Analyzing SQL Error Logs with Kusto

We can leverage Azure Kusto to analyze SQL error logs. It is easy to learn if you know SQL querying, in fact here is a link on how SQL translates to Kusto. My favorite two operators to reduce large amount of errors to a small number of patterns are: autocluster and reduce

Autocluster

It will find a common pattern on the given columns. In the example below, 60% of the column values in host, source_name, and message, are from replication errors on a particular host

Reduce

It will find common patterns in the message and replace them with "*" to easily aggregate them. In the example below we can see the frequency of the most common errors.