Buildbot requires a connection to a database to maintain certain state
information, such as tracking pending build requests. By default this is
stored in a sqlite file called 'state.sqlite' in the base directory of your
master. This can be overridden with the db_url parameter.
The format of this parameter is completely documetned at http://www.sqlalchemy.org/docs/dialects/, but is generally of the form:
driver://[username:password@]host:port/database[?args]
For sqlite databases, since there is no host and port, relative paths are
specified with sqlite:/// and absolute paths with sqlite:////.
Examples:
Notes for particular database backends:
c['db_url'] = "sqlite:///state.sqlite"
No special configuration is required to use SQLite.
c['db_url'] = "mysql://user:pass@somehost.com/database_name?max_idle=300"
The max_idle argument for MySQL connections is unique to Buildbot, and
should be set to something less than the wait_timeout configured for your
server. This controls the SQLAlchemy pool_recycle parameter, which
defaults to no timeout. Setting this parameter ensures that connections are
closed and re-opened after the configured amount of idle time. If you see
errors such as _mysql_exceptions.OperationalError: (2006, 'MySQL server
has gone away'), this means your max_idle setting is probably too high.
show global variables like 'wait_timeout'; will show what the currently
configured wait_timeout is on your MySQL server.
Buildbot requires use_unique=True and charset=utf8, and will add
them automatically, so they do not need to be specified in db_url.
MySQL defaults to the MyISAM storage engine, but this can be overridden with
the storage_engine URL argument. Note that, because of InnoDB's
extremely short key length limitations, it cannot be used to run Buildbot. See
http://bugs.mysql.com/bug.php?id=4541 for more information.
Buildbot uses temporary tables internally to manage large transactions. MySQL
has trouble doing replication with temporary tables, so if you are using a
replicated MySQL installation, you may need to handle this situation carefully.
The MySQL documentation
(http://dev.mysql.com/doc/refman/5.5/en/replication-features-temptables.html)
recommends using --replicate-wild-ignore-table to ignore temporary
tables that should not be replicated. All Buildbot temporary tables begin with
bbtmp_, so an option such as
--replicate-wild-ignore-table=bbtmp_.* may help.
c['db_url'] = "postgresql://username@hostname/dbname"
No special configuration is required to use Postgres.