Deadlocks

Expand the “Deadlocks” row to view a chart that shows the number of deadlocks for each database.

SQL Server detects a deadlock when two or more sessions block each other so none can proceed. To resolve the conflict, SQL Server selects a victim and terminates that session’s statement. QMonitor captures deadlock events and stores the deadlock graph (XML) for analysis.

Under the chart is a list of deadlock events with columns for time, sequence, database, and user name. Use the column filters and sort controls to filter and sort the table.

Click a row to open the Deadlock detail dashboard.

The Deadlock XML panel displays the deadlock graph in XML format. That graph contains nodes for processes, resources, execution stacks and inputbuf; documenting every node is beyond the scope of this documentation.

The XML includes one or more nodes that identify the victim and the participating processes, and that provide details about the resources and SQL statements involved. Use the graph and statements to identify the conflict and to find candidate fixes (indexing, query changes, or retry logic).

The bottom grid lists sessions that were running around the event time, giving a quick overview of related activity. Use the buttons above the grid to set the time window around the event from 1 to 15 minutes.