The new Deadlock and Blocking charts and features are a much needed addition to DPA. What I was doing prior to the feature being added was using Extended Events to capture deadlock and blocking events and reporting them via Excel/PowerQuery.
The most useful way to view the deadlocks was a heat map, instead of a bar or line chart. The heat map allowed me to break down the events by day of month and hour of day, and then drill down further if needed. The heat map makes any relationship to the time of events clear across a longer period of time. This allowed me to identify cases where interactions between scheduled jobs were causing blocking issues, and to be able to take action to resolve them. It also allowed me to see a case where an issue in an application release started causing an escalated number deadlocks. I could tie down the time of the release to the point where deadlocks escalated.
The image below is an example that shows the temporal relationship of events.
In one case, a couple of jobs that ran at 15:00 UTC, were fighting with each other. Restructuring the jobs to eliminate clash time resolved the majority of the issue.
In the other case, on the 22nd, an application defect was allowing a user to block themselves in a particular case & retry logic compounded the problem.
Having the ability to see blocking and deadlock event in a matrix like this is invaluable in being able to spot patterns.
