Capture deadlocks

[DavidWiseman]

DBA Dash already captures Deadlocks/sec performance counter by default. This lets us know if we have any deadlocks but doesn't provide any detail on the deadlocks to assist with troubleshooting. It's possible to get this data from the system_health trace or from sys.fn_xe_telemetry_blob_target_read_file (for AzureDB).

It might be nice to pull this data into DBA Dash with some longer retention than system_health to assist with troubleshooting deadlocks. The data could be pulled from system_health or deadlocks could be added to the existing DBA Dash extended event.

From the UI side the deadlocks could be displayed in a grid. Probably not worth the effort of re-creating the deadlock viewer in DBA Dash.. Click a link to download the deadlock file (*.xdl) and open in SSMS. Could also show XML within the app.

Azure: https://techcommunity.microsoft.com/t5/azure-database-support-blog/lesson-learned-19-how-to-obtain-the-deadlocks-of-your-azure-sql/ba-p/368847