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Lock:Timeout Event Class

The Lock:Timeout event class indicates that a request for a lock on a resource, such as a page, has timed out because another transaction is holding a blocking lock on the required resource. Time-out is determined by the @@LOCK_TIMEOUT system function and can be set with the SET LOCK_TIMEOUT statement.

Use the Lock:Timeout event class to monitor when time-out conditions occur. This information is useful to determine if time-outs are significantly affecting the performance of your application, and which objects are involved. You can examine the application code that modifies these objects to determine if changes to minimize time-outs can be made.

Lock:Timeout events with a duration of 0 are commonly the result of internal lock probes and are not necessarily an indication of a problem. The Lock:Timeout (timeout > 0) event can be used to ignore time-outs with a duration of 0.

Lock:Timeout Event Class Data Columns

Data column name

Data type

Description

Column ID

Filterable

ApplicationName

nvarchar

Name of the client application that created the connection to an instance of SQL Server. This column is populated with the values passed by the application rather than the displayed name of the program.

10

Yes

BinaryData

image

Lock resource identifier.

2

Yes

ClientProcessID

int

ID assigned by the host computer to the process where the client application is running. This data column is populated if the client provides the client process ID.

9

Yes

DatabaseID

int

ID of the database in which the lock time-out occurred. SQL Server Profiler displays the name of the database if the ServerName data column is captured in the trace and the server is available. Determine the value for a database by using the DB_ID function.

3

Yes

DatabaseName

nvarchar

Name of the database in which the time-out occurred.

35

Yes

Duration

bigint

Amount of time (in microseconds) between the time the lock request was issued and the lock was timed out.

13

Yes

EndTime

datetime

Time at which the event ended.

15

Yes

EventClass

int

Type of event = 27.

27

No

EventSequence

int

The sequence of a given event within the request.

51

No

GroupID

int

ID of the workload group where the SQL Trace event fires.

66

Yes

HostName

nvarchar

Name of the computer on which the client is running. This data column is populated if the client provides the host name. To determine the host name, use the HOST_NAME function.

8

Yes

IntegerData2

int

Identified for informational purposes only. Not supported. Future compatibility is not guaranteed.

55

Yes

IsSystem

int

Indicates whether the event occurred on a system process or a user process. 1 = system, 0 = user.

60

Yes

LoginName

nvarchar

Name of the login of the user (either SQL Server security login or the Microsoft Windows login credentials in the form of DOMAIN\username).

11

Yes

LoginSid

image

Security identification number (SID) of the logged-in user. You can find this information in the sys.server_principals catalog view. Each SID is unique for each login in the server.

41

Yes

Mode

int

The resulting mode after the time-out.

0=NULL - Compatible with all other lock modes (LCK_M_NL)

1=Schema Stability lock (LCK_M_SCH_S)

2=Schema Modification Lock (LCK_M_SCH_M)

3=Shared Lock (LCK_M_S)

4=Update Lock (LCK_M_U)

5=Exclusive Lock (LCK_M_X)

6=Intent Shared Lock (LCK_M_IS)

7=Intent Update Lock (LCK_M_IU)

8=Intent Exclusive Lock (LCK_M_IX)

9=Shared with intent to Update (LCK_M_SIU)

10=Shared with Intent Exclusive (LCK_M_SIX)

11=Update with Intent Exclusive (LCK_M_UIX)

12=Bulk Update Lock (LCK_M_BU)

13=Key range Shared/Shared (LCK_M_RS_S)

14=Key range Shared/Update (LCK_M_RS_U)

15=Key Range Insert NULL (LCK_M_RI_NL)

16=Key Range Insert Shared (LCK_M_RI_S)

17=Key Range Insert Update (LCK_M_RI_U)

18=Key Range Insert Exclusive (LCK_M_RI_X)

19=Key Range Exclusive Shared (LCK_M_RX_S)

20=Key Range Exclusive Update (LCK_M_RX_U)

21=Key Range Exclusive Exclusive (LCK_M_RX_X)

32

Yes

NTDomainName

nvarchar

Windows domain to which the user belongs.

7

Yes

NTUserName

nvarchar

Windows user name.

6

Yes

ObjectID

int

ID of the object which was timed out, if available and applicable.

22

Yes

ObjectID2

bigint

ID of the related object or entity, if available and applicable.

56

Yes

OwnerID

int

1=TRANSACTION

2=CURSOR

3=SESSION

4=SHARED_TRANSACTION_WORKSPACE

5=EXCLUSIVE_TRANSACTION_WORKSPACE

58

Yes

RequestID

int

ID of the request containing the statement.

49

Yes

ServerName

nvarchar

Name of the instance of SQL Server being traced.

26

No

SessionLoginName

nvarchar

Login name of the user who originated the session. For example, if you connect to SQL Server using Login1 and execute a statement as Login2, SessionLoginName shows Login1; while LoginName shows Login2. This column displays both SQL Server and Windows logins.

64

Yes

SPID

int

ID of the session on which the event occurred.

12

Yes

StartTime

datetime

Time at which the event started, if available.

14

Yes

TextData

ntext

Text value dependent on the lock type that was being acquired when the time-out occurred.

1

Yes

TransactionID

bigint

System-assigned ID of the transaction.

4

Yes

Type

int

1=NULL_RESOURCE

2=DATABASE

3=FILE

5=OBJECT

6=PAGE

7=KEY

8=EXTENT

9=RID

10=APPLICATION

11=METADATA

12=AUTONAMEDB

13=HOBT

14=ALLOCATION_UNIT

57

Yes