OK. Well it seems here is what goes on. The "read only" stance by Citrix is not that at all. You can use transactional replication but the Citrix servers that are configured for that secondary DB will update the primary DB (although I wouldn't do it with something big like a MF install). Anyway they recommend using the two-phase commit for the transactions. In other words the remote "read-only" DB will take the request from the Client MF server. Then instead of updating its DB it will pass the request up to the primary distributed database (the master) the master will make the change and all the replicas will receive it. So the initial comments of the remote machines not able to update (or having to update) the data store was incorrect. They have even outlined this and now recommend it in the advanced concepts guide(but they never mention what the check box does). Anyway for any of you that want to know, here ya go., Ron Oglesby Senior Technical Architect =20 RapidApp Office 312.372.7188 Mobile 312.961.2380 email roglesby@xxxxxxxxxxxx =20 -----Original Message----- From: Ron Oglesby=20 Sent: Monday, January 20, 2003 9:01 AM To: thin@xxxxxxxxxxxxx Subject: [THIN] SQL Replication possible long term problems? Ok. I have been working with a client on their XP migration. Hundreds of Servers across 4 data centers. We were going to use SQL 2k with Merge replication for the data stores. This worked great in a lab and seemed stabile as could be. Anyway Citrix told us that they wont support Merge replication only transitive (one-way, master -slave) replication. SO in thinking about this design change I started thinking about possible problems with this in a large env with lots of remote servers. I mean think about the simple things like the way the server will update the data store if a print driver (or anything else) is installed. Lets say that a driver is updated on a remote citrix server that talks to the DataStore via one of the read-only replicas. This driver update can be through Citrix replication, or via a script that updates them remotely. Anyway a new driver is installed on the server, the IMA service attempts to update the DS once it "sees" the new driver on the OS. Since the DataStore that this server is talking to is read only what happens?=3D20 My guess is that it will attempt to write this info to the DS (which will fail or be over written by the next replication) and since it can not write this info will it continue to try and write that info? What happens when I have 50 or 100 remote servers all failing to write this type of info.? What will be the effect on server performance and data store performance. Changing all the servers to talk to the master/ writeable DS just to add a print driver or hotfix would be a pain. =3D20 Obviously this will also be a problem with things like Services packs, MS hotfixes, Citrix hotfixes, IP changes, etc. So every time anything is updated that writes to the DS we have to run a dsmaint, change the DSN so the server talks to the writeabile DS, restart the IMA service, do the update, then change it back then restart the IMA service again. = =3D20 Anyone else dealing with this? Or have any thought on long term ramifications of this inherently "weak" design? Ron Oglesby Senior Technical Architect =3D20 RapidApp Office 312.372.7188 Mobile 312.961.2380 email roglesby@xxxxxxxxxxxx ******************************************************************** This Week's Sponsor: RTO Software - TScale TScale increases Terminal Server capacity. Get 30-40% more users per server to save $$$ and time. Add users now! - Not more servers. If you're using Citrix, you must learn about TScale! =20 Free 30-day eval: http://www.rtosoft.com/Enter.asp?ID=3D79 ********************************************************************* For Archives, to Unsubscribe, Subscribe or=20 set Digest or Vacation mode use the below link: http://thethin.net/citrixlist.cfm ******************************************************************** This Week's Sponsor: RTO Software - TScale TScale increases Terminal Server capacity. Get 30-40% more users per server to save $$$ and time. Add users now! - Not more servers. If you?re using Citrix, you must learn about TScale! Free 30-day eval: http://www.rtosoft.com/Enter.asp?ID=79 ********************************************************************* For Archives, to Unsubscribe, Subscribe or set Digest or Vacation mode use the below link: http://thethin.net/citrixlist.cfm