Resolving SharePoint PowerPivot Service error–“We're no longer connected to the database and can't refresh your connection. please close and reopen the workbook and refresh it”

One of my SharePoint environment had all SharePoint related services configured in one server (Single server topology). PowerPivot service application was one of them. Due to various reasons the Server had very limited resources.

Due to resource limitation, I was getting the above issue repeatedly. Until I upgrade the server I performed following actions to resolve the issue.

1. Restart PowerPivot instance in my SQL Server

2. Navigate to Manage Service Applications > Excel Services Application > Data Model Settings, and check the PowerPivot instance is available

3. Navigate to “Service on this Server” and restart “Excel Calculation Services” service

4. Navigate to “Service on this Server” and restart “SQL Server PowerPivot System Service ” service

5. Check the firewall and the network connectivity between SharePoint server and PowerPivot SQL instance