Hi,
When working with large projects, it is sometimes the case that you run into
problems where some edge case causes a pathologically high number of queries
for processing a specific request. These cases are hard to debug, because it is
not always easy to reconstruct the edge-case and even identify the exact
request (because post-data is not always available). Django collects all the
queries on a connection if DEBUG=True, but when it's hard to reproduce, you
sometimes need some sort of monitoring in production, where DEBUG=True is not
really an option.
Something that could be very helpful is just to count the queries -- a counter
cab be incremented with no noticeable overhead in CursorWrapper, and it can be
reset and/or examined at request start/end points (even with a Middleware, as
long as we have them). This would enable a project to define alerts or errors
or whatever when there are two many database queries, at a level where enough
information can be given to help solve the problem.
Similar measures may be applicable to other resources as well, if they are
handled by thread-local objects like the database connections. I'm not sure
which ones apply.
Thoughts?
Thanks,
Shai.
