| Brendan,
It seems from your last message that you have 2 things you want to do:
1. Maintain a consistent state between applications using the same database and 2. Use some kind of replication feature of your database vendor to have a mostly live backup.
For #1, I suggest you look into one of the change notification frameworks from Dave Neumann and Wirehose ( http://www.wirehose.com) or Project Wonder. These tools send messages between your instances to keep multiple instances of the same app and/or apps that are different but access the same model in sync.
For #2, again, your DB vendor is what matters. I would warn against updating multiple masters - there's always a chance that something can go awry. Unless it's absolutely necessary, it's a headache you don't want. I do believe OpenBase runs on 10.4 and has replication - you might want to look at their product.
If I'm misinterpreting something, please let me know!
Ken On Oct 17, 2005, at 1:16 PM, Brendan Duddridge wrote: Hi Ken,
I have multiple applications that share the same set of EOModels. Each application does reads and writes. One of the application does more reads than writes though, so I could possibly refactor it to do reads only and put the entities that need to be written to in a separate model.
I'd like to use replication for fail-over and load balancing purposes. There's a Postgres project called pgcluster that might work where you can update multiple masters, but I'm not sure if it's mature enough or ready for production work. Has anyone here used it? I'm not even sure if it runs on OS X Tiger Server, which is what we're using for our database server.
I was thinking of implementing the delegate editingContextDidSaveChanges() in order to redirect inserts, updates, and deletions to the replication master. Not sure if that would work though, but it's an idea.
Thanks,
____________________________________________________________________
Brendan Duddridge | CTO | 403-277-5591 x24 | [EMAIL PROTECTED]
ClickSpace Interactive Inc.
Suite L100, 239 - 10th Ave. SE
Calgary, AB T2G 0V9
http://www.clickspace.com On Oct 17, 2005, at 11:02 AM, Ken Anderson wrote: Brendan,
If you're using vendor supplied replication, I'm not sure why your webobjects app would be affected at all. Can you elaborate?
Is the purpose of the replication for backup, reporting, or online transactions? Some vendors do allow for transactions to be committed against both sides of a replicated environment, but the fallout and contingencies are often very messy.
Ken On Oct 17, 2005, at 12:56 PM, Brendan Duddridge wrote: Yes, we will be using vendor supplied replication. Either FrontBase or PostgreSQL (if we can find a good one). We're currently running FrontBase, but we're investigating a migration to PostgreSQL 8.0.3.
Thanks,
____________________________________________________________________
Brendan Duddridge | CTO | 403-277-5591 x24 | [EMAIL PROTECTED]
ClickSpace Interactive Inc.
Suite L100, 239 - 10th Ave. SE
Calgary, AB T2G 0V9
http://www.clickspace.com On Oct 17, 2005, at 10:50 AM, Ken Anderson wrote: What kind of database? It would be my suggestion to use database vendor supplied replication rather than rolling your own...
Ken On Oct 17, 2005, at 12:45 PM, Brendan Duddridge wrote: Hi,
Does anyone here have any experience with WebObjects and database replication? We'd like to implement a replicated database environment, but we have some questions about how our WO application will interact with it.
Is it possible to intercept updates, insertions, and deletions so they automatically go to the replication master and all selects can go to either the replication master or client?
Does that seem like a decent way to handle it? Or is it better to re-work the application so that updates go to one EOModel and selects to go another EOModel (and hence different database connections)?
Thanks,
____________________________________________________________________
Brendan Duddridge | CTO | 403-277-5591 x24 | [EMAIL PROTECTED]
ClickSpace Interactive Inc.
Suite L100, 239 - 10th Ave. SE
Calgary, AB T2G 0V9
http://www.clickspace.com _______________________________________________ Do not post admin requests to the list. They will be ignored. Help/Unsubscribe/Update your Subscription:
|
