Important Update on Replication

We’ve been informed that some people have noticed their MusicBrainz slave servers have stopped applying replication packets. We’ve tracked the problem down and now have a fix for this problem.

How Do I Tell If I’m Affected?

To determine if you are affected, connect to the MusicBrainz PostgreSQL database (we recommend using ./admin/psql from your musicbrainz-server checkout) and run the following:

SELECT now() - last_replication_date FROM replication_control;

If you see a date that is larger than a few days, there’s a good chance you are affected by this bug and should upgrade.

How Do I Fix This?

Fixing this is easy, you simply need to update your Git checkout. We suggest the following:

cd musicbrainz-server
git fetch --tags origin
git checkout v-2013-10-14-replication-fix-2

EDIT: formerly used a different (broken) tag and recommended a different method of fetching tags.

When replication next runs, the data that cannot be applied will be rewritten and replication will continue as normal.

One thought on “Important Update on Replication

  1. Stewart Dickson

    I applied the update to my GIt checkout, but my replication seems to be stuck in a loop:
    bin/check-replication-lock
    Mon Feb 3 15:44:17 2014 : Continuing a previously aborted load
    … LAST_REPLICATION_SEQUENCE file missing or malformed
    This packet was produced (or begins) at 2013-11-27 18:00:19.389518+00
    LAST_TIMESTAMP file missing or malformed, setting to TIMESTAMP
    ./admin/psql
    musicbrainz=> SELECT now() – last_replication_date FROM replication_control;
    ?column?
    ————————
    68 days 04:32:11.01539
    (1 row)
    The replication is not progressing past 2013/11/27
    Thanks!

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