close_if_unusuable_or_obsolete should handle InterfaceError

[Raymond Penners]

With Django 1.6.2 I ran into the following stack trace:

...
    close_old_connections()
  File "/somewhere/virtualenv/local/lib/python2.7/site-packages/django/db/__init__.py", line 94, in close_old_connections
    conn.close_if_unusable_or_obsolete()
  File "/somewhere/virtualenv/local/lib/python2.7/site-packages/django/db/backends/__init__.py", line 462, in close_if_unusable_or_obsolete
    if self.is_usable():
  File "/somewhere/virtualenv/local/lib/python2.7/site-packages/django/db/backends/postgresql_psycopg2/base.py", line 192, in is_usable
    self.connection.cursor().execute("SELECT 1")
InterfaceError: connection already closed
<... at 0xac6ec0c> failed with InterfaceError

I see that close_if_unusuable_or_obsolete gracefully handles DatabaseError exceptions. Shouldn't InterfaceError be caught as well?

FWIW -- I am invoking close_old_connections myself because I am making heavy use of greenlets. I would like to call a Django method to close connections if needed, without having to worry about exceptions like these.

[Tim Graham]

Can you please try with 1.6.4? This may have been fixed in #21202.

[Raymond Penners]

I cannot reproduce it with 1.6.4, thanks!