If you don’t configure your 2013 platform for SQL mirroring from the outset (or at least, prior to deploying the Lync Reports), then add mirroring later, you’ll find your Lync Monitoring Reports stop working when you failover the SQL servers.
Reason being is the report deployment will configure its datasources for the SQL instance(s) its aware of at deployment time, and subsequent changes to SQL topology wont be updated in the datasources later.
Not a major to fix, you’ll just need to change your datasource connection strings.
1. Open your SSRS front end http://<server>/reports
2. Open the Reports_Content Folder
3. Edit the properties of both CDRDB and QMSDB datasources
4. Change the connection strings to use the following syntax:
Data Source=SQLServer1SQLInstance;Failover Partner=SQLServer2SQLInstance;initial catalog=<DBName>
5. Re-enter your report user password and hit Test Connection to ensure it works, then Apply and you’re done.