We use App Insights at work to collect all our logged messages. App Insights comes with a very powerful query language confusingly named Kusto Query Language (KQL) that lets you get whatever you want from the logs. However App Insights shows you surprisingly little out of the box. So without some configuration you may not be getting as much value from your logs as you could.
The thing I really wanted to see was the most common log messages ordered by how often they had happened in the specified time. This is the KQL query for that:
// Setup mapping array to make severity level use friendly …