Identify Deadlocks Using Graphical Deadlock Chain Event in SQL Server Profiler

In SQL Server, a deadlock occurs when two or more processes attempt to acquire exclusive locks on resources in such a way that a circular chain is formed, where each process is waiting for another process to release the lock it holds. Deadlocks can be resolved by having one of the processes involved in the deadlock abort, so that its locks are released and the other process can continue.

When a deadlock occurs, SQL Server automatically detects it and ends one of the user processes (the "victim"), allowing the other process to complete. This event is then recorded in the SQL Server error log.

To identify which process was aborted during a deadlock, you can use the Graphical Deadlock Chain Event in SQL Server Profiler. This event will show you the processes involved in the deadlock, as well as which process was aborted.

To use the Graphical Deadlock Chain Event in SQL Server Profiler:

1. Start SQL Server Profiler and connect to the instance of SQL Server where the deadlock occurred.

2. Create a new trace or use an existing trace that includes the events you want to capture. For more information, see designing a Trace (SQL Server Profiler).

3. In the Events Selection tab, select the checkbox for the Graphical Deadlock Chain event under the Locks category.

4. Run the trace.

When a deadlock occurs, the Graphical Deadlock Chain event will be recorded in the trace. This event will show you the processes involved in the deadlock, as well as which process was aborted.

5. To view the details of the event, double-click it in the trace results.

6. In the Event Properties dialog box, click the Deadlock tab.

7. The details of the deadlock will be displayed in a graphical format, showing which processes were involved and which process was aborted.

8. To save the deadlock information to a file, click Save As and choose a location for the file.

When troubleshooting deadlocks, it is important to remember that SQL Server automatically detects and resolves them. In most cases, there is no need to take any further action. However, if you are seeing frequent deadlocks, or if they are causing performance problems, you may need to investigate further and take steps to prevent them from occurring.

For more information, see Deadlocks (SQL Server).

When a deadlock occurs, SQL Server automatically detects it and ends one of the user processes (the "victim"), allowing the other process to complete. This event is then recorded in the SQL Server error log.

To identify which process was aborted during a deadlock, you can use the Graphical Deadlock Chain Event in SQL Server Profiler. This event will show you the processes involved in the deadlock, as well as which process was aborted.

To use the Graphical Deadlock Chain Event in SQL Server Profiler:

1. Start SQL Server Profiler and connect to the instance of SQL Server where the deadlock occurred.

2. Create a new trace or use an existing trace that includes the events you want to capture. For more information, see designing a Trace (SQL Server Profiler).

3. In the Events Selection tab, select the checkbox for the Graphical Deadlock Chain event under the Locks category.

4. Run the trace.

When a deadlock occurs, the Graphical Deadlock Chain event will be recorded in the trace. This event will show you the processes involved in the deadlock, as well as which process was aborted.

5. To view the details of the event, double-click it in the trace results.

6. In the Event Properties dialog box, click the Deadlock tab.

7. The details of the deadlock will be displayed in a graphical format, showing which processes were involved and which process was aborted.

8. To save the deadlock information to a file, click Save As and choose a location for the file.

Conclusion:

When troubleshooting deadlocks, it is important to remember that SQL Server automatically detects and resolves them. In most cases, there is no need to take any further action. However, if you are seeing frequent deadlocks, or if they are causing performance problems, you may need to investigate further and take steps to prevent them from occurring.