It looks like I've run into a limit on batch size for the web sync using 2008 R2.  I'm getting the following error the log.

2015-02-25 16:27:42.325 The format of a message during Web synchronization was invalid. Ensure that replication components are properly configured at the Web server.

According to the following post I need to use pre-computed partitions in order for the WebSyncMaxXmlSize registry setting to have any effect. 

http://blogs.technet.com/b/claudia_silva/archive/2011/05/12/replication-unable-to-synchronize-subscribers-via-web-synchronization.aspx

I did not setup any partitions when creating the publication or enable the pre-computed partition setting.   If I change the pre-computed option to true and rerun a snapshot do I need to re-init all the subscriptions?  Are there any other settings I need to modify to get around the size limit?

Hi deo.is,

Change the Precompute partitions value to true which would need a re-generation of a snapshot and which will force us to do a re-init.

However, for SQL Server 2008 R2, to help avoid potential memory problems on Subscriber computers Web synchronization uses a default maximum size of 100 MB for the XML file used to transfer changes.  You can directly raise the by setting the following registry key and you dont need to re-init all the subscriptions.

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Microsoft SQL Server\100\Replication

WebSyncMaxXmlSize DWORD 2000000

For more information about configuring Web Synchronization, please review the following article:
https://msdn.microsoft.com/en-us/library/ms151255(v=sql.105).aspx

Thanks,
Lydia Zhang

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Having to reinitialize may a problem.  There are many data changes on the subscriber that need to be pushed to the publisher.  Is there any way to fix the data so a sync can take place before the settings are changed?

How about starting merge agent manually?

Change the registry key firstly to check if you can fix the issue HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Microsoft SQL Server\100\Replication

WebSyncMaxXmlSize DWORD 2000000

The registry setting has been changed.  I would like to know if I I will loose all the changes on the subscriber if I reinitialize the subscription.

The registry setting has been changed.  I would like to know if I I will loose all the changes on the subscriber if I reinitialize the subscription.

Yes. You will lose. You need to manually apply the changes again.

• Proposed as answer by Lydia ZhangMicrosoft contingent staff, Moderator 22 hours 28 minutes ago
• Marked as answer by deo.is 15 hours 59 minutes ago
• Unmarked as answer by deo.is 10 hours 7 minutes ago

I got the following error when I applied the changes and tried to rerun a snapshot.

Cannot use partition groups with unfiltered publications.
Set "use_partition_groups" to "false" using sp_changemergepublication.