Item13537: Cache failures on Foswiki.org

Edited the SKIN setting in SitePreferences. Save hangs - one occasion, it timed out in fcgi.

Other window reported the following error:

rollback ineffective with AutoCommit enabled at /usr/home/foswiki.org/public_html/lib/Foswiki/PageCache/DBI.pm line 115.

-- GeorgeClark - 18 Jul 2015

During the time of the failure there were a large number of errors in the apache log, all similar to:

[Sat Jul 18 16:12:18.260038 2015] [fcgid:warn] [pid 17206] [client 66.102.6.140:50051] mod_fcgid: stderr: ERROR: unable to create tables in Foswiki::PageCache::DBI: database is locked, referer: http://foswiki.org/Main/AsdfZxcv
[Sat Jul 18 16:12:18.260077 2015] [fcgid:warn] [pid 17206] [client 66.102.6.140:50051] mod_fcgid: stderr: DBD::SQLite::db do failed: database is locked [for Statement "      create table foswiki_cache_pages (, referer: http://foswiki.org/Main/AsdfZxcv
[Sat Jul 18 16:12:18.260081 2015] [fcgid:warn] [pid 17206] [client 66.102.6.140:50051] mod_fcgid: stderr:         topic varchar(255),, referer: http://foswiki.org/Main/AsdfZxcv
[Sat Jul 18 16:12:18.260085 2015] [fcgid:warn] [pid 17206] [client 66.102.6.140:50051] mod_fcgid: stderr:         variation varchar(1024),, referer: http://foswiki.org/Main/AsdfZxcv
[Sat Jul 18 16:12:18.260088 2015] [fcgid:warn] [pid 17206] [client 66.102.6.140:50051] mod_fcgid: stderr:         md5 char(32),, referer: http://foswiki.org/Main/AsdfZxcv
[Sat Jul 18 16:12:18.260091 2015] [fcgid:warn] [pid 17206] [client 66.102.6.140:50051] mod_fcgid: stderr:         contenttype varchar(255),, referer: http://foswiki.org/Main/AsdfZxcv
[Sat Jul 18 16:12:18.260095 2015] [fcgid:warn] [pid 17206] [client 66.102.6.140:50051] mod_fcgid: stderr:         lastmodified varchar(255),, referer: http://foswiki.org/Main/AsdfZxcv
[Sat Jul 18 16:12:18.260098 2015] [fcgid:warn] [pid 17206] [client 66.102.6.140:50051] mod_fcgid: stderr:         etag varchar(255),, referer: http://foswiki.org/Main/AsdfZxcv
[Sat Jul 18 16:12:18.260101 2015] [fcgid:warn] [pid 17206] [client 66.102.6.140:50051] mod_fcgid: stderr:         status int,, referer: http://foswiki.org/Main/AsdfZxcv
[Sat Jul 18 16:12:18.260104 2015] [fcgid:warn] [pid 17206] [client 66.102.6.140:50051] mod_fcgid: stderr:         location varchar(255),, referer: http://foswiki.org/Main/AsdfZxcv
[Sat Jul 18 16:12:18.260107 2015] [fcgid:warn] [pid 17206] [client 66.102.6.140:50051] mod_fcgid: stderr:         expire int,, referer: http://foswiki.org/Main/AsdfZxcv
[Sat Jul 18 16:12:18.260111 2015] [fcgid:warn] [pid 17206] [client 66.102.6.140:50051] mod_fcgid: stderr:         isdirty int, referer: http://foswiki.org/Main/AsdfZxcv
[Sat Jul 18 16:12:18.260114 2015] [fcgid:warn] [pid 17206] [client 66.102.6.140:50051] mod_fcgid: stderr:   ), referer: http://foswiki.org/Main/AsdfZxcv
[Sat Jul 18 16:12:18.260117 2015] [fcgid:warn] [pid 17206] [client 66.102.6.140:50051] mod_fcgid: stderr: "] at /usr/home/foswiki.org/public_html/lib/Foswi, referer: http://foswiki.org/Main/AsdfZxcv
[Sat Jul 18 16:12:18.267165 2015] [fcgid:warn] [pid 17206] [client 66.102.6.140:50051] mod_fcgid: stderr: ki/PageCache/DBI.pm line 599., referer: http://foswiki.org/Main/AsdfZxcv

-- GeorgeClark - 18 Jul 2015

Yes I've experienced the same editing SitePreferences. Save takes so long because all of the cache is invalidated and that takes probably too long for apache as it is configured on foswiki.org. So it tries to kill the fcgi backend being busy leaving a stale lock on behind on the sqlite. Maybe using a mysql store for the cache metadata works out better. We surely need to investigate whether a total cache invalidation editing SitePreferences is so inefficient.

The following processes try to rebuild the cache but run against the hanging lock. Only way to recover is to delete the sqlite.db file on disk.

-- MichaelDaum - 18 Jul 2015

Downgraded to Normal.

-- GeorgeClark - 24 Aug 2015

Problem still exists

-- BeatDoebeli - 12 Jul 2019 - 16:29

Commenting is disabled while not logged in