Advice: django deploy vps error 502

56 views
Skip to first unread message

carlos

unread,
Feb 28, 2017, 3:51:31 PM2/28/17
to django...@googlegroups.com
Hi, all 
i have one vps for one application,

 vps description

16GB RAM
8 core processor
160 GB SSD
6TB Transfer

ok, i am using, uwsgi(2.0.14), nginx(1.10), mysql(5.6 )and ubuntu 16.04 LTS
this site working well when is visited or hits 1k even 6k, but when visited 10k or 12k
raiser error 502,

When I do a test of ab like these command line
ab -k -c 350 -n 20000 mydomain.com/
again raiser the error 502 in almost pages

these are configs all, wsgi, nginx

---- uwsgi script in /etc/uwsgi/app-availabre/website.ini -----

---- nginx conf in /etc/nginx/nginx.conf  ------

----- nginx vhost for my website mydpmain --------

How can I do so that the site does not throw the error?

Are the settings correct?

How can i know the layer support the vps?

In nginx how to stop the ab test, if many people do the test the web site throws the error 502 ngixn

I would appreciate it if someone gave me an idea or advice to configure better when there is high traffic or are doing ab test or another benchmarking test

cheers

--
att.
Carlos Rocha

Antonis Christofides

unread,
Mar 1, 2017, 1:59:00 AM3/1/17
to django...@googlegroups.com

Hello,

502 usually means the backend isn't running. After you finish the test, has the backend stopped running? Does it continue to throw 502s? If that is the case, I'm wildly guessing that processes might be growing and growing in memory and being eventually killed, but I don't really know. Do you have DEBUG = False? Does uwsgi write something in its log? Does the system write something in the syslog?

Regards,

Antonis

Antonis Christofides
http://djangodeployment.com
--
You received this message because you are subscribed to the Google Groups "Django users" group.
To unsubscribe from this group and stop receiving emails from it, send an email to django-users...@googlegroups.com.
To post to this group, send email to django...@googlegroups.com.
Visit this group at https://groups.google.com/group/django-users.
To view this discussion on the web visit https://groups.google.com/d/msgid/django-users/CAM-7rO1u-ih5pd9b2AEEDLBJRL7DUvhVDs9hfZjpyGH_fHKJbQ%40mail.gmail.com.
For more options, visit https://groups.google.com/d/optout.

carlos

unread,
Mar 1, 2017, 10:35:08 AM3/1/17
to django...@googlegroups.com
Hello, Antonis i have debug = false, yes
uwsgi dont write anything in the log :/
When i see the syslog i see error but not understand!
i share this output


thak for you help

To unsubscribe from this group and stop receiving emails from it, send an email to django-users+unsubscribe@googlegroups.com.

--
You received this message because you are subscribed to the Google Groups "Django users" group.
To unsubscribe from this group and stop receiving emails from it, send an email to django-users+unsubscribe@googlegroups.com.

To post to this group, send email to django...@googlegroups.com.
Visit this group at https://groups.google.com/group/django-users.
To view this discussion on the web visit https://groups.google.com/d/msgid/django-users/7624c177-e769-5fd6-496e-5ab07a927783%40djangodeployment.com.

For more options, visit https://groups.google.com/d/optout.



--
att.
Carlos Rocha

Antonis Christofides

unread,
Mar 2, 2017, 3:58:48 AM3/2/17
to django...@googlegroups.com

Your logs contain this:

    IOError: write error

However, more information is needed in order to understand what is going on. A simple "write error" on its own is insufficient—is it a hardware error? Too many open files? Out of disk space? Something else? If your system writes nothing else in /var/log/syslog at the time the error occurs, it may be the fault of uwsgi that it doesn't show more information about the error. Try to increase error message verbosity, if there is an option to do that.

Incidentally, the reason I migrated from uwsgi to gunicorn a few years ago was that every once in a while I was having a different problem with uwsgi, which was taking me hours to solve, largely because of insufficient documentation. After I switched to gunicorn I never looked back.

Regards,

Antonis

Antonis Christofides
http://djangodeployment.com
To unsubscribe from this group and stop receiving emails from it, send an email to django-users...@googlegroups.com.

To post to this group, send email to django...@googlegroups.com.
Visit this group at https://groups.google.com/group/django-users.

carlos

unread,
Mar 2, 2017, 12:56:55 PM3/2/17
to django...@googlegroups.com
Hi, ok i change the uwsgi to gunicorn right now, the problem with error 502 in this moment he disappeared
but the website in time it gets slow i dont now what is.
this is the all syslog for today i this moments

Mar  2 17:21:02 prueba gunicorn[1834]: [2017-03-02 17:21:02 +0000] [21405] [INFO] Booting worker with pid: 21405
Mar  2 17:25:01 prueba CRON[21454]: (root) CMD (command -v debian-sa1 > /dev/null && debian-sa1 1 1)
Mar  2 17:25:23 prueba gunicorn[1834]: [2017-03-02 17:25:23 +0000] [1834] [CRITICAL] WORKER TIMEOUT (pid:1844)
Mar  2 17:25:24 prueba gunicorn[1834]: [2017-03-02 17:25:24 +0000] [21459] [INFO] Booting worker with pid: 21459
Mar  2 17:35:01 prueba CRON[21563]: (root) CMD (command -v debian-sa1 > /dev/null && debian-sa1 1 1)
Mar  2 17:37:43 prueba gunicorn[1834]: /home/user/virtuales/website/local/lib/python2.7/site-packages/django/db/backends/mysql/base.py:110: Warning: Invalid utf8mb4 character string: 'F1613B'
Mar  2 17:37:43 prueba gunicorn[1834]:   return self.cursor.execute(query, args)
Mar  2 17:37:43 prueba gunicorn[1834]: /home/user/virtuales/website/local/lib/python2.7/site-packages/django/db/backends/mysql/base.py:110: Warning: Incorrect string value: '\xF1a;FBI...' for column 'user_agent' at row 1
Mar  2 17:37:43 prueba gunicorn[1834]:   return self.cursor.execute(query, args)
Mar  2 17:45:01 prueba CRON[21679]: (root) CMD (command -v debian-sa1 > /dev/null && debian-sa1 1 1)

any good config for nginx and gunicor for high traffic website??

or stop atack for many people make test like ab or other tools??


thank for you help



--
You received this message because you are subscribed to the Google Groups "Django users" group.
To unsubscribe from this group and stop receiving emails from it, send an email to django-users+unsubscribe@googlegroups.com.
To post to this group, send email to django...@googlegroups.com.
Visit this group at https://groups.google.com/group/django-users.
To view this discussion on the web visit https://groups.google.com/d/msgid/django-users/95dd8c2a-a68b-e5b4-d01d-6f7047202cc1%40djangodeployment.com.

For more options, visit https://groups.google.com/d/optout.



--
att.
Carlos Rocha

Antonis Christofides

unread,
Mar 2, 2017, 3:19:30 PM3/2/17
to django...@googlegroups.com

350 concurrent requests for a single machine is really much. If your app is very fast (e.g. by caching stuff a lot) it might be possible, but again it might require some tuning (for example, you could increase the gunicorn workers, but you need to be monitoring RAM consumption).

Do you really need 350 concurrent requests? Do you have 100 thousand users?

Antonis Christofides
http://djangodeployment.com
To unsubscribe from this group and stop receiving emails from it, send an email to django-users...@googlegroups.com.

To post to this group, send email to django...@googlegroups.com.
Visit this group at https://groups.google.com/group/django-users.

ludovic coues

unread,
Mar 3, 2017, 5:12:13 AM3/3/17
to django...@googlegroups.com
First message clearly state that the site is running fine with 6,000 visitors but have issues with 10,000 and more.

I'm most intrigued by the error message from MySQL on bad value for user agent. 

--
You received this message because you are subscribed to the Google Groups "Django users" group.
To unsubscribe from this group and stop receiving emails from it, send an email to django-users+unsubscribe@googlegroups.com.
To post to this group, send email to django...@googlegroups.com.
Visit this group at https://groups.google.com/group/django-users.
To view this discussion on the web visit https://groups.google.com/d/msgid/django-users/9284e7b8-4b8a-ec46-86a0-0c111bea8878%40djangodeployment.com.

Antonis Christofides

unread,
Mar 3, 2017, 5:37:59 AM3/3/17
to django...@googlegroups.com

Hi,

No, the first message says it works with 6k requests, of which 350 are concurrent, and doesn't work with 10k requests, of which 350 are concurrent. I merely made some back-of-the-napkin calculation with some very crude assumptions that 350 concurrent requests means you have a total of 100k users.

Regards,

Antonis

Antonis Christofides
http://djangodeployment.com
To unsubscribe from this group and stop receiving emails from it, send an email to django-users...@googlegroups.com.

To post to this group, send email to django...@googlegroups.com.
Visit this group at https://groups.google.com/group/django-users.

Daniel Hepper

unread,
Mar 7, 2017, 3:24:58 PM3/7/17
to Django users
Have a look at the Nginx module ngx_http_limit_req_module http://nginx.org/en/docs/http/ngx_http_limit_req_module.html

It allows you to limit the number of requests coming from a single address. This will probably be good enough to protect your site against a single person running ab, but it won't help against a proper DDoS attack.

Note that if you configure request limiting, that one person running ab will see errors, but the site will still work for anyone with a different IP address.

Hope that helps,

Daniel Hepper
To unsubscribe from this group and stop receiving emails from it, send an email to django-users...@googlegroups.com.
--
You received this message because you are subscribed to the Google Groups "Django users" group.
To unsubscribe from this group and stop receiving emails from it, send an email to django-users...@googlegroups.com.



--
att.
Carlos Rocha
--
You received this message because you are subscribed to the Google Groups "Django users" group.
To unsubscribe from this group and stop receiving emails from it, send an email to django-users...@googlegroups.com.

To post to this group, send email to django...@googlegroups.com.
Visit this group at https://groups.google.com/group/django-users.

--
You received this message because you are subscribed to the Google Groups "Django users" group.
To unsubscribe from this group and stop receiving emails from it, send an email to django-users...@googlegroups.com.

To post to this group, send email to django...@googlegroups.com.
Visit this group at https://groups.google.com/group/django-users.



--
att.
Carlos Rocha
Reply all
Reply to author
Forward
0 new messages