Cool Azure Log Analytics: Joining requests and dependencies

Another cool thing you can do with App Insights Analytics is join different data types to get a good understanding of what’s happening in your app.

A great example are remote dependencies – this is an out-of-the-box feature in App Insights that logs all remote dependency calls such as SQL, Azure, http etc. If you’ve got that data flowing, you can get amazing insights with just a few small queries.

Here’s a small example – Lets’ try and find out which resources are real time-hogs in my service. The query I spun out is – per http request, get the average duration spent calling each dependency type.

| where timestamp > ago(1d)
| project timestamp, operation_Id
| join (dependencies
        | where timestamp > ago(1d)
        | summarize sum(duration) by operation_Id, type 
        ) on operation_Id
| summarize avg_duration_by_type=avg(sum_duration) by type, bin(timestamp, 20m)
| render barchart


Cool AppInsights Analytics: Custom dimensions and measurements

In App Analytics you can slice and dice on your App Insights custom dimensions and measurements just as easily as any of the so-called “standard” properties.

The only thing that’s a little bit tricky is extracting them first.

It’s tricky because of 2 things:

  1. You have to explicitly set the type of the measurement/dimension after you extract it.
  2. Extracting properties that contain spaces and special characters is a little bit of a hassle.

Here is an example of me doing both:

| where timestamp > ago(3h)
| where name == "Query"
| extend query_time = todouble(customMeasurements.['Query Time'])
| extend query_name = tostring(customDimensions.['Query Name'])
| project query_time, query_name
| summarize avg(query_time) by query_name 
| render barchart


If you liked this, check out some other cool analytics queries: