如何复制 SCH_S、SCH_M 死锁
How to replicate a SCH_S, SCH_M deadlock
我有一个大型迁移脚本（大约 2000 行）由于某些元数据上的死锁而失败，根据我的一些 xEvents 数据，锁类型为 SCH_S 和 SCH_M捕获在它上面。该脚本非常复杂，因此我尝试使用最少的脚本重新创建相同的场景，以便我可以进一步调查它。我的场景与我在网上找到的一些场景之间的一个区别是我的迁移脚本是在单个进程中执行的，这与使用一个 window 进行一些模式更改和另一个 window查询。
下面的脚本有点乱，但我试图重现这个问题，但它不起作用。
SET NOEXEC OFF;
DROP FUNCTION IF EXISTS dbo.testfunc;
DROP TABLE IF EXISTS dbo.test;
-- Create some objects.
BEGIN TRANSACTION;
CREATE TABLE test
(
testid INT
);
GO
IF @@error <> 0
AND @@trancount > 0
SET NOEXEC ON;
GO
CREATE FUNCTION testfunc
()
RETURNS INT
WITH SCHEMABINDING
AS
BEGIN
RETURN
(
SELECT 2 * SUM(testid) FROM dbo.test
);
END;
GO
IF @@error <> 0
AND @@trancount > 0
SET NOEXEC ON;
GO
IF @@error <> 0
AND @@trancount > 0
ROLLBACK TRANSACTION;
ELSE IF @@trancount > 0
COMMIT TRANSACTION;
GO
-- Try to induce a SCH_S x SCH_M deadlock.
BEGIN TRANSACTION;
GO
IF @@error <> 0
AND @@trancount > 0
SET NOEXEC ON;
GO
ALTER FUNCTION dbo.testfunc
()
RETURNS INT
AS
BEGIN
RETURN
(
SELECT 2 * SUM(testid) FROM dbo.test
);
END;
GO
EXECUTE sp_lock
IF @@error <> 0
AND @@trancount > 0
ROLLBACK TRANSACTION;
GO
ALTER TABLE dbo.test ADD teststring VARCHAR(12) NULL;
GO
IF @@error <> 0
AND @@trancount > 0
SET NOEXEC ON;
GO
SELECT TOP (1)
testid
FROM test;
GO
EXECUTE sp_lock
go
ALTER FUNCTION testfunc
()
RETURNS INT
WITH SCHEMABINDING
AS
BEGIN
RETURN
(
SELECT TOP 1 testid FROM dbo.test ORDER BY testid DESC
);
END;
GO
EXECUTE sp_lock
IF @@error <> 0
AND @@trancount > 0
SET NOEXEC ON;
GO
ALTER TABLE dbo.test ADD test_bit BIT NULL;
GO
EXECUTE sp_lock
IF @@error <> 0
AND @@trancount > 0
ROLLBACK TRANSACTION;
ELSE IF @@trancount > 0
COMMIT TRANSACTION;
GO
谁能帮我在单进程中重现这种场景？
这是死锁 xml 报告：
<deadlock>
<victim-list>
<victimProcess id="process1fbf61b8ca8" />
</victim-list>
<process-list>
<process id="process1fbf61b8ca8" taskpriority="0" logused="0" waitresource="METADATA: database_id = 5 USER_TYPE(user_type_id = 264), lockPartitionId = 11" waittime="2517" ownerId="46927562" transactionname="@OptionIDs" lasttranstarted="2020-01-16T13:03:44.790" XDES="0x1fb0b790490" lockMode="Sch-S" schedulerid="12" kpid="20032" status="suspended" spid="63" sbid="0" ecid="0" priority="0" trancount="1" lastbatchstarted="2020-01-16T13:03:44.787" lastbatchcompleted="2020-01-16T13:03:44.783" lastattention="1900-01-01T00:00:00.783" clientapp="Microsoft SQL Server Management Studio - Query" hostname="userhost" hostpid="11492" loginname="CORP\user" isolationlevel="serializable (4)" xactid="46926609" currentdb="5" lockTimeout="4294967295" clientoption1="671287392" clientoption2="390200">
<executionStack>
<frame procname="unknown" line="39" stmtstart="-1" sqlhandle="0x0300050048c3ee382a43d70044ab000000000000000000000000000000000000000000000000000000000000">
unknown </frame>
<frame procname="adhoc" line="66" stmtstart="-1" sqlhandle="0x010005009a7e7609c0be4a35fb01000000000000000000000000000000000000000000000000000000000000">
CREATE FUNCTION [dbo].[tvf_GetRawPOLineDataRelatedToOption]
(
@CommunityID INT,
@FloorPlanID INT,
@OptionID INT,
@RelatedIncludedOptionIDToRemove INT
)
RETURNS @ReturnData TABLE
(
[POTemplateID] INT NOT NULL,
[POTemplateItemID] INT NOT NULL,
[POTemplateItemQuantityTypeID] INT NOT NULL,
[Quantity] DECIMAL(12, 5) NULL,
[FloorPlanQuantityTypeID] INT NULL,
[DynamicQuantityPercentage] INT NULL,
[QuantityForFlooringMaterialTypeID] INT NULL,
[HomesiteQuantityTypeID] INT NULL
)
WITH SCHEMABINDING
AS
BEGIN
DECLARE @DependencyData dbo.DependencyDataKeyValueTable;
DECLARE @POTemplateDependencyFilterData dbo.DependencyFilterKeyValueTable;
DECLARE @POTemplateItemDependencyFilterData dbo.DependencyFilterKeyValueTable;
DECLARE @POTemplateIDs dbo.IndexedIntTable;
/*
* Get the default dependency data for this floor plan in this community.
*/
INSERT INTO @DependencyData
SELECT [Key],
[Value]
FROM dbo. </frame>
</executionStack>
<inputbuf>
CREATE FUNCTION [dbo].[tvf_GetRawPOLineDataRelatedToOption]
(
@CommunityID INT,
@FloorPlanID INT,
@OptionID INT,
@RelatedIncludedOptionIDToRemove INT
)
RETURNS @ReturnData TABLE
(
[POTemplateID] INT NOT NULL,
[POTemplateItemID] INT NOT NULL,
[POTemplateItemQuantityTypeID] INT NOT NULL,
[Quantity] DECIMAL(12, 5) NULL,
[FloorPlanQuantityTypeID] INT NULL,
[DynamicQuantityPercentage] INT NULL,
[QuantityForFlooringMaterialTypeID] INT NULL,
[HomesiteQuantityTypeID] INT NULL
)
WITH SCHEMABINDING
AS
BEGIN
DECLARE @DependencyData dbo.DependencyDataKeyValueTable;
DECLARE @POTemplateDependencyFilterData dbo.DependencyFilterKeyValueTable;
DECLARE @POTemplateItemDependencyFilterData dbo.DependencyFilterKeyValueTable;
DECLARE @POTemplateIDs dbo.IndexedIntTable;
/*
* Get the default dependency data for this floor plan in this community.
*/
INSERT INTO @DependencyData
SELECT [Key],
[Value]
FROM dbo </inputbuf>
</process>
</process-list>
<resource-list>
<metadatalock subresource="USER_TYPE" classid="user_type_id = 264" dbid="5" lockPartition="11" id="lock1fb8a56df00" mode="Sch-M">
<owner-list>
<owner id="process1fbf61b8ca8" mode="Sch-M" />
<owner id="process1fbf61b8ca8" mode="Sch-S" requestType="wait" />
</owner-list>
<waiter-list>
<waiter id="process1fbf61b8ca8" mode="Sch-S" requestType="wait" />
</waiter-list>
</metadatalock>
</resource-list>
</deadlock>
Can someone help me recreate this kind of scenario in single process?
这个问题有一个简单的演示here。
BEGIN TRAN
go
CREATE TYPE dbo.OptionIDs AS TABLE( OptionID INT PRIMARY KEY )
go
DECLARE @OptionIDs dbo.OptionIDs;
go
ROLLBACK
涉及单个进程和单个资源的死锁当然不常见。
资源是metadatalock subresource="USER_TYPE" classid="user_type_id = 264"
会话已经在用户定义的类型上持有 SCH-M 元数据锁（可能是您在脚本之前创建的），这会阻止尝试在同一类型上获得 SCH-S 锁稍后在同一个会话中反对。
死锁图中显示的事务名称是 @OptionIDs - 这是一个 内部 系统事务，在创建 tempdb 事务日志时写入与上面的 DECLARE @OptionIDs 对应的 table 类型的实例。这是一个独立于周围用户事务的事务，这就是会话意外无法获得 SCH-S 锁的原因，尽管它已经持有 SCH-M 锁。
这是 Aaron Bertrand 的博客 here
我有一个大型迁移脚本（大约 2000 行）由于某些元数据上的死锁而失败，根据我的一些 xEvents 数据，锁类型为 SCH_S 和 SCH_M捕获在它上面。该脚本非常复杂，因此我尝试使用最少的脚本重新创建相同的场景，以便我可以进一步调查它。我的场景与我在网上找到的一些场景之间的一个区别是我的迁移脚本是在单个进程中执行的，这与使用一个 window 进行一些模式更改和另一个 window查询。
下面的脚本有点乱，但我试图重现这个问题，但它不起作用。
SET NOEXEC OFF;
DROP FUNCTION IF EXISTS dbo.testfunc;
DROP TABLE IF EXISTS dbo.test;
-- Create some objects.
BEGIN TRANSACTION;
CREATE TABLE test
(
testid INT
);
GO
IF @@error <> 0
AND @@trancount > 0
SET NOEXEC ON;
GO
CREATE FUNCTION testfunc
()
RETURNS INT
WITH SCHEMABINDING
AS
BEGIN
RETURN
(
SELECT 2 * SUM(testid) FROM dbo.test
);
END;
GO
IF @@error <> 0
AND @@trancount > 0
SET NOEXEC ON;
GO
IF @@error <> 0
AND @@trancount > 0
ROLLBACK TRANSACTION;
ELSE IF @@trancount > 0
COMMIT TRANSACTION;
GO
-- Try to induce a SCH_S x SCH_M deadlock.
BEGIN TRANSACTION;
GO
IF @@error <> 0
AND @@trancount > 0
SET NOEXEC ON;
GO
ALTER FUNCTION dbo.testfunc
()
RETURNS INT
AS
BEGIN
RETURN
(
SELECT 2 * SUM(testid) FROM dbo.test
);
END;
GO
EXECUTE sp_lock
IF @@error <> 0
AND @@trancount > 0
ROLLBACK TRANSACTION;
GO
ALTER TABLE dbo.test ADD teststring VARCHAR(12) NULL;
GO
IF @@error <> 0
AND @@trancount > 0
SET NOEXEC ON;
GO
SELECT TOP (1)
testid
FROM test;
GO
EXECUTE sp_lock
go
ALTER FUNCTION testfunc
()
RETURNS INT
WITH SCHEMABINDING
AS
BEGIN
RETURN
(
SELECT TOP 1 testid FROM dbo.test ORDER BY testid DESC
);
END;
GO
EXECUTE sp_lock
IF @@error <> 0
AND @@trancount > 0
SET NOEXEC ON;
GO
ALTER TABLE dbo.test ADD test_bit BIT NULL;
GO
EXECUTE sp_lock
IF @@error <> 0
AND @@trancount > 0
ROLLBACK TRANSACTION;
ELSE IF @@trancount > 0
COMMIT TRANSACTION;
GO
谁能帮我在单进程中重现这种场景？
这是死锁 xml 报告：
<deadlock>
<victim-list>
<victimProcess id="process1fbf61b8ca8" />
</victim-list>
<process-list>
<process id="process1fbf61b8ca8" taskpriority="0" logused="0" waitresource="METADATA: database_id = 5 USER_TYPE(user_type_id = 264), lockPartitionId = 11" waittime="2517" ownerId="46927562" transactionname="@OptionIDs" lasttranstarted="2020-01-16T13:03:44.790" XDES="0x1fb0b790490" lockMode="Sch-S" schedulerid="12" kpid="20032" status="suspended" spid="63" sbid="0" ecid="0" priority="0" trancount="1" lastbatchstarted="2020-01-16T13:03:44.787" lastbatchcompleted="2020-01-16T13:03:44.783" lastattention="1900-01-01T00:00:00.783" clientapp="Microsoft SQL Server Management Studio - Query" hostname="userhost" hostpid="11492" loginname="CORP\user" isolationlevel="serializable (4)" xactid="46926609" currentdb="5" lockTimeout="4294967295" clientoption1="671287392" clientoption2="390200">
<executionStack>
<frame procname="unknown" line="39" stmtstart="-1" sqlhandle="0x0300050048c3ee382a43d70044ab000000000000000000000000000000000000000000000000000000000000">
unknown </frame>
<frame procname="adhoc" line="66" stmtstart="-1" sqlhandle="0x010005009a7e7609c0be4a35fb01000000000000000000000000000000000000000000000000000000000000">
CREATE FUNCTION [dbo].[tvf_GetRawPOLineDataRelatedToOption]
(
@CommunityID INT,
@FloorPlanID INT,
@OptionID INT,
@RelatedIncludedOptionIDToRemove INT
)
RETURNS @ReturnData TABLE
(
[POTemplateID] INT NOT NULL,
[POTemplateItemID] INT NOT NULL,
[POTemplateItemQuantityTypeID] INT NOT NULL,
[Quantity] DECIMAL(12, 5) NULL,
[FloorPlanQuantityTypeID] INT NULL,
[DynamicQuantityPercentage] INT NULL,
[QuantityForFlooringMaterialTypeID] INT NULL,
[HomesiteQuantityTypeID] INT NULL
)
WITH SCHEMABINDING
AS
BEGIN
DECLARE @DependencyData dbo.DependencyDataKeyValueTable;
DECLARE @POTemplateDependencyFilterData dbo.DependencyFilterKeyValueTable;
DECLARE @POTemplateItemDependencyFilterData dbo.DependencyFilterKeyValueTable;
DECLARE @POTemplateIDs dbo.IndexedIntTable;
/*
* Get the default dependency data for this floor plan in this community.
*/
INSERT INTO @DependencyData
SELECT [Key],
[Value]
FROM dbo. </frame>
</executionStack>
<inputbuf>
CREATE FUNCTION [dbo].[tvf_GetRawPOLineDataRelatedToOption]
(
@CommunityID INT,
@FloorPlanID INT,
@OptionID INT,
@RelatedIncludedOptionIDToRemove INT
)
RETURNS @ReturnData TABLE
(
[POTemplateID] INT NOT NULL,
[POTemplateItemID] INT NOT NULL,
[POTemplateItemQuantityTypeID] INT NOT NULL,
[Quantity] DECIMAL(12, 5) NULL,
[FloorPlanQuantityTypeID] INT NULL,
[DynamicQuantityPercentage] INT NULL,
[QuantityForFlooringMaterialTypeID] INT NULL,
[HomesiteQuantityTypeID] INT NULL
)
WITH SCHEMABINDING
AS
BEGIN
DECLARE @DependencyData dbo.DependencyDataKeyValueTable;
DECLARE @POTemplateDependencyFilterData dbo.DependencyFilterKeyValueTable;
DECLARE @POTemplateItemDependencyFilterData dbo.DependencyFilterKeyValueTable;
DECLARE @POTemplateIDs dbo.IndexedIntTable;
/*
* Get the default dependency data for this floor plan in this community.
*/
INSERT INTO @DependencyData
SELECT [Key],
[Value]
FROM dbo </inputbuf>
</process>
</process-list>
<resource-list>
<metadatalock subresource="USER_TYPE" classid="user_type_id = 264" dbid="5" lockPartition="11" id="lock1fb8a56df00" mode="Sch-M">
<owner-list>
<owner id="process1fbf61b8ca8" mode="Sch-M" />
<owner id="process1fbf61b8ca8" mode="Sch-S" requestType="wait" />
</owner-list>
<waiter-list>
<waiter id="process1fbf61b8ca8" mode="Sch-S" requestType="wait" />
</waiter-list>
</metadatalock>
</resource-list>
</deadlock>
Can someone help me recreate this kind of scenario in single process?
这个问题有一个简单的演示here。
BEGIN TRAN
go
CREATE TYPE dbo.OptionIDs AS TABLE( OptionID INT PRIMARY KEY )
go
DECLARE @OptionIDs dbo.OptionIDs;
go
ROLLBACK
涉及单个进程和单个资源的死锁当然不常见。
资源是metadatalock subresource="USER_TYPE" classid="user_type_id = 264"
会话已经在用户定义的类型上持有 SCH-M 元数据锁（可能是您在脚本之前创建的），这会阻止尝试在同一类型上获得 SCH-S 锁稍后在同一个会话中反对。
死锁图中显示的事务名称是 @OptionIDs - 这是一个 内部 系统事务，在创建 tempdb 事务日志时写入与上面的 DECLARE @OptionIDs 对应的 table 类型的实例。这是一个独立于周围用户事务的事务，这就是会话意外无法获得 SCH-S 锁的原因，尽管它已经持有 SCH-M 锁。
这是 Aaron Bertrand 的博客 here