Schema change release, 2016-05-23 (with upgrade instructions)

Starting with this release, PostgreSQL 9.5 is now our minimum supported version. In order to import any future data sets, you will need to upgrade your installation to version 9.5.

Due to unforeseen problems with the Live Data Feed (AKA replication), users with slave databases will be required to first import a fresh data dump into their new 9.5 installation. We apologize that this is the case, but even had this stream not been broken, doing a clean import is faster and easier than doing the migration. For details on what happened during this rather lengthy schema change release, stay tuned for a post mortem blog post that covers the details.

If you have a non-replicated standalone database, you can use pg_upgrade and run ./upgrade.sh directly, but for simplicity we strongly recommend importing the latest data dump. Thus, we will only provide instructions for a clean import:

Make sure you have PostgreSQL 9.5 installed, and your database settings in lib/DBDefs.pm are updated to point to the 9.5 installation if you currently have an older version of postgres running. If you already have postgres 9.5 and want to replace the existing database there, you’ll need to drop it first (using dropdb or from within psql). Be careful that you’re not dropping any important data if this is a standalone database that you’ve made changes to.
Take down the web server running MusicBrainz, if you’re running a web server.
Turn off cron jobs if you are automatically updating the database via cron jobs.
Switch to the new code with git fetch origin followed by git checkout v-2016-05-23-schema-change-v2
Run cpanm --installdeps --notest . to ensure your perl-based dependencies are up to date. Note the dot at the end.
Set DB_SCHEMA_SEQUENCE to 23 in lib/DBDefs.pm
Download the latest data dumps. If you don’t need historical edit data, excluding the edit dump will speed up your import significantly.
Initialize a new database from the data dumps downloaded in step 7. Detailed instructions for doing this are located in INSTALL.md in the musicbrainz-server repository; if your data dumps are in /tmp, the command should simply be something like ./admin/InitDb.pl --createdb --import /tmp/mbdump*.tar.bz2.
After the import has finished, turn cron jobs back on, if applicable.
Restart the MusicBrainz web server, as well as memcached, if applicable.

We would like to thank bitmap, Gentlecat, zas, chirlu, reosarevok, gcilou for contributing directly to the release and we’d also like to thank all of the people who helped test, debug or otherwise offer support in this quite difficult release. Thank you!

And finally, here’s the list of changes you can expect in the upgrade:

Bug

[MBS-6406] – Admins can’t change email addresses
[MBS-8288] – Missing indexes for inverse lookup on *_gid_redirect tables
[MBS-8669] – Primary key for place table missing on old slaves
[MBS-8906] – Release pages ISE if CB doesn’t return JSON from its API for whatever reason
[MBS-8928] – If you submit the release editor without being logged in, it displays “[object Object]” as an error mesage
[MBS-8943] – Some pages do not respect DB_READ_ONLY setting

Improvement

[MBS-1873] – Fix vote tallies for edits
[MBS-3887] – Duplicate artist and label names not being checked against alias
[MBS-8287] – Log deleted entities that were in a subscribed collection
[MBS-8433] – Work attributes don’t have a uuid
[MBS-8716] – Store the edit data in a JSONB column
[MBS-8717] – Move the edit data to a separate table
[MBS-8838] – Add gids to all *_type* tables
[MBS-8873] – Convert and unify artist credit editors to React
[MBS-8909] – Add logos to IMDb and VGMdb links in the sidebar
[MBS-8939] – Update the Instagram logo used in the sidebar
[MBS-8940] – Let banner message editors dismiss the banner only temporarily

Task

[MBS-8656] – Bring edit table indexes back into sync
[MBS-8719] – Stop materializing of edit and vote counts
[MBS-8720] – Add a materialized view of edit note recipients
[MBS-8727] – Prevent duplicate votes
[MBS-8800] – Create the earthdistance extension and add a geodetic index for place coordinates
[MBS-8804] – Add BRIN indexes for timestamp columns
[MBS-8897] – add new entity icons
[MBS-8938] – Schema changes to support alternative tracklists

Server capacity update

Zas and I have been working hard to improve the capacity and stability of the site. In the last week, we’ve identified and fixed at least 3 problems with the search servers and we’ve added a timeout function that times out queries that take longer than 3 seconds. We think that the main cause of trouble was that queries were piling up after a slow query ran too long and that the servers never recovered from that and consequently crashed.

We won’t go as far as saying that the search servers are fixed — every time we have a smidgen of hope that things are improving, they crash again. Seemingly out of spite! So, the search servers are better. 😉

Zas has also made a number of changes to the gateways and how we rate limit our incoming traffic. The rate limiting is now being done in a smarter way that reduces the overall traffic on our web servers. Well done!

We’ve also increased our bandwidth budget by 4mbits per second, which makes the site feel considerably more responsive.

Let me put these improvement into numbers: About a week ago were were struggling to keep up 250 requests per second and the site felt very sluggish. Now we can handle 500 requests a second and the site feels considerably faster. For large chunks of the day we are managing to handle all the traffic we should handle. And, the search servers haven’t crashed in 4 days!

We hope that this will give us a solid base from which to release the scheme upgrade tomorrow. Then once that is complete, we will start work on moving to the new hosting company.

Thanks for being patient with us!

State of the Onion: MetaBrainz

In the past few weeks we’ve been hit with several traffic increases to MusicBrainz which is putting considerably more strain on our aging infrastructure than we’re happy with. If it seems that we’re not doing anything about it, that is because we’ve been busy behind the scenes trying to keep things moving forward. This sometimes doesn’t leave us a lot of time to keep the public informed on our work. Hopefully this blog post will fix this in the short term:

In 2011 we started to make plans to move MusicBrainz hosting into the cloud, but then out of the blue we were donated a pile of machines. There were so many machines that I postponed the cloud plans and prepared the donated machines for service. That has carried us for 4+ years with almost no hardware cost, which was really great. The plan was to move to the cloud sometime around 2015, but then I spent most of 2014/2015 dealing with conflicts in the team, putting us seriously behind schedule while our hardware decayed.

On top of that, we’ve recently had some “bad luck”. We have had some disrespectful commercial customers hit us really hard and we had to find and block them. We have had unexpected traffic spikes and when trying to address these unexpected traffic spikes, we had two more machines fail on us. These were the donated machines that we kept in reserve for just this moment. The loss of two machines caught us short on capacity to handle the increased demands on our servers.

So, now we face the tough question: Do we buy expensive hardware that we might use for 6 months (~$5000) or do we try and save the money and tough it out? I’d rather not spend so much money on such short term use if we can avoid it. We’re going to try and move to a new hosting facility somewhere in the EU, since that is where most of our users are.

Moving to a new hosting facility has an incredible number of dependencies that Christina (our Biz Dev manager), Zas and I have been working through. It may not seem like we have a plan, but we do, and we’re incredibly busy trying to make the plan happen. To give you a taste of what we’re up against:

We want to move our hosting to Europe and have a business presence in Europe in order to reduce the costs and inefficiencies of being a solely US based business. A lot of our traffic, customers and contractors are in the EU and it simply makes sense to have a presence here.
To establish a presence in the EU I needed local help to help with the business matters as well as researching and establishing an EU organization. So I needed to find a Biz Dev manager and that person is Christina.
Once Christina was on board she researched our options about what was suited for us. Getting that process moving involved getting certified documents from California, board approval for spending funds to establish the organization, EU labor law research, (and we needed to swap a board member, too!), hiring help to establish the org. and generally navigating the Spanish bureaucracy. (See this only slightly exaggerated short film for some clues of our ordeal.)
Once the org. had been established we needed to convince the bank to open a bank account for us. The draconian US banking laws extend worldwide and the local bank had to ensure that they were not opening themselves up to thousands of $$$ in accounting hassles just to allow a tiny non-profit to open a bank account. We finally have a bank account and have started paying our contractors with it!
At the same time we’re also working to set up an office for the growing team here in Barcelona. That required a byzantine process that barely started when you sign the lease. Getting power, internet and water set up has taken a frustratingly long time. Had I known how long, I would have stayed at my co-working space for a while longer while addressing hosting issues.
While Christina has been focused on the hardcore paperwork, Zas is keeping the site running, which itself requires many heroics. Zas and I have started planning the move to the EU hosting provider. We’ve got a 5-page document that collects some of the open questions and requirements around this process: https://docs.google.com/document/d/16KNm4KksNwz29Opk1aILOMtCmPIeXFuxxUjMoPT3th0/edit#heading=h.dpfvoz1idcro. Right now Zas and Bitmap are here in Barcelona and we’re going to work on establishing a formal plan for moving to the new hosting company. We’re currently comparing hosting company offerings – see what we’ve collected so far if you care to follow along. The amount of work required to make this happen is making my head hurt. (A special shoutout to KodeStar, lead developer of FanArt.tv, for providing a lot of useful feedback about our various options.)
While Christina, Zas and I have our hands full, Bitmap and Gentlecat continue to release new features and work on the schema change. Not to mention all the contributions from Freso and Reosarevok to keep the community happy and polite while we deal with less than optimal site conditions. That said, I am really happy and proud of my team, trying to keep things running in sub-optimal conditions.

This is just a snapshot of everything that is happening behind the scenes that will culminate with the goal of moving to a new hosting company and being set up in the EU. And mind you, we’re doing this with a minuscule budget trying to be careful of how we spent our money.

Server update, 2016-04-04

This is a small bug-fix release while we work on finishing the May schema change update. Thanks go to reosarevok and ethus3h for their patches this time around. The git tag is v-2016-04-04 and you can find the complete changelog below.

Bug

[MBS-8850] – No events tab for tags
[MBS-8861] – Vertical spacing off on editor profile if “last login” is missing (account admins only)
[MBS-8874] – Editing an entity sometimes shows it as a possible duplicate of itself
[MBS-8886] – Header menus should work without JavaScript

Improvement

[MBS-8591] – Increase pagination item count

Server update, 2016-03-21

The most noticeable change in this release is that we’re using Wikidata links to fetch images for any entity that has them. Thanks to Roman Tsukanov for working on this cool new feature! We’ve also made the header menus require clicks to open and close, and fixed several bugs listed below. The git tag is v-2016-03-21.

Bug

[MBS-7914] – alias list not included in track level artist credits when fetching release information
[MBS-8837] – Event edits fail to apply with ERROR: invalid input syntax for type time: “1970-01-01T19:00:00”
[MBS-8848] – Own private collections ignored on entity pages
[MBS-8858] – Edit medium edit stuck trying to use a deleted recording
[MBS-8862] – Search edits: release group condition is broken

Improvement

[MBS-6381] – Use Wikidata URLs to fetch images for entities
[MBS-8843] – Require clicking on the header menus to open them

New Feature

[MBS-6152] – Provide a better way to list private collections in /ws/2/release output

Task

[MBS-8805] – Drop the completely unused pre-NGS tables on totoro

May 2016 schema change release details

In about two months time we’ll have the next schema change release: May 16, 2016. Even after skipping the fall schema change release, this release is going to have few changes that will impact our downstream users. Most of the tickets in this release will make minor improvements to database indexes and edit tables. If you are one of the few users of our edit data, then you should delve deeper into the list of tickets in this release. For everyone else, I will summarize the tickets with a greater impact.

In a previous blog post we also talked about upgrading the minimum required version of postgres. We received no real feedback requesting for us to upgrade to 9.4, but we did receive some feedback that some people would prefer 9.5, which is our preference as well. Based on that feedback, we’re going to make PostgreSQL version 9.5 the minimum required version. If you’d like to run a MusicBrainz replicated instance via our Live Data Feed, you will need to run Postgres 9.5!

The official minimum supported Ubuntu release as of now is still Ubuntu 10.04 LTS (Lucid Lynx) which reached end-of-life a year ago. We will upgrade that to Ubuntu 14.04 LTS (Trusty Tahr) at the schema change release. In particular, this means that we might start using Perl 5.18 features in the MusicBrainz Server code (as opposed to Perl 5.10 currently).

We understand that this is potentially a lot of work for some of our users, but occasionally we need to upgrade our requirements. We try and limit these sorts of upgrades as much as possible, so please bear with us.

Finally onward to the details of the release. Please take a look at the list of issues that will be addressed in this release. The few tickets worth discussing in details are:

MBS-8838 – “Add gids to all *_type tables“. This ticket adds MBIDs (GIDs in schema lingo) to all of our tables that define a type for some database element. Given that we recommend that external users never reference our data by row ids, we really need to provide proper permanent MBIDs to all elements of our database.
MBS-6024 – “Support more than one barcode on same release (SQL edition)“. This ticket adds the ability for the database to contain more than one barcode for a given release. However, this ticket does not include the user interface portions of this feature. The team will add the user interface/edit portions of this feature in a later, non schema change release.
MBS-4501 – “Alternative tracklists“. This ticket creates a new feature that would allow an alternative tracklist to be used for a given release. This is a better solution for handling conflicts between our style guidelines and how the data appears on the release. It is also a more elegant solution for translations of releases into different languages.

As usual, we will post final details about the release shortly before the release happens. If you have any questions about this release, feel free to ask specific questions in the tickets or general questions in the comments below.

(Edited 2016-03-16 at 12:55 UTC to add the upgraded Ubuntu requirement.)

Server update, 2016-03-07

This release fixes the web service to support all the new entity types that can be added to collections since the last release, including to support submission, and introduces a few new browse requests (browsing collections by entity gid or editor name; browsing entities by collection gid). These are documented at https://musicbrainz.org/doc/Development/XML_Web_Service/Version_2.

Area pages now have a “Users” tab where you can see other editors from that area, provided they’ve filled out that info in their profile.

A “single sign-on” endpoint has been added for logging into our new community forum, to replace the previous OAuth2 method. The main benefit over OAuth2 is that it now keeps peoples’ usernames and email addresses in sync with their MusicBrainz account.

Thanks to Roman Tsukanov (Gentlecat) and Frederik “Freso” S. Olesen for their work on today’s release. The git tag is v-2016-03-07 and the complete changelog is below.

Bug

[MBS-3125] – collection queries via the webservice are broken
[MBS-5323] – GET request for releases in a collection returns unordered results
[MBS-8459] – WS doesn’t have work collection endpoints
[MBS-8651] – collection add and delete endpoints
[MBS-8652] – PUT requests for invalid webservice collection URLs return the same content as a GET
[MBS-8825] – Links in the header force the default cursor via CSS

Improvement

[MBS-6120] – web service browse release where collection equals mbid

New Feature

[MBS-6152] – Provide a better way to list private collections in /ws/2/release output
[MBS-6511] – Show tab for “editors” on an area page when logged in
[MBS-8839] – Implement Discourse SSO endpoint

Task

[MBS-8841] – Update links to forums
[MBS-8842] – Update Picard’s logo on https://musicbrainz.org/

Server update, 2016-02-22

New Style

The style of the website has changed to use our new logo and better match the rest of the *Brainz family. It may be rough around the edges in some areas, but we’ll continue to make improvements as we receive feedback. Thanks to Roman Tsukanov (Gentlecat) who did all of the initial work on this.

Other Changes

Nicolás Tamargo (reosarevok) has fixed our header menus to be clickable on touch devices, and we have some other fixes and improvements from Ulrich Klauer (chirlu) and myself listed below. The git tag for today’s release is v-2016-02-22.

Bug

[MBS-8007] – Can’t change collection type of existing collection
[MBS-8624] – Components for server-side rendering are not equivalent to TT macros
[MBS-8771] – Contact-URL on start page result in “Page Not Found”
[MBS-8772] – Big Audio Dynamite is high-lighted, but no open edits seem around
[MBS-8776] – JSON-formatted collection release list shows page total and not overall collection total
[MBS-8789] – “{user} has not tagged anything” in user/tags seems broken
[MBS-8801] – “A group of artists cannot have a gender” when removing the gender

Improvement

[MBS-739] – Menu items with dropdowns should not have actions under them (other than the drop down opening)
[MBS-6212] – No link to edit profile on the profile
[MBS-8004] – Extend collections to other entities
[MBS-8787] – Add CORS headers to JSON-LD responses
[MBS-8790] – “ended” shows differently in add and edit relationship edits

Task

[MBS-8778] – Point About → Team to meb.o/team
[MBS-8779] – Restructure footer and add MetaBrainz to it
[MBS-8784] – Add Triple J Unearthed to the Other DBs whitelist

Server update, 2016-02-08

This update hopefully fixes some issues with “Edit Medium” edits that, in rare cases, resulted in an incorrect track listing. Sometimes tracks were being inexplicably deleted. The git tag for today’s release is v-2016-02-08.

Bug

[MBS-8752] – Database inconsistencies when updating medium
[MBS-8765] – instrument_annotation should not be backed up in mbdump.tar.bz2
[MBS-8770] – Banner not displayed

Task

[MBS-7475] – Get rid of Algorithm::Merge

Server update, 2016-01-25

Backwards-Incompatible JSON Web Service Changes

In an effort to get our JSON Web Service out of “beta” status, we’ve made some backwards-incompatible changes to it in this release:

The video flag on recordings is now outputted as true or false instead of 1 or 0.
Empty relations arrays are not outputted for linked entities anymore, since linked entities never include relationships.
The iso_3166_1_codes, iso_3166_2_codes, and iso_3166_3_codes properties have been renamed to iso-3166-1-codes, iso-3166-2-codes, and iso-3166-3-codes, respectively. This only applies to lookup and browse requests; search requests already outputted these with hyphens.
The iso-3166- properties mentioned in the previous point are not outputted if they’re empty.

Some other changes to the web service have been made, but are considered additions (not changes to existing output), so hopefully shouldn’t cause any problems. You can review them in the changelog below.

Other Changes

An issue where entities deleted from the database (but still present in the cache) remained visible has hopefully been fixed. There are several other miscellaneous bug fixes linked below. Thanks again to Ulrich Klauer for his contributions. The git tag is v-2016-01-25.

Bug

[MBS-5676] – JSON relationships output doesn’t include target-type
[MBS-6166] – Deleted accounts can still have details edited
[MBS-7241] – Non-transactional cache means the cache can sometimes fail to delete entities that are gone at the database level
[MBS-7735] – ws/2: recording’s “video” flag inconsistent between xml and json
[MBS-7921] – Internal server error when requesting /ws/2/isrc as JSON
[MBS-8367] – ws2 JSON incorrectly returns non-included field as null value
[MBS-8396] – JSON output has no ordering key attribute for release group series
[MBS-8563] – Release & Release Group browse requests without type/status filters return results which contradicts the documentation
[MBS-8688] – Random tagged entity type display inconsistency in personal tag page
[MBS-8722] – Edit stuck trying to change the gender of a group
[MBS-8726] – Replicated updates don’t invalidate cache entries on slave servers
[MBS-8730] – Reordering of sub work parts causes unwanted reordering of main work parts
[MBS-8746] – JSON web service doesn’t distinguish between relationships not existing vs. not being loaded