On Jun 15, 6:18 pm, James Gregory <[email protected]> wrote: > I am creating a web app with Django. I use a local MySQL database to > store users etc, but also connect to a remote Oracle database to pull > in some information to display. > > Due to Django's lack of multiple database support I have written my > own very smalI Oracle wrapper, using cx_Oracle. In an effort to be > more efficient, I create a new Oracle connection when my oracle python > code is first included, and then only reconnect if the connection is > closed. I note that Django's own database wrapper code does the same > thing. > > This works fine when running with Django's development server, but if > I: > 1. Run my application via Apache and mod_wsgi > 2. Then hit the server with two requests in rapid succession > > The second request displays a database error of "ORA-24909: call in > progress. Current operation cancelled". It seems this is caused by > attempting to use a database connection/cursor before the last query > has finished - i.e. the Oracle client library doesn't like multiple > threads attempting to use the same cursor simultanously. > > Questions: > 1. Is this a bug in Oracle? I see some one web reference implying that > this is a bug in Oracle version 10.2.0.1, and that is indeed the > version I am using. However, I only get the error when multiple > threads are attempting to use the same connection at the same time, so > it might well be a valid error message regardless of version. > > 2. If it is not a bug in Oracle, then how does Django's own Oracle > wrapper avoid this problem? I was reading through the source but can't > see anything obvious. > > 3. If it is not a bug but Django's own wrapper doesn't deal with this > problem, how do I deal with it? Should I simply create a new database > connection for every single web request? > > James
Connections aren't thread safe - you have to ensure every thread gets its own connection. You can create a new connection every request or use a thread-local to cache connections. Miles --~--~---------~--~----~------------~-------~--~----~ You received this message because you are subscribed to the Google Groups "Django users" group. To post to this group, send email to [email protected] To unsubscribe from this group, send email to [email protected] For more options, visit this group at http://groups.google.com/group/django-users?hl=en -~----------~----~----~----~------~----~------~--~---
