >>>> >>>> In the apache error log we are seeing the error message as below ? >>>> >>>> [Wed Jan 02 14:05:53.349209 2019] [wsgi:error] [pid 21559:tid >>>> 139722408036096] (11)Resource temporarily unavailable: [client >>>> 172.31.12.61:51748] mod_wsgi (pid=21559): Unable to connect to WSGI >>>> daemon process 'pe-ta-dev.knowdl.com' on >>>> '/run/httpd/wsgi.21472.0.1.sock' after multiple attempts as listener >>>> backlog limit was exceeded or the socket does not exist. >>>> >>>> >>>> Any idea how we can resolve the issue ? >>>> >>>> >>>> >>>> Regards >>>> >>>> Mahesh >>>> >>>> -- >>>> 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 post to this group, send email to [email protected]. >>>> Visit this group at https://groups.google.com/group/modwsgi. >>>> For more options, visit https://groups.google.com/d/optout. >>>> >>>> >>>> >>>> -- >>>> You received this message because you are subscribed to a topic in the >>>> Google Groups "modwsgi" group. >>>> To unsubscribe from this topic, visit >>>> https://groups.google.com/d/topic/modwsgi/aIcET2VqJbA/unsubscribe. >>>> To unsubscribe from this group and all its topics, send an email to >>>> [email protected]. >>>> To post to this group, send email to [email protected]. >>>> Visit this group at https://groups.google.com/group/modwsgi. >>>> For more options, visit https://groups.google.com/d/optout. >>>> >>> >>> -- >>> 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 post to this group, send email to [email protected]. >>> Visit this group at https://groups.google.com/group/modwsgi. >>> For more options, visit https://groups.google.com/d/optout. >>> >>> >>> >>> -- >>> You received this message because you are subscribed to a topic in the >>> Google Groups "modwsgi" group. >>> To unsubscribe from this topic, visit >>> https://groups.google.com/d/topic/modwsgi/aIcET2VqJbA/unsubscribe. >>> To unsubscribe from this group and all its topics, send an email to >>> [email protected]. >>> To post to this group, send email to [email protected]. >>> Visit this group at https://groups.google.com/group/modwsgi. >>> For more options, visit https://groups.google.com/d/optout. >>> >> > -- > 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 post to this group, send email to [email protected]. > Visit this group at https://groups.google.com/group/modwsgi. > For more options, visit https://groups.google.com/d/optout. > > > -- > You received this message because you are subscribed to a topic in the > Google Groups "modwsgi" group. > To unsubscribe from this topic, visit > https://groups.google.com/d/topic/modwsgi/aIcET2VqJbA/unsubscribe. > To unsubscribe from this group and all its topics, send an email to > [email protected]. > To post to this group, send email to [email protected]. > Visit this group at https://groups.google.com/group/modwsgi. > For more options, visit https://groups.google.com/d/optout. > -- 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 post to this group, send email to [email protected]. Visit this group at https://groups.google.com/group/modwsgi. For more options, visit https://groups.google.com/d/optout.
