What is the ContactsMerge.aspx Administration Page?

Question

In Sitecore 9.1.1, and possibly other versions, the "/sitecore/admin/xdb/ContactsMerge.aspx" administration tools page exists.

It takes no inputs, has no description of what it does, but a ready and available Start Button to click.

Does anyone know specifically what this page does? My hope was that I could merge two Identifier Sources together. Specifically, the xDB Migration maps all contacts with xDB.Identifier. But that's never used anywhere else in Sitecore, and lists (unless you're paying STRICT attention) get uploaded with the Identifier Source of ListManager. I suddenly have two contacts with the same Identifier, but different Sources.

Can this page help me?

Answer 1

You need this ContactsMerge.aspx just if you upgrade your site for 9.0.1 or bellow. If you upgrade from 9.0.2 or later you can ignore this file.

If you are upgrading from Sitecore XP 9.0 or Sitecore XP 9.0 Update 1, you must merge your contacts. When you perform these actions, interactions are copied from the source contact to the target contact and the source contact is marked as obsolete.

For this manipulations with existing contacts Sitecore uses a new admin page '\Website\sitecore\admin\xdb\ContactsMerge.aspx' .

Also, the log file "contactMergeDataUpgrade.log.{date}.txt" is added to the logs folder. It is defined in the Sitecore.Xdb.Processing.ContactMerge.config file.

The page reports about errors and warnings into the mentioned log file. If you do not use the page a log file will be empty.

Upgrade the Contact Merge Data

In Sitecore XP 9.0 Update 2, the contact merge behavior has changed. In Sitecore XP 9.0 Update 2, when you merge contacts, interactions are copied from the source contact to the target contact and the source contact is marked as obsolete. To apply the Sitecore XP 9.0.2 contact merge logic to existing contacts that have previously been merged:

1. On the xDB Processing server, open the /sitecore/admin/xdb/ContactsMerge.aspx page.
2. Click Start. This copies all the interactions from the source contact to the target contact and significantly improves the performance of data retrieval. When the contact merge upgrade process is complete, the Process State changes to Completed.

You find this information on upgrade guide :

For Sitecore 9.0.2 https://dev.sitecore.net/~/media/A24AE0FB3EC947ACB8F6FCCFBA0CD8C3.ashx

For Sitecore 10: https://dev.sitecore.net/~/media/7096C102E774454CAFC4BA5F39AB5A9F.ashx