The AA Query frequently returns too much data, resulting in a 502 Bad Gateway Message. The gateway can only handle 8MB of data at a time.
You built a dashboard that operated in December 2016 and provided you with all requests dating back to the beginning of the month. It's already January 2017, and it's failing miserably. Using a query like the one below, you utilise the PowerBI Dashboard to derive various metrics from the raw data.
requests | where timestamp > datetime(2016-12-01)
Decide how many days are important to you. Limiting the time range to this month AND only projecting the columns you need will help you cut out a lot of additional data if your goal is to obtain all requests and the timing from the first of the month.
requests | where timestamp > startofmonth(now()) | project name, duration
If you're computing averages and percentiles, you could just let Analytics handle it and PowerBI display the results.
requests | where timestamp > startofmonth(now()) | summarize count(), avg(duration), min(duration), max(duration), stdev(duration), percentiles(duration, 50, 75, 90, 95, 99) by name