![]() The following table explains the components of a process. In a wait-for graph, the process node contains information about the process. The lock mode is included in the edge description. An owner edge occurs when a resource waits for a process. A request edge occurs when a process waits for a resource. The components of wait-for graphs are defined in the following table:Ī thread that performs a task for example, INSERT, UPDATE, or DELETE.Ī database object for example, a table, index, or row.Ī relationship between a process and a resource. The deadlock wait-for graph contains process nodes, resource nodes, and edges representing the relationships between the processes and the resources. SQL Server Profiler and SQL Server Management Studio use a deadlock wait-for graph to describe a deadlock. Individual events can also be extracted and saved by right-clicking a specific event and choosing Extract Event Data. Using the Extract SQL Server Events option on the File menu. Note that this tab does not appear until you select the Deadlock graph event on the Events Selection tab. This extraction can be done in any of the following ways:Īt trace configuration time, using the Events Extraction Settings tab. You can configure SQL Server Profiler to extract Deadlock graph events to a single file that contains all Deadlock graph events, or to separate files. SQL Server Profiler can extract the XML document to a deadlock XML (.xdl) file which you can view later in SQL Server Management Studio. This event class populates the TextData data column in the trace with XML data about the process and objects that are involved in the deadlock. To trace deadlock events, add the Deadlock graph event class to a trace. Using SQL Server Profiler, you can create a trace that records, replays, and displays deadlock events for analysis. ![]() A deadlock occurs when there is a cyclic dependency between two or more threads, or processes, for some set of resources within SQL Server. Use SQL Server Profiler to identify the cause of a deadlock. New Deadlock Visualizations in SQL Sentry and Plan Explorerĭisclaimer: I used to work for SQL Sentry.Applies to: SQL Server Azure SQL Managed Instance.As a bonus, these are captured for you automatically on monitored servers without having to configure trace flags, run your own traces, etc.: Have you considered third party monitoring tools? SQL Sentry and Plan Explorer, for example, have a much nicer deadlock graph, showing you object / index names, as well as the order in which the locks were taken. Finding SQL Server Deadlocks Using Trace Flag 1222Īlso note that if your system experiences a lot of deadlocks, this can really hammer your error log, and can become quite a lot of noise, drowning out other, important errors.However, you can run it only for the current running instance of the service (which won't require a restart, but which won't resume upon the next restart) using the following global trace flag command: DBCC TRACEON(1222, -1) I would set this as a startup trace flag (in which case you'll need to restart the service). However, the error log is textual, so you won't get nice deadlock graph pictures - you'll have to read the text of the deadlocks to figure it out. This will write deadlock information to the error log. In order to capture deadlock graphs without using a trace (you don't need profiler necessarily), you can enable trace flag 1222. JOIN sys.dm_exec_connections CN ON CN.session_id = ES.session_idĬROSS APPLY sys.dm_exec_sql_text(CN.most_recent_sql_handle) AS ST JOIN sys.dm_tran_active_transactions AT ON TST.transaction_id = AT.transaction_id ![]() JOIN sys.dm_tran_session_transactions TST ON ES.session_id = TST.session_id JOIN sys.dm_exec_sessions ES ON ES.session_id = L.request_session_id JOIN sys.objects O ON O.object_id = P.object_id ![]() ![]() JOIN sys.partitions P ON P.hobt_id = L.resource_associated_entity_id TST.is_user_transaction as IsUserTransaction, SELECT L.request_session_id AS SPID,ĭB_NAME(L.resource_database_id) AS DatabaseName, The only other way I could suggest is digging through the information by using EXEC SP_LOCK (Soon to be deprecated), EXEC SP_WHO2 or the sys.dm_tran_locks table. You can use a deadlock graph and gather the information you require from the log file. ![]()
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