Web Application on Merge Publisher?

Problem Statement:

Referring back to two my previous posts on Merge Replication with SQL Server, there are few concerns as well with Merge Pub on few specific scenarios such as:

- Merge Pub always wins so writing directly on the publisher is not recommended for proper conflict resolution practices

- Data issue could fail entire merge topology in case data is written directly on the publisher than the subscribers

- Excessive locking could be an issue at the publisher end in case we have more subscribers

- Application performance which completely relying on publisher apart from merge partners could be impacted due to lower priority

Possible Solution:

In case you are facing any of the scenarios/issues, we recommend you to have a separate subscriber from where you can perform all the application specific read/write operations. Depending upon the server configuration, you might want to setup a separate subscriber hosted on separate box or it could be hosted on the publisher itself as the local subscriber with a new DB.

But we need to make sure that we don’t have any resource bottleneck on the publisher box otherwise the architecture wouldn’t really help but create more problems. Primarily we suggest you to review CPU and IO usage during peak usage hours on the publisher box using perfmon counters. Please refer to https://technet.microsoft.com/en-us/library/cc722414.aspx for more information on how to collect the performance data using perfmon. Also, https://pal.codeplex.com/ would help in assessing perfmon data.