March 28th, 2016

Problem

  • Client complain that leave application data, such as dates, leave hours, etc... takes a lot of time
  • After investigation I found that Leave Data table OnUpdate triggers takes considerable time to execute
  • Key issue is that each time user updates leave data, system needs to recalculate leave balances, as well as other data

Current System Synchronous workflow

Synchronous

Solution

  • Take5People implements Service Broker services, which is part of SQL Server 2008 and above
  • Complicated calculation logic, which was part of Database Leave Detail Table OnUpdate Trigger will move to independent Stored Procedure -- SQL Server will asynchroniously call given stored procedure when a new update message arrives

Next generation system workflow

Asynchronous

Key questions

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select * from sys.transmission_queue

to see the messages in the transmission queue and to find if an error occured

Enable broker for given database:

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ALTER DATABASE test SET SINGLE_USER WITH ROLLBACK IMMEDIATE
GO
ALTER DATABASE test SET ENABLE_BROKER
ALTER DATABASE test SET MULTI_USER WITH ROLLBACK IMMEDIATE
GO

Creating TARGET queue & define message

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CREATE MESSAGE TYPE [//t5p.hk/Leave/UpdateLeave];
CREATE MESSAGE TYPE [//t5p.hk/Leave/LeaveUpdated];
CREATE CONTRACT [//t5p.hk/Leave/UpdateLeaveContract]
([//t5p.hk/Leave/UpdateLeave] SENT BY INITIATOR,
[//t5p.hk/Leave/LeaveUpdated] SENT BY TARGET);
CREATE SERVICE [//t5p.hk/LeaveDataService] ON QUEUE dbo.LeaveDataQueue
([//t5p.hk/Leave/UpdateLeaveContract]);
CREATE SERVICE [//t5p.hk/LeaveTriggerService] ON QUEUE dbo.LeaveDataQueue
([//t5p.hk/Leave/UpdateLeaveContract]);  
CREATE PROCEDURE dbo.usp_LeaveUpdateProc AS
  RETURN 0;
GO  
CREATE QUEUE dbo.LeaveDataQueue WITH ACTIVATION (
PROCEDURE_NAME = dbo.usp_LeaveUpdateProc, MAX_QUEUE_READERS = 2,
EXECUTE AS SELF);

Creating INITIATOR queue & define message

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CREATE PROCEDURE dbo.usp_LeaveUpdateProc2 AS
  RETURN 0;
GO  
CREATE QUEUE dbo.LeaveTriggerQueue WITH ACTIVATION (
PROCEDURE_NAME = dbo.usp_LeaveUpdateProc2, MAX_QUEUE_READERS = 2,
EXECUTE AS SELF);

CREATE SERVICE [//t5p.hk/LeaveTriggerService] ON QUEUE dbo.LeaveTriggerQueue
([//t5p.hk/Leave/UpdateLeaveContract]);

Main problem with asynchronous solution

  • User has sent an update leave message, but when it will be updated?
  • We have no control anymore on "WHEN"

Problem

March 29th, 2016

  • To test memory optimization solution for SQL 2014
  • To share results during meeting with a client