MetaBrainz Blog – MetaBrainz Foundation Community Blog

GSoC 2026: Modernize search storage format for the MusicBrainz database

Hello Everyone!

I’m Junaid (fettuccinae), an undergraduate Computer Science student at MGIT in India. This summer, I returned to MetaBrainz for my second GSoC project, where I worked on modernizing the MusicBrainz search under the mentorship of @kartikohri13 and @bitmap.

Project Overview:

MusicBrainz uses Apache Solr for search queries.
The previous implementation serialized all the response data into a single _store field.
The response writers reads _store, unmarshal the XML into a MusicBrainz XML Metadata Format (MMD) object and then serialize it again as XML or JSON for the response.
Few problems with this design are:
1. The indexer must construct a complete XML representation for every document, even though much of the same information is already available in normal Solr fields.
2. Most of the response data is stored in an opaque _store XML blob.

This project focused on moving the fields from one _store XML blob into their own flat fields (and JSON strings for nested fields).

The main goals of this project were:
1. Upgrade the Solr schema version from 1.5 to 1.7
2. Add fields (in configsets and indexer) to store all the data to be returned
3. Create response writers to return data from fields

The proposal for this project can be found here.

Growing pains: An update on the ListenBrainz service status

TL;DR: The growth of ListenBrainz has caught up with us, and our limited team is working on replacing central parts of our infrastructure. In the meantime, many features are unstable.

We are victims of our success. While in the long term this is a good problem to have, the sharp increase in users over the past year and a half has left our infrastructure cracking at the seams.

The good news: Your listens are being stored and imported without issue, even if there are delays. The core service is not compromised and we ask that you please keep submitting your listens. Your stats and playlists will be back!

However, we know that every other week your statistics, weekly playlists, and other features fail to generate for everyone, and cause crashes. We know it is frustrating, and we share that feeling.

While we are aware of the issues, fixing them is far from simple and requires us to completely rework all the crucial parts of our infrastructure.

In the interest of transparency, here are our main issues and what we are doing to fix them:

Picard 3 beta 9 released

Today, we have released MusicBrainz Picard 3 beta 9. This new versions brings several fixes over the last beta 7 (yes, we have skipped a beta number again), but also improvements and some new features.

Since we are near a final release, we tried to focus on quality of life and UI/UX improvements, some changes in the UI are quite important (release preferences UI is a complete overhaul, and the new About dialog also got a nice refresh). Among the highlights are:

MetaBrainz OAuth2 support and various OAuth improvements and bug fixes
ISRC reading (from files or CD) and optional submission
Word diff for tags in the Metadata Box
UI/UX improvements: Redesign of some option pages, along re-organization and performance improvements
Plugin API improvements

Download links and a detailed list of changes since Picard 3 beta 7 are available below. For a more detailed overview of what is new in Picard 3 please see the previous blog post Picard 3 Alpha Release.

While we have all the major features implemented and with the latest bug fixes we are confident in the current code, this is still a pre-release and there might be bugs. If you use this, do so with care, backup your files and please report any issues you encounter.

Some of the changes are also backward incompatible, hence we recommend you make a backup of your Picard.ini config file before trying the beta version. You can do so in Picard’s Options under Advanced > Maintenance.

MusicBrainz Server update, 2026-07-30

We’re happy to release our first MusicBrainz Server update since the schema change, following our migration of user accounts to the MetaBrainz website, which we’ve been spending most of our development time on until now. (This blog post also lags a bit behind the date we tagged the release, as you can tell from the title.)

In case you’re running a local MusicBrainz Server for development purposes, know that you can preserve the ability to log in without OAuth by adding sub LOCAL_ACCOUNTS_ENABLED { 1 } to lib/DBDefs.pm. (It’s already enabled by default if DEVELOPMENT_SERVER is.)

We’ve also made changes to digest authentication in the web service, detailed in the blog post linked above. If you don’t use digest authentication or any apps that do, it’s recommended you disable it from the Applications page.

A new release of MusicBrainz Docker is also available that matches this update of MusicBrainz Server. See the release notes for update instructions.

Thanks to julian45 and rinsuki for having contributed to the code. Thanks to affronttonature, Anesidora, arsinclair, chirlu, DarkAdonis, jesus2099, julian45, Lotheric, practik, rinsuki, and wileyfoxyx for having reported bugs and suggested improvements. Thanks to 7Stars, ApeKattQuest/MonkeyPython, Denatura, Early6431, EmO686, Flavia Telcean, GABG, Jeluang, JerryBest, KevinOpperman, LAY.JOSHI97, Lummerkurt, MFreedom89, Philipp Wolfer, ROManceJP, RalfZhang, The
ParaziT, afterthemagic, blueday, coffeeicus, cuhsy, jerry155756294, julian45, karpuzikov, meze, mfmeulenbelt, mr_monkey, salo.rock, sashimi3433, scientists360, silentbird, soonaf, sq, welikeheon, wileyfoxyx, and
zatto13 for updating the translations. And thanks to all others who tested the beta version!

The git tag is v-2026-07-30.1.

Spotify users will need to reconnect every 6 months to ListenBrainz

Spotify recently announced a drastic change in their API: connections to your account will now expire after 6 months, starting July 20th.

If you have your Spotify account connected to ListenBrainz, this means you will have to reconnect your Spotify account every 6 months, or ListenBrainz will not be able to keep your listening history in sync.
To get us started, all users will need to reconnect their Spotify account this coming Monday July 20th.

In addition to sending you an email, you will see an error message at the top of the page in ListenBrainz:

To minimize disruption and potential loss of listening history in the future, we will send you an email a month ahead, and one week ahead of the disconnection for you to disconnect and reconnect your Spotify account in your music services settings.

This is quite the thorn in our side but alas we have no other choice as the internet continues to enshittify.

Picard 3 beta 7 released

Today, we have released MusicBrainz Picard 3 beta 7. This new versions brings several fixes over the last beta 5 (yes, we have skipped a beta number again), but also improvements and some new features. Among the highlights are:

Option profiles can now be exported and imported as TOML files. This makes sharing options much easier. We are excited to see how this will be used by you all.
Artist name standardization can now be set to one of three values: no standardization, standardizing only variations of the artist name (“Beatles” vs. “The Beatles”) or standardizing also actual artist name changes (“Diddy”, who previously performed under the names “P. Diddy” and “Puff Daddy”). Standardizing name variations is the new default setting. See also the documentation.
Plugins can now implement custom CD ripper log file support, and there is built-in support for Cyanrip log files.
Picard can now much better handles wrongly or differently encoded filenames when loading files.
The setup wizard got some improvements, allowing users to configure their update notification settings for the app and plugins. Also the setup wizard can now be started again from the help menu. This is not yet the final version of the wizard, but it’s getting closer.
The User Guide was updated to document the latest changes.

Download links and a detailed list of changes since Picard 3 beta 5 are available below. For a more detailed overview of what is new in Picard 3 please see the previous blog post Picard 3 Alpha Release.

libdiscid 0.7.0

Version 0.7.0 of libdiscid has been released. libdiscid is a C library that allows applications to easily calculate MusicBrainz and freedb disc IDs from audio CDs or CD TOC details. It also can extract MCN and ISRC information.

This release fixes several issues with the build system and addresses compiler warnings. As a compile time option it is now possible to have methods returning URLs to use HTTPs instead of HTTP, see then changelog for details. Thanks to Riku Viitanen for this contribution. Also the binary packages now include a build for the Windows ARM64 platform.

Version 0.7.0 of libdiscid provides the following changes:

Current ListenBrainz server issues/high load, Part 2

This follow-up post covers how and why our servers are still being impacted, an explanation and examples of what we consider “botting” in ListenBrainz – and an apology, because our last post had some baaad comms!

Firstly, we are still experiencing massive server load from an increase in listen submissions related to the BTS fan exodus from last.fm (not all bad! more on this below) – and we are now being hit by another influx of AI scrapers.

Our apologies to our users, new and old, as we continue to work to mitigate the extra load. Remain assured that listens are not being lost – our processing queue is lagging behind, so listens may take (up to) hours to appear.

LB radio and the popularity endpoints have been temporarily disabled, to reduce server load.

Current ListenBrainz server issues/high load

Our apologies if you are experiencing outages or slowness on ListenBrainz currently. First it was AI scrapers, now it’s K-pop fans…

In short, we are experiencing massive server load from an unexpected and massive increase in listen submissions. Please bear with us as the small (but mighty) ListenBrainz team works on possible mitigations.

None of your listens are being lost, they are all sitting safely in our (massively overloaded) processing queue:

Picard 3 beta 5 released

Today, we’re making available the fifth beta version for the upcoming MusicBrainz Picard 3. This new versions brings some important changes:

The Options menu was reworked with generalized quick settings and easier access to scripts and options.
Handling of the Options dialog and the File Naming Script Editor was streamlined. Editing file naming scripts is now available in the menu in Options > File naming scripts > Edit scripts… or via Ctrl+Shift+S.
Option profiles can now be used with plugin settings, the “Attached option profiles” dialog allows changing selected options.
Plugins can be installed from a local directory without git, which simplifies local development and plugins created just for personal use.

Download links and a detailed list of changes since Picard 3 beta 4 are available below. For a more detailed overview of what is new in Picard 3 please see the previous blog post Picard 3 Alpha Release.