AA> Am 03.10.2007 um 12:36 schrieb Andrey Khavryuchenko:
AA> It's possible to use circular replication together with some free AA> load balancing software. As I've told earlier, I know perfectly about circular replication. AA> Then there's MySQL Proxy that allows you to manipulate queries on AA> their way to the server to implement load balancing and, in the near AA> future, connection pooling. With the embedded lua engine, it should be AA> even possible to do query redirection/filtering but I haven't AA> investigated it yet. So I think that in the middle/long term there's AA> no need to put more logic in this regard into Django. Reread what you've wrote: MySQL Proxy manipulates *queries*, not transactions. Imagine something like: sql: BEGIN TRANSACTION; sql: SELECT * FROM something WHERE id=198273; py: if queryset.count()==0: py: MyObject.objects.create(**data) sql: END TRANSACTION; MySQL proxy or any other query-level solution has no way to know that first select should go to the master server, so it would be routed to a slave, that, what a coinsidence, is a second behind the master and the master *just* got that specific record. Voila, duplicate records and you can't reproduce it unless you already know the cause. Transaction-level solution requires some effort from developer to tell which transactions modify data and which don't - exactly the stuff I wrote in the post [1]. Footnotes: [1] http://a.khavr.com/2007/10/01/how-to-use-mysql-replication-in-django/ -- Andrey V Khavryuchenko - http://a.khavr.com/ Django NewGate - http://www.kds.com.ua/djiggit/ Chytach - http://www.chytach.com/ --~--~---------~--~----~------------~-------~--~----~ You received this message because you are subscribed to the Google Groups "Django users" group. To post to this group, send email to django-users@googlegroups.com To unsubscribe from this group, send email to [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/django-users?hl=en -~----------~----~----~----~------~----~------~--~---
