Re: Mysql connections after started django app

[cercatrova2]

On 04/07/14 16:11, Zemian Deng wrote: @cercatrova2, Yes, my original problem also was (and still is) with "MySQL Connection not available" after the 8 hours timeout inactivity on webfaction hosting. I have to restart it whenever this happens and then problem will go away. My current workaround is to schedule a dummy crontab to hit my site every hour to keep connection timeout refresh. Not ideal, but better than nothing so far. Thus I am looking for some help here. I really like MySQL, and I have tested my app with it already. It would be a bummer to switch because of this just now. I have tried direct usage of mysql.connection with just open and close a connection, and I do see the process go away properly. This plus the number of process list is increasing when I try simple "mysite" app lead me to think it might be django related. I am not sure. Further testing would be need to verify which end is causing the problem. But good to hear PostgreSQL doesn't have the same issue though. On Fri, Jul 4, 2014 at 1:06 AM, cercatrova2 <cercatro...@gmail.com> wrote: On 04/07/14 05:04, Zemian Deng wrote: Hi, In my django settings.py I have set CONN_MAX_AGE=0 to use with MySQL DB, which I understood as closing conn after each request. However when I start a simple "mysite" tutorial with "python manage.py runserver", I see immediately 3 connections in mysql that will not close but in Sleep mode. Did I miss something here? How do we ensure these connections will get closed while the app is running? mysql> show full processlist; +-----+------+-----------------+------+---------+------+-------+-----------------------+ | Id  | User | Host            | db   | Command | Time | State | Info                  | +-----+------+-----------------+------+---------+------+-------+-----------------------+ | 316 | root | localhost       | NULL | Query   |    0 | init  | show full processlist | | 317 | root | localhost:61695 | test | Sleep   |    3 |       | NULL                  | | 318 | root | localhost:61696 | test | Sleep   |    3 |       | NULL                  | | 319 | root | localhost:61697 | test | Sleep   |    3 |       | NULL                  | +-----+------+-----------------+------+---------+------+-------+-----------------------+ 4 rows in set (0.00 sec) Thanks Zemian -- 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+unsubscr...@googlegroups.com. To post to this group, send email to django-users@googlegroups.com. Visit this group at http://groups.google.com/group/django-users. To view this discussion on the web visit https://groups.google.com/d/msgid/django-users/33fcf156-42bd-4c07-819f-952a6b214b76%40googlegroups.com. For more options, visit https://groups.google.com/d/optout. Zemian - I've run into this also (I think), but the problem showed up in a different way. First, after the mysql connection timeout expired, django would throw a "MySQL Connection not available" exception when trying to access the server. Second, it would throw the same exception when trying to access the server after the server had been restarted. This was all with CONN_MAX_AGE=0 which as you say should make django open and close a connection on each request. I didn't have time to research things further, but it seems to me that the issue is with mysql.connector.django i.e. mysql connector/python - it is somehow keeping its connection open client-side and when that connection goes away server-side then it gives up. I tried to bring the problem to the attention of the developer on his blog but he didn't respond. I guess a bug report should be posted instead. Anyway, these problems, coupled with some unsolvable timezone issues when trying to use mezzanine django cms with mysql connector/python, forced me to switch to postgresql, which is working very well so far. Good luck. -- 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+unsubscr...@googlegroups.com. To post to this group, send email to django-users@googlegroups.com. Visit this group at http://groups.google.com/group/django-users. To view this discussion on the web visit https://groups.google.com/d/msgid/django-users/53B6363A.8090601%40gmail.com. For more options, visit https://groups.google.com/d/optout. -- 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+unsubscr...@googlegroups.com. To post to this group, send email to django-users@googlegroups.com. Visit this group at http://groups.google.com/group/django-users. To view this discussion on the web visit https://groups.google.com/d/msgid/django-users/CAK3t1y24v3x7Op1Gw1QgemyRsW4jCsJA6RvvQzpVJT0hE%3Dy6wQ%40mail.gmail.com. For more options, visit https://groups.google.com/d/optout. Well, I assume you're using python3 like I am. That's the only reason I tried mysql connector/python. If you're using python2 you could use the mysqldb adapter built into django which is very solid but isn't python3-compatible yet. But in any case all of the python database adapters when used with django require a django backend module. For most of the adapters the backend seems to be provided by the django project but with mysql connector/python it's provided by Oracle. You're right that In normal python usage mysql connector/python doesn't have the problem we're discussing (I also verified that), so the problem seems to be in just this Oracle-provided backend module and in that sense it is django-specific but not the django project's fault. I see in the django 1.7 doc that mysql connector/python is mentioned, so perhaps the django project will take a closer look at the backend. And perhaps mysqldb will be released for python3 soon. -- 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+unsubscr...@googlegroups.com. To post to this group, send email to django-users@googlegroups.com. Visit this group at http://groups.google.com/group/django-users. To view this discussion on the web visit https://groups.google.com/d/msgid/django-users/53B6BE58.7050606%40gmail.com. For more options, visit https://groups.google.com/d/optout.