Author Archives: gavinclarkeuk

Server Updates

(This change log includes all changes made to the server since the date
of the last release.  Some of these changes are new as of the
above date; some were introduced between the previous release and this one).

Changes mainly of interest to MusicBrainz Users

Advanced Relationships

The much awaited Advanced Relationships feature is finally complete. Advanced Relationships allows
the user to create a relationship between an Artist, Album, Track or URL. Each relationship may
have optional attributes (e.g. instrument performed, guest performance) and/or a date range
for which the links applies.

This feature is best explained with some examples:

  • Artist – Artist relationship: The Edge is a member of U2
  • Album – Artist relationship: Incendio has acoustic guitar performed by Jim Stubblefield
  • Artist – Track relationship: Symphony No. 5 was conduced by Herbert von Karajan
  • Artist – URL relationship: Morcheeba has a home page at:

To see a good example of what is possible with Advanced Relationships, take a look at the album Incendio.
For complete documentation on the AdvancedRelationships feature, please see the Advanced Relationships Documentation on the wiki.

Artist changes

It is now possible to enter multiple artists with the same name. If you are adding an artist with the same
(or very similar) name to an existing artist, you will be prompted to enter an artist comment. This short artist
comment is used to differentiate this artist from other similar artists and will be shown whenever
artists appear in a list and the user needs to chose the correct artist.

Artists can now also be differentiated as a Group or as a Person (via the add or edit artist pages). Artists
can also have formed/born or dissolved/died dates (for groups and persons, respectively).

Moderating and Voting now requires a verified email address

As per discussion on the mb-users mailing list, users must now provide a verified email address
in order to vote or moderate. Hopefully this will increase the communication between moderators
and reduce the number of random voters.

New Preference: “Show ‘Inline’ Moderations”

Due to problems with some new moderators randomly voting NO on moderations, we have
turned off showing random moderations in the inline moderation i-frame. The inline moderation feature
is now only available to moderators who have had their account for more than two weeks
and will be disabled by default.

If you do opt to be shown inline moderations, then they will no longer
include moderations unrelated to the page you’re on.  (Previously
the system would select a moderation for the artist you’re looking at,
or otherwise one of your subscribed artists, or otherwise a related artist,
or otherwise any artist.  Now that final part has been removed).


  • JMP3Rename and MP3Tag were added to the related projects page.
  • The completely out of date and improbable design for MusicBrainz II has been removed from the DB Structure pages. Please
    refer to the more up to date MusicBrainz database structure page.
  • The funky “A” graphic that used to indicate an automoderation has been replaced by an (automod) text in a smaller font on the left hand side.

Changes mainly of interest to MusicBrainz Administrators has been cleaned up a bit. 
You can now use it to create the database (and user, and language, etc)
but with no tables in it: ./admin/ --createdb --empty-database.

If you try to import the wrong tar files (where the schema sequence
of the tar file doesn’t match that of your database), then previously would decompress all of the tar files, then find the error
(and then delete all the decompressed files).  It now finds the
error much sooner, without wasting all that time decompressing the
tar files first.

The Pending/PendingData tables are now built in to the main SQL scripts;
all MusicBrainz databases (including replication masters, and replication
slaves, and ones that aren’t replicating at all) will always include these

Bugs and RFEs Closed

Dave Evans and Robert Kaye

TRM Database Pruned

At about 1100hrs UTC on January 25th the TRM database
was “pruned” again.  Here are the pertinent facts and figures:

  • the criterion used was: select trm from trm where lookupcount > 0;
  • before the prune,
    • the TRM server contained 3540483 TRMs,
    • the MB database contained 2199812 TRMs, of which 206335 had never been looked up
  • after the prune,
    • the TRM server contained 1993316 TRMs
    • although the sigserver said “Read 1978201 total signatures from all indexes”

For pretty pictures illustrating this, check out our
MRTG pages.

See server news for details of previous pruning.

Server Updates

(This change log includes all changes made to the server since the date
of the last release.  Some of these changes are new as of the
above date; some were introduced between the previous release and this one).

Changes mainly of interest to MusicBrainz Users

Artist Subscriptions Made Public

So far your list of subscribed artists has always been completely
private – no-one could see which artists you’re subscribed to, and
no-one could see who is subscribed to any given artist. 
This is now changing.

A new preference has been added, called
“Allow other users to see my subscribed artists“. 
The default setting of this new preference is ON, the opposite of
the previous behaviour, meaning that your artist subscription list
will become public
.  If you don’t want your subscription list to
become public, you have 30 days from the date of this release
to log in and change this preference to “off”.  (You can change the
setting at any time, but if you want to be sure that no-one ever sees
your subscription list, you’ll have to change it to “off” within the first
30 days).

From the date of this release, you can
see how many users are subscribed to any given artist, including
users who have are “privately” subscribed.  However you won’t
immediately be able to see a list of users subscribed to an artist, or
vice versa. 
From 30 days after this release,
you’ll be able to see other users’ subscription lists (if their preferences
let you), and you can see what users are subscribed to any given
artist (but only those users whose lists are “public”). 
During the first 30 days those pages will simply show an error message.

Please read these notes about this
feature if you are concerned about the privacy implications.

New Preference: “When I Vote, Mail Me Notes”

A new preference has been added: “When I vote on a moderation,
mail me all future notes for that moderation”.  Hopefully
the meaning of this is quite clear.  The setting is checked
as each note is added, so you can globally turn this
behaviour on or off for all moderations (i.e. you can’t have this
option “on” for some moderations and “off” for others).

If you are an “Automatic Moderator”

The search page will
now notify you whenever there are any elections in which you may
participate (but have not yet done so).

There is a new preference, “Enable auto-moderator privileges”. 
If you turn this setting off, you can temporarily revoke your automod
privilege from yourself, allowing you to put some moderation to the vote
where it would otherwise have been automatically applied.  To
regain your automod privilege, simply
return to your preferences page and re-enable
the option.  This setting is not saved to the database; if you log
out and in again, the option will always be reset to “on”.

When nominating another user for auto-moderator status, there is now a
“confirm” page, so it’s harder to accidentally nominate someone.


When editing a track, the allowed track number range is
shown and checked against.

The Albums with superfluous data tracks
report now only shows tracks if they are the last track on the album
in question.

The sidebar “Quick Search” now includes search for Editor
(aka user, aka moderator).

On the preferences page, most options now have HTML labels (so you can click
on the text next to the tick box, as well as the tick box itself).  The
voting buttons on the main voting pages have been re-arranged to be easier
to read.  (Changes by Eli Miller – thanks!)

The “login” page is now never shown to logged-in users.  This happened
from time to time, and was always very confusing when it did.  The HTML
for the login box has also been tidied up.  One side-effect of this is
that the odd “jumping” behaviour seen by some Mozilla / Firefox users seems
to have been fixed.

If you use the “Picard” Tagger, then the
artist “album list” page now includes “tagger” links on all the
albums.  Also, the problem whereby sometimes you would see the “Nothing
to see here, move along” page has been fixed.

If you use the “Use Javascript to move the input focus when the page loads”
preference (which is on by default), then the tagger “lookup” page now
doesn’t move the focus, but the “submit a new CD” page

Each album now includes an “Edit releases” link at the bottom, next to where
the releases are shown.

has contributed search
plugins for Firefox

The “Reveal my e-mail address” option has been removed from the moderation
note window.

The album “release editor” now checks for valid dates.

The main artist page no longer shows the “more…” link for related artists
when there are, in fact, no more related artists to show.  (patch by
Matthew Exon)

You can now search for moderations by date / time:
example one,
example two
Searching for moderations (when your search includes both open and closed
moderations) is faster now, after
work by Yary Hluchan
.  Thanks Yary!

From a moderator’s “profile” page, you can now search for their
Deleted Moderations.

When editing your own profile, you can
re-send yourself a “confirm my e-mail address” message at any time,
without having to change your e-mail address to something else and
back again. 
P.S.: all user accounts which have a
stored e-mail address have now had that address validated at least once.

Various things in moderation notes are now automatically turned into
hyperlinks to moderations: e.g. “moderation #123”,
auto hyperlinks in mod notes to other mods: e.g. “moderation #123”,
“mod 245725” or “edit #36483” would all become links to their respective

New and Changed Documentation

The page about disc IDs contained a link to what
is now some rubbishy “link farm” web site; that link has therefore been
ruaok’s bio has been updated. 
The home page contained some invalid HTML, which has now
been fixed. 

Changes mainly of interest to MusicBrainz Server Programmers

The INSTALL file has been updated; PostgreSQL 7.4 or later is required,
and the list of dependencies from CPAN has been updated. 
Also a link to the DebianServerSetup
wiki page
has been added.

admin/RemoveOldSessions now also removes orphaned lock files.

admin/ now correctly sets the next sequence values
on the three “*_open” tables.  (This bug would manifest itself as
duplicate key errors whenever the moderation was closed).

The URL rewriting (e.g. of /artist/GUID etc) is now implemented
via MusicBrainz::Server::Handlers, not mod_rewrite.  In doing so
it’s now possible to use the “/artist/…” URL space for other things, e.g.
HTML pages (note: this page currently gives an error).

The SQL scripts have been tidied up (sorted, layout standardised etc). 
DropViews.sql now drops the views, not creates them 🙂

Artists, users and countries are now cached using memcached
The country list is no longer stored in each user’s %session.

The MusicBrainz::Server::DateTime module has been added. 
The MusicBrainz::Server::DeferredUpdate module has been rewritten
somewhat, including the ability to handle deadlocks. 

You can now customise the cookie name used (the default is
We now check for, trap, and work around HTML::Mason‘s unhelpful
behaviour of turning repeated arguments into an array reference.

Extra logging has been added TRM requests and to the
TrackInfoFromTRMId query.  In the latter query,
results are limited to 100 tracks, and looking up the “silence” TRM is now

Bugs and RFEs Closed

Dave Evans

TRM Database Pruned

At about 2300hrs UTC on January 25th the TRM database
was “pruned” again. 
As we did last time, we removed all TRMs apart from the ones attached to
MusicBrainz tracks, this time using the additional criterion that
the TRM had to have been looked up at least twice. 

Just before the prune we had about 3633572 TRMs; after the prune we had about 1898435. 
For pretty pictures illustrating this, check out our
MRTG pages.

See also prune 1,
prune 2
and prune 3.

TRM Database Pruned

At about 2200hrs UTC on December 22nd the TRM database
was “pruned” again.
As we did last time, we removed all TRMs apart from the ones attached to
MusicBrainz tracks, where the TRM had been looked up at least once. 

Just before the prune we had about 3632598 TRMs; after the prune we had about 1989632. 
For pretty pictures illustrating this, check out our
MRTG pages.

See also Prune 1 and
Prune 2.

Server Updates

Changes mainly of interest to MusicBrainz Users

“Add Disc ID” Moderations

Whenever a disc ID is added to an existing album, it is now tracked
via an “Add Disc ID” moderation.  This applies both to disc IDs added
via the “CD lookup” interface (in which case the moderation is credited to
whoever performed the lookup), and also to those added as a result of a
FreeDB lookup (which fall under the “FreeDB” moderator). 
“Add Disc ID” moderations are not used in the case where
an album and a disc ID are added at the same time.


Annotations allow you to add notes to artists and albums. 
See How Annotations Work
and the Annotations FAQ
Thanks to Matthias Friedrich for building the foundations of this feature.

Bugs and RFEs Closed

Dave Evans

TRM Database Pruned

At about 1930hrs UTC on November 4th the TRM database
was “pruned” again (see the previous time
for more information about this). 
This time we removed all TRMs apart from the ones attached to
MusicBrainz tracks, where the TRM had been looked up at least once. 
This is a slightly more aggressive prune compared to the previous time. 

The TRM database is now about
40% of the size it was before, which (like last time) means that
it now fits easily into the server’s memory, so the server as a whole
runs quickly
and reliably.