Performance Issues with SSAS Connector

[deldersveld]

A colleague of mine is attempting to diagnose a severe performance issue while using the SSAS Connector. He has a PBI Desktop report that runs 26 separate DAX queries (as logged in Profiler). When running in Desktop, they all begin execution at the same time. When the report is published to Service, Profiler shows that the queries themselves take about the same amount of time, but only three queries at a time begin executing every second.

Does anyone know if this is a limitation of the current SSAS Connector, or could it be Service throttling performance in some other manner?

Another avenue that is under consideration is what happens when a query is sent. The SSAS Connector deep dive mentions that the effective username is sent with each DAX query. Is *each* query trying to re-authenticate, and if so, could Azure AD authentication be a bottleneck?

[iatg]

A client of ours is having a similar issue so I do not know if this got answered elsewhere?

[brodtgaard]

We have only expirienced bad performance with SSAS Live Connector to tabular cubes on premises.

Everything seems fine on the server where the cubes are responding in few milliseconds. But in PowerBI.com the same filtration can easily take 10 seconds. Everything in the SQL Profiler looks fine.

Any clues?

[deldersveld]

If you are in a position to upgrade from the SSAS connector to the new Enterprise Gateway preview, query performance is substantially better. 

[brodtgaard]

Can I change the connector from the SSAS connector to the new "Enterprice Gateway" without creating a new Power BI "dataset" and thereby having my users to rebuild all the reports and dashboards?

[deldersveld]

You can upgrade to the Gateway and leave everything in place. Any user setup on the gateway will use that connection instead of the SSAS connector, and you don't need to change your datasets.