sql-server – 在删除/插入的同一个独占锁定的集群密钥(使用NHibernate)上的SQL死锁

发布时间：2020-05-24 18:42:34 所属栏目：MsSql 来源：互联网

导读：我已经在这个僵局问题上工作了好几天,无论我做什么,它都会以这种或那种方式存在. 一,一般前提：我们通过VisitItems与一对多关系进行访问. VisitItems相关信息： CREATE TABLE [BAR].[VisitItems] ( [Id] INT IDENTITY (1, 1) NOT NULL, [Visit

我已经在这个僵局问题上工作了好几天,无论我做什么,它都会以这种或那种方式存在.

一,一般前提：
我们通过VisitItems与一对多关系进行访问.

VisitItems相关信息：

CREATE TABLE [BAR].[VisitItems] (
    [Id]                INT             IDENTITY (1,1) NOT NULL,[VisitType]         INT             NOT NULL,[FeeRateType]       INT             NOT NULL,[Amount]            DECIMAL (18,2) NOT NULL,[GST]               DECIMAL (18,[Quantity]          INT             NOT NULL,[Total]             DECIMAL (18,[ServiceFeeType]    INT   NOT NULL,[ServiceText]       NVARCHAR (200)  NULL,[InvoicingProviderId] INT   NULL,[FeeItemId]        INT             NOT NULL,[VisitId]          INT             NULL,[IsDefault] BIT NOT NULL DEFAULT 0,[SourceVisitItemId] INT NULL,[OverrideCode] INT NOT NULL DEFAULT 0,[InvoiceToCentre] BIT NOT NULL DEFAULT 0,[IsSurchargeItem] BIT NOT NULL DEFAULT 0,CONSTRAINT [PK_BAR.VisitItems] PRIMARY KEY CLUSTERED ([Id] ASC),CONSTRAINT [FK_BAR.VisitItems_BAR.FeeItems_FeeItem_Id] FOREIGN KEY ([FeeItemId]) REFERENCES [BAR].[FeeItems] ([Id]),CONSTRAINT [FK_BAR.VisitItems_BAR.Visits_Visit_Id] FOREIGN KEY ([VisitId]) REFERENCES [BAR].[Visits] ([Id]),CONSTRAINT [FK_BAR.VisitItems_BAR.VisitTypes] FOREIGN KEY ([VisitType]) REFERENCES [BAR].[VisitTypes]([Id]),CONSTRAINT [FK_BAR.VisitItems_BAR.FeeRateTypes] FOREIGN KEY ([FeeRateType]) REFERENCES [BAR].[FeeRateTypes]([Id]),CONSTRAINT [FK_BAR.VisitItems_CMN.Users_Id] FOREIGN KEY (InvoicingProviderId) REFERENCES [CMN].[Users] ([Id]),CONSTRAINT [FK_BAR.VisitItems_BAR.VisitItems_SourceVisitItem_Id] FOREIGN KEY ([SourceVisitItemId]) REFERENCES [BAR].[VisitItems]([Id]),CONSTRAINT [CK_SourceVisitItemId_Not_Equal_Id] CHECK ([SourceVisitItemId] <> [Id]),CONSTRAINT [FK_BAR.VisitItems_BAR.OverrideCodes] FOREIGN KEY ([OverrideCode]) REFERENCES [BAR].[OverrideCodes]([Id]),CONSTRAINT [FK_BAR.VisitItems_BAR.ServiceFeeTypes] FOREIGN KEY ([ServiceFeeType]) REFERENCES [BAR].[ServiceFeeTypes]([Id])
)

CREATE NONCLUSTERED INDEX [IX_FeeItem_Id]
    ON [BAR].[VisitItems]([FeeItemId] ASC)

CREATE NONCLUSTERED INDEX [IX_Visit_Id]
    ON [BAR].[VisitItems]([VisitId] ASC)

访问信息：

CREATE TABLE [BAR].[Visits] (
    [Id]                     INT            IDENTITY (1,[VisitType]              INT            NOT NULL,[DateOfService]          DATETIMEOFFSET  NOT NULL,[InvoiceAnnotation]      NVARCHAR(255)  NULL,[PatientId]              INT            NOT NULL,[UserId]                 INT            NULL,[WorkAreaId]             INT            NOT NULL,[DefaultItemOverride] BIT NOT NULL DEFAULT 0,[DidNotWaitAdjustmentId] INT NULL,[AppointmentId] INT NULL,CONSTRAINT [PK_BAR.Visits] PRIMARY KEY CLUSTERED ([Id] ASC),CONSTRAINT [FK_BAR.Visits_CMN.Patients] FOREIGN KEY ([PatientId]) REFERENCES [CMN].[Patients] ([Id]) ON DELETE CASCADE,CONSTRAINT [FK_BAR.Visits_CMN.Users] FOREIGN KEY ([UserId]) REFERENCES [CMN].[Users] ([Id]),CONSTRAINT [FK_BAR.Visits_CMN.WorkAreas_WorkAreaId] FOREIGN KEY ([WorkAreaId]) REFERENCES [CMN].[WorkAreas] ([Id]),CONSTRAINT [FK_BAR.Visits_BAR.VisitTypes] FOREIGN KEY ([VisitType]) REFERENCES [BAR].[VisitTypes]([Id]),CONSTRAINT [FK_BAR.Visits_BAR.Adjustments] FOREIGN KEY ([DidNotWaitAdjustmentId]) REFERENCES [BAR].[Adjustments]([Id]),);

CREATE NONCLUSTERED INDEX [IX_Visits_PatientId]
    ON [BAR].[Visits]([PatientId] ASC);

CREATE NONCLUSTERED INDEX [IX_Visits_UserId]
    ON [BAR].[Visits]([UserId] ASC);

CREATE NONCLUSTERED INDEX [IX_Visits_WorkAreaId]
    ON [BAR].[Visits]([WorkAreaId]);

多个用户希望以下列方式同时更新VisitItems表：

单独的Web请求将创建一个VisitItems访问(通常为1).
然后(问题请求)：

> Web请求进来,打开NHibernate会话,启动NHibernate事务(使用带有READ_COMMITTED_SNAPSHOT的Repeatable Read).
>阅读VisitId给定访问的所有访问项目.
>代码评估项目是否仍然相关或者我们是否需要使用复杂规则的新项目(如此长时间运行,例如40ms).
>代码发现需要添加1个项目,使用NHibernate Visit.VisitItems.Add(..)添加它
>代码标识需要删除一个项目(不是我们刚刚添加的项目),使用NHibernate Visit.VisitItems.Remove(item)删除它.
>代码提交交易

使用工具,我可以模拟12个并发请求,这很可能在未来的生产环境中发生.

[编辑]根据要求,删除了我在这里添加的很多调查细节,以保持简短.

经过大量研究后,下一步是想办法如何锁定与where子句中使用的索引不同的索引(即主键,因为它用于删除),所以我将我的锁定语句改为：

var items = (List<VisitItem>)_session.CreateSQLQuery(@"SELECT * FROM BAR.VisitItems WITH (XLOCK,INDEX([PK_BAR.VisitItems]))
        WHERE VisitId = :visitId")
        .AddEntity(typeof(VisitItem))
        .SetParameter("visitId",qi.Visit.Id)
        .List<VisitItem>();

这略微减少了频率上的死锁,但它们仍在发生.这里是我开始迷路的地方：

<deadlock-list>
  <deadlock victim="process3f71e64e8">
    <process-list>
      <process id="process3f71e64e8" taskpriority="0" logused="0" waitresource="KEY: 5:72057594071744512 (a5e1814e40ba)" waittime="3812" ownerId="8004520" transactionname="user_transaction" lasttranstarted="2015-12-14T10:24:58.010" XDES="0x3f7cb43b0" lockMode="X" schedulerid="1" kpid="15788" status="suspended" spid="63" sbid="0" ecid="0" priority="0" trancount="1" lastbatchstarted="2015-12-14T10:24:58.013" lastbatchcompleted="2015-12-14T10:24:58.013" lastattention="1900-01-01T00:00:00.013" clientapp=".Net SqlClient Data Provider" hostname="ABC" hostpid="10016" loginname="bsapp" isolationlevel="repeatable read (3)" xactid="8004520" currentdb="5" lockTimeout="4294967295" clientoption1="671088672" clientoption2="128056">
        <executionStack>
          <frame procname="adhoc" line="1" stmtstart="18" stmtend="254" sqlhandle="0x0200000024a9e43033ef90bb631938f939038627209baafb0000000000000000000000000000000000000000">
            unknown
          </frame>
          <frame procname="unknown" line="1" sqlhandle="0x0000000000000000000000000000000000000000000000000000000000000000000000000000000000000000">
            unknown
          </frame>
        </executionStack>
        <inputbuf>
          (@p0 int)SELECT * FROM BAR.VisitItems WITH (XLOCK,INDEX([PK_BAR.VisitItems]))
          WHERE VisitId = @p0
        </inputbuf>
      </process>
      <process id="process4105af468" taskpriority="0" logused="1824" waitresource="KEY: 5:72057594071744512 (8194443284a0)" waittime="3792" ownerId="8004519" transactionname="user_transaction" lasttranstarted="2015-12-14T10:24:58.010" XDES="0x3f02ea3b0" lockMode="S" schedulerid="8" kpid="15116" status="suspended" spid="65" sbid="0" ecid="0" priority="0" trancount="2" lastbatchstarted="2015-12-14T10:24:58.033" lastbatchcompleted="2015-12-14T10:24:58.033" lastattention="1900-01-01T00:00:00.033" clientapp=".Net SqlClient Data Provider" hostname="ABC" hostpid="10016" loginname="bsapp" isolationlevel="repeatable read (3)" xactid="8004519" currentdb="5" lockTimeout="4294967295" clientoption1="671088672" clientoption2="128056">
        <executionStack>
          <frame procname="adhoc" line="1" stmtstart="18" stmtend="98" sqlhandle="0x0200000075abb0074bade5aa57b8357410941428df4d54130000000000000000000000000000000000000000">
            unknown
          </frame>
          <frame procname="unknown" line="1" sqlhandle="0x0000000000000000000000000000000000000000000000000000000000000000000000000000000000000000">
            unknown
          </frame>
        </executionStack>
        <inputbuf>
          (@p0 int)DELETE FROM BAR.VisitItems WHERE Id = @p0
        </inputbuf>
      </process>
    </process-list>
    <resource-list>
      <keylock hobtid="72057594071744512" dbid="5" objectname="BAR.VisitItems" indexname="PK_BAR.VisitItems" id="lock449e27500" mode="X" associatedObjectId="72057594071744512">
        <owner-list>
          <owner id="process4105af468" mode="X"/>
        </owner-list>
        <waiter-list>
          <waiter id="process3f71e64e8" mode="X" requestType="wait"/>
        </waiter-list>
      </keylock>
      <keylock hobtid="72057594071744512" dbid="5" objectname="BAR.VisitItems" indexname="PK_BAR.VisitItems" id="lock46a525080" mode="X" associatedObjectId="72057594071744512">
        <owner-list>
          <owner id="process3f71e64e8" mode="X"/>
        </owner-list>
        <waiter-list>
          <waiter id="process4105af468" mode="S" requestType="wait"/>
        </waiter-list>
      </keylock>
    </resource-list>
  </deadlock>
</deadlock-list>

（编辑：安卓应用网）

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