---
title: Analyze Deadlocks
titleSuffix: SQL Server Profiler
description: Identify the cause of a deadlock by replaying and displaying deadlock events for analysis in SQL Server Profiler and by generating wait-for graphs.
author: rwestMSFT
ms.author: randolphwest
ms.date: 06/05/2025
ms.service: sql
ms.subservice: profiler
ms.topic: conceptual
ms.collection:
  - data-tools
---

# Analyze deadlocks with SQL Server Profiler

[!INCLUDE [SQL Server Azure SQL Managed Instance](../../includes/applies-to-version/sql-asdbmi.md)]

Use [!INCLUDE [ssSqlProfiler](../../includes/sssqlprofiler-md.md)] to identify the cause of a deadlock. A deadlock occurs when there's a cyclic dependency between two or more threads, or processes, for some set of resources within SQL Server. Using [!INCLUDE [ssSqlProfiler](../../includes/sssqlprofiler-md.md)], you can create a trace that records, replays, and displays deadlock events for analysis.

To trace deadlock events, add the **Deadlock graph** event class to a trace. 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. [!INCLUDE [ssSqlProfiler](../../includes/sssqlprofiler-md.md)] can extract the XML document to a deadlock XML (.xdl) file which you can view later in SQL Server Management Studio. You can configure [!INCLUDE [ssSqlProfiler](../../includes/sssqlprofiler-md.md)] to extract **Deadlock graph** events to a single file that contains all **Deadlock graph** events, or to separate files. This extraction can be done in any of the following ways:

- At trace configuration time, using the **Events Extraction Settings** tab. This tab doesn't appear until you select the **Deadlock graph** event on the **Events Selection** tab.

- Using the **Extract SQL Server Events** option on the **File** menu.

- Individual events can also be extracted and saved by right-clicking a specific event and choosing **Extract Event Data**.

## Deadlock graphs

[!INCLUDE [ssSqlProfiler](../../includes/sssqlprofiler-md.md)] and [!INCLUDE [ssManStudioFull](../../includes/ssmanstudiofull-md.md)] use a deadlock wait-for graph to describe a deadlock. The deadlock wait-for graph contains process nodes, resource nodes, and edges representing the relationships between the processes and the resources. The components of wait-for graphs are defined in the following table:

| Node | Description |
| --- | --- |
| Process node | A thread that performs a task; for example, `INSERT`, `UPDATE`, or `DELETE`. |
| Resource node | A database object; for example, a table, index, or row. |
| Edge | A relationship between a process and a resource. A **request** edge occurs when a process waits for a resource. An **owner** edge occurs when a resource waits for a process. The lock mode is included in the edge description. For example, **Mode: X**. |

## Deadlock process node

In a wait-for graph, the process node contains information about the process. The following table explains the components of a process.

| Component | Definition |
| --- | --- |
| Server process ID | Session ID (SPID), a server assigned identifier for the process owning the lock. |
| Server batch ID | Server batch identifier (SBID). |
| Execution context ID | Execution context identifier (ECID). The execution context ID of a given thread associated with a specific session ID.<br /><br />ECID = { 0, 1, 2, 3, *...n* }, where 0 always represents the main or parent thread, and { 1, 2, 3, *...n* } represent the subthreads. |
| Deadlock priority | Deadlock priority for the process. For more information about possible values, see [SET DEADLOCK_PRIORITY](../../t-sql/statements/set-deadlock-priority-transact-sql.md). |
| Log Used | Amount of log space used by the process. |
| Owner Id | Transaction ID for the processes which are using transactions and currently waiting on a lock. |
| Transaction descriptor | Pointer to the transaction descriptor that describes the state of the transaction. |
| Input buffer | Input buffer of the current process, defines the type of event and the statement being executed. Possible values include:<br /><br />**Language**<br />**RPC**<br />**None** |
| Statement | Type of statement. Possible values are:<br /><br />**NOP**<br />**SELECT**<br />**UPDATE**<br />**INSERT**<br />**DELETE**<br />**Unknown** |

## Deadlock resource node

In a deadlock, two processes are each waiting for a resource held by the other process. In a deadlock graph, the resources are displayed as resource nodes.

## Related content

- [SQL Server Profiler](sql-server-profiler.md)