On Tue, Feb 23, 2010 at 03:43:42PM +0700, [email protected] wrote: > Hi. There were some inquiries recently on how to get scripts using slave > databases, in order to reduce load on the master databases. I've taken this > opportunity to improve the syntax and write improved documentation. The new > documentation is in lib/canonical/launchpad/doc/db-policy.txt and is > reproduced below. > > Storm Stores & Database Policies > ================================ > > Launchpad has multiple master and slave databases. Changes to data are > made on the master and replicated asynchronously to the slave > databases. Slave databases will usually lag a few seconds behind their > master. Under high load they may lag a few minutes behind, during > maintenance they may lag a few hours behind and if things explode > while admins are on holiday they may lag days behind. > > If know your code needs to change data, or must have the latest posible > information, you retrieve objects from the master databases that stores > the data for your database class. > > >>> from canonical.launchpad.interfaces.lpstorm import IMasterStore > >>> from lp.registry.model.person import Person > >>> import transaction > > >>> writable_janitor = IMasterStore(Person).find( > ... Person, Person.name == 'janitor').one()
All these examples deal with the Person class directly. A lot of scripts use getUtility(IFooSet) to get security proxied objects. Can you give an example of how that works? -- Björn Tillenius | https://launchpad.net/~bjornt _______________________________________________ Mailing list: https://launchpad.net/~launchpad-dev Post to : [email protected] Unsubscribe : https://launchpad.net/~launchpad-dev More help : https://help.launchpad.net/ListHelp
