Shared SSP and Web-application creation in Sharepoint 2007 (Alternate URL Synchronizer)

ketaanhs — Sat, 12 Sep 2009 16:11:00 GMT

At one of my customers we have a situation where we are Sharing the SSP from one Farm (i.e. Parent Farm) to another Farm (Child Farm). We also need to create a web-application with the same host header name (e.g. http://secure.msft.com) in both the Farms.

Following is the main crux of the issue:

1. We have a Parent Farm (This farm provides the SSP to child Farms), lets call this Farm ASIAFARM.

2. We create a web-app with url “secure.msft.com“ in the ASIAFARM, and the web-app is created.

3. Now we create the AAM entries for this web-app in the Parent farm (3 entries).

4. We now go to the Child Farm (This farm consumes the SSP provided by the Parent Farm), lets call this Farm USFARM.

5. We try creating a web-app with the same url i.e. “secure.msft.com“ in the USFARM and the web-app creation fails with the error: http://secure.msft.com is already routed to the Default zone of another application. Remove that mapping or use a different URL.

6. This is because of the reason that “Alternate URL Synchronizer” timer job syncs all the entries from the Parent Farm to the Child Farm and hence can’t create the web-app.

7. Then we disabled this (“Alternate URL Synchronizer” ) timer job in the Child Farm and deleted all the AAM entries from the Child Farm.

8. Then we tried creating a web-app with the same url i.e. “secure.msft.com“ in the USFARM and it succeeded. And we were able to create the additional AAM entries.

So bottom line is the (“Alternate URL Synchronizer” ) timer job Synchs the information (AAM) from Parent Farm into the Child Farms. If you want to take a look at the EXECUTE method of this timer job (using Reflector), just open the Assembly name: Microsoft.Office.Sharepoint.Administration

Class Name: AlternateUrlSynchronizerJob [This is basically a SEALED class).

After looking @ the source code of this TIMER JOB we found that it only writes the AAM (Alternate Access Mapping) from the Parent Farm to Child Farm, so now if you try to create a web-application with a host header that is already created in Parent Farm it will not be successful and it will not allow you to create a web-application in Child Farm with that host header. [PLEASE NOTE: This scenario only happens when you are sharing the SSP (Shared Service Provider) with two farms i.e. Child Farm uses SSP of Parent Farm, and that creates this Alternate URL Synchronizer Timer Job).

So be cautious (while architecting) when you propose this approach, as you will not be able to create a web-app with same host headers. I am still to find the answer for where all these AAMs are use (my *guess* is Search might be using it, dont what else would be using it).

As disabling this Timer Job (thru Central Admin-->Operations-->Timer Job Definition-->Disable) you will be able to create the web-apps requied in both the farms but not sure if you would be in a supported state, as we are still not aware of where all the AAMs are used.

Audiences in Inter Farm SSP (Sharepoint 2007 / MOSS)

ketaanhs — Wed, 24 Jun 2009 18:19:00 GMT

We were doing some brain storming on Sharing the SSP (Shared Service Provider) between multiple farms i.e. the Parent Farm will be the provider/source of the SSP and the Child farm will consume the SSP. (Needless to say this is MOSS or sharepoint 2007).

It is very easy to set up the sharing of the SSP between farms basically going to the Central Administration àApplication ManagementàUnder office Shared Service provider (Grant or configure shared services between farms ) and here you can configure whether the current farm on which CA is hosted for that farm will be a consumer or provider of the SSP.

Ok so now we wanted to keep the Audiences in one place i.e. in the Parent farm and share these Audiences between the Parent and the Child farm. The question came in what would happen if the Parent farm is down for maintenance i.e. Service Pack upgrades, etc. What would happen to Audience targeting that is done on some of the content pages on the Child farm sites? Will it work or will it not? Will the Audiences resolve or not. So we did a quick small POC and following were our findings on that:

Case 1: All WFE’s and CA box from the Parent farm is down but not the SQL box from the parent farm: Audience still works (as Parent SQL box is still up and running).

Case 2: The entire farm is down (all WFEs, CA box) along with the Parent farm SQL Box: The audiences don’t work as expected.

So bottom line is the Child farm talks directly to the SQL box of the parent farm (i.e. the SSP db of the parent farm) and it is independent of any services on the WFE/CA box of the Parent farm.

Thank you to Ben Risher our in-house MOSS Infra Guru for guiding and helping me thru this. We worked together on this and got this to a conclusion.

Microsoft Tech Blogs : ssp

Shared SSP and Web-application creation in Sharepoint 2007 (Alternate URL Synchronizer)

Audiences in Inter Farm SSP (Sharepoint 2007 / MOSS)