Trac slow / unreachable objects / database locked

[cmarschalek]

Since I've upgraded trac to 0.11 (0.11.1 didn't fix this) it became very slow.

If you open a few changesets in tabs, they sometimes take very long to get ready, but when they do, they all load at the same time. While they're loading the apache process takes up pretty much the whole cpu. The speed somewhat improves but trac is a lot slower as a whole since the upgrade. Nothing else has changed on the server. Looking at my trac.log file I see lots of unreachable objects messages like:

2008-11-05 10:37:26,680 Trac[main] DEBUG: 880 unreachable objects found.
2008-11-05 10:37:29,217 Trac[main] DEBUG: Dispatching <Request "GET u'/changeset/12445'">
2008-11-05 10:37:29,233 Trac[session] DEBUG: Retrieving session for ID u'marschalek'
2008-11-05 10:37:29,250 Trac[chrome] DEBUG: Prepare chrome data for request
2008-11-05 10:37:36,715 Trac[main] DEBUG: 1533 unreachable objects found.
2008-11-05 10:37:37,171 Trac[main] DEBUG: Dispatching <Request "GET u'/changeset/12446'">
2008-11-05 10:37:37,195 Trac[session] DEBUG: Retrieving session for ID u'marschalek'
2008-11-05 10:37:37,211 Trac[chrome] DEBUG: Prepare chrome data for request
2008-11-05 10:37:39,828 Trac[main] DEBUG: 694 unreachable objects found.

Could this be the problem? At least the timestamps show a significant increase in time.

Rarely I also get database locked errors, which go away after a short while. Here's the last one I got:

How to Reproduce

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

(please provide additional details here)

System Information

Trac	0.11.1
Python	2.3.3 (#1, Nov 2 2005, 16:31:23) [GCC 3.3.3 (SuSE Linux)]
setuptools	0.6c8
SQLite	2.8.12
pysqlite	1.0.1
Genshi	0.5
mod_python	< 3.2
Subversion	1.3.0 (r17949)

Python Traceback

Traceback (most recent call last):
  File "/usr/lib/python2.3/site-packages/Trac-0.11.1-py2.3.egg/trac/web/main.py", line 423, in _dispatch_request
    dispatcher.dispatch(req)
  File "/usr/lib/python2.3/site-packages/Trac-0.11.1-py2.3.egg/trac/web/main.py", line 222, in dispatch
    req.session.save()
  File "/usr/lib/python2.3/site-packages/Trac-0.11.1-py2.3.egg/trac/web/session.py", line 97, in save
    (self.sid,))
  File "/usr/lib/python2.3/site-packages/Trac-0.11.1-py2.3.egg/trac/db/util.py", line 50, in execute
    return self.cursor.execute(sql_escape_percent(sql), args)
  File "/usr/lib/python2.3/site-packages/sqlite/main.py", line 237, in execute
    self.con._begin()
  File "/usr/lib/python2.3/site-packages/sqlite/main.py", line 503, in _begin
    self.db.execute("BEGIN")
OperationalError: database is locked

I don't know if these problems are related though.