OperationalError: database is locked

[guest]

How to Reproduce

While doing a GET operation on /ticket/883, Trac issued an internal error.

I simply navigated to the page for 883 following some discussion of it yesterday.

Request parameters:

{'id': u'883'}

System Information

Trac	0.11.7
Python	2.6.6 (r266:84292, Dec 26 2010, 22:31:48) [GCC 4.4.5]
setuptools	0.6
SQLite	3.7.3
pysqlite	2.6.0
Genshi	0.6
Pygments	1.3.1
Monotone	interface: 12.1

Python Traceback

Traceback (most recent call last):
  File "/usr/lib/python2.6/dist-packages/trac/web/main.py", line 450, in _dispatch_request
    dispatcher.dispatch(req)
  File "/usr/lib/python2.6/dist-packages/trac/web/main.py", line 229, in dispatch
    req.session.save()
  File "/usr/lib/python2.6/dist-packages/trac/web/session.py", line 129, in save
    (self.last_visit, self.sid, authenticated))
  File "/usr/lib/python2.6/dist-packages/trac/db/util.py", line 64, in execute
    return self.cursor.execute(sql_escape_percent(sql), args)
  File "/usr/lib/python2.6/dist-packages/trac/db/sqlite_backend.py", line 80, in execute
    result = PyFormatCursor.execute(self, *args)
  File "/usr/lib/python2.6/dist-packages/trac/db/sqlite_backend.py", line 59, in execute
    args or [])
  File "/usr/lib/python2.6/dist-packages/trac/db/sqlite_backend.py", line 51, in _rollback_on_error
    return function(self, *args, **kwargs)
OperationalError: database is locked

[killyourtv]

This is due to the nature of sqlite. Something had the db locked. Try again a bit later and it'll work.

[killyourtv]

This will cease to be a problem when the DB is migrated to PostgreSQL.

[killyourtv]

Also: ​http://trac.edgewall.org/ticket/8708

[killyourtv]

A few reasons for the DB being locked.

• The DB could be locked while a backup is being taken
• The DB could be locked due to several accesses at once.